WO2021232706A1

WO2021232706A1 - Three-bridge arm topology apparatus, control method, inverter system and uninterrupted power supply system

Info

Publication number: WO2021232706A1
Application number: PCT/CN2020/128151
Authority: WO
Inventors: 罗峰
Original assignee: 广州视源电子科技股份有限公司; 广州视琨电子科技有限公司
Priority date: 2020-05-22
Filing date: 2020-11-11
Publication date: 2021-11-25
Also published as: CN115136443A

Abstract

A three-bridge arm topology apparatus, a control method, an inverter system and an uninterrupted power supply system. The three-bridge arm topology apparatus achieves charging or discharging of a battery pack by multiplexing a voltage conversion circuit, and can implement a charging function of the battery pack without additionally providing a charger. In addition, whether in an external power supply mode or a battery power supply mode, both the voltage conversion circuit and a three-bridge arm circuit participate in the work, i.e. all devices of the three-bridge arm topology apparatus participate in the work. When the three-bridge arm topology apparatus is applied to a battery low-voltage large-current UPS system or an inverter system, the device multiplexing rate of the system can be improved, the device design redundancy is avoided, and thus the costs of the battery low-voltage large-current UPS system or inverter system are reduced.

Description

Three-leg topology device, control method, inverter system and uninterruptible power supply system

This application is required to be submitted to the Chinese Patent Office on May 22, 2020, the application number is 202010444170.4, the application name is "Three-Bridge Arm Topology Device, Control Method, and Uninterruptible Power Supply System", and, on May 22, 2020 The Chinese Patent Office, the application number is 202020885385.5, is the priority of the Chinese patent application with the application name "Three-Bridge Arm Topology Device and Uninterruptible Power Supply System", the entire content of which is incorporated into this application by reference.

Technical field

The embodiments of the present application relate to power supply technology, and in particular, to a three-leg topology device, a control method, an inverter system, and an uninterruptible power supply system.

Background technique

A battery low-voltage and high-current power supply system refers to a power supply system that uses a small number of batteries as the battery pack. When the power supply system uses this kind of battery pack to supply power to the load, it can output electric energy with low voltage and high current. At present, common battery low-voltage and high-current power supply systems include uninterrupted power supply (UPS) systems, inverter systems, and so on.

Since the number of battery cells in the battery pack used in the battery low-voltage and high-current power supply system is small, the battery low-voltage and high-current power supply system is widely used. However, the device reuse rate of the existing battery low-voltage and high-current power supply system is low, resulting in high cost of the battery low-voltage and high-current power supply system.

Summary of the invention

The embodiments of the present application provide a three-leg topology device, a control method, an inverter system, and an uninterruptible power supply system, which are used to solve the technical problem of the low device reuse rate of the existing battery low-voltage and high-current UPS system. The technical solution is as follows:

In the first aspect, an embodiment of the present application provides a three-leg topology device, the three-leg topology device includes: a battery pack, a voltage conversion circuit, and a three-leg circuit; the three-leg circuit includes: a first bridge Arm, second bridge arm, third bridge arm, first inductor, second inductor, DC bus capacitor, first capacitor; said first bridge arm includes a first switch tube and a second switch tube connected in series; The second bridge arm includes a third switching tube and a fourth switching tube connected in series; the third bridge arm includes a fifth switching tube and a sixth switching tube connected in series;

The first bridge arm, the second bridge arm, the third bridge arm, and the DC bus capacitor are connected in parallel between the positive output end of the bus and the negative output end of the bus; the midpoint of the first bridge arm Connected to the first end of the first inductor, and the second end of the first inductor is used as the positive voltage input end of the three-leg topology device; the midpoint of the second bridge arm or the negative output of the bus Terminal is used as the negative voltage input terminal of the three-leg topology device; the midpoint of the third bridge arm is connected to the first terminal of the second inductor, and the second terminal of the second inductor is connected to the first terminal of the second inductor. The first end of the capacitor is connected, the second end of the first capacitor is connected to the midpoint of the second bridge arm, and the first end of the first capacitor is the first output end of the three bridge arm topology device , The second end of the first capacitor is the second output end of the three-leg topology device, and both the first output end and the second output end are connected to a load;

The positive pole of the battery pack is connected to the first end of the voltage conversion circuit, the negative pole of the battery pack is connected to the second end of the voltage conversion circuit, and the third end of the voltage conversion circuit is connected to the bus positive. The output terminal is connected, the fourth terminal of the voltage conversion circuit is connected with the negative output terminal of the bus, the first terminal of the external power supply is connected with the positive voltage input terminal, and the second terminal of the external power supply is connected with the Negative voltage input terminal connection;

The voltage conversion circuit is used for charging the battery pack in the external power supply mode; and discharging the battery pack in the battery power supply mode.

In the second aspect, an embodiment of the present application provides an uninterruptible power supply system, the system includes: an external power supply, a load, and the three-leg topology device as described in the first aspect; wherein the external power supply The first end of is connected to the positive voltage input end of the three-leg topology device, the second end of the external power supply is connected to the negative voltage input end of the three-leg topology device, the three-leg topology device Both the first output terminal and the second output terminal are connected to the load.

In a third aspect, an embodiment of the present application provides an uninterruptible power supply system, the system includes: a first external power supply, a second external power supply, a load, and the three-arm topology device as described in the first aspect Wherein, the first terminal of the first external power supply is connected to the first positive voltage input terminal of the three-leg topology device, and the second terminal of the first external power supply is connected to the three-leg topology device The first negative voltage input terminal of the second external power supply is connected to the second positive voltage input terminal of the three bridge arm topology device, and the second terminal of the second external power supply is connected to the The second negative voltage input terminal of the three bridge arm topology device is connected, and the first output terminal and the second output terminal of the three bridge arm topology device are both connected with the load.

In a fourth aspect, an embodiment of the present application provides a method for controlling a three-leg topology device. When the three-leg topology device described in the first aspect is in an external power supply mode through the switch, the voltage conversion circuit is controlled To charge the battery pack, in the battery power supply mode, when the voltage conversion circuit is controlled to discharge the battery pack, if the switch includes: a first switch, a second switch, and balancing components; and the voltage The third terminal of the conversion circuit is connected to the fixed terminal of the first switch, the first selection terminal of the first switch is connected to the first terminal of the balanced component, and the second terminal of the balanced component is connected to the fixed terminal of the first switch. The positive output terminal of the bus is connected, the second selection terminal of the first switch is connected to the positive voltage input terminal, the first terminal of the second switch is connected to the first terminal of the external power supply, and the first terminal of the second switch is connected to the first terminal of the external power supply. The second end of the two switches is connected to the positive voltage input end, and the fourth end of the voltage conversion circuit is connected to the negative output end of the bus bar, the three-leg topology device can be controlled by the following method, which includes : In the external power supply mode, the fixed terminal of the first switch is controlled to communicate with the first selection terminal of the first switch, and the second switch is closed; in the battery power mode, the fixed terminal of the first switch is controlled to be connected to the The second selection terminal of the first switch is connected, and the second switch is disconnected.

Optionally, if the balance component is a resistor, the switch further includes: a third switch; the third terminal of the voltage conversion circuit is connected to the first terminal of the third switch, and the second terminal of the third switch The two ends are connected with the positive output end of the bus; or, the third switch is connected in parallel with the resistor. Then, in this implementation manner, the three-leg topology device can be controlled by the following method, the method includes: in the external power supply mode, controlling the fixed terminal of the first switch to communicate with the first selection terminal of the first switch, The second switch is closed, and when the voltage difference between the bus bar and the voltage conversion circuit of the three-arm topology device is less than or equal to the preset threshold, the third switch is controlled to be closed; in the battery power supply mode, the first switch is controlled The fixed end of a switch is connected to the second selection end of the first switch, and the second switch and the third switch are disconnected.

In a fifth aspect, an embodiment of the present application provides a method for controlling a three-leg topology device. When the three-leg topology device in the first aspect is in an external power supply mode through the switch, the voltage conversion circuit is controlled To charge the battery pack, in the battery power supply mode, when the voltage conversion circuit is controlled to discharge the battery pack, if the switch includes: a first switch, a second switch, and balancing components; and the voltage The third terminal of the conversion circuit is respectively connected to the first terminal of the first switch and the first selection terminal of the second switch, and the second terminal of the first switch is connected to the first terminal of the balance component. Terminal connection, the second terminal of the balance component is connected to the positive output terminal of the bus, the second selection terminal of the second switch is connected to the first terminal of the external power supply, and the second switch is fixed Terminal is connected to the positive voltage input terminal, and the fourth terminal of the voltage conversion circuit is connected to the negative output terminal of the bus bar, the three-leg topology device can be controlled by the following method, the method includes: in the external power supply mode When the first switch is controlled to be closed, the fixed end of the second switch is connected to the second selection end of the second switch; in the battery power supply mode, the first switch is controlled to open, and the fixed end of the second switch Connected with the first selection terminal of the second switch.

Optionally, the balance element is a resistor, and the switch further includes: a third switch; the third terminal of the voltage conversion circuit is connected to the first terminal of the third switch, and the third switch The second end is connected to the positive output end of the bus; or, the third switch is connected in parallel with the resistor. Then in this implementation mode, the three-leg topology device can be controlled by the following method, the method includes: in the external power supply mode, controlling the first switch to close, the fixed end of the second switch and the second switch of the second switch The second selection terminal is connected, and when the voltage difference between the bus bar and the voltage conversion circuit of the three-arm topology device is less than or equal to the preset threshold, the third switch is controlled to close; in the battery power supply mode, the first switch is controlled The third switch is disconnected from the first switch, and the fixed end of the second switch is connected to the first selection end of the second switch.

In a sixth aspect, an embodiment of the present application provides a method for controlling a three-leg topology device. When the three-leg topology device described in the first aspect is in an external power supply mode through the switch, the voltage conversion circuit is controlled When charging the battery pack, in the battery power supply mode, when the voltage conversion circuit is controlled to discharge the battery pack, if the switch includes: a first switch, a second switch, a third switch and balancing components; The third terminal of the voltage conversion circuit is respectively connected to the first terminal of the first switch and the first terminal of the third switch, and the second terminal of the first switch is connected to the positive voltage input terminal, The first terminal of the second switch is connected to the first terminal of the external power supply, the second terminal of the second switch is connected to the positive voltage input terminal, and the second terminal of the third switch is connected to the The first end of the balanced component is connected, the second end of the balanced component is connected to the positive output end of the bus, and the fourth end of the voltage conversion circuit is connected to the negative output end of the bus. A method of controlling the three-leg topology device includes: in the external power supply mode, controlling the first switch to open, and the second switch and the third switch to close; in the battery power supply mode, controlling the first switch to close, The second switch and the third switch are turned off.

Optionally, the balance element is a resistor, and the switch further includes: a fourth switch; the third terminal of the voltage conversion circuit is connected to the first terminal of the fourth switch, The second end is connected to the positive output end of the bus; or, the fourth switch is connected in parallel with the resistor. In this implementation mode, the three-leg topology device can be controlled by the following method. The method includes: in the external power supply mode, controlling the first switch to open, the second switch and the third switch to close, and the bus and the third switch are closed. When the voltage difference between the voltage conversion circuits of the three-leg topology device is less than or equal to the preset threshold, the fourth switch is controlled to be closed; in the battery power supply mode, the first switch is controlled to be closed, and the second switch is controlled to be closed. , The third switch and the fourth switch are turned off.

In a seventh aspect, an embodiment of the present application provides a method for controlling a three-leg topology device. In the three-leg topology device described in the first aspect, the voltage conversion circuit in the three-leg topology device multiplexes the second leg of the three-leg circuit. When the two-way DCDC topology is formed with the bus capacitor, the three-leg topology device can be controlled by the following method, and the method includes:

In the first stage of the external power supply mode, control the second switching tube, the fourth switching tube, the fifth switching tube, and the eleventh switching tube to turn on;

In the second stage of the external power supply mode, controlling the second switching tube, the fourth switching tube, the fifth switching tube, and the twelfth switching tube to conduct;

In the third stage of the external power supply mode, controlling the fourth switching tube, the fifth switching tube, and the eleventh switching tube to be turned on;

In the fourth stage of the external power supply mode, controlling the fourth switching tube, the fifth switching tube, and the twelfth switching tube to be turned on;

In the fifth stage of the external power supply mode, controlling the second switching tube, the fourth switching tube, the sixth switching tube, and the eleventh switching tube to be turned on;

In the sixth stage of the external power supply mode, controlling the second switching tube, the fourth switching tube, the sixth switching tube, and the twelfth switching tube to be turned on;

In the seventh stage of the external power supply mode, controlling the fourth switching tube, the sixth switching tube, and the eleventh switching tube to be turned on;

In the eighth stage of the external power supply mode, controlling the fourth switching tube, the sixth switching tube, and the twelfth switching tube to be turned on;

In the ninth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the sixth switching tube, and the twelfth switching tube to turn on;

In the tenth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the sixth switching tube, and the eleventh switch to conduct;

In the eleventh stage of the external power supply mode, controlling the third switching tube, the sixth switching tube, and the twelfth switching tube to be turned on;

In the twelfth stage of the external power supply mode, controlling the third switching tube, the sixth switching tube, and the eleventh switching tube to be turned on;

In the thirteenth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the fifth switching tube, and the twelfth switching tube to be turned on;

In the fourteenth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the fifth switching tube, and the eleventh switching tube to be turned on;

In the fifteenth stage of the external power supply mode, controlling the third switching tube, the fifth switching tube, and the twelfth switching tube to be turned on;

In the sixteenth stage of the external power supply mode, controlling the third switching tube, the fifth switching tube, and the eleventh switching tube to be turned on;

In the first stage of the battery power supply mode, controlling the fourth switching tube, the fifth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to conduct;

In the second stage of the battery power supply mode, controlling the fourth switching tube, the fifth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube to be turned on;

In the third stage of the battery power supply mode, controlling the fourth switching tube, the sixth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to conduct;

In the fourth stage of the battery power supply mode, controlling the fourth switching tube, the sixth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube to conduct;

In the fifth stage of the battery power supply mode, controlling the third switching tube, the sixth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to be turned on;

In the sixth stage of the battery power supply mode, controlling the third switching tube, the sixth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube to be turned on;

In the seventh stage of the battery power supply mode, controlling the third switching tube, the fifth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to be turned on;

In the eighth stage of the battery power supply mode, the third switching tube, the fifth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube are controlled to be turned on.

In an eighth aspect, an embodiment of the present application provides a three-leg topology device, the three-leg topology device includes: a battery pack, a voltage conversion circuit, and a three-leg circuit; the three-leg circuit includes: a first bridge Arm, second bridge arm, third bridge arm, DC bus capacitor, filter; the first bridge arm includes a first switch tube and a second switch tube connected in series; the second bridge arm includes a third switch connected in series Tube and a fourth switching tube; the third bridge arm includes a fifth switching tube and a sixth switching tube connected in series;

The first bridge arm, the second bridge arm, the third bridge arm and the DC bus capacitor are connected in parallel between the positive output end of the bus and the negative output end of the bus; the midpoint of the second bridge arm And the midpoint of the third bridge arm are both connected to the filter; the positive pole of the battery pack is connected to the first end of the voltage conversion circuit, and the negative pole of the battery pack is connected to the first end of the voltage conversion circuit. Two-terminal connection, the third terminal and the fourth terminal of the voltage conversion circuit are both connected to the three-leg circuit, and the filter is provided with the first external connection terminal of the three-leg topology device and the three The second external connection terminal of the bridge arm topology device is connected to the load in the battery power supply mode;

The voltage conversion circuit discharges the battery pack in the battery power supply mode.

In a ninth aspect, an embodiment of the present application provides an inverter system, the system includes: a load, and the three-leg topology device as described in the eighth aspect; in the battery power supply mode, the three-leg topology Both the first external connection terminal and the second external connection terminal of the device are connected to the load.

In a tenth aspect, an embodiment of the present application provides a method for controlling a three-leg topology device. In the eighth aspect, the three-leg topology device uses a voltage conversion circuit, a first leg of the three-leg circuit, and a bus capacitor When a two-way DCDC topology is formed, the three-arm topology device can be controlled by the following method, and the method includes:

In the first stage of the battery power supply mode, control the second switch tube, the eighth switch tube, the ninth switch tube, and the eleventh switch tube to turn on;

In the second stage of the battery power supply mode, controlling the first switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to be turned on;

In the first stage of the battery charging mode, controlling the second switching tube and the eleventh switching tube to be turned on;

In the second stage of the battery charging mode, the first switching tube and the twelfth switching tube are controlled to be turned on.

In an eleventh aspect, an embodiment of the present application provides a method for controlling a three-leg topology device. In the eighth aspect, the three-leg topology device passes through the voltage conversion circuit, the first leg of the three-leg circuit, and the first leg of the three-leg circuit. When the second bridge arm and the bus capacitor form a bidirectional DCDC topology, the three bridge arm topology device can be controlled by the following method, and the method includes:

In the first stage of the battery power supply mode, control the second switching tube, the fourth switching tube, the fifth switching tube, the seventh switching tube, and the tenth switching tube to conduct;

In the second stage of the battery power supply mode, controlling the first switching tube, the fourth switching tube, the fifth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the third stage of the battery power supply mode, controlling the second switching tube, the fourth switching tube, the sixth switching tube, the seventh switching tube, and the tenth switching tube to conduct;

In the fourth stage of the battery power supply mode, controlling the first switching tube, the fourth switching tube, the sixth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the fifth stage of the battery power supply mode, controlling the first switching tube, the third switching tube, the sixth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the sixth stage of the battery power supply mode, the first switching tube, the second switching tube, the third switching tube, the sixth switching tube, the seventh switching tube, and the tenth switching tube are controlled Tube conduction;

In the seventh stage of the battery power supply mode, controlling the first switching tube, the third switching tube, the fifth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the eighth stage of the battery power supply mode, the first switching tube, the second switching tube, the third switching tube, the fifth switching tube, the seventh switching tube, and the first switching tube are controlled. Ten switch tube is turned on;

In the first stage of the battery charging mode, controlling the first switching tube, the fourth switching tube, and the sixth switching tube to conduct;

In the second stage of the battery charging mode, controlling the second switching tube, the fourth switching tube, and the sixth switching tube to conduct;

In the third stage of the battery charging mode, controlling the first switching tube, the fourth switching tube, and the fifth switching tube to conduct;

In the fourth stage of the battery charging mode, controlling the second switching tube, the fourth switching tube, and the fifth switching tube to conduct;

In the fifth stage of the battery charging mode, controlling the second switching tube, the third switching tube, and the fifth switching tube to conduct;

In the sixth stage of the battery charging mode, controlling the first switching tube, the third switching tube, and the fifth switching tube to conduct;

In the seventh stage of the battery charging mode, controlling the second switching tube, the third switching tube, and the sixth switching tube to conduct;

In the eighth stage of the battery charging mode, the first switching tube, the third switching tube, and the sixth switching tube are controlled to be turned on.

The three-leg topology device, control method, inverter system, and uninterruptible power supply system provided by the embodiments of the present application realize the charging or discharging of the battery pack through the multiplexing voltage conversion circuit, and the battery pack can be realized without adding an additional charger Charging function. In addition, whether charging or discharging the battery pack, the voltage conversion circuit and the three-leg circuit are involved in the work, that is, all devices of the three-leg topology device are involved in the work. When the three-leg topology device is applied to a battery low-voltage and high-current UPS system or an inverter system, the device reuse rate of the system can be improved, and device design redundancy can be avoided, thereby reducing the battery low-voltage and high-current UPS system or inverter The cost of the system.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description These are some examples of the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor.

Figure 1 is a schematic structural diagram of a battery low-voltage high-current UPS system provided by the prior art;

FIG. 1A is a schematic structural diagram of a battery low-voltage high-current inverter system provided in the prior art;

2 is a schematic diagram 1 of the first three-arm topology device provided by an embodiment of this application;

FIG. 3 is a second schematic diagram of the first three-arm topology device provided by an embodiment of this application;

4 is a schematic diagram of a second three-arm topology device provided by an embodiment of the application;

Fig. 5 is a schematic diagram of a third three-arm topology device provided by an embodiment of the application;

Fig. 6 is a schematic diagram of a fourth three-arm topology device provided by an embodiment of the application;

FIG. 7 is a schematic diagram of a fifth three-arm topology device provided by an embodiment of the application;

FIG. 8 is a schematic diagram 1 of the current of the fourth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 9 is a second schematic diagram of current in the external power supply mode of the fourth three-leg topology device provided by an embodiment of the application; FIG.

FIG. 10 is a third schematic diagram of current in the external power supply mode of the fourth three-leg topology device provided by an embodiment of the application; FIG.

FIG. 11 is a fourth schematic diagram of current in the external power supply mode of the fourth three-leg topology device provided by an embodiment of the application; FIG.

FIG. 12 is a schematic diagram 5 of current in the battery power supply mode of the fourth three-leg topology device provided by an embodiment of the application; FIG.

FIG. 13 is a sixth schematic diagram of current in the battery power supply mode of the fourth three-leg topology device provided by an embodiment of the application; FIG.

14 is a schematic diagram of a sixth three-arm topology device provided by an embodiment of the application;

15 is a schematic diagram of a seventh three-arm topology device provided by an embodiment of the application;

FIG. 16 is a schematic diagram of an eighth three-arm topology device provided by an embodiment of the application;

FIG. 17 is a schematic diagram of a ninth three-arm topology device provided by an embodiment of the application;

18 is a schematic diagram of a tenth three-leg topology device provided by an embodiment of the application;

FIG. 19 is a schematic diagram of an eleventh three-arm topology device provided by an embodiment of this application;

20 is a schematic diagram of a twelfth three-arm topology device provided by an embodiment of the application;

21 is a schematic diagram of a thirteenth three-arm topology device provided by an embodiment of the application;

22 is a schematic diagram of a fourteenth three-arm topology device provided by an embodiment of this application;

FIG. 23 is a schematic diagram of a fifteenth three-leg topology device provided by an embodiment of the application; FIG.

FIG. 24 is a schematic diagram of a sixteenth three-leg topology device provided by an embodiment of this application;

FIG. 25 is a first schematic diagram of partial connection of a voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 26 is a second schematic diagram of partial connection of a voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 27 is a third schematic diagram of partial connections of the voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 28 is a fourth schematic diagram of partial connection of a voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 29 is a fifth schematic diagram of partial connections of the voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 30 is a sixth schematic diagram of partial connections of the voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 31 is a seventh schematic diagram of partial connection of the voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 32 is a first structural diagram of a first voltage conversion unit provided by an embodiment of the application; FIG.

FIG. 33 is a second schematic diagram of the structure of the first voltage conversion unit provided by an embodiment of the application; FIG.

FIG. 34 is a third structural diagram of a first voltage conversion unit provided by an embodiment of the application; FIG.

FIG. 35 is a fourth structural diagram of the first voltage conversion unit provided by an embodiment of the application; FIG.

FIG. 36 is a schematic diagram of a seventeenth three-arm topology device provided by an embodiment of the application; FIG.

36A is an eighth schematic diagram of partial connections of a voltage conversion circuit provided by an embodiment of the application;

36B is a ninth schematic diagram of partial connections of the voltage conversion circuit provided by the embodiment of the application;

FIG. 37 is a schematic diagram 1 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 38 is a second schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 39 is the third schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to the embodiment of the application; FIG.

40 is a schematic diagram 4 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application;

FIG. 41 is a current schematic diagram 5 of the seventeenth three-leg topology device in an external power supply mode according to an embodiment of the application; FIG.

FIG. 42 is a current schematic diagram 6 of the seventeenth three-leg topology device in an external power supply mode according to an embodiment of the application; FIG.

FIG. 43 is a current schematic diagram 7 of the seventeenth three-leg topology device in an external power supply mode according to an embodiment of the application; FIG.

FIG. 44 is a schematic diagram 8 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 45 is a schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode provided by an embodiment of the application.

FIG. 46 is a tenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 47 is a schematic diagram eleven of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 48 is a current schematic diagram 12 of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 49 is a schematic diagram 13 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 50 is a fourteenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 51 is a fifteenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 52 is a sixteenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application; FIG.

FIG. 53 is a schematic diagram 1 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 54 is a schematic diagram 2 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 55 is the third schematic diagram of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 56 is a schematic diagram 4 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 57 is a schematic diagram 5 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 58 is a current schematic diagram 6 of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 59 is a schematic diagram 7 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 60 is a schematic diagram 8 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 61 is a schematic diagram of an eighteenth three-arm topology device according to an embodiment of the application;

FIG. 62 is a schematic diagram of a nineteenth three-leg topology device provided by an embodiment of the application;

FIG. 63 is a schematic diagram of a twentieth three-arm topology device provided by an embodiment of this application;

FIG. 63A is a tenth schematic diagram of partial connections of a voltage conversion circuit provided by an embodiment of the application; FIG.

FIG. 63B is an eleventh schematic diagram of partial connections of the voltage conversion circuit provided by the embodiment of the application; FIG.

FIG. 64 is a schematic diagram 1 of the current of the twentieth three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

65 is the second schematic diagram of the current of the twentieth three-leg topology device in the battery power supply mode according to an embodiment of the application;

FIG. 66 is a schematic diagram 1 of the current of the twentieth three-leg topology device in the battery charging mode according to an embodiment of the application; FIG.

FIG. 67 is a second schematic diagram of the current of the twentieth three-leg topology device in the battery charging mode according to an embodiment of the application; FIG.

FIG. 68 is a schematic diagram of a twenty-first three-leg topology device provided by an embodiment of this application;

68A is a twelfth schematic diagram of partial connections of a voltage conversion circuit provided by an embodiment of the application;

68B is a thirteenth schematic diagram of partial connections of a voltage conversion circuit provided by an embodiment of the application;

FIG. 69 is a schematic diagram of a twenty-second three-arm topology device provided by an embodiment of this application;

FIG. 70 is a schematic diagram 1 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 71 is a second schematic diagram of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application;

FIG. 72 is the third schematic diagram of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 73 is a schematic diagram 4 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 74 is a schematic diagram 5 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 75 is a sixth schematic diagram of current in the battery power supply mode of the twenty-first three-leg topology device provided by an embodiment of the application; FIG.

FIG. 76 is a schematic diagram 7 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 77 is a schematic diagram 8 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application; FIG.

FIG. 78 is a schematic diagram 1 of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application; FIG.

79 is a second schematic diagram of the current in the battery charging mode of the twenty-first three-leg topology device provided by an embodiment of the application;

FIG. 80 is the third schematic diagram of current in the battery charging mode of the twenty-first three-leg topology device provided by an embodiment of the application; FIG.

FIG. 81 is a fourth schematic diagram of current in the battery charging mode of the twenty-first three-leg topology device provided by an embodiment of the application; FIG.

FIG. 82 is a schematic diagram 5 of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application; FIG.

FIG. 83 is a current schematic diagram 6 of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application; FIG.

FIG. 84 is a schematic diagram 7 of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application; FIG.

FIG. 85 is a schematic diagram 8 of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application; FIG.

FIG. 86 is a schematic diagram of a connection relationship between an LC filter and a second bridge arm and a third bridge arm according to an embodiment of the application;

FIG. 87 is a schematic diagram of the connection relationship between the LCL filter and the second bridge arm and the third bridge arm according to an embodiment of the application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the embodiments of the present application.

The battery low-voltage high-current UPS system is an online medium and small power UPS system. That is, regardless of whether the grid voltage is normal or not, the AC voltage used by the load must pass through the inverter circuit for inversion of a UPS system. According to the power division, the online medium and small power UPS system usually refers to the online UPS system with the power between 1 kilowatt and 3 kilowatts.

Fig. 1 is a schematic structural diagram of a battery low-voltage high-current UPS system provided in the prior art. As shown in Figure 1, at present, common battery low-voltage high-current UPS systems include: chargers, battery packs, unidirectional direct current (Direct Current-Direct Current, referred to as DCDC) converters, and mains AC power (Alternating Current, Abbreviation: AC), Vienna rectifier converter, half-bridge inverter.

In the external power supply mode (in the battery low-voltage high-current UPS system, the external power supply is AC power supply AC, therefore, in this example, the external power supply mode is AC power supply), the Vienna rectifier converter provides AC power supply The AC power is converted to DC power, and the half-bridge inverter converts DC power to AC power to be supplied to the load, and the charger charges the battery pack. In the external power supply mode, the Vienna rectifier converter, half-bridge inverter and charger participate in the work. In this mode, the DCDC converter is in an idle state.

In the battery-powered mode (that is, when the battery pack is powered), the DCDC converter boosts the DC power output by the battery pack, and the half-bridge inverter converts the DC power to AC power and provides it to the load. That is, the DCDC converter and the half-bridge inverter participate in the work. In battery-powered mode, the Vienna rectifier converter and charger are in an idle state.

That is to say, when the existing battery low-voltage and high-current UPS system is working, some components are in an idle state, which makes the device reuse rate of the existing battery low-voltage and high-current UPS system low, resulting in a relatively high cost of the battery low-voltage and high-current UPS system. high.

FIG. 1A is a schematic structural diagram of a battery low-voltage high-current inverter system provided in the prior art. As shown in FIG. 1A, at present, common low-voltage and high-current battery inverter systems in the prior art include: battery packs, bidirectional DCDC converters, Buck converters, and full-bridge inverters. That is, the existing battery low-voltage high-current inverter system (ie, bidirectional DCAC converter) is composed of a three-stage converter. Among them, the Buck converter can also be called a step-down converter, which is used to step down the voltage.

In the battery-powered mode, the DC power output by the battery pack is boosted to the bus capacitor E1 through the bidirectional DCDC converter, and then the full-bridge inverter is inverted to output AC power to the load. In the battery charging mode, the full-bridge inverter acts as a full-bridge rectifier PFC converter. After boosting the AC power provided by the mains AC power supply AC, it is output to the bus capacitor E1, and the DC power output by the bus capacitor E1 is reduced by the Buck converter. After voltage, the battery pack is charged through the bidirectional DCDC converter.

It can be seen from the above description that the Buck converter does not participate in the work of the existing battery low-voltage and high-current inverter system in the battery power supply mode, resulting in the low integration of the existing battery low-voltage and high-current inverter system and the reuse rate of devices. Not high, resulting in high cost of the battery low-voltage high-current inverter system.

In summary, the device reuse rate of the existing battery low-voltage and high-current power supply system is low, resulting in high cost of the battery low-voltage and high-current power supply system.

Considering the above-mentioned problems, the embodiment of the present application provides a three-leg topology device. When the device is applied to a battery low-voltage and high-current UPS system or an inverter system, whether it is to charge the battery pack or discharge the battery pack, the device All devices are involved in the work, which improves the device reuse rate of the battery low-voltage and high-current UPS system or inverter system, thereby reducing the cost of the battery low-voltage and high-current UPS or inverter system.

It should be understood that the embodiment of the present application does not limit the external power supply of the battery low-voltage high-current UPS system. For example, the external power supply of the UPS system can be a commercial AC power supply AC, a photovoltaic PV DC power supply, or a photovoltaic PV DC power supply + a commercial AC power supply AC, etc. For ease of description, the following embodiments are described by taking the AC power source AC as the external power supply of the battery low-voltage high-current UPS system as an example. However, those skilled in the art can understand that the mains AC power supply AC involved in the subsequent figures can be replaced with other independent external power supplies. For a UPS system with two external power supplies at the same time, it can be based on the external power supply in the UPS system. The actual connection mode of the power supply and the adaptive adjustment of the circuit connection mode will not be repeated here.

The three-arm topology device provided by the embodiment of the present application may include the following structures, for example:

Structure A: The three-leg topology device includes: a battery pack, a voltage conversion circuit, a switch and a three-leg circuit. The switch controls the voltage conversion circuit to charge or discharge the battery pack, so that all the components of the three-leg topology device participate in work whether they are charging or discharging the battery pack.

The three-leg topology device provided by Structure A can be applied to a battery low-voltage high-current UPS system.

Structure B: The three-arm topology device includes: a battery pack, a voltage conversion circuit and a three-arm circuit, and no switch is provided. The voltage conversion circuit can charge or discharge the battery pack, so that all the components of the three-leg topology device are involved in the work whether they are charging or discharging the battery pack.

Optionally, in some embodiments, the voltage conversion circuit of the three-leg topology device shown in structure B can multiplex the DC bus capacitance of the three-leg circuit, or multiplex the second leg of the three-leg circuit and The DC bus capacitor realizes the voltage conversion function to achieve the purpose of simplifying the voltage conversion circuit, thereby further improving the device reuse rate of the three-leg topology device.

The three-arm configuration of the topology provided by Structure B can be applied to a battery low-voltage high-current UPS system or a battery low-voltage high-current inverter system.

The three-arm topology device provided in the embodiment of the present application will be described in detail below in conjunction with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

Structure A: The three-leg topology device includes: a battery pack, a voltage conversion circuit, a switch and a three-leg circuit. The three-leg topology device provided by structure A can be applied to battery low-voltage high-current UPS systems, for example, battery low-voltage high-current UPS systems with a wide range of battery pack input voltages, and exemplary battery low-voltage high-current UPSs using lead-acid batteries system. It should be understood that the battery pack input voltage mentioned here refers to the voltage output by the battery pack when the battery pack is used to supply power to the load. In some embodiments, the three-arm topology device may also be applied to an emergency power supply (Emergency Power Supply, EPS) system.

FIG. 2 is a first schematic diagram of the first three-arm topology device according to an embodiment of the application. As shown in FIG. 2, the three-leg topology device may include: a battery pack, a voltage conversion circuit, a switch, and a three-leg circuit.

The three bridge arm circuit may include: a first bridge arm, a second bridge arm, a third bridge arm, a first inductor L1, a DC bus capacitor E1, and an LC filter. Wherein, the LC filter includes: a first capacitor Co and a second inductor L2.

The first bridge arm includes a first switching tube Q1 and a second switching tube Q2. The first switching tube Q1 and the second switching tube Q2 are connected in series between BUS+ and BUS-, and BUS+ is the positive output terminal of the bus. -That is, the negative output terminal of the bus. For example, the first terminal of the first switching tube Q1 is connected to BUS+, the second terminal of the first switching tube Q1 is connected to the first terminal of the second switching tube Q2, and the second terminal of the second switching tube Q2 is connected to BUS- connect. Among them, the common end of the first switching tube Q1 and the second switching tube Q2 is called the midpoint of the first bridge arm. When the three-leg topology device is applied to a battery low-voltage high-current UPS system, the first bridge arm may also be referred to as a power factor correction (Power Factor Correction, PFC) side high-frequency bridge arm.

The second bridge arm includes a third switching tube Q3 and a fourth switching tube Q4, and the third switching tube Q3 and the fourth switching tube Q4 are connected in series between BUS+ and BUS-. For example, the first terminal of the third switching tube Q3 is connected to BUS+, the second terminal of the third switching tube Q3 is connected to the first terminal of the fourth switching tube Q4, and the second terminal of the fourth switching tube Q4 is connected to BUS- connect. Among them, the common end of the third switching tube Q3 and the fourth switching tube Q4 is called the midpoint of the second bridge arm. When the three-leg topology device is applied to a battery low-voltage high-current UPS system, the second leg can also be referred to as a bridge leg shared by PFC and an inverter (inverter, INV).

The third bridge arm includes a fifth switching tube Q5 and a sixth switching tube Q6, and the fifth switching tube Q5 and the sixth switching tube Q6 are connected in series between BUS+ and BUS-. For example, the first terminal of the fifth switching tube Q5 is connected to BUS+, the second terminal of the fifth switching tube Q5 is connected to the first terminal of the sixth switching tube Q6, and the second terminal of the sixth switching tube Q6 is connected to BUS- connect. Among them, the common end of the fifth switching tube Q5 and the sixth switching tube Q6 is called the midpoint of the third bridge arm. When the three-leg topology device is applied to a battery low-voltage high-current UPS system, the third leg can also be referred to as an INV-side high-frequency bridge leg.

The DC bus capacitor E1 is connected between BUS+ and BUS-. That is, the first bridge arm, the second bridge arm, the third bridge arm and the DC bus capacitor E1 are connected in parallel between BUS+ and BUS-.

The first inductor L1 is a high-frequency inductor on the PFC side. The midpoint of the first bridge arm is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is used as the positive voltage input terminal AC_L of the three bridge arm topology device. The midpoint of the second bridge arm is used as the negative voltage input terminal AC_N of the three bridge arm topology device.

The second inductor L2 is a high-frequency inductor on the INV side. The midpoint of the third bridge arm is connected to the first end of the second inductor L2, the second end of the second inductor L2 is connected to the first end of the first capacitor Co, and the second end of the first capacitor Co is connected to the second bridge arm. The midpoint of the connection. The first terminal of the first capacitor Co is the first output terminal of the three-leg topology device, and the second terminal of the first capacitor Co is the second output terminal of the three-leg topology device.

The positive pole of the battery pack is connected to the first end of the voltage conversion circuit, and the negative pole of the battery pack is connected to the second end of the voltage conversion circuit. The third end of the voltage conversion circuit is connected to BUS+ and the positive voltage input terminal AC_L through a switch, the fourth end of the voltage conversion circuit is connected to BUS-, and the live wire of the mains AC power supply AC (that is, the first end of the external power supply) passes through The switch is connected to the positive voltage input terminal AC_L, and the neutral line of the commercial AC power supply AC (that is, the second terminal of the external power supply) is connected to the negative voltage input terminal AC_N. Both the first output terminal and the second output terminal of the three-leg topology device are connected to the load, and provide alternating current for the load.

The aforementioned battery pack may include at least one battery, which may be specifically determined according to the power of the UPS system applied by the three-leg topology device. For example, the UPS system may be an online type with a power between 1 kW and 3 kW. The UPS system, in other words, the UPS can be a battery low-voltage high-current UPS system.

The three-leg circuit involved in this embodiment is used to implement rectification and inverter functions when the three-leg topology device supplies power to the load. Specifically, it can be combined with the power supply mode adopted when the three-leg topology device supplies power to the load. Introduction and description. Therefore, in some embodiments, the three bridge arm circuit involved in this embodiment may also be referred to as a three bridge arm conversion circuit.

Specifically, there are two power supply modes in the three-leg topology device, namely: an external power supply mode and a battery power supply mode. Corresponding to the UPS system involved in this embodiment, the external power supply mode mentioned here may be a mode in which a stable mains power is provided by the mains AC power supply AC; the battery power supply mode may be a mode in which the battery pack of the UPS system is powered. When the mains AC power supply AC input is high-voltage, or low-voltage, or, the frequency is abnormal, or there is no mains input. Through the switch, the three-leg topology device can switch between the above two modes.

In the external power supply mode, the switch can control the mains AC power supply AC to supply power to the three-leg circuit. At this time, the three-leg circuit works in AC-AC mode. For example, the PFC of the three-leg circuit converts the AC input of the AC power supply AC into DC (that is, rectifies the AC input AC power of the AC AC power supply), and the DC bus capacitor E1 filters the DC power converted by the PFC (also can It is called voltage stabilization) to obtain a stable direct current. The INV of the three-leg circuit converts the stable direct current into alternating current and then outputs it to the load to supply power to the load.

It should be noted that although the above-mentioned PFC converts AC power into DC power, the DC power still contains a certain pulsating AC component, and this pulsating AC component is called ripple voltage. Therefore, in the external power supply mode, the DC bus capacitor E1 can filter the DC power obtained by the PFC conversion (also referred to as voltage stabilization) to filter the ripple voltage in the DC power and obtain a smooth and stable DC voltage. At the same time, the DC bus capacitor E1 can store energy.

In the external power supply mode, the switch can control the voltage conversion circuit to charge the battery pack. For example, the switch can control the voltage conversion circuit to charge the battery pack when the battery pack is in the external power supply mode. That is, the charging of the battery pack is realized by the multiplexing voltage conversion circuit, and no additional charger is required. At this time, in the external power supply mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work.

Exemplarily, the switch can control the voltage conversion circuit to be connected between BUS+ and BUS-, the voltage conversion circuit works in the BUCK mode (i.e. step-down mode), and the BUS voltage output by the DC bus capacitor E1 (ie the DC bus capacitor E1) The voltage obtained by filtering the DC power obtained by the PFC conversion) is stepped down to obtain the charging voltage of the battery pack, and the charging voltage is used to charge the battery pack. At this time, the battery pack serves as the output source of the voltage conversion circuit.

1, in the prior art, when a charger is used to charge a battery pack, the charger needs to be provided with: a rectifier circuit and a step-down circuit. The rectifier circuit is used to rectify the AC power provided by the AC power source to obtain DC power. . The step-down circuit is used to step-down the DC power to obtain the charging voltage of the battery pack. Such a charger equipped with a rectifier circuit and a step-down circuit is usually called a flyback charger.

Since the AC power provided by the mains AC power supply fluctuates in a wide voltage range, the step-down circuit set in the charger needs to achieve a wide range of voltage regulation, resulting in low voltage conversion efficiency of the step-down circuit. Therefore, this When a flyback-like charger charges the battery pack, the charging efficiency of the charger is low.

In the embodiment of the present application, the BUS voltage output by the DC bus capacitor E1 is a stable DC voltage obtained by the PFC rectification of the three-leg circuit. Therefore, when the BUS voltage output by the DC bus capacitor E1 is used to charge the battery pack, The voltage conversion circuit can be reused to reduce the BUS voltage output by the DC bus capacitor E1, and there is no need to separately set a rectifier circuit. In other words, the PFC of the three-leg circuit is multiplexed to obtain the direct current for charging the battery pack.

In addition, because the BUS voltage output by the DC bus capacitor E1 is a stable DC current, the BUS voltage output by the DC bus capacitor E1 can be stepped down without using a voltage conversion circuit with a wide range of voltage regulation, which improves the voltage conversion. The conversion efficiency of the circuit further improves the charging efficiency of the battery pack.

In the battery power supply mode, the switch can control the voltage conversion circuit to discharge the battery pack. Exemplarily, the switch can control the voltage conversion circuit to switch on between the high-frequency inductor (ie, the first inductor L1) and BUS- on the PFC side. At this time, the voltage conversion circuit is connected in series with “the first inductance L1 and the first leg of the three-leg circuit constitute a Boost booster circuit”, and a two-stage boosting process is realized when discharging the battery pack. Specifically, the voltage conversion circuit works in Boost mode (ie, boost mode), and performs a one-stage boosting process on the output voltage of the battery pack. The first inductor L1 and the first leg of the three-leg circuit form a Boost boost circuit. The output voltage of the battery pack is subjected to a two-stage boosting process, and the boosted voltage is input to the DC bus capacitor E1 of the three-leg circuit to maintain the bus voltage balance.

In a UPS system with low-voltage and high-current batteries, the output voltage of the battery pack is relatively low, while the voltage required by the load is relatively high. Therefore, when the three-leg topology device is applied to a battery low-voltage and high-current UPS system, when a battery pack is used to power the load in a battery low-voltage and high-current UPS system, the three-leg topology device needs to be a lower voltage Raise to a higher voltage, that is, need to perform a step-up process with a larger pressure difference. If the voltage conversion circuit is connected in parallel with "the first inductance L1 and the first leg of the three-leg circuit constitutes a Boost boost circuit", the voltage conversion circuit is used to perform the boost operation (that is, the voltage conversion circuit is used to perform the first step). Boost processing), there will be the following problems:

1. The maximum boost ratio of the voltage conversion circuit (for example, the output voltage divided by the input voltage) is limited, which may cause the voltage boosted by the voltage conversion circuit to use the maximum boost ratio, which is still less than the load required by the UPS system with low battery and high current The voltage cannot meet the needs of the UPS system with low voltage and high current battery.

2. The higher the boost ratio, the lower the conversion efficiency of the voltage conversion circuit, and the greater the risk of current stress and heat loss of the voltage conversion circuit. Therefore, the above-mentioned use of the voltage conversion circuit for the first-level boosting process causes the voltage conversion circuit to perform a higher boosting ratio boosting process, resulting in lower conversion efficiency of the voltage conversion circuit, risk of current stress and heat loss of the voltage conversion circuit The risk is higher.

Considering the above-mentioned problems of using the voltage conversion circuit to perform one-stage boost processing, the embodiment of the present application connects the voltage conversion circuit and "the first inductor L1 and the first leg of the three-leg circuit to form a Boost boost circuit" in series. The two-stage boost is realized by connecting the first inductor L1 and the first leg of the three-leg circuit to share a part of the voltage boosting operation, so as to obtain a larger boost ratio while at the same time. In addition, the voltage conversion circuit itself does not need to perform a step-up process with a large voltage difference. When the voltage difference between the input voltage and the output voltage of the voltage conversion circuit is smaller, that is, the step-up ratio is smaller, the voltage conversion efficiency of the voltage conversion circuit is higher. Therefore, the conversion efficiency of the voltage conversion circuit can be improved through the above-mentioned two-stage boosting method, thereby reducing the risk of current stress and heat loss of the voltage conversion circuit, and improving the reliability of the UPS system with low battery and high current.

In the battery power supply mode, the battery pack is the input source of the voltage conversion circuit, and the output of the voltage conversion circuit is the power supply of the three-leg circuit. At this time, the first leg of the three-leg circuit works in the DC-DC mode. For example, the first leg of the three-leg circuit and the first inductor L1 work in Boost mode, the DC bus capacitor E1 filters the boosted DC power to obtain a stable DC power, and the second and third bridge arms work in In the inverter mode, the stable direct current is converted into alternating current and then output to the load to supply power to the load. At the same time, the DC bus capacitor E1 can store energy. At this time, in the battery-powered mode, the voltage conversion circuit and the three-leg circuit are both involved in the work, that is, all devices of the three-leg topology device are involved in the work.

It can be understood that the voltage conversion circuit involved in the embodiment of the present application may be any circuit with a bidirectional voltage conversion function. For example, a voltage conversion circuit with soft switching, a voltage conversion circuit with hard switching, and so on. The voltage conversion circuit may be a voltage conversion circuit with electrical isolation, or a voltage conversion circuit without electrical isolation. Exemplarily, the voltage conversion circuit may also be referred to as a DCDC converter.

FIG. 3 is a second schematic diagram of the first three-leg topology device provided by an embodiment of the application. As shown in FIG. 3, exemplarily, the voltage conversion circuit involved in the embodiment of the application may include, for example, a first voltage conversion unit , The second voltage conversion unit, the transformer TX1 and the LC resonant cavity;

Wherein, the first voltage conversion unit is connected to the low voltage side of the transformer, and the high voltage side of the transformer is connected to the resonant cavity and the second voltage conversion unit. The LC resonant cavity includes: a fifth inductor Lik and a third capacitor Cr. It should be understood that the fifth inductance Lik may be an inductance independent of the transformer TX1, or may be a leakage inductance in the transformer TX1. In other words, the fifth inductor Lik and the transformer TX1 may be independent devices, or may be a component belonging to the transformer TX1, which is not limited in the embodiment of the present application.

The first voltage conversion unit may include: a fourth bridge arm and a fifth bridge arm, and the second voltage conversion unit may include: a sixth bridge arm, a seventh bridge arm, and a second capacitor E2.

Wherein, the fourth bridge arm includes a seventh switching tube Q7 and an eighth switching tube Q8 connected in series, and a first end of the seventh switching tube Q7 is connected to a first end of the eighth switching tube Q8. At this time, the common end of the seventh switching tube Q7 and the eighth switching tube Q8 is called the midpoint of the fourth bridge arm.

The fifth bridge arm includes a ninth switching tube Q9 and a tenth switching tube Q10 connected in series, and a first end of the ninth switching tube Q9 is connected to a first end of the tenth switching tube Q10. At this time, the common end of the ninth switching tube Q9 and the tenth switching tube Q10 is called the midpoint of the fifth bridge arm.

The sixth bridge arm includes an eleventh switching tube Q11 and a twelfth switching tube Q12 connected in series, and a first end of the eleventh switching tube Q11 is connected to a first end of the twelfth switching tube Q12 . At this time, the common end of the eleventh switch transistor Q11 and the twelfth switch transistor Q12 is called the midpoint of the sixth bridge arm.

The seventh bridge arm includes a thirteenth switching tube Q13 and a fourteenth switching tube Q14 connected in series, and a first end of the thirteenth switching tube Q13 is connected to a first end of the fourteenth switching tube Q14 . At this time, the common end of the thirteenth switching tube Q13 and the fourteenth switching tube Q14 is called the midpoint of the seventh bridge arm.

The fourth bridge arm is connected in parallel with the fifth bridge arm. For example, the second terminal of the seventh switching tube Q7 is connected to the second terminal of the ninth switching tube Q9, and the second terminal of the eighth switching tube Q8 is connected to the second terminal of the tenth switching tube Q10. connect.

The sixth bridge arm, the seventh bridge arm, and the second capacitor E2 are connected in parallel. For example, the second terminal of the eleventh switch tube Q11 is connected to the second terminal of the thirteenth switch tube Q13 and the first terminal of the second capacitor E2, and the second terminal of the twelfth switch tube Q12 The two ends are connected to the second end of the fourteenth switch tube Q14 and the second end of the second capacitor E2. It should be understood that the second capacitor E2 may be a DC capacitor for providing a filtering function, so that the voltage conversion circuit provides stable DC power when charging or discharging the battery pack.

The first terminal A of the transformer TX1 (that is, the synonymous terminal on the low voltage side of the transformer TX1) is connected to the midpoint of the fourth bridge arm, and the second terminal B of the transformer TX1 (that is, the same name terminal on the low voltage side of the transformer TX1) is connected to the midpoint of the fourth bridge arm. ) Is connected to the midpoint of the fifth bridge arm, the third terminal C of the transformer TX1 (that is, the terminal with the same name on the high-voltage side of the transformer TX1) is connected to the first terminal of the fifth inductor Lik, and the fifth inductor The second end of Lik is connected to the midpoint of the sixth bridge arm, and the fourth end D of the transformer TX1 (that is, the synonymous end of the high voltage side of the transformer TX1) is connected to the first end of the third capacitor Cr, The second end of the third capacitor Cr is connected to the midpoint of the seventh bridge arm.

In this voltage conversion circuit, the second terminal of the seventh switch tube Q7 is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube Q8 is the second terminal of the voltage conversion circuit. The second terminal of the thirteenth switch tube Q13 is the third terminal of the voltage conversion circuit, and the second terminal of the fourteenth switch tube Q14 is the fourth terminal of the voltage conversion circuit.

When the voltage conversion circuit shown in Figure 3 is used to charge the battery pack, the voltage conversion circuit works in the full-bridge LLC resonant converter mode. That is, the second voltage conversion unit of the voltage conversion circuit, the LC resonant cavity, and the inductance in the transformer TX1 (not shown in the figure) form a full-bridge LLC resonant network, so that the voltage conversion circuit forms a full-bridge LLC resonant converter. At this time, the full-bridge phase-shifting control strategy can be used to control the full-bridge LLC resonant converter, so that the leading arm of the full-bridge LLC resonant converter can realize zero voltage turn-on, and the lag arm of the full-bridge LLC resonant converter can realize zero voltage. For specific operating principles of turn-on and zero-current turn-off, please refer to the introduction of the full-bridge LLC resonant converter in the prior art, which will not be repeated here.

In the full-bridge LLC resonant converter mode, Q11, Q12, Q13, and Q14 are used as switch tubes, and external diodes (also called parasitic diodes, etc.) of Q7, Q8, Q9, and Q10 are used as rectifiers. For example, it is possible to use a phase shifting method to change the duty cycle to control the switch tube in the second voltage conversion unit to be turned on or off to charge the battery pack. The phase-shifting duty cycle referred to here refers to changing the conduction time of the switch tube in the second voltage conversion unit by adjusting the phase difference between the leading arm and the lagging arm in the full-bridge LLC resonant converter. The fixed frequency mentioned here refers to the use of fixed frequency for voltage regulation control.

When the voltage conversion circuit shown in Figure 3 is used to discharge the battery pack, the voltage conversion circuit works in the full-bridge secondary LC resonant converter mode, that is, the first voltage conversion unit of the voltage conversion circuit, the secondary side of the transformer TX1 and The LC resonant cavity constitutes a full-bridge secondary side LC resonant converter, which realizes zero voltage turn-on and zero current turn-off. For the specific working principle, please refer to the introduction of the full-bridge secondary side LC resonant converter in the prior art, which will not be repeated here.

It should be understood that when the voltage conversion circuit is discharging the battery pack, the secondary side of the transformer TX1 connected to the LC resonant cavity is the high-voltage side of the voltage conversion circuit, and when the voltage conversion circuit is charging the battery pack, the transformer TX1 connected to the first voltage conversion unit The secondary side is the low-voltage side of the voltage conversion circuit.

In this full-bridge secondary LC resonant converter mode, Q7, Q8, Q9, and Q10 are used as switch tubes, and the external diodes of Q11, Q12, Q13, and Q14 (also called parasitic diodes, etc.) are used as rectifiers. For example, a fixed frequency and constant duty cycle control method can be used to discharge the battery pack. Among them, Q7 and Q10 are turned on at the same time, and Q8 and Q9 are turned on at the same time. The constant duty cycle mentioned here refers to the use of the same duty cycle to control Q7, Q8, Q9, and Q10, so that the conduction duration of Q7 and Q10 is the same as the conduction duration of Q8 and Q9. The fixed frequency mentioned here refers to the use of fixed frequency for voltage regulation control.

Through the above-mentioned structure of the voltage conversion circuit, the soft switching of the voltage conversion circuit can be realized. Soft-Switching is a kind of switching technology relative to Hard-Switching. The soft switching technology can make the switch tube in the voltage conversion circuit lower the voltage to zero before turning on, and before the switch tube is turned off, the current is first reduced to zero (ie, zero voltage turn on, zero current turn off) to eliminate The overlap of voltage and current in the switching process of the switch tube reduces their rate of change, thereby greatly reducing or even eliminating the switching loss of the voltage conversion circuit, and realizing the high frequency of the voltage conversion circuit.

Because of the poor voltage regulation capability of the voltage conversion circuit with soft switching. That is to say, when the voltage conversion circuit achieves a large voltage difference, the voltage conversion circuit can only achieve zero voltage turn-on, and cannot achieve zero current turn-off, resulting in the voltage conversion circuit unable to achieve zero voltage turn-on and zero current turn-off. Soft switching under full working conditions, that is, the voltage conversion circuit cannot work under the full working conditions of zero voltage turn-on and zero current shut-off, which in turn causes the conversion efficiency of the voltage conversion circuit to be lower than the conversion efficiency under full working conditions, increasing the voltage The risk of current stress and heat loss of the conversion circuit.

Therefore, when the above-mentioned voltage conversion circuit with soft switching is applied to the three-leg topology device provided in the embodiment of the present application, the voltage conversion circuit is combined with the "first inductance L1 and the first leg of the three-leg circuit". The "Boost boost circuit" is connected in series, so that the voltage conversion circuit can achieve a fixed boost ratio (for example, the fixed boost ratio can achieve a smaller voltage difference) soft switching function, the first inductor L1 and the third bridge The Boost boost circuit formed by the first leg of the arm circuit realizes the voltage regulation function, that is, while obtaining a larger boost ratio, the voltage conversion circuit with soft switching itself does not need to perform a boost with a larger voltage difference. deal with. In this way, the voltage conversion circuit with soft switching can work under the full working conditions of zero voltage turn-on and zero current turn-off, which improves the conversion efficiency of the voltage conversion circuit with soft switching, thereby reducing the cost of the voltage conversion circuit with soft switching. Current stress risk and heat loss risk improve the reliability of UPS systems with low battery voltage and high current.

It should be understood that FIG. 3 is only a schematic diagram of a voltage conversion circuit with soft switching. In specific implementation, the solution of the embodiment of the present application may also adopt other voltage conversion circuits with soft switching.

In addition, the first voltage conversion unit in the voltage conversion circuit shown in FIG. 3 can also be implemented by other circuit structures, and other connection methods can also be used between the transformer TX1 and the LC resonant cavity and the second voltage conversion unit. Refer to the description of these parts in the subsequent embodiments (for example, the description of FIG. 25 to FIG. 35), the implementation principles are similar, and details are not repeated here.

In addition, although the above-mentioned FIG. 3 is a schematic diagram of an example of a voltage conversion circuit provided with electrical isolation (for example, the transformer in FIG. 3 realizes the electrical isolation of the voltage conversion circuit), it should be understood that the voltage conversion circuit involved in the embodiment of the present application It can be a voltage conversion circuit with electrical isolation, or a voltage conversion circuit without electrical isolation. For example, the voltage conversion circuit has electrical isolation, the first leg of the three-leg circuit has no electrical isolation, or the voltage conversion circuit has no electrical isolation, and the first leg of the three-leg circuit has electrical isolation, or the voltage conversion circuit has Electrical isolation, the first leg of the three-leg circuit has electrical isolation, or the voltage conversion circuit has no electrical isolation, and the first leg of the three-leg circuit has no electrical isolation, etc.

It should be noted that when the above-mentioned three-leg topology device switches from the external power supply mode to the battery power supply mode, or when switching from the battery power supply mode to the external power supply mode, there is a certain time difference due to the mode switching (for example, from the mains There may be a time difference of X seconds when the battery pack is disconnected. Therefore, within this time difference, the three-leg topology device can use the voltage stored in the DC bus capacitor E1 to supply power to the load, so as to provide stable AC power to the load and avoid the load. Power down.

The three-leg topology device provided by the embodiment of the present application realizes the charging or discharging of the battery pack by multiplexing the voltage conversion circuit, that is, the voltage conversion circuit, and can realize the charging function of the battery pack without adding an additional charger. In addition, whether in the external power supply mode or the battery power supply mode, the voltage conversion circuit and the three-leg circuit are involved in the work, that is, all the devices of the three-leg topology device are involved in the work. When the three-leg topology device is applied to a battery low-voltage high-current UPS system, the device reuse rate of the system can be improved, device design redundancy can be avoided, and the cost of the battery low-voltage high-current UPS system can be reduced.

The following is an example of the implementation of the above switch:

Continuing to refer to FIG. 2, in the three-leg topology device, the switch may include, for example, a first switch K1, a second switch K2, and balance components.

Wherein, the third terminal of the voltage conversion circuit is connected to the fixed terminal of the first switch K1, the first selection terminal of the first switch K1 is connected to the first terminal of the balance component, and the second terminal of the balance component is connected to BUS+. The second selection terminal of a switch K1 is connected to the positive voltage input terminal AC_L, the first terminal of the second switch K2 is connected to the live wire of the mains AC power supply AC, and the second terminal of the second switch K2 is connected to the positive voltage input terminal AC_L, The fourth terminal of the voltage conversion circuit is connected to BUS-.

In the external power supply mode, the fixed terminal of the first switch K1 is connected to the first selection terminal of the first switch K1, and the second switch K2 is closed; in the battery power supply mode, the fixed terminal of the first switch K1 is connected to the first switch K1. The second selection terminal is connected, and the second switch K2 is disconnected. For example, the first switch K1 may be any selective switch that can be turned on or off according to a control signal, such as a double-throw relay, a bidirectional electronic switch, or a thyristor. The second switch K2 can be any switch that can be turned on or off according to a control signal, for example, a single-throw relay, a one-way electronic switch, a thyristor, and the like.

The above-mentioned balancing components are used to balance the voltage between the BUS of the three-leg circuit and the voltage conversion circuit in the external power supply mode, so as to avoid the moment when the fixed terminal of the first switch K1 is connected to the first selection terminal of the first switch K1 , Input a larger current to the voltage conversion circuit, so as to achieve overcurrent protection for the voltage conversion circuit.

Continuing to refer to FIG. 2, in the first possible implementation manner, the above-mentioned balancing component may be, for example, a varistor RZ.

Fig. 4 is a schematic diagram of a second three-arm topology device provided by an embodiment of the application. As shown in FIG. 4, in the second possible implementation manner, the above-mentioned balance component may be, for example, a thermistor RT with a negative temperature coefficient.

FIG. 5 is a schematic diagram of a third three-arm topology device provided by an embodiment of the application. As shown in FIG. 5, in a third possible implementation manner, the above-mentioned balancing component may be, for example, a third inductor L3.

Fig. 6 is a schematic diagram of a fourth three-arm topology device provided by an embodiment of the application. As shown in FIG. 6, in a fourth possible implementation manner, the above-mentioned balancing component may be, for example, a resistor R1. In this implementation manner, the above-mentioned switch may further include: a third switch K3.

Continuing to refer to FIG. 6, the third terminal of the voltage conversion circuit is connected to the first terminal of the third switch K3, and the second terminal of the third switch K3 is connected to BUS+. FIG. 7 is a schematic diagram of a fifth three-arm topology device provided by an embodiment of the application. As shown in Fig. 7, in the fifth possible connection manner, the third switch K3 is connected in parallel with the resistor R1.

6 or 7, in the external power supply mode and when the voltage difference between the bus and the voltage conversion circuit is less than or equal to the preset threshold, the third switch K3 is closed, so that the voltage conversion circuit is Charging the battery pack. In the battery power supply mode, the third switch K3 is turned off. The preset threshold value may be less than or equal to 20V, for example, and may be specifically determined according to the use environment of the UPS system to which the three-leg topology device is applied.

Exemplarily, the aforementioned third switch K3 may be any switch that can be turned on or off according to a control signal, for example, a single-throw relay, a one-way electronic switch, a thyristor, and the like.

It should be understood that the second switch K2 and the third switch K3 can be the same switch or different switches. For example, the second switch K2 uses a thyristor, and the third switch K3 uses a unidirectional electronic switch.

Taking the structure of the three-leg topology device shown in Figure 6 as an example, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device in different power supply modes are schematically described below:

External power supply mode: control the fixed end of the first switch K1 to connect with the first selection end of the first switch K1, the second switch K2 is closed, and the voltage conversion circuit between the BUS+ of the three-leg topology device and the voltage conversion circuit of the three-leg topology device When the voltage difference between the two is less than or equal to the preset threshold, the third switch K3 is controlled to be closed. At this time, the voltage conversion circuit works in Buck mode. The preset threshold value may be less than or equal to 20V, for example, and may be specifically determined according to the use environment of the UPS system to which the three-leg topology device is applied.

FIG. 8 is the first schematic diagram of the current of the fourth three-leg topology device in the external power supply mode according to the embodiment of the application. As shown in FIG. 8, in the first phase of the positive half cycle of the alternating current, the second switching tube Q2 and the fourth switching tube Q4 of the three-leg circuit are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The live wire of the mains AC power supply AC→the first inductor L1→the second switch tube Q2→the fourth switch tube Q4→the neutral wire of the mains AC power supply AC, forming an energy storage loop of the first inductor L1.

2. BUS+→the positive pole of the voltage conversion circuit→the positive pole of the battery pack→the negative pole of the battery pack→the negative pole of the voltage conversion circuit→BUS-, which constitutes the energy storage circuit of the battery pack.

FIG. 9 is the second schematic diagram of the current of the fourth three-leg topology device in the external power supply mode according to the embodiment of the application. As shown in FIG. 9, in the second phase of the positive half cycle of the alternating current, the first switching tube Q1 is controlled And the fourth switch tube Q4 is turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The live wire of the mains AC power supply AC→the first inductance L1→the first switch tube Q1→the DC bus capacitor E1→the fourth switch tube Q4→the neutral wire of the mains AC power supply AC, forming the first inductance L1 and the mains At the same time, it is the energy storage circuit of the DC bus capacitor E1.

FIG. 10 is the third schematic diagram of the current in the external power supply mode of the fourth three-leg topology device provided by the embodiment of the application. As shown in FIG. 10, in the first stage of the negative half cycle of the alternating current, the first switch transistor Q1 is controlled And the third switch tube Q3 is turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The neutral line of the mains AC power supply AC → the third switching tube Q3 → the first switching tube Q1 → the first inductor L1 → the live wire of the mains AC power supply AC, forming an energy storage loop of the first inductor L1.

FIG. 11 is a schematic diagram IV of the current of the fourth three-leg topology device in the external power supply mode according to the embodiment of the application. As shown in FIG. 11, in the second phase of the negative half cycle of the alternating current, the second switch Q2 is controlled And the third switch tube Q3 is turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The neutral line of the mains AC power supply AC→the third switch tube Q3→the DC bus capacitor E1→the second switch tube Q2→the first inductance L1→the live wire of the mains AC power supply AC, forming the first inductance L1 and the mains At the same time, it is the energy storage circuit of the DC bus capacitor E1.

Battery power supply mode: control the fixed end of the first switch K1 to communicate with the second selection end of the first switch K1, and the second switch K2 and the third switch K3 are disconnected. At this time, the voltage conversion circuit works in Boost mode.

FIG. 12 is a schematic diagram 5 of current in the battery power supply mode of the fourth three-leg topology device provided by an embodiment of the application. As shown in FIG. 12, in the first stage of the battery power supply mode, the second switch Q2 is controlled to be turned on . At this time, the current flow in the three-leg topology device is as follows:

The positive pole of the battery pack → the positive pole of the voltage conversion circuit → the first inductor L1 → the second switch tube Q2 → the negative pole of the voltage conversion circuit → the negative pole of the battery pack, forming an energy storage loop of the first inductor L1.

FIG. 12 is a schematic diagram 6 of the current of the fourth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in FIG. 13, in the second stage of the battery power supply mode, the first switching tube Q1 is controlled to be turned on . At this time, the current flow in the three-leg topology device is as follows:

The positive pole of the battery pack → the positive pole of the voltage conversion circuit → the first inductor L1 → the first switch tube Q1 → the DC bus capacitor E1 → the negative pole of the voltage conversion circuit → the negative pole of the battery pack, forming an energy storage circuit of the DC bus capacitor E1.

It should be understood that although the current trends of the three-leg topology devices shown in FIG. 8 to FIG. 12 are all schematically illustrated by taking the fourth three-leg topology device shown in FIG. 6 as an example. However, those skilled in the art can understand that the current trend and the states of each switch and each switch tube are also applicable to the three-leg topology device shown in FIG.

In addition, when the three-leg topology device of any structure of Figures 2 to 5 is used, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device in different modes are as follows:

External power supply mode: control the fixed end of the first switch K1 to communicate with the first selection end of the first switch K1, and the second switch K2 is closed. At this time, the voltage conversion circuit works in Buck mode.

In this mode, the state of each switch tube of the three-leg topology device in the external power supply mode is the same as the state of each switch tube of the three-leg topology device shown in FIG. 6 in the external power supply mode. The current trend of the three-leg topology device is the same as the current trend of the three-leg topology device shown in FIG. 6 in the external power supply mode. For details, reference may be made to the corresponding descriptions of FIG. 8 to FIG.

Battery power supply mode: control the fixed terminal of the first switch K1 to be connected with the second selection terminal of the first switch K1, and the second switch K2 is turned off. At this time, the voltage conversion circuit works in Boost mode.

In this mode, the state of each switch tube of the three-leg topology device in the battery power supply mode is the same as the state of each switch tube of the three-leg topology device shown in FIG. 6 in the battery power supply mode. The current trend of the three-leg topology device is the same as the current trend of the three-leg topology device shown in FIG. 6 in the battery power supply mode. For details, please refer to the corresponding descriptions of FIG. 12 to FIG.

FIG. 14 is a schematic diagram of a sixth three-arm topology device provided by an embodiment of the application. As shown in FIG. 4, in the three-leg topology device, the switch may include, for example, a first switch K1, a second switch K2, and balance components.

The third terminal of the voltage conversion circuit is respectively connected to the first terminal of the first switch K1 and the first selection terminal of the second switch K2, and the second terminal of the first switch K1 is connected to the first terminal of the balancing component, which is balanced The second end of the component is connected to BUS+, the second selection end of the second switch K2 is connected to the live wire of the AC power supply, the fixed end of the second switch K2 is connected to the positive voltage input terminal AC_L, and the fourth end of the voltage conversion circuit Connect with BUS-.

In the external power supply mode, the first switch K1 is closed, and the fixed end of the second switch K2 is connected to the second selection end of the second switch K2; in the battery power supply mode, the first switch K1 is open, and the second switch K2 is fixed The terminal is connected with the first selection terminal of the second switch K2. For example, the first switch K1 may be any switch that can be turned on or off according to a control signal, for example, a single-throw relay, a one-way electronic switch, a thyristor, etc. The second switch K2 can be any selection switch that can be turned on or off according to a control signal, such as a double-throw relay, a bidirectional electronic switch, or a thyristor.

The above-mentioned balancing components are used to balance the voltage between the BUS+ of the three-leg circuit and the voltage conversion circuit in the external power supply mode, so as to avoid the moment when the fixed terminal of the first switch K1 is connected to the first selection terminal of the first switch K1 , Input a larger current to the voltage conversion circuit, so as to achieve overcurrent protection for the voltage conversion circuit.

Continuing to refer to FIG. 14, in the sixth possible implementation manner, the above-mentioned balancing component may be, for example, a varistor RZ.

FIG. 15 is a schematic diagram of a seventh three-arm topology device provided by an embodiment of the application. As shown in FIG. 15, in a seventh possible implementation manner, the above-mentioned balance component may be, for example, a thermistor RT with a negative temperature coefficient.

FIG. 16 is a schematic diagram of an eighth three-arm topology device provided by an embodiment of the application. As shown in FIG. 16, in an eighth possible implementation manner, the above-mentioned balancing component may be, for example, a third inductor L3.

When the three-leg topology device of any structure of Figure 14 to Figure 16 is used, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device in different modes are as follows:

External power supply mode: control the first switch K1 to close, and the fixed end of the second switch K2 is connected to the second selection end of the second switch K2. At this time, the voltage conversion circuit works in Buck mode.

Battery power supply mode: the first switch K1 is controlled to be turned off, and the fixed end of the second switch K2 is connected to the first selection end of the second switch K2. At this time, the voltage conversion circuit works in Boost mode.

FIG. 17 is a schematic diagram of a ninth three-arm topology device provided by an embodiment of the application. As shown in FIG. 17, in a ninth possible implementation manner, the above-mentioned balancing component may be, for example, a resistor R1. In this implementation manner, the above-mentioned switch may further include: a third switch K3.

Continuing to refer to FIG. 17, the third terminal of the voltage conversion circuit is connected to the first terminal of the third switch K3, and the second terminal of the third switch K3 is connected to BUS+. FIG. 18 is a schematic diagram of a tenth three-arm topology device according to an embodiment of the application. As shown in FIG. 18, in the tenth possible connection manner, the third switch K3 is connected in parallel with the resistor R1.

Referring to the switch shown in Figure 17 or Figure 18, in the external power supply mode and when the voltage difference between the bus and the voltage conversion circuit is less than or equal to the preset threshold, the third switch K3 is closed so that the voltage conversion circuit is Charging the battery pack. In the battery power supply mode, the third switch K3 is turned off. The preset threshold value may be less than or equal to 20V, for example, and may be specifically determined according to the use environment of the UPS system to which the three-leg topology device is applied.

It should be understood that the first switch K1 and the third switch K3 may be the same switch or different switches. For example, the first switch K1 uses a thyristor, and the third switch K3 uses a unidirectional electronic switch.

When the three-leg topology device of any structure of Figure 17 to Figure 18 is used, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device in different modes are as follows:

External power supply mode: control the first switch K1 to be closed, the fixed end of the second switch K2 is connected to the second selection end of the second switch K2, and is connected between the BUS of the three-leg topology device and the voltage conversion circuit of the three-leg topology device When the voltage difference between the two is less than or equal to the preset threshold, the third switch K3 is controlled to be closed. At this time, the voltage conversion circuit works in Buck mode. The preset threshold value may be less than or equal to 20V, for example, and may be specifically determined according to the use environment of the UPS system to which the three-leg topology device is applied.

Battery power supply mode: control the first switch K1 and the third switch K3 to be turned off, and the fixed end of the second switch K2 is connected to the first selection end of the second switch K2. At this time, the voltage conversion circuit works in Boost mode.

FIG. 19 is a schematic diagram of an eleventh three-leg topology device provided by an embodiment of this application. As shown in FIG. 19, in the three-leg topology device, the switch may include, for example, a first switch K1, a second switch K2, a third switch K3, and balance components.

Wherein, the third terminal of the voltage conversion circuit is respectively connected to the first terminal of the first switch K1 and the first terminal of the third switch K3, the second terminal of the first switch K1 is connected to the positive voltage input terminal AC_L, and the second switch K2 The first end of the second switch K2 is connected to the live wire of the AC power supply AC, the second end of the second switch K2 is connected to the positive voltage input terminal AC_L, the second end of the third switch K3 is connected to the first end of the balance element, and the balance element The second end of the device is connected to BUS+, and the fourth end of the voltage conversion circuit is connected to BUS-.

In the external power supply mode, the first switch K1 is opened, and the second switch K2 and the third switch K3 are closed; in the battery power supply mode, the first switch K1 is closed, and the second switch K2 and the third switch K3 are opened.

The above-mentioned balancing components are used to balance the voltage between the BUS of the three-leg circuit and the voltage conversion circuit in the external power supply mode, so as to avoid the moment when the first switch K3 is closed, a large current is input to the voltage conversion circuit, thereby Realize over-current protection for the voltage switch circuit.

Continuing to refer to FIG. 19, in the eleventh possible implementation manner, the above-mentioned balancing component may be, for example, a varistor RZ.

FIG. 20 is a schematic diagram of a twelfth three-arm topology device provided by an embodiment of the application. As shown in FIG. 20, in a twelfth possible implementation manner, the above-mentioned balance component may be, for example, a thermistor RT with a negative temperature coefficient.

FIG. 21 is a schematic diagram of a thirteenth three-arm topology device provided by an embodiment of the application. As shown in FIG. 21, in the thirteenth possible implementation manner, the above-mentioned balancing component may be, for example, the third inductor L3.

When the three-leg topology device of any structure of Figure 19 to Figure 21 is used, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device in different modes are as follows:

External power supply mode: control the first switch K1 to open, and the second switch K2 and the third switch K3 to close. At this time, the voltage conversion circuit works in Buck mode.

Battery power supply mode: control the first switch K1 to close, and the second switch K2 and the third switch K3 to open. At this time, the voltage conversion circuit works in Boost mode.

FIG. 22 is a schematic diagram of a fourteenth three-arm topology device provided by an embodiment of the application. As shown in FIG. 22, in the fourteenth possible implementation manner, the above-mentioned balancing component may be, for example, a resistor R1. In this implementation manner, the above-mentioned switch may further include: a fourth switch K4.

Continuing to refer to FIG. 22, the third terminal of the voltage conversion circuit is connected to the first terminal of the fourth switch K4, and the second terminal of the fourth switch is connected to BUS+. FIG. 23 is a schematic diagram of a fifteenth three-leg topology device provided by an embodiment of this application. As shown in Fig. 23, in the fifteenth possible connection mode, the fourth switch K4 is connected in parallel with the resistor R1.

Referring to the switch shown in FIG. 22 or FIG. 23, in the external power supply mode and when the voltage difference between the bus and the voltage conversion circuit is less than or equal to the preset threshold, the fourth switch K4 is closed, so that the voltage conversion circuit is Charging the battery pack. In the battery power supply mode, the fourth switch K4 is turned off. The preset threshold value may be less than or equal to 20V, for example, and may be specifically determined according to the use environment of the UPS system to which the three-leg topology device is applied.

Exemplarily, the aforementioned fourth switch K4 may be any switch that can be turned on or off according to a control signal, for example, a single throw relay, a one-way electronic switch, a thyristor, and the like.

In this embodiment, the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 can be any switch that can be turned on or off according to a control signal, for example, a single-throw relay, a one-way electronic Switches, thyristors, etc. It should be understood that the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 may be the same switch or different switches. For example, the first switch K1 uses a thyristor, the second switch K2, the third switch K3, and the fourth switch K4 use single-throw relays, etc., which is not limited in this embodiment.

When the three-leg topology device of any structure of Figure 22 to Figure 23 is used, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device in different modes are as follows:

External power supply mode: control the first switch K1 to open, the second switch K2 and the third switch K3 to close, and the voltage difference between the BUS of the three-leg topology device and the voltage conversion circuit of the three-leg topology device is less than or When it is equal to the preset threshold, the fourth switch K4 is controlled to be closed. At this time, the voltage conversion circuit works in Buck mode. The preset threshold value may be less than or equal to 20V, for example, and may be specifically determined according to the use environment of the UPS system to which the three-leg topology device is applied.

Battery power supply mode: control the first switch K1 to close, the second switch K2, the third switch K3 and the fourth switch K4 to open. At this time, the voltage conversion circuit works in Boost mode.

It should be understood that the above-mentioned Figure 2, Figures 4 to 7, and the switch shown in Figures 14 to 23 are only an example. Due to the numerous implementations of the switch, the application to the three bridges will not be listed here. Switch for arm topology device. In specific implementation, the switch can be selected according to actual needs to realize the function of controlling the voltage conversion circuit to charge the battery pack in the external power supply mode, and the function of controlling the voltage conversion circuit to discharge the battery pack in the battery power supply mode. This will not be repeated here. .

In the examples of the three-leg topology devices shown in FIGS. 2, 4 to 7 and FIGS. 14 to 23, the voltage conversion circuit may be any circuit with a bidirectional voltage conversion function. For example, the voltage conversion circuit shown in FIG. 3 is not limited to this.

Structure B: Three-leg topology device includes: battery pack, voltage conversion circuit and three-leg circuit, without switch. The three-leg topology device can be applied to a battery low-voltage high-current inverter system or a battery low-voltage high-current UPS system. It should be noted that the following embodiments involve the same or similar concepts or processes as those in the aforementioned three-arm topology device, and will not be repeated one by one. For details, please refer to the description of the aforementioned three-arm topology device.

FIG. 24 is a schematic diagram of a sixteenth three-leg topology device provided by an embodiment of the application. As shown in FIG. 24, the three-leg topology device may include: a battery pack, a voltage conversion circuit, and a three-leg circuit. Among them, the voltage conversion circuit is respectively connected with the battery pack and the three bridge arm circuit.

The three bridge arm circuit includes: a first bridge arm, a second bridge arm, a third bridge arm, a DC bus capacitor E1, and an LC filter. Among them, the first bridge arm includes a first switching tube and a second switching tube connected in series; the second bridge arm includes a third switching tube and a fourth switching tube connected in series; the third bridge arm includes a fifth switching tube and a sixth switching tube connected in series. Switch tube; LC filter includes: a first capacitor Co and a second inductor L2. The first bridge arm, the second bridge arm, the third bridge arm and the DC bus capacitor E1 are connected in parallel between the positive output terminal BUS+ and the negative output terminal BUS-; The first end is connected, the second end of the second inductor L2 is connected to the first end of the first capacitor Co, and the second end of the first capacitor Co is connected to the midpoint of the second bridge arm. The first terminal of the first capacitor Co is the first output terminal of the three-leg topology device, and the second terminal of the first capacitor Co is the second output terminal of the three-leg topology device.

In this embodiment, the voltage conversion circuit can implement the voltage conversion function through its own circuit structure, or multiplexing the bus capacitance E1 of the three-leg circuit, or “multiplexing the second bridge arm and the bus capacitance E1”. Therefore, whether it is charging or discharging the battery pack, all devices of the three-leg topology device participate in the work, which improves the device reuse rate of the three-leg topology device. When the three-leg topology device is applied to a battery low-voltage and high-current UPS system or an inverter system, the device reuse rate of the battery low-voltage and high-current UPS system or the inverter system can be increased, thereby reducing the cost of the system.

The specific structure and working principle of the three-arm topology device are described below, specifically:

Structure B1: The voltage conversion circuit in the three-leg topology device realizes the voltage conversion function through its own circuit structure. The three-leg topology device is applied to a battery low-voltage high-current UPS system with a mains AC power supply AC as an external power supply. For example, a battery voltage high current UPS system with a narrow range of battery pack input voltage, for example, a battery voltage high current UPS system using a lithium battery. It should be understood that the battery pack input voltage mentioned here refers to the voltage output by the battery pack when the battery pack is used to supply power to the load. In some embodiments, the three-arm topology device may also be applied to an emergency power supply (Emergency Power Supply, EPS) system.

Continuing to refer to FIG. 24, in the structure B1, the three-leg circuit of the three-leg topology device further includes a first inductor L1.

The first inductor L1 is a high-frequency inductor on the PFC side, and the inductor (for example, the second inductor L2) included in the filter is a high-frequency inductor on the INV side. The midpoint of the first bridge arm is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is used as the positive voltage input terminal AC_L of the three bridge arm topology device. The midpoint of the second bridge arm is used as the negative voltage input terminal AC_N of the three bridge arm topology device. The live wire of the commercial AC power source AC is connected to the positive voltage input terminal AC_L, and the neutral wire of the commercial AC power source AC is connected to the negative voltage input terminal AC_N.

Optionally, in some embodiments, the live wire of the mains AC power supply AC is connected to the positive voltage input terminal AC_L through the switch K5 to meet the safety requirements of the three-leg topology device. It should be understood that the switch K5 may be, for example, a unidirectional electronic switch, a bidirectional thyristor, or the like.

The midpoint of the third bridge arm is connected to the first end of the second inductor L2, the second end of the second inductor L2 is connected to the first end of the first capacitor Co, and the second end of the first capacitor Co is connected to the second bridge arm. The midpoint of the connection. The first terminal of the first capacitor Co is the first output terminal of the three-leg topology device, and the second terminal of the first capacitor Co is the second output terminal of the three-leg topology device, both of which are connected to the load.

The positive pole of the battery pack is connected to the first end of the voltage conversion circuit, and the negative pole of the battery pack is connected to the second end of the voltage conversion circuit. The third end of the voltage conversion circuit is connected to BUS+, and the fourth end of the voltage conversion circuit is connected to BUS-.

Specifically, there are two power supply modes in the three-leg topology device, namely: an external power supply mode and a battery power supply mode.

In the external power supply mode, the mains AC power supply AC supplies power for the three-leg circuit, and the voltage conversion circuit charges the battery pack. At this time, the three-leg circuit works in AC-AC mode, and the voltage conversion circuit works in BUCK mode (ie, step-down mode). The BUS voltage output by the DC bus capacitor E1 is stepped down to obtain the charging voltage of the battery pack. This charging voltage charges the battery pack. At this time, the battery pack serves as the output source of the voltage conversion circuit.

In this way, in the external power supply mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work. Regarding the technical effect of using the voltage conversion circuit to charge the battery pack, refer to the description of using the voltage conversion circuit to charge the battery pack in FIG. 2 of the foregoing embodiment.

In the battery power supply mode, the battery pack is the input source of the voltage conversion circuit, and the output of the voltage conversion circuit is the power supply of the three-leg circuit. That is, the voltage conversion circuit discharges the battery pack. At this time, the voltage conversion circuit works in Boost mode (boost mode), and boosts the output voltage of the battery pack. The boosted voltage is input to the DC bus capacitor E1 of the three-leg circuit to maintain the bus voltage balance. The first leg of the three-leg circuit works in DC-DC mode, and the DC bus capacitor E1 filters the boosted DC power to obtain a stable DC power. The second and third legs of the three-leg circuit work in In the inverter mode, the stable direct current is converted into alternating current and then output to the load to supply power to the load. At the same time, the DC bus capacitor E1 can store energy. In this way, in the battery-powered mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work.

It can be understood that the voltage conversion circuit involved in the embodiments of the present application may be a voltage conversion circuit with electrical isolation, or a voltage conversion circuit without electrical isolation. Exemplarily, the voltage conversion circuit may also be referred to as a DCDC converter.

Continuing to refer to FIG. 24, for example, the voltage conversion circuit involved in the embodiment of the present application may include, for example, a first voltage conversion unit, a transformer, an LC resonant cavity, and a second voltage conversion unit. The first voltage conversion unit is connected to the low voltage side of the transformer, and the high voltage side of the transformer is connected to the LC resonant cavity and the second voltage conversion unit.

Continuing to refer to FIG. 24, exemplarily, the first voltage conversion unit includes: a fourth bridge arm and a fifth bridge arm. The LC resonant cavity includes: a fifth inductor Lik and a third capacitor Cr. The second voltage conversion unit includes: a sixth bridge arm and a seventh bridge arm. That is, the second voltage conversion unit involved in this embodiment is a full-bridge topology.

Among them, the fourth bridge arm includes: a seventh switching tube Q7 and an eighth switching tube Q8 connected in series (that is, the first end of the seventh switching tube Q7 is connected to the first end of the eighth switching tube Q8); the fifth bridge arm It includes: a ninth switching tube Q9 and a tenth switching tube Q10 connected in series (that is, the first end of the ninth switching tube Q9 is connected to the first end of the tenth switching tube Q10). The fourth bridge arm is connected in parallel with the fifth bridge arm (that is, the second end of the seventh switching tube Q7 is connected to the second end of the ninth switching tube Q9, and the second end of the eighth switching tube Q8 is connected to the tenth The second end of the switch tube Q10 is connected).

The sixth bridge arm includes: the eleventh switching tube Q11 and the twelfth switching tube Q12 connected in series (that is, the first end of the eleventh switching tube Q11 is connected to the first end of the twelfth switching tube Q12); The bridge arm includes a thirteenth switching tube Q13 and a fourteenth switching tube Q14 connected in series (that is, the first end of the thirteenth switching tube Q13 is connected to the first end of the fourteenth switching tube Q14). The seventh bridge arm is connected in parallel with the sixth bridge arm (that is, the second end of the eleventh switching tube Q11 is connected to the second end of the thirteenth switching tube Q13, and the second end of the twelfth switching tube Q12 is connected to the fourteenth The second end of the switch tube Q14 is connected).

For the description of the fourth bridge arm, the fifth bridge arm, the sixth bridge arm, the seventh bridge arm and the LC resonant cavity, please refer to the fourth bridge arm, the fifth bridge arm, the sixth bridge arm, and the seventh bridge arm in FIG. 3 above. The description of the bridge arm and the resonant cavity will not be repeated here. In some embodiments, the first voltage conversion unit shown in FIG. 24 may also be referred to as a full-bridge conversion circuit.

The second terminal of the seventh switch tube Q7 is the first terminal of the voltage conversion circuit, the second terminal of the eighth switch tube Q8 is the second terminal of the voltage conversion circuit, and the thirteenth switch The second terminal of the tube Q13 is the third terminal of the voltage conversion circuit, and the second terminal of the fourteenth switch tube Q14 is the fourth terminal of the voltage conversion circuit.

The midpoint of the fourth bridge arm is connected to the synonymous end of the low-voltage side of the transformer TX1, and the midpoint of the fifth bridge arm is connected to the same-named end of the low-voltage side of the transformer TX1. The end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductance Lik, the second end of the fifth inductance Lik is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor Cr. The second end of the third capacitor Cr is connected to the midpoint of the seventh bridge arm.

When the voltage conversion circuit is used to charge the battery pack, the voltage conversion circuit works in the full-bridge LLC resonant converter mode. That is, the second voltage conversion unit of the voltage conversion circuit, the LC resonant cavity, and the inductance in the transformer TX1 (not shown in the figure) form a full-bridge LLC resonant network, so that the voltage conversion circuit forms a full-bridge LLC resonant converter. At this time, the full-bridge phase-shifting control strategy can be used to control the full-bridge LLC resonant converter, so that the leading arm of the full-bridge LLC resonant converter can realize zero voltage turn-on, and the lag arm of the full-bridge LLC resonant converter can realize zero voltage. For specific operating principles of turn-on and zero-current turn-off, please refer to the introduction of the full-bridge LLC resonant converter in the prior art, which will not be repeated here.

When the voltage conversion circuit is used to discharge the battery pack, the voltage conversion circuit works in the full-bridge secondary side LC resonant converter mode, that is, the first voltage conversion unit of the voltage conversion circuit, the secondary side of the transformer TX1 and the LC resonant cavity constitute The full-bridge secondary LC resonant converter realizes zero voltage turn-on and zero current turn-off. The specific working principle can be referred to the introduction of the full-bridge secondary side LC resonant converter in the prior art, which will not be repeated here.

It should be understood that when the voltage conversion circuit is discharging the battery pack, the secondary side of the transformer TX1 connected to the LC resonator is the high-voltage side of the voltage conversion circuit. When the voltage conversion circuit is charging the battery pack, it is connected to the first voltage conversion unit. The secondary side of the connected transformer TX1 is the low-voltage side of the voltage conversion circuit.

Optionally, the above-mentioned high-voltage side of the transformer, the LC resonant cavity and the second voltage conversion unit may also adopt the following connection modes:

FIG. 25 is a first schematic diagram of partial connection of a voltage conversion circuit provided by an embodiment of the application. As shown in Figure 25, the end of the same name on the high voltage side of the transformer TX1 is connected to the first end of the third capacitor Cr, the second end of the third capacitor Cr is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer TX1 It is connected to the first end of the fifth inductor Lik, and the second end of the fifth inductor Lik is connected to the midpoint of the seventh bridge arm.

FIG. 26 is a second schematic diagram of partial connections of the voltage conversion circuit provided by an embodiment of the application. As shown in Figure 26, the end of the same name on the high voltage side of the transformer TX1 is connected to the first end of the third capacitor Cr, the second end of the third capacitor Cr is connected to the first end of the fifth inductor Lik, and the second end of the fifth inductor Lik The terminal is connected to the midpoint of the sixth bridge arm, and the synonymous end of the high-voltage side of the transformer TX1 is connected to the midpoint of the seventh bridge arm.

FIG. 27 is a third schematic diagram of partial connections of the voltage conversion circuit provided by an embodiment of the application. As shown in Figure 27, the end of the same name on the high voltage side of the transformer TX1 is connected to the first end of the fifth inductor Lik, the second end of the fifth inductor Lik is connected to the first end of the third capacitor Cr, and the second end of the third capacitor Cr The terminal is connected to the midpoint of the sixth bridge arm, and the synonymous end of the high-voltage side of the transformer TX1 is connected to the midpoint of the seventh bridge arm.

FIG. 28 is a fourth schematic diagram of partial connection of the voltage conversion circuit provided by an embodiment of the application. As shown in Figure 28, the end of the same name on the high voltage side of the transformer TX1 is connected to the midpoint of the sixth bridge arm, the end of the same name on the high voltage side of the transformer TX1 is connected to the first end of the third capacitor Cr, and the second end of the third capacitor Cr It is connected to the first end of the fifth inductor Lik, and the second end of the fifth inductor Lik is connected to the midpoint of the seventh bridge arm.

FIG. 29 is the fifth schematic diagram of partial connection of the voltage conversion circuit provided by the embodiment of the application. As shown in Figure 29, the end of the same name on the high voltage side of the transformer TX1 is connected to the midpoint of the sixth bridge arm, the end of the same name on the high voltage side of the transformer TX1 is connected to the first end of the fifth inductor Lik, and the second end of the fifth inductor Lik It is connected to the first end of the third capacitor Cr, and the second end of the third capacitor Cr is connected to the midpoint of the seventh bridge arm.

FIG. 30 is a sixth schematic diagram of partial connections of the voltage conversion circuit provided by an embodiment of the application. As shown in Figure 30, the first end of the sixth bridge arm (that is, the second end of the eleventh switch tube Q11) is connected to the first synonymous end of the high-voltage side of the transformer TX1, and the second end of the sixth bridge arm (Ie, the second end of the twelfth switch tube Q12) is connected to the second synonymous end of the high voltage side of the transformer TX1, and the first end of the seventh bridge arm (ie, the second end of the thirteenth switch tube Q13) ) Is connected to the first terminal with the same name on the high-voltage side of the transformer TX1, and the second terminal of the seventh bridge arm (that is, the second terminal of the fourteenth switch tube Q14) is connected to the second terminal with the same name on the high-voltage side of the transformer TX1 Connected, the midpoint of the sixth bridge arm is connected to the first end of the fifth inductor Lik, the second end of the fifth inductor Lik is connected to the first end of the third capacitor Cr, and the second end of the third capacitor Cr is connected to The midpoint of the seventh bridge arm is connected.

FIG. 31 is a seventh schematic diagram of partial connections of the voltage conversion circuit provided by an embodiment of the application. As shown in Figure 31, the first end of the sixth bridge arm (that is, the second end of the eleventh switch tube Q11) is connected to the first synonymous end of the high-voltage side of the transformer TX1, and the second end of the sixth bridge arm (Ie, the second end of the twelfth switch tube Q12) is connected to the second synonymous end of the high voltage side of the transformer TX1, and the first end of the seventh bridge arm (ie, the second end of the thirteenth switch tube Q13) ) Is connected to the first terminal with the same name on the high-voltage side of the transformer TX1, and the second terminal of the seventh bridge arm (that is, the second terminal of the fourteenth switch tube Q14) is connected to the second terminal with the same name on the high-voltage side of the transformer TX1 Connected, the midpoint of the sixth bridge arm is connected to the first end of the third capacitor Cr, the second end of the third capacitor Cr is connected to the first end of the fifth inductor Lik, and the second end of the fifth inductor Lik is connected to The midpoint of the seventh bridge arm is connected.

Optionally, the above-mentioned first voltage conversion unit may also adopt the following structure:

FIG. 32 is a first structural schematic diagram of a first voltage conversion unit provided by an embodiment of the application. As shown in FIG. 32, in another implementation manner, the above-mentioned first voltage conversion unit may include: a seventh switch tube Q7 and an eighth switch tube Q8.

In this implementation, the first end of the seventh switching tube Q7 is connected to the first end of the same name on the low-voltage side of the transformer TX1, the first end of the eighth switching tube Q8 is connected to the opposite end of the low-voltage side of the transformer TX1, and the seventh switch The second end of the tube Q7 is connected to the second end of the eighth switch tube Q8.

The first terminal with the same name on the low-voltage side of the transformer TX1 is the first terminal of the voltage conversion circuit, and the second terminal of the seventh switch tube Q7 is the second terminal of the voltage conversion circuit. In some embodiments, the first voltage conversion unit shown in FIG. 32 may also be referred to as a push-pull conversion circuit.

FIG. 33 is a second structural diagram of the first voltage conversion unit provided by an embodiment of the application. As shown in FIG. 33, in another implementation manner, the above-mentioned first voltage conversion unit may include: a seventh switching tube Q7, an eighth switching tube Q8, and a ninth switching tube Q9.

In this implementation, the first end of the seventh switch tube Q7 is connected to the first end of the same name on the low voltage side of the transformer TX1, the first end of the ninth switch tube Q9 is connected to the second end of the same name on the low voltage side of the transformer TX1, and the eighth The first end of the switch tube Q8 is connected to the synonymous end of the low voltage side of the transformer TX1, and the second end of the seventh switch tube Q7 is connected to the second end of the eighth switch tube Q8.

The second terminal of the ninth switch tube Q9 is the first terminal of the voltage conversion circuit, and the second terminal of the seventh switch tube Q7 is the second terminal of the voltage conversion circuit.

In some embodiments, the first voltage conversion unit shown in FIG. 33 may also be referred to as a three-tube push-pull conversion circuit.

FIG. 34 is a third structural diagram of the first voltage conversion unit provided by an embodiment of the application. As shown in FIG. 34, in another implementation manner, the above-mentioned first voltage conversion unit may include: a fourth bridge arm, a fifth bridge arm, and a fourth capacitor E4.

The fourth bridge arm includes: a seventh switching tube Q7 and an eighth switching tube Q8 connected in series (that is, the first end of the seventh switching tube Q7 is connected to the first end of the eighth switching tube Q8); The bridge arm includes a ninth switching tube and a tenth switching tube Q10 connected in series (that is, the first end of the ninth switching tube Q9 is connected to the first end of the tenth switching tube Q10).

In this implementation manner, the second terminal of the seventh switch tube Q7 is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube Q8 is the second terminal of the voltage conversion circuit.

The first end of the fourth bridge arm (that is, the second end of the seventh switch tube Q7) is connected to the first synonymous end of the low-voltage side of the transformer TX1, and the second end of the fourth bridge arm (that is, the The second end of the eight switch tube Q8) is connected to the second synonymous end of the low voltage side of the transformer TX1, the first end of the fifth bridge arm (that is, the second end of the ninth switch tube Q9), the first The first terminals of the four capacitors E4 are all connected to the first terminal with the same name on the low-voltage side of the transformer TX1, the second terminal of the fifth bridge arm (that is, the second terminal of the tenth switch tube Q10), the fourth capacitor The second end of E4 is connected to the second end of the same name on the low voltage side of the transformer TX1, and the midpoint of the fourth bridge arm is connected to the midpoint of the fifth bridge arm.

In some embodiments, the first voltage conversion unit shown in FIG. 34 may also be referred to as a full-bridge conversion circuit.

FIG. 35 is a fourth structural diagram of the first voltage conversion unit provided by an embodiment of the application. As shown in FIG. 35, if the battery pack of the three-arm topology device includes a first battery sub-group and a second battery sub-group connected in series. Wherein, the negative electrode of the first battery sub-group is connected to the positive electrode of the second battery sub-group, the positive electrode of the first battery sub-group is the positive electrode of the battery group, and the negative electrode of the second battery sub-group is the battery group The negative electrode. In this example, the above-mentioned first voltage conversion unit may include: a fourth bridge arm; the fourth bridge arm includes: a seventh switching tube Q7 and an eighth switching tube Q8 (that is, the seventh switching tube Q7 connected in series) The first end is connected to the first end of the eighth switch tube Q8).

The negative electrode of the first battery sub-group is connected to the opposite end of the low voltage side of the transformer TX1, and the midpoint of the fourth bridge arm is connected to the same end of the low voltage side of the transformer TX1.

In some embodiments, the first voltage conversion unit shown in FIG. 35 may also be referred to as a half-bridge conversion circuit.

It should be understood that when the voltage conversion circuit is implemented by any of the above-mentioned variants, the working mode of the voltage conversion circuit when charging the battery pack and the working mode when the battery pack is discharged are the same as the voltage shown in Fig. 24. The conversion circuit is the same and will not be repeated here.

In addition, when the three-leg topology device of the B1 structure is adopted, the state of each switch tube of the three-leg topology device in the external power supply mode is the same as that of the three-leg topology device shown in FIG. 6 in the external power supply mode. The state of the tube is similar. The current trend of the three-leg topology device is similar to the current trend of the three-leg topology device shown in FIG. 6 in the external power supply mode. For details, reference may be made to the corresponding descriptions of FIG. 8 to FIG.

Correspondingly, in the battery power supply mode, the states of the switch tubes of the three-leg topology device in the battery power supply mode are similar to the states of the switch tubes of the three-leg topology device shown in FIG. 6 in the battery power supply mode. The current trend of the three-leg topology device is similar to the current trend of the three-leg topology device shown in FIG. 6 in the battery power supply mode. For details, please refer to the corresponding descriptions of FIG. 12 to FIG.

Structure B2: The voltage conversion circuit in the three-leg topology device realizes the voltage conversion function by multiplexing the second leg of the three-leg circuit and the bus capacitor E1, or only multiplexing the bus capacitor E1. The three-leg topology device can be applied to battery low-voltage high-current inverter systems and battery low-voltage high-current UPS systems. The external power supply of the UPS system can be a commercial AC power supply AC, a photovoltaic PV DC power supply, or a photovoltaic PV DC power supply + a commercial AC power supply AC, etc.

In the following, the structure B2 is respectively applied to a battery low-voltage high-current inverter system and a battery low-voltage high-current UPS system as an example for description and introduction.

Structure B21: Used in battery low voltage high current UPS system.

FIG. 36 is a schematic diagram of a seventeenth three-arm topology device provided by an embodiment of this application. As shown in Figure 36, taking the three-leg topology device applied to a battery low-voltage high-current UPS system with a mains AC power supply AC as an external power supply as an example, the three-leg topology device shown in structure B21 and structure B1 The difference between the three-leg topology device shown is the structure of the voltage conversion circuit and the connection mode of the voltage conversion circuit and the three-leg circuit. The following focuses on the differences:

Specifically, in the three-leg topology device shown in structure B21, the positive electrode of the battery pack is connected to the first end of the voltage conversion circuit, the negative electrode of the battery pack is connected to the second end of the voltage conversion circuit, and the third end of the voltage conversion circuit is Connected to BUS+, the fourth end of the voltage conversion circuit is connected to BUS-, and the fifth end of the voltage conversion circuit is connected to the midpoint of the second bridge arm. Among them, the voltage conversion circuit multiplexes the second bridge arm of the three bridge arm circuit and the bus capacitor E1 to form a bidirectional DCDC topology to realize the function of bidirectional voltage conversion.

In this embodiment, the three-leg topology device also has two power supply modes, namely: an external power supply mode and a battery power supply mode.

In the external power supply mode, the mains AC power supply AC powers the three-leg circuit, and the "voltage conversion circuit multiplexes the two-way DCDC topology formed by the second bridge leg and the bus capacitor E1" to charge the battery pack. At this time, the three-leg circuit works in AC-AC mode, and the "two-way DCDC topology composed of the voltage conversion circuit multiplexing the second bridge arm and the bus capacitor E1" works in the BUCK mode (that is, the step-down mode), and the DC bus capacitor E1 The output BUS voltage is stepped down to obtain the charging voltage of the battery pack, and the charging voltage is used to charge the battery pack. At this time, the battery pack serves as the output source of "the voltage conversion circuit multiplexes the two-way DCDC topology formed by the second bridge arm and the bus capacitor E1".

In this way, in the external power supply mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work. Regarding the technical effect of using the "voltage conversion circuit multiplexing the second bridge arm and the bus capacitor E1 to form a bidirectional DCDC topology" to charge the battery pack, refer to the description of using the voltage conversion circuit to charge the battery pack in FIG. 2 of the foregoing embodiment.

In the battery power supply mode, the battery pack is the input source of "the voltage conversion circuit multiplexes the two-way DCDC topology formed by the second bridge arm and the bus capacitor E1", and the "voltage conversion circuit multiplexes the two-way DCDC topology formed by the second bridge arm and the bus capacitor E1 The output of the "DCDC topology" supplies power to the three-leg circuit. That is, "the voltage conversion circuit multiplexes the two-way DCDC topology formed by the second bridge arm and the bus capacitor E1" to discharge the battery pack. At this time, the bidirectional DCDC topology works in Boost mode (boost mode) to boost the output voltage of the battery pack, and the boosted voltage is input to the DC bus capacitor E1 of the three-leg circuit to maintain the bus voltage balance. The DC bus capacitor E1 filters the boosted DC power to obtain a stable DC power. The second and third bridge arms of the three-leg circuit work in inverter mode and convert the stable DC power to AC power and then output to the load. To supply power to the load. At the same time, the DC bus capacitor E1 can store energy. In this way, in the battery-powered mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work.

It can be understood that the voltage conversion circuit involved in the embodiments of the present application may be a voltage conversion circuit with electrical isolation, or a voltage conversion circuit without electrical isolation.

Continuing to refer to FIG. 36, the voltage conversion circuit involved in the embodiment of the present application may include, for example, a first voltage conversion unit, a transformer, an LC resonant cavity, and a second voltage conversion unit. The first voltage conversion unit is connected to the low voltage side of the transformer, and the high voltage side of the transformer is connected to the LC resonant cavity and the second voltage conversion unit.

Continuing to refer to FIG. 36, exemplarily, the first voltage conversion unit includes: a fourth bridge arm and a fifth bridge arm. The LC resonant cavity includes: a fifth inductor Lik and an inductor Cr. The second voltage conversion unit includes: a sixth bridge arm. That is, the second voltage conversion unit involved in this embodiment is a half-bridge topology.

The sixth bridge arm includes: an eleventh switching tube Q11 and a twelfth switching tube Q12 connected in series (that is, the first end of the eleventh switching tube Q11 is connected to the first end of the twelfth switching tube Q12). The sixth bridge arm is connected in parallel between BUS+ and BUS- (that is, the second end of the eleventh switch tube Q11 is connected to BUS+, and the second end of the twelfth switch tube Q12 is connected to BUS-).

For the description of the fourth bridge arm, the fifth bridge arm, the sixth bridge arm and the LC resonant cavity, please refer to the description of the fourth bridge arm, the fifth bridge arm, the sixth bridge arm and the LC resonant cavity in FIG. This will not be repeated here. In some embodiments, the first voltage conversion unit shown in FIG. 36 may also be referred to as a full-bridge conversion circuit.

The second terminal of the seventh switch tube Q7 is the first terminal of the voltage conversion circuit, the second terminal of the eighth switch tube Q8 is the second terminal of the voltage conversion circuit, and the eleventh switch The second terminal of the tube Q11 is the third terminal of the voltage conversion circuit, and the second terminal of the twelfth switch tube Q12 is the fourth terminal of the voltage conversion circuit.

The midpoint of the fourth bridge arm is connected to the synonymous end of the low-voltage side of the transformer TX1, and the midpoint of the fifth bridge arm is connected to the same-named end of the low-voltage side of the transformer TX1. The end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductance Lik, the second end of the fifth inductance Lik is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor Cr. The second end of the third capacitor Cr is connected to the midpoint of the second bridge arm. That is, the second terminal of the third capacitor Cr is the fifth terminal of the voltage conversion circuit.

When the voltage conversion circuit is used to charge the battery pack, "the voltage conversion circuit multiplexes the two-way DCDC topology formed by the second bridge arm and the bus capacitor E1" works in the half-bridge LLC resonant converter mode. That is, the LC resonant cavity and the inductance of the transformer TX1 (not shown in the figure) form an LLC resonant network, so that the bidirectional DCDC topology forms a half-bridge LLC resonant converter, which realizes a wide range of voltage regulation and zero voltage turn-on. For the working principle, please refer to the introduction of the half-bridge LLC resonant converter in the prior art, which will not be repeated here.

When the voltage conversion circuit is used to discharge the battery pack, the "voltage conversion circuit multiplexes the two-way DCDC topology composed of the second bridge arm and the bus capacitor E1" works in the full-bridge secondary LC resonant voltage doubler converter mode, that is, the transformer The secondary side of TX1 and the LC resonant cavity form a double voltage rectifier circuit, so that the bidirectional DCDC topology forms a full-bridge secondary side LC resonant voltage doubler converter. The output voltage of the bidirectional DCDC topology is twice the voltage of the transformer TX1 secondary side, reaching two The purpose of double boost is to improve the boost ratio of the bidirectional DCDC topology.

Specifically, during the positive half cycle of the output voltage V2 on the secondary side of the transformer TX1, the third capacitor Cr of the resonant cavity stores energy. At this time, the voltage of the third capacitor Cr can reach twice the root sign of the peak value of V2 and remain unchanged. In the negative half cycle of the output voltage V2 of the secondary side of the transformer TX1, the secondary side of the transformer TX1 and the third capacitor Cr of the resonant cavity provide the output voltage at the same time, so that the output voltage of the bidirectional DCDC topology reaches twice the root V2 peak value and remains unchanged . At this time, the output voltage of the bidirectional DCDC topology is twice the voltage on the secondary side of the transformer TX1.

Exemplarily, taking the output voltage of a bidirectional DCDC topology of 200V as an example, in the above-mentioned mode of the full-bridge secondary LC resonant voltage doubler converter, the transformer TX1 only needs to raise the output voltage of the battery pack to 100V to make The output voltage of the bidirectional DCDC topology reaches 200V.

It should be understood that when the battery pack is discharged, the secondary side of the transformer TX1 connected to the LC resonant cavity is the high-voltage side of the voltage conversion circuit, and when the battery pack is charged, the secondary side of the transformer TX1 connected to the first voltage conversion unit is the voltage conversion The low-voltage side of the circuit.

Optionally, the high-voltage side of the transformer, the LC resonant cavity, the second voltage conversion unit, and the second bridge arm may also be connected as shown in FIGS. 25 to 31. The only difference is that when the connection manner shown in FIGS. 25 to 31 is applied to this embodiment, the second bridge arm is used instead of the seventh bridge arm in FIGS. 25 to 31. In these implementations, the end of the voltage conversion circuit connected to the midpoint of the second bridge arm is the fifth end of the voltage conversion circuit, which will not be repeated here.

36A is an eighth schematic diagram of partial connection of the voltage conversion circuit provided by an embodiment of this application, and FIG. 36B is a ninth schematic view of partial connection of the voltage conversion circuit provided by an embodiment of this application. Referring to FIGS. 36A and 36B, when the high-voltage side of the transformer and the LC resonant cavity, the second voltage conversion unit, and the second bridge arm adopt the connection method shown in FIG. 30 or FIG. 31, the high-voltage side of the transformer TX1 The first terminal with the same name is the third terminal of the voltage conversion circuit, and the second terminal with the same name on the high-voltage side of the transformer TX1 is the fourth terminal of the voltage conversion circuit, which will not be repeated here. At this time, the connection between the high voltage side of the transformer and the LC resonant cavity, the second voltage conversion unit, and the second bridge arm may be as shown in FIG. 36A or FIG. 36B, for example.

Correspondingly, the first voltage conversion unit involved in this embodiment can also be replaced by the structure shown in FIG. 32 to FIG. 35, which will not be repeated here.

It should be understood that when a voltage conversion circuit is implemented using any of the above-mentioned variants, the working mode of "the voltage conversion circuit multiplexes the bidirectional DCDC topology formed by the second bridge arm and the bus capacitor E1" when charging the battery pack, and, The working mode when the battery pack is discharged is the same as the voltage conversion circuit shown in FIG. 36, and will not be repeated here.

Taking the structure of the three-leg topology device shown in FIG. 36 as an example, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device under different power supply modes are schematically described below:

FIG. 37 is a schematic diagram 1 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 37, in the first phase of the external power supply mode, that is, in the first phase of the positive half cycle of the input AC power (ie, the AC power input through the positive voltage input terminal and the negative voltage input terminal of the three-leg topology device) , Controlling the second switching tube Q2, the fourth switching tube Q4, the fifth switching tube Q5, and the eleventh switching tube Q11 to be turned on. At this time, the current flow in the three-leg topology device is as follows:

2. BUS+→the fifth switch tube Q5→the second inductor L2→the first capacitor Co→the fourth switch tube Q4→BUS-, to provide energy for the load through the bus capacitor E1. Among them, the second inductor L2 and the first capacitor Co are used to implement the filtering function.

3. BUS+→the eleventh switching tube Q11→the fifth inductor Lik→the end of the same name on the high-voltage side of TX1→the synonymous terminal on the high-voltage side of TX1→the third capacitor Cr→the fourth switching tube Q4→BUS-, so that the bus capacitance E1 It transmits energy for the transformer TX1 and forms an energy storage loop of the third capacitor Cr. The end of the same name on the low-voltage side of TX1→the ninth switch tube Q9→the positive electrode of the battery pack→the negative terminal of the battery pack→the eighth switch tube Q8→the synonymous end of the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the ninth switching tube Q9 and the eighth switching tube Q8 are used to implement the rectification function.

FIG. 38 is the second schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to the embodiment of the application. As shown in Figure 38, in the second stage of the external power supply mode, that is, in the second stage of the positive half cycle of the input AC power, the second switching tube Q2, the fourth switching tube Q4, the fifth switching tube Q5, and the tenth switching tube are controlled. The second switch tube Q12 is turned on. At this time, the current flow in the three-leg topology device is as follows:

3. Cr positive → synonymous end of TX1 high voltage side → same name end of TX1 high voltage side → fifth inductor Lik → twelfth switching tube Q12 → fourth switching tube Q4 → Cr negative electrode, so that Cr transfers energy for transformer TX1. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1, which constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

FIG. 39 is the third schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 39, in the third stage of the external power supply mode, that is, in the third stage of the positive half cycle of the input alternating current, the fourth switching tube Q4, the fifth switching tube Q5, and the eleventh switching tube Q11 are controlled to be turned on . At this time, the current flow in the three-leg topology device is as follows:

1. The live wire of the mains AC power supply AC → the first inductor L1 → the first switching tube Q1 → the bus capacitor E1 → the fourth switching tube Q4 → the neutral line of the mains AC power supply AC, forming an energy storage circuit of the bus capacitor E1. At this time, the mains and the first inductor L1 provide energy for the bus capacitor E1 at the same time.

FIG. 40 is a schematic diagram 4 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 40, in the fourth stage of the external power supply mode, that is, in the fourth stage of the positive half cycle of the input AC power, the fourth switching tube Q4, the fifth switching tube Q5, and the twelfth switching tube Q12 are controlled to be turned on . At this time, the current flow in the three-leg topology device is as follows:

3. Cr positive → synonymous end of TX1 high voltage side → same name end of TX1 high voltage side → fifth inductor Lik → twelfth switching tube Q12 → fourth switching tube Q4 → Cr negative electrode, so that Cr transfers energy for transformer TX1. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

FIG. 41 is a schematic diagram 5 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 41, in the fifth stage of the external power supply mode, that is, in the fifth stage of the positive half cycle of the input alternating current, the second switching tube Q2, the fourth switching tube Q4, the sixth switching tube Q6, and the tenth switching tube are controlled. A switch Q11 is turned on. At this time, the current flow in the three-leg topology device is as follows:

2. The second inductor L2→the first capacitor Co→the fourth switch tube Q4→the sixth switch tube Q6→the second inductor L2, so as to provide energy to the load through the second inductor L2. Among them, the second inductor L2 and the first capacitor Co are used to implement the filtering function.

FIG. 42 is a current schematic diagram 6 of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 42, in the sixth stage of the external power supply mode, that is, in the sixth stage of the positive half cycle of the input alternating current, the second switching tube Q2, the fourth switching tube Q4, the sixth switching tube Q6, and the tenth switching tube are controlled. The second switch tube Q12 is turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 43 is a current schematic diagram 7 of the seventeenth three-leg topology device in an external power supply mode according to an embodiment of the application. As shown in Figure 43, in the seventh stage of the external power supply mode, that is, in the seventh stage of the positive half cycle of the input AC power, the fourth switching tube Q4, the sixth switching tube Q6, and the eleventh switching tube Q11 are controlled to be turned on . At this time, the current flow in the three-leg topology device is as follows:

FIG. 44 is a schematic diagram 8 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 44, in the eighth stage of the external power supply mode, that is, in the eighth stage of the positive half cycle of the input alternating current, the fourth switching tube Q4, the sixth switching tube Q6, and the twelfth switching tube Q12 are controlled to be turned on . At this time, the current flow in the three-leg topology device is as follows:

FIG. 45 is a schematic diagram 9 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 45, in the ninth phase of the external power supply mode, that is, in the first phase of the negative half cycle of the input AC power, the first switching tube Q1, the third switching tube Q3, the sixth switching tube Q6, and the tenth switching tube are controlled. The second switch tube Q12 is turned on. At this time, the current flow in the three-leg topology device is as follows:

2. BUS+→the third switch tube Q3→the first capacitor Co→the second inductor L2→the sixth switch tube Q6→BUS-, to provide energy for the load through the bus capacitor E1. Among them, the second inductor L2 and the first capacitor Co are used to implement the filtering function.

3. BUS+→the third switch tube Q3→the third capacitor Cr→the synonymous terminal on the high-voltage side of TX1→the same-name terminal on the high-voltage side of TX1→the fifth inductor Lik→the twelfth switch tube Q12→BUS-, so that the bus capacitance E1 It transmits energy for the transformer TX1 and forms an energy storage loop of the third capacitor Cr. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1, which constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

FIG. 46 is a tenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 46, in the tenth stage of the external power supply mode, that is, in the second stage of the negative half cycle of the input alternating current, the first switching tube Q1, the third switching tube Q3, the sixth switching tube Q6, and the tenth switching tube are controlled. A switch Q11 is turned on. At this time, the current flow in the three-leg topology device is as follows:

3. Cr anode → third switching tube Q3 → eleventh switching tube Q11 → fifth inductor Lik → end of the same name on the high-voltage side of TX1 → synonymous end of the high-voltage side of TX1 → negative terminal of Cr, so that Cr transfers energy for the transformer TX1. The end of the same name on the low-voltage side of TX1→the ninth switch tube Q9→the positive electrode of the battery pack→the negative terminal of the battery pack→the eighth switch tube Q8→the synonymous end of the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the ninth switching tube Q9 and the eighth switching tube Q8 are used to implement the rectification function.

FIG. 47 is the eleventh schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode provided by an embodiment of the application. As shown in Figure 47, in the eleventh stage of the external power supply mode, that is, in the third stage of the negative half cycle of the input AC power, the third switching tube Q3, the sixth switching tube Q6, and the twelfth switching tube Q12 are controlled to conduct Pass. At this time, the current flow in the three-leg topology device is as follows:

1. The neutral wire of the mains AC power supply AC→the third switch tube Q3→the bus capacitor E1→the second switch tube Q2→the first inductance L1→the live wire of the mains AC power supply AC, forming the energy storage circuit of the bus capacitor E1. At this time, the mains and the first inductor L1 provide energy for the bus capacitor E1 at the same time.

FIG. 48 is the twelfth diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 48, in the twelfth stage of the external power supply mode, that is, in the fourth stage of the negative half cycle of the input alternating current, the third switching tube Q3, the sixth switching tube Q6, and the eleventh switching tube Q11 are controlled to conduct Pass. At this time, the current flow in the three-leg topology device is as follows:

FIG. 49 is a schematic diagram 13 of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 49, in the thirteenth stage of the external power supply mode, that is, in the fifth stage of the negative half cycle of the input AC power, the first switching tube Q1, the third switching tube Q3, the fifth switching tube Q5, and the third switching tube are controlled. The twelve switch tube Q12 is turned on. At this time, the current flow in the three-leg topology device is as follows:

2. The second inductor L2→the fifth switch tube Q5→the third switch tube Q3→the first capacitor Co→the second inductor L2, so as to provide energy to the load through the second inductor L2. Among them, the second inductor L2 and the first capacitor Co are used to implement the filtering function.

3. BUS+→the third switch tube Q3→the third capacitor Cr→the synonymous terminal on the high-voltage side of TX1→the same-name terminal on the high-voltage side of TX1→the fifth inductor Lik→the twelfth switch tube Q12→BUS-, so that the bus capacitance E1 It transmits energy for the transformer TX1 and forms an energy storage loop of the third capacitor Cr. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

FIG. 50 is a fourteenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 50, in the fourteenth stage of the external power supply mode, that is, in the sixth stage of the negative half cycle of the input AC power, the first switching tube Q1, the third switching tube Q3, the fifth switching tube Q5, and the second switching tube are controlled. The eleven switch tube Q11 is turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 51 is a fifteenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 51, in the fifteenth stage of the external power supply mode, that is, in the seventh stage of the negative half cycle of the input alternating current, the third switching tube Q3, the fifth switching tube Q5, and the twelfth switching tube Q12 are controlled to conduct Pass. At this time, the current flow in the three-leg topology device is as follows:

FIG. 52 is a sixteenth schematic diagram of the current of the seventeenth three-leg topology device in the external power supply mode according to an embodiment of the application. As shown in Figure 52, in the sixteenth stage of the external power supply mode, that is, in the eighth stage of the negative half cycle of the input alternating current, the third switching tube Q3, the fifth switching tube Q5, and the eleventh switching tube Q11 are controlled to conduct Pass. At this time, the current flow in the three-leg topology device is as follows:

FIG. 53 is a schematic diagram 1 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 53, in the first phase of the battery power supply mode, that is, in the first phase of the positive half cycle of the output alternating current (that is, the alternating current output through the first output terminal and the second output terminal of the three-leg topology device) , Controlling the fourth switching tube Q4, the fifth switching tube Q5, the seventh switching tube Q7, the tenth switching tube Q10, and the twelfth switching tube Q12 to conduct. At this time, the current flow in the three-leg topology device is as follows:

1. The positive electrode of the battery pack → the seventh switch tube Q7 → the synonymous end of the low voltage side of TX1 → the same name end of the low voltage side of TX1 → the tenth switch tube Q10 → the negative electrode of the battery pack, so that the battery pack can transmit energy to the transformer TX1. The synonymous terminal on the high-voltage side of TX1→the third capacitor Cr→the fourth switch tube Q4→the twelfth switch tube Q12→the fifth inductor Lik→the terminal with the same name on the high-voltage side of TX1 forms an energy storage loop of the third capacitor Cr.

FIG. 54 is the second schematic diagram of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 54, in the second stage of the battery power supply mode, that is, in the second stage of the positive half cycle of the output alternating current, the fourth switching tube Q4, the fifth switching tube Q5, the eighth switching tube Q8, and the ninth switching tube are controlled. The switching tube Q9 and the eleventh switching tube Q11 are turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The positive pole of the battery pack → the ninth switch tube Q9 → the end of the same name on the low voltage side of TX1 → the synonymous end of the low voltage side of TX1 → the eighth switch tube Q8 → the negative pole of the battery pack, so that the battery pack can transmit energy to the transformer TX1. The end of the same name on the high-voltage side of TX1→the fifth inductor Lik→the eleventh switch tube Q11→BUS+→BUS-→the fourth switch tube Q4→the third capacitor Cr→the synonymous terminal on the high-voltage side of TX1, which constitutes the energy storage of the bus capacitor E1 Loop. At this time, the transformer TX1 and the third capacitor Cr provide energy for the bus capacitor E1 at the same time.

FIG. 55 is the third schematic diagram of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 55, in the third stage of the battery power supply mode, that is, in the third stage of the positive half cycle of the output alternating current, the fourth switching tube Q4, the sixth switching tube Q6, the seventh switching tube Q7, and the tenth switching tube are controlled. The switching tube Q10 and the twelfth switching tube Q12 are turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 56 is a fourth schematic diagram of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 56, in the fourth stage of the battery power supply mode, that is, in the fourth stage of the positive half cycle of the output alternating current, the fourth switching tube Q4, the sixth switching tube Q6, the eighth switching tube Q8, and the ninth switching tube are controlled. The switching tube Q9 and the eleventh switching tube Q11 are turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 57 is a schematic diagram 5 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 57, in the fifth stage of the battery power supply mode, that is, in the first stage of the negative half cycle of the output alternating current, the third switching tube Q3, the sixth switching tube Q6, the seventh switching tube Q7, and the tenth switching tube are controlled. The switching tube Q10 and the twelfth switching tube Q12 are turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The positive electrode of the battery pack → the seventh switch tube Q7 → the synonymous end of the low voltage side of TX1 → the same name end of the low voltage side of TX1 → the tenth switch tube Q10 → the negative electrode of the battery pack, so that the battery pack can transmit energy to the transformer TX1. Synonymous end of TX1 high voltage side → third capacitor Cr → third switching tube Q3 → BUS+ → BUS- → twelfth switching tube Q12 → fifth inductor Lik → the same name terminal on the high voltage side of TX1, which constitutes the energy storage of bus capacitor E1 Loop. At this time, the transformer TX1 and the third capacitor Cr provide energy for the bus capacitor E1 at the same time.

FIG. 58 is a current schematic diagram 6 of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 58, in the sixth stage of the battery power supply mode, that is, in the second stage of the negative half cycle of the output alternating current, the third switching tube Q3, the sixth switching tube Q6, the eighth switching tube Q8, and the ninth switching tube are controlled. The switching tube Q9 and the eleventh switching tube Q11 are turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The positive pole of the battery pack → the ninth switch tube Q9 → the end of the same name on the low voltage side of TX1 → the synonymous end of the low voltage side of TX1 → the eighth switch tube Q8 → the negative pole of the battery pack, so that the battery pack can transmit energy to the transformer TX1. The end of the same name on the high-voltage side of TX1→the fifth inductor Lik→the eleventh switch tube Q11→the third switch tube Q3→the third capacitor Cr→the synonymous end of the high-voltage side of TX1 forms an energy storage loop of the third capacitor Cr.

FIG. 59 is a schematic diagram 7 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 59, in the seventh stage of the battery power supply mode, that is, in the third stage of the negative half cycle of the output alternating current, the third switching tube Q3, the fifth switching tube Q5, the seventh switching tube Q7, and the tenth switching tube are controlled. The switching tube Q10 and the twelfth switching tube Q12 are turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 60 is a schematic diagram 8 of the current of the seventeenth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 60, in the eighth stage of the battery power supply mode, that is, in the fourth stage of the negative half cycle of the output alternating current, the third switching tube Q3, the fifth switching tube Q5, the eighth switching tube Q8, and the ninth switching tube are controlled. The switching tube Q9 and the eleventh switching tube Q11 are turned on. At this time, the current flow in the three-leg topology device is as follows:

Although the above example is applied to a battery low-voltage high-current UPS system with a mains AC power supply AC as an external power supply as an example, the three-leg topology device provided in this embodiment is illustrated as an example. However, those skilled in the art can understand that the three-leg topology device can also be applied to UPS systems that use other external power supplies.

FIG. 61 is a schematic diagram of an eighteenth three-leg topology device provided by an embodiment of the application. Exemplarily, the mains AC power supply AC in FIG. 36 can be replaced with a photovoltaic PV DC power supply to obtain a three-leg topology device as shown in FIG. 61. At this time, the three-leg topology device of the B21 structure shown in FIG. 61 can be applied to a battery low-voltage high-current UPS system that uses a photovoltaic PV DC power supply as an external power supply.

In this application scenario, the second terminal of the first inductor L1 serves as the positive voltage input terminal PV+ of the three-leg topology device. BUS- serves as the negative voltage input terminal PV- of the three-leg topology device. The positive pole of the photovoltaic PV DC power supply is connected to the positive voltage input terminal PV+, and the negative pole of the photovoltaic PV DC power supply is connected to the negative voltage input terminal PV-.

Optionally, in some embodiments, the positive pole of the photovoltaic PV DC power supply is connected to the positive voltage input terminal PV+ through the switch K6, so as to meet the safety requirements for the three-leg topology device. It should be understood that the switch K6 may be, for example, a unidirectional electronic switch, a bidirectional thyristor, or the like.

It should be understood that the working principle and technical effects of the three-leg topology device shown in FIG. 61 can be referred to the description of the three-leg topology device in FIG. 36, which will not be repeated here.

FIG. 62 is a schematic diagram of a nineteenth three-leg topology device provided by an embodiment of the application. Exemplarily, on the basis of FIG. 36, a photovoltaic PV DC power supply, an eighth bridge arm, and a sixth inductor L6 can be added to the three-leg topology device. At this time, the three-leg topology device of the B21 structure shown in FIG. 62 can be applied to a battery low-voltage high-current UPS system that uses photovoltaic PV DC power supply + mains AC power supply AC as an external power supply at the same time.

The eighth bridge arm includes a seventeenth switching tube Q17 and an eighteenth switching tube Q18, and the seventeenth switching tube Q17 and the eighteenth switching tube Q18 are connected in series between BUS+ and BUS-. For example, the first terminal of the seventeenth switch tube Q17 is connected to BUS+, the second terminal of the seventeenth switch tube Q17 is connected to the first terminal of the eighteenth switch tube Q18, and the second terminal of the eighteenth switch tube Q18 is connected. The terminal is connected with BUS-. Among them, the common end of the seventeenth switching tube Q17 and the eighteenth switching tube Q18 is called the midpoint of the eighth bridge arm. That is, the eighth bridge arm and the bus capacitor E1 are connected in parallel between the positive output end of the bus and the negative output end of the bus. Through the above-mentioned eighth bridge arm, the output voltage or current of the photovoltaic PV DC power supply can be changed to make the photovoltaic PV DC power supply work at the maximum power point to realize the maximum power point tracking (MPPT) of the photovoltaic PV DC power supply. .

The second terminal of the first inductor L1 serves as the first positive voltage input terminal AC_L of the three-leg topology device. The midpoint of the second bridge arm is used as the first negative voltage input terminal AC_N of the three bridge arm topology device. The live wire of the commercial AC power source AC is connected to the first positive voltage input terminal AC_L, and the neutral wire of the commercial AC power source AC is connected to the first negative voltage input terminal AC_N.

The midpoint of the eighth bridge arm is connected to the first end of the sixth inductor L6, and the second end of the sixth inductor L6 is used as the second positive voltage input terminal PV+ of the three bridge arm topology device. The negative output terminal of the bus is used as the second negative voltage input terminal PV- of the three-leg topology device. The positive pole of the photovoltaic PV DC power supply is connected to the second positive voltage input terminal PV+, and the negative pole of the photovoltaic PV DC power supply is connected to the second negative voltage input terminal PV-.

Optionally, in some embodiments, the positive pole of the photovoltaic PV DC power supply is connected to the second positive voltage input terminal PV+ through the switch K6, so as to meet the safety requirements for the three-leg topology device. It should be understood that the switch K6 may be, for example, a unidirectional electronic switch, a bidirectional thyristor, or the like.

Optionally, the photovoltaic PV DC power supply and the mains AC power supply AC are mutually backup power sources. In specific implementation, the photovoltaic PV DC power supply and/or the mains AC power supply AC can be selected as the external power supply of the three-arm topology device according to actual needs. The power supply is not limited.

In the application scenario provided by this embodiment, the working principle and technical effect of the three-arm topology device shown in FIG. 62 can be referred to the description of the three-arm topology device in FIG. 36, which will not be repeated here.

In addition, although the current trends of the three-leg topology devices shown in FIG. 37 to FIG. 60 are all illustrated schematically using the seventeenth three-leg topology device shown in FIG. 36 as an example. However, those skilled in the art can understand that the current trend and the state of each switch and each switch tube are also applicable to the three-leg topology devices shown in FIG. 61 and FIG. 62. The implementation principle is similar. Go into details again.

Structure B22: Used in battery low voltage high current inverter system.

FIG. 63 is a schematic diagram of a twentieth three-arm topology device provided by an embodiment of this application. As shown in FIG. 63, in this embodiment, the first terminal of the first capacitor Co is the first external connection terminal of the three-leg topology device, and the second terminal of the first capacitor Co is the second terminal of the three-leg topology device. External connection terminal.

When discharging the battery pack, the first external connection terminal can be called the first output terminal of the three-leg topology device, and the second external connection terminal can be called the second output terminal of the three-leg topology device, both of which are connected to the load . When charging the battery pack, the first external connection terminal can be referred to as the positive voltage input terminal of the three-leg topology device, which is connected to the first terminal of the external power supply, and the second external connection terminal can be referred to as the three-leg topology device The negative voltage input terminal is connected to the second terminal of the external power supply.

For example, taking the external power supply as a photovoltaic direct current power supply as an example, the first end of the external power supply is the positive pole of the photovoltaic direct current power supply, and the second end of the external power supply is the photovoltaic direct current power supply. negative electrode. Taking the external power supply as a mains AC power supply as an example, the first end of the external power supply is the live wire of the mains AC power supply, and the second end of the external power supply is the mains AC power supply The zero line.

Taking the external power supply as a commercial AC power supply as an example, the commercial AC power supply AC and the load are respectively connected to the first end of the first capacitor Co and the second end of the first capacitor Co through a relay. When discharging the battery pack, the relay turns on the path between the load and the first capacitor Co. When charging the battery pack, the relay turns on the path between the mains AC power source AC and the first capacitor Co.

For ease of description, the figure is represented by AC. It should be understood that when discharging the battery pack, the AC here represents the alternating current output by the three-leg topology device. When charging the battery pack, the AC here represents the mains AC power supply AC that supplies power to the three-leg topology device.

The positive pole of the battery pack is connected to the first end of the voltage conversion circuit, and the negative pole of the battery pack is connected to the second end of the voltage conversion circuit. The third end of the voltage conversion circuit is connected to BUS+, the fourth end of the voltage conversion circuit is connected to BUS-, and the fifth end of the voltage conversion circuit is connected to the midpoint of the first bridge arm.

In this embodiment, the voltage conversion circuit, the first leg of the three-leg circuit, and the bus capacitor E1 form a bidirectional DCDC topology (also called a bidirectional DCDC converter) to realize the function of bidirectional voltage conversion. The bus capacitor E1 of the three-leg circuit, the second leg, the third leg, and the LC filter form a bidirectional DCAC topology (also called a bidirectional DCAC converter) to realize the inverter or rectifier function. In other words, the two-way DCDC topology and the two-way DCAC topology multiplex the bus capacitance E1 of the three-leg circuit.

In this embodiment, there are two modes of the three-leg topology device, namely: a battery charging mode and a battery power supply mode.

In the battery charging mode, the mains AC power supply AC supplies power for the three-leg circuit, and the two-way DCDC topology charges the battery pack. At this time, the bidirectional DCAC topology works in AC-DC mode (that is, full-bridge rectifier PFC converter mode), and the bidirectional DCDC topology works in BUCK mode (that is, step-down mode) to step down the BUS voltage output by the DC bus capacitor E1 The charging voltage of the battery pack is obtained by processing, and the charging voltage is used to charge the battery pack. At this time, the battery pack serves as the output source of the bidirectional DCDC topology. In this way, in the battery charging mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work.

In the battery-powered mode, the battery pack is the input source of the bidirectional DCDC topology, and the output of the bidirectional DCDC topology is the bidirectional DCAC topology power supply. That is, the bidirectional DCDC topology discharges the battery pack. At this time, the bidirectional DCDC topology works in Boost mode (ie, boost mode), and boosts the output voltage of the battery pack. The boosted voltage is input to the DC bus capacitor E1 to maintain the bus voltage balance. The two-way DCAC topology works in DC-AC mode (ie, full-bridge inverter mode), where the DC bus capacitor E1 filters the boosted DC power to obtain a stable DC power. The second leg of the three-leg circuit and The third bridge arm works in the inverter mode, converts the stable direct current into alternating current and then outputs it to the load to supply power to the load. At the same time, the DC bus capacitor E1 can store energy. In this way, in the battery-powered mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work.

Continuing to refer to FIG. 63, the voltage conversion circuit involved in the embodiment of the present application may include, for example, a first voltage conversion unit, a transformer, an LC resonant cavity, and a second voltage conversion unit. The first voltage conversion unit is connected to the low voltage side of the transformer, and the high voltage side of the transformer is connected to the LC resonant cavity and the second voltage conversion unit.

Continuing to refer to FIG. 63, exemplarily, the first voltage conversion unit includes: a fourth bridge arm and a fifth bridge arm. The LC resonant cavity includes: a fifth inductor Lik and an inductor Cr. The second voltage conversion unit includes: a sixth bridge arm. That is, the second voltage conversion unit involved in this embodiment is a half-bridge topology.

It should be understood that the structure of the voltage conversion circuit involved in this embodiment is the same as the structure of the voltage conversion circuit used in the three-leg topology device shown in FIG. 36. For the description of the fourth bridge arm, the fifth bridge arm and the LC resonant cavity, please refer to the description of this part in FIG. 36, which will not be repeated. The difference is that the fifth end of the voltage conversion circuit in this embodiment is connected to the midpoint of the first bridge arm, while the fifth end of the voltage conversion circuit used in the three bridge arm topology device shown in FIG. 36 is connected to the first bridge arm. The midpoint of the second bridge arm is connected.

When the voltage conversion circuit shown in Figure 63 is used to charge the battery pack, the bidirectional DCDC topology works in the full-bridge LLC resonant converter mode. At this time, the full-bridge phase-shifting control strategy can be used to control the full-bridge LLC resonant converter, so that the leading arm of the full-bridge LLC resonant converter can realize zero voltage turn-on, and the lag arm of the full-bridge LLC resonant converter can realize zero voltage. For specific operating principles of turn-on and zero-current turn-off, please refer to the introduction of the full-bridge LLC resonant converter in the prior art, which will not be repeated here.

When the voltage conversion circuit shown in Figure 63 is used to discharge the battery pack, the bidirectional DCDC topology works in the full-bridge secondary LC resonant converter mode to achieve zero voltage turn-on and zero current turn-off. For specific working principles, please refer to the prior art For the introduction of the LC resonant converter on the secondary side of the full-bridge, it will not be repeated here.

It should be understood that when the voltage conversion circuit is used to discharge the battery pack, the secondary side of the transformer TX1 connected to the LC resonant cavity is the high-voltage side of the voltage conversion circuit. When the voltage conversion circuit is used to charge the battery pack, The secondary side of the transformer TX1 connected to the first voltage conversion unit is the low-voltage side of the voltage conversion circuit.

Optionally, the high-voltage side of the transformer, the LC resonant cavity, the second voltage conversion unit, and the second bridge arm may also be connected as shown in FIGS. 25 to 31. The only difference is that when the connection manner shown in FIGS. 25 to 31 is applied to this embodiment, the first bridge arm is used instead of the seventh bridge arm in FIGS. 25 to 31. In these implementations, the end of the voltage conversion circuit connected to the midpoint of the first bridge arm is the fifth end of the voltage conversion circuit, which will not be repeated here.

FIG. 63A is a tenth schematic diagram of the partial connection of the voltage conversion circuit provided by an embodiment of the application, and FIG. 63B is a schematic diagram eleventh of the partial connection of the voltage conversion circuit provided by the embodiment of the present application. Referring to FIGS. 63A and 63B, when the high-voltage side of the transformer and the LC resonant cavity, the second voltage conversion unit, and the second bridge arm adopt the connection method shown in FIG. 30 or FIG. 31, the high-voltage side of the transformer The first terminal with the same name is the third terminal of the voltage conversion circuit, and the second terminal with the same name on the high-voltage side of the transformer is the fourth terminal of the voltage conversion circuit; The output terminal is connected, the fourth terminal of the voltage conversion circuit is connected to the negative output terminal of the bus; the voltage conversion circuit further includes a fifth terminal, and the fifth terminal of the voltage conversion circuit is connected to the first bridge arm. Midpoint connection.

It should be understood that when a voltage conversion circuit is implemented using any of the above-mentioned variants, the “bidirectional DCDC topology composed of the voltage conversion circuit, the first bridge arm and the bus capacitor E1” works when charging the battery pack, and, The working mode when the battery pack is discharged is the same as the voltage conversion circuit shown in Fig. 63, and will not be repeated here.

Taking the structure of the three-leg topology device shown in Figure 63 as an example, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device under different power supply modes are schematically described below:

FIG. 64 is a schematic diagram 1 of the current of the twentieth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 64, in the first stage of the battery power supply mode, that is, during the positive half cycle of the output alternating current, the second switching tube Q2, the eighth switching tube Q8, the ninth switching tube Q9, and the eleventh switching tube Q11 are controlled. Conduction. At this time, the current flow in the three-leg topology device is as follows:

1. The positive pole of the battery pack → the ninth switch tube Q9 → the end of the same name on the low voltage side of TX1 → the synonymous end of the low voltage side of TX1 → the eighth switch tube Q8 → the negative pole of the battery pack, so that the battery pack can transmit energy to the transformer TX1. The end of the same name on the high-voltage side of TX1→the fifth inductor Lik→the eleventh switch tube Q11→BUS+→BUS-→the second switch tube Q2→the third capacitor Cr→the synonymous terminal on the high-voltage side of TX1, which constitutes the energy storage of the bus capacitor E1 Loop. At this time, the transformer TX1 and the third capacitor Cr provide energy for the bus capacitor E1 at the same time.

FIG. 65 is a second schematic diagram of the current of the twentieth three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 65, in the second stage of the battery power supply mode, that is, during the negative half cycle of the output alternating current, the first switching tube Q1, the seventh switching tube Q7, the tenth switching tube Q10, and the twelfth switching tube Q12 are controlled. Conduction. At this time, the current flow in the three-leg topology device is as follows:

1. The positive electrode of the battery pack → the seventh switch tube Q7 → the synonymous end of the low voltage side of TX1 → the same name end of the low voltage side of TX1 → the tenth switch tube Q10 → the negative electrode of the battery pack, so that the battery pack can transmit energy to the transformer TX1. Synonymous end of TX1 high voltage side → third capacitor Cr → first switching tube Q1 → BUS+ → BUS- → twelfth switching tube Q12 → fifth inductor Lik → the same name terminal on the high voltage side of TX1, which constitutes the energy storage of bus capacitor E1 Loop. At this time, the transformer TX1 and the third capacitor Cr provide energy for the bus capacitor E1 at the same time.

FIG. 66 is a schematic diagram 1 of the current of the twentieth three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 66, in the first stage of the battery charging mode, that is, during the positive half cycle of the input AC power, the second switching tube Q2 and the eleventh switching tube Q11 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

1. BUS+→the eleventh switch Q11→the fifth inductor Lik→the end of the same name on the high voltage side of TX1→the synonymous end on the high voltage side of TX1→the third capacitor Cr→the second switch tube Q2→BUS-, so that the bus capacitance E1 It transmits energy for the transformer TX1 and forms an energy storage loop of the third capacitor Cr. The end of the same name on the low-voltage side of TX1→the ninth switch tube Q9→the positive electrode of the battery pack→the negative terminal of the battery pack→the eighth switch tube Q8→the synonymous end of the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the ninth switching tube Q9 and the eighth switching tube Q8 are used to implement the rectification function.

FIG. 67 is the second schematic diagram of the current of the twentieth three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 67, in the second stage of the battery charging mode, that is, during the negative half cycle of the input AC power, the first switching tube Q1 and the twelfth switching tube Q12 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

1. BUS+→the first switch tube Q1→the third capacitor Cr→the synonymous terminal on the high voltage side of TX1→the same name terminal on the high voltage side of TX1→the fifth inductor Lik→the twelfth switch tube Q12→BUS-, so that the bus capacitance E1 It transmits energy for the transformer TX1 and forms an energy storage loop of the third capacitor Cr. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

Structure B23: The voltage conversion circuit in the three-leg topology device realizes the voltage conversion function by multiplexing the second leg of the three-leg circuit and the bus capacitor E1. The three-leg topology device can be applied to a battery low-voltage high-current inverter system.

FIG. 68 is a schematic diagram of a twenty-first three-arm topology device provided by an embodiment of this application. As shown in FIG. 68, in this embodiment, the first terminal of the first capacitor Co is the first external connection terminal of the three-leg topology device, and the second terminal of the first capacitor Co is the second terminal of the three-leg topology device. External connection terminal.

The positive pole of the battery pack is connected to the first end of the voltage conversion circuit, and the negative pole of the battery pack is connected to the second end of the voltage conversion circuit. The third end of the voltage conversion circuit is connected to the midpoint of the first bridge arm, and the fourth end of the voltage conversion circuit is connected to the midpoint of the second bridge arm.

In this embodiment, the voltage conversion circuit, the first bridge arm, the second bridge arm of the three-leg circuit, and the bus capacitor E1 form a bidirectional DCDC topology (also called a bidirectional DCDC converter) to achieve bidirectional voltage conversion. Function. The bus capacitor E1, the second bridge arm, the third bridge arm and the LC filter of the three-leg circuit form a bidirectional DCAC topology (also called a bidirectional DCAC converter). In other words, the two-way DCDC topology and the two-way DCAC topology multiplex the second bridge arm and the bus capacitor E1.

In the battery charging mode, the mains AC power supply AC powers the three-leg circuit, the two-way DCAC topology works in AC-DC mode (that is, the full-bridge rectifier PFC converter mode), and the two-way DCDC topology works in the BUCK mode (that is, step-down). Mode), the BUS voltage output by the DC bus capacitor E1 is stepped down to obtain the charging voltage of the battery pack, and the charging voltage is used to charge the battery pack. At this time, the battery pack serves as the output source of the bidirectional DCDC topology. In this way, in the battery charging mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work.

In the battery power supply mode, the battery pack is the input source of the bidirectional DCDC topology, and the output of the bidirectional DCDC topology is the power supply of the three-leg circuit. That is, the bidirectional DCDC topology discharges the battery pack. At this time, the bidirectional DCDC topology works in Boost mode (ie, boost mode), and boosts the output voltage of the battery pack. The boosted voltage is input to the DC bus capacitor E1 to maintain the bus voltage balance. The two-way DCAC topology works in DC-AC mode (ie full-bridge inverter mode). The DC bus capacitor E1 filters the boosted DC power to obtain stable DC power. The second and third bridge arms work in reverse In the variable mode, the stable DC power is converted into AC power and then output to the load to supply power to the load. At the same time, the DC bus capacitor E1 can store energy. In this way, in the battery-powered mode, both the voltage conversion circuit and the three-leg circuit participate in the work, that is, all the devices of the three-leg topology device participate in the work.

Continuing to refer to the existing battery low-voltage high-current inverter system shown in FIG. 1A, the existing battery low-voltage high-current inverter system has the following problems in addition to low integration and low device reuse rate problem:

The first point: The switching devices of the Buck converter are connected in series in the main power circuit of the battery low-voltage high-current inverter system, which increases the conduction loss and thermal cost of the existing battery low-voltage high-current inverter system, and reduces the reliability.

The second point: In the battery charging mode, multiple voltage regulation (that is, the AC power provided by the mains AC power supply AC is first boosted by the full-bridge rectifier PFC converter, and then stepped down by the Buck converter, and then supplied to the bidirectional DCDC converter), Increase the system complexity of the battery low-voltage high-current inverter system, and reduce the system efficiency.

Compared with the battery low-voltage high-current inverter system with three-level converter provided in FIG. 1A, the three-leg topology device provided in FIG. 63 and FIG. 68 of the embodiment of the present application is applied to a battery voltage high-current inverter system. Through the two-way DCDC topology and the two-way DCAC topology, the battery low-voltage high-current inverter system is modified from a three-level converter topology to a two-level converter topology.

Under this two-level converter topology, whether it is battery power supply mode or battery charging mode, all components of the three-leg topology device participate in the work, which improves the integration of the battery low-voltage and high-current inverter system and the reuse of components It reduces the material cost of the system, reduces the conduction loss and thermal cost of the existing battery low-voltage high-current inverter system, and improves the reliability.

In addition, after the battery low-voltage high-current inverter system is modified from a three-level converter topology to a two-level converter topology, the power conversion path is shorter and the system efficiency is improved.

Fig. 69 is a schematic diagram of a twenty-second three-arm topology device provided by an embodiment of the application. As shown in Figure 69, when the three-leg topology device shown in Figure 68 is applied to a one-way battery low-voltage high-current inverter system (that is, the system only supports power supply for the load, the charging of the battery pack requires external charging The first switch tube and the second switch tube included in the first bridge arm of the three-leg topology device shown in FIG. 68 can be replaced with two diodes, such as the three-leg topology shown in FIG. 69 The structure of the device. Under this structure, the realization principle of the three-leg topology device for supplying power to the load is similar to the principle of the three-leg topology device as shown in FIG. 68 for supplying power to the load, and will not be repeated here.

In addition, the voltage conversion circuit involved in the embodiments of the present application may be a voltage conversion circuit with electrical isolation, or a voltage conversion circuit without electrical isolation.

Continuing to refer to FIG. 68, the voltage conversion circuit involved in the embodiment of the present application may include, for example, a first voltage conversion unit, a transformer, and an LC resonant cavity. The first voltage conversion unit is connected to the low voltage side of the transformer, and the high voltage side of the transformer is connected to the LC resonant cavity.

Continuing to refer to FIG. 68, exemplarily, the first voltage conversion unit includes: a fourth bridge arm and a fifth bridge arm. The LC resonant cavity includes: a fifth inductor Lik and an inductor Cr.

For the description of the fourth bridge arm, the fifth bridge arm and the LC resonant cavity, please refer to the description of the fourth bridge arm, the fifth bridge arm and the LC resonant cavity in the foregoing FIG. 3, which will not be repeated here. In some embodiments, the first voltage conversion unit shown in FIG. 68 may also be referred to as a full-bridge conversion circuit.

The second terminal of the seventh switch tube Q7 is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube Q8 is the second terminal of the voltage conversion circuit.

The midpoint of the fourth bridge arm is connected to the synonymous end of the low-voltage side of the transformer TX1, and the midpoint of the fifth bridge arm is connected to the same-named end of the low-voltage side of the transformer TX1. The end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor Lik, the second end of the fifth inductor Lik is connected to the midpoint of the first bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor Cr. The second end of the third capacitor Cr is connected to the midpoint of the second bridge arm. That is, the second end of the fifth inductor Lik is the third end of the voltage conversion circuit, and the second end of the third capacitor Cr is the fourth end of the voltage conversion circuit.

When the voltage conversion circuit is used to charge the battery pack, the bidirectional DCDC topology works in the half-bridge LLC resonant converter mode to achieve a wide range of voltage regulation and zero voltage turn-on. When the voltage conversion circuit is used to discharge the battery pack, the bidirectional DCDC topology works in the full-bridge secondary LC resonant voltage doubler converter mode to achieve the purpose of double boosting and improve the boost ratio of the bidirectional DCDC topology.

Optionally, the high-voltage side of the transformer and the LC resonant cavity, the first bridge arm and the second bridge arm may also be connected as shown in FIG. 25 to FIG. 31. The only difference is that when the connection method shown in FIGS. 25 to 31 is applied to this embodiment, the first bridge arm is used instead of the sixth bridge arm in FIGS. 25 to 31, and the second bridge arm is used instead of FIG. 25 To the seventh bridge arm in Figure 31. In these implementations, the end of the voltage conversion circuit connected to the midpoint of the first bridge arm is the third end of the voltage conversion circuit, and the end of the voltage conversion circuit connected to the midpoint of the second bridge arm is the voltage conversion The fourth end of the circuit will not be repeated here.

FIG. 68A is a twelfth schematic diagram of partial connections of a voltage conversion circuit provided by an embodiment of this application, and FIG. 68B is a thirteenth schematic diagram of partial connections of a voltage conversion circuit provided by an embodiment of this application. Referring to FIG. 68A, when the high-voltage side of the transformer and the LC resonant cavity, the first bridge arm and the second bridge arm are connected as shown in FIG. 30, the second end of the first switch tube is connected to the high-voltage transformer The first synonymous end of the transformer side is connected, the second end of the second switch tube is connected to the second synonymous end of the high voltage side of the transformer; the first synonymous end of the high voltage side of the transformer is connected to the positive output end of the bus Connected, the second end of the same name on the high voltage side of the transformer is connected to the negative output end of the bus; the first end of the fifth inductor is the third end of the voltage conversion circuit, and the second end of the fifth inductor Connected to the first terminal of the third capacitor, and the second terminal of the third capacitor is the fourth terminal of the voltage conversion circuit.

Referring to FIG. 68B, when the high-voltage side of the transformer and the LC resonant cavity, the first bridge arm and the second bridge arm adopt the connection mode shown in FIG. 31, the second end of the first switch tube and the high-voltage transformer The first synonymous end of the transformer side is connected, the second end of the second switch tube is connected to the second synonymous end of the high voltage side of the transformer; the first synonymous end of the high voltage side of the transformer is connected to the positive output end of the bus Connected, the second terminal with the same name on the high voltage side of the transformer is connected to the negative output terminal of the bus; the first terminal of the third capacitor is the third terminal of the voltage conversion circuit, and the second terminal of the third capacitor Connected to the first terminal of the fifth inductor, and the second terminal of the fifth inductor is the fourth terminal of the voltage conversion circuit.

It should be understood that when a voltage conversion circuit is implemented using any of the above-mentioned variants, the "bidirectional DCDC topology composed of the voltage conversion circuit, the first bridge arm, the second bridge arm, and the bus capacitor E1" is a model that works when charging the battery pack. The state, and the working mode when the battery pack is discharged, are the same as the voltage conversion circuit shown in FIG. 68, and will not be repeated here.

Taking the structure of the three-leg topology device shown in Figure 68 as an example, the state of each switch, the state of each switch tube, and the current trend of the three-leg topology device under different power supply modes are schematically described below:

FIG. 70 is a schematic diagram 1 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 70, in the first stage of the battery power supply mode, that is, in the first stage of the positive half cycle of the output alternating current, the second switching tube Q2, the fourth switching tube Q4, the fifth switching tube Q5, and the seventh switching tube are controlled. The switching tube Q7 and the tenth switching tube Q10 are turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The positive electrode of the battery pack → the seventh switch tube Q7 → the synonymous end of the low voltage side of TX1 → the same name end of the low voltage side of TX1 → the tenth switch tube Q10 → the negative electrode of the battery pack, so that the battery pack can transmit energy to the transformer TX1. The synonymous terminal on the high-voltage side of TX1→the third capacitor Cr→the fourth switch tube Q4→the second switch tube Q2→the fifth inductor Lik→the terminal with the same name on the high-voltage side of TX1 forms an energy storage loop of the third capacitor Cr.

FIG. 71 is a second schematic diagram of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 71, in the second stage of the battery power supply mode, that is, in the second stage of the positive half cycle of outputting alternating current, the first switching tube Q1, the fourth switching tube Q4, the fifth switching tube Q5, and the eighth switching tube are controlled. The switching tube Q8 and the ninth switching tube Q9 are turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The positive pole of the battery pack → the ninth switch tube Q9 → the end of the same name on the low voltage side of TX1 → the synonymous end of the low voltage side of TX1 → the eighth switch tube Q8 → the negative pole of the battery pack, so that the battery pack can transmit energy to the transformer TX1. The end of the same name on the high-voltage side of TX1→the fifth inductor Lik→the first switch tube Q1→BUS+→BUS-→the fourth switch tube Q4→the third capacitor Cr→the synonymous terminal on the high-voltage side of TX1, forming the energy storage circuit of the bus capacitor E1 . At this time, the transformer TX1 and the third capacitor Cr provide energy for the bus capacitor E1 at the same time.

FIG. 72 is the third schematic diagram of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 72, in the third stage of the battery power supply mode, that is, in the third stage of the positive half cycle of the output alternating current, the second switching tube Q2, the fourth switching tube Q4, the sixth switching tube Q6, and the seventh switching tube are controlled. The switching tube Q7 and the tenth switching tube Q10 are turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 73 is a fourth schematic diagram of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 73, in the fourth stage of the battery power supply mode, that is, in the fourth stage of the positive half cycle of the output alternating current, the first switching tube Q1, the fourth switching tube Q4, the sixth switching tube Q6, and the eighth switching tube are controlled. The switching tube Q8 and the ninth switching tube Q9 are turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 74 is a schematic diagram 5 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 74, in the fifth stage of the battery power supply mode, that is, in the first stage of the negative half cycle of the output alternating current, the first switching tube Q1, the third switching tube Q3, the sixth switching tube Q6, and the eighth switching tube are controlled. The switching tube Q8 and the ninth switching tube Q9 are turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The positive pole of the battery pack → the ninth switch tube Q9 → the end of the same name on the low voltage side of TX1 → the synonymous end of the low voltage side of TX1 → the eighth switch tube Q8 → the negative pole of the battery pack, so that the battery pack can transmit energy to the transformer TX1. The end of the same name on the high-voltage side of TX1→the fifth inductor Lik→the first switch tube Q1→the third switch tube Q3→the third capacitor Cr→the synonymous end of the high-voltage side of TX1 forms an energy storage loop of the third capacitor Cr.

FIG. 75 is a current schematic diagram 6 of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 75, in the sixth stage of the battery power supply mode, that is, in the second stage of the negative half cycle of the output alternating current, the first switching tube Q1, the second switching tube Q2, the third switching tube Q3, and the sixth switching tube are controlled. The switching tube Q6, the seventh switching tube Q7, and the tenth switching tube Q10 are turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The positive electrode of the battery pack → the seventh switch tube Q7 → the synonymous end of the low voltage side of TX1 → the same name end of the low voltage side of TX1 → the tenth switch tube Q10 → the negative electrode of the battery pack, so that the battery pack can transmit energy to the transformer TX1. Synonymous end of TX1 high voltage side → third capacitor Cr → first switching tube Q1 → BUS+ → BUS- → second switching tube Q2 → fifth inductor Lik → the same name end of TX1 high voltage side, forming the energy storage circuit of bus capacitor E1 . At this time, the transformer TX1 and the third capacitor Cr provide energy for the bus capacitor E1 at the same time.

76 is a schematic diagram 7 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 76, in the seventh stage of the battery power supply mode, that is, in the third stage of the negative half cycle of the output alternating current, the first switching tube Q1, the third switching tube Q3, the fifth switching tube Q5, and the eighth switching tube are controlled. The switching tube Q8 and the ninth switching tube Q9 are turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 77 is a schematic diagram 8 of the current of the twenty-first three-leg topology device in the battery power supply mode according to an embodiment of the application. As shown in Figure 77, in the eighth stage of the battery power supply mode, that is, in the fourth stage of the negative half cycle of the output alternating current, the first switching tube Q1, the second switching tube Q2, the third switching tube Q3, and the fifth switching tube are controlled. The switching tube Q5, the seventh switching tube Q7, and the tenth switching tube Q10 are turned on. At this time, the current flow in the three-leg topology device is as follows:

FIG. 78 is the first schematic diagram of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 78, in the first stage of the battery charging mode, that is, in the first stage of the positive half cycle of the input AC power, the first switching tube Q1, the fourth switching tube Q4, and the sixth switching tube Q6 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The live wire of the mains AC power supply AC→the second inductor L2→the sixth switch tube Q6→the fourth switch tube Q4→the neutral wire of the mains AC power supply AC, forming an energy storage circuit of the second inductor L2.

2. BUS+→the first switch tube Q1→the fifth inductor Lik→the end of the same name on the high voltage side of TX1→the synonymous end on the high voltage side of TX1→the third capacitor Cr→the fourth switch tube Q4→BUS-, so that the bus capacitance E1 is The transformer TX1 transmits energy and forms an energy storage loop of the third capacitor Cr.

The end of the same name on the low-voltage side of TX1→the ninth switch tube Q9→the positive electrode of the battery pack→the negative terminal of the battery pack→the eighth switch tube Q8→the synonymous end of the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the ninth switching tube Q9 and the eighth switching tube Q8 are used to implement the rectification function.

FIG. 79 is a second schematic diagram of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 79, in the second stage of the battery charging mode, that is, in the second stage of the positive half cycle of the input alternating current, the second switching tube Q2, the fourth switching tube Q4, and the sixth switching tube Q6 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

2. Cr positive → synonymous end of TX1 high voltage side → same name end of TX1 high voltage side → fifth inductor Lik → second switching tube Q2 → fourth switching tube Q4 → Cr negative electrode, so that Cr transfers energy for transformer TX1. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

FIG. 80 is the third schematic diagram of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 80, in the third stage of the battery charging mode, that is, in the third stage of the positive half cycle of the input AC power, the first switching tube Q1, the fourth switching tube Q4, and the fifth switching tube Q5 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The live wire of the mains AC power supply AC→the second inductance L2→the fifth switch tube Q5→BUS+→BUS-→the fourth switch tube Q4→the neutral wire of the mains AC power supply AC, forming the second inductance L2 and the mains At the same time, it is the energy storage circuit of the DC bus capacitor E1.

FIG. 81 is a fourth schematic diagram of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 81, in the fourth stage of the battery charging mode, that is, in the fourth stage of the positive half cycle of the input AC power, the second switching tube Q2, the fourth switching tube Q4, and the fifth switching tube Q5 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

2. Cr anode → synonymous end of TX1 high voltage side → same name end of TX1 high voltage side → fifth inductor Lik → second switching tube Q2 → fourth switching tube Q4 → Cr negative electrode, so that Cr transfers energy for transformer TX1. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

FIG. 82 is a schematic diagram 5 of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 82, in the fifth stage of the battery charging mode, that is, in the first stage of the negative half cycle of the input AC power, the second switching tube Q2, the third switching tube Q3, and the fifth switching tube Q5 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The neutral line of the mains AC power supply AC→the third switching tube Q3→the fifth switching tube Q5→the second inductor L2→the live wire of the mains AC power supply AC, forming an energy storage circuit of the second inductor L2.

2. BUS+→the third switch tube Q3→the third capacitor Cr→the synonymous terminal on the high-voltage side of TX1→the same-name terminal on the high-voltage side of TX1→the fifth inductor Lik→the second switch tube Q2→BUS-, so that the bus capacitance E1 is The transformer TX1 transmits energy and forms an energy storage loop of the third capacitor Cr. The synonymous terminal on the low-voltage side of TX1→the seventh switch tube Q7→the positive electrode of the battery pack→the negative terminal of the battery pack→the tenth switch tube Q10→the end of the same name on the low-voltage side of TX1 constitutes the energy storage circuit of the battery pack. Among them, the seventh switching tube Q7 and the tenth switching tube Q10 are used to implement the rectification function.

FIG. 83 is a current schematic diagram 6 of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 83, in the sixth stage of the battery charging mode, that is, in the second stage of the negative half cycle of the input AC power, the first switching tube Q1, the third switching tube Q3, and the fifth switching tube Q5 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

2. Cr positive electrode → third switching tube Q3 → first switching tube Q1 → fifth inductor Lik → end of the same name on the high-voltage side of TX1 → end of the same name on the high-voltage side of TX1 → negative terminal of Cr, so that Cr transfers energy for the transformer TX1.

FIG. 84 is a schematic diagram 7 of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 84, in the seventh stage of the battery charging mode, that is, in the third stage of the negative half cycle of the input AC power, the second switching tube Q2, the third switching tube Q3, and the sixth switching tube Q6 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

1. The neutral line of the mains AC power supply AC → the third switching tube Q3 → BUS+ → BUS- → the sixth switching tube Q6 → the second inductance L2 → the live wire of the mains AC power supply AC, forming the second inductance L2 and the mains At the same time, it is the energy storage circuit of the DC bus capacitor E1.

FIG. 85 is a schematic diagram 8 of the current of the twenty-first three-leg topology device in the battery charging mode according to an embodiment of the application. As shown in FIG. 85, in the eighth stage of the battery charging mode, that is, in the fourth stage of the negative half cycle of the input AC power, the first switching tube Q1, the third switching tube Q3, and the sixth switching tube Q6 are controlled to be turned on. At this time, the current flow in the three-leg topology device is as follows:

It should be noted that in the above-mentioned three-leg topology device (the three-leg topology device shown in Figure 63 to Figure 85) applied to the battery low-voltage high-current inverter system, the LC filter is connected to the second leg and the third leg. The connection relationship of the bridge arms can also be as follows, for example:

FIG. 86 is a schematic diagram of the connection relationship between the LC filter and the second bridge arm and the third bridge arm according to an embodiment of the application. As shown in Figure 86, the midpoint of the second bridge arm is connected to the first end of the second inductor L2, the second end of the second inductor L2 is connected to the second end of the first capacitor Co, and the first end of the first capacitor Co is connected. The end is connected with the midpoint of the third bridge arm. The first terminal of the first capacitor Co is the first external connection terminal of the three-leg topology device, and the second terminal of the first capacitor Co is the second external connection terminal of the three-leg topology device.

In some implementations, the LC filter in the three-leg topology device (the three-leg topology device shown in FIGS. 63 to 85) applied to the battery low-voltage high-current inverter system can also use the LCL filter (ie A filter consisting of two inductors and one capacitor) is replaced.

FIG. 87 is a schematic diagram of the connection relationship between the LCL filter and the second bridge arm and the third bridge arm according to an embodiment of the application. Taking the LCL filter including "the second inductor L2, the first capacitor Co, and the fourth inductor L4" as an example, the connection relationship may be as follows:

The midpoint of the third bridge arm is connected to the first end of the second inductor L2, the second end of the second inductor L2 is connected to the first end of the first capacitor Co, and the second end of the first capacitor Co is connected to the fourth inductor L4. The first end of the fourth inductor L4 is connected to the second end of the fourth inductor L4 is connected to the midpoint of the second bridge arm. The first terminal of the first capacitor Co is the first external connection terminal of the three-leg topology device, and the second terminal of the first capacitor Co is the second external connection terminal of the three-leg topology device.

It should be understood that although the above three-leg topology devices are all applied to battery low-voltage and high-current UPS systems or battery low-voltage and high-current inverter systems as examples, those skilled in the art can understand that for the application of battery low-voltage and high-current The three-leg topology device of the UPS system can also be applied to other UPS systems (such as high-power UPS systems), or other systems (such as inverter systems) that use different power sources (mains or battery packs) in different situations. , I won’t repeat it here. For the three-leg topology device applied to the battery low-voltage high-current inverter system, it can also be applied to other inverter systems (such as high-power UPS systems), etc., which will not be repeated.

It can be understood that the various numbers (such as the first switch tube, the second switch tube, the first switch, the second switch, etc.) involved in the embodiments of the present application are only for the convenience of description, and are not used to limit the present invention. Apply for the scope of the embodiment.

It is understandable that each switch tube involved in the embodiments of the present application may be any switch tube that can be turned on or off based on control, for example, an insulated gate bipolar transistor (IGBT), or , Metal-oxide-semiconductor field effect transistor (Metal Oxide Semiconductor, MOS) or, triode, or, thyristor. The switching tubes used in different circuits can be different or the same. For example, the switching tubes in the voltage conversion circuit use MOS tubes, and the switching tubes in the three-leg circuit use IGBT, or the voltage conversion circuit and the three-leg circuit The switches are all IGBTs. In addition, the same switching tube may be used in the same circuit, or different switching tubes may be used, which is not limited.

In addition, although the foregoing embodiments schematically illustrate the states of the switch tubes and the current trends of the three-leg topology devices of various structures provided in the embodiments of the present application under different power supply modes. However, those skilled in the art can understand that, for the switching tubes not mentioned in the above description, in the external power supply mode or battery power supply mode of the three-leg topology device, they can be in the off state, or through the switching tube. The external diode realizes rectification, or the body of the switch tube is turned on to realize rectification, which can be determined according to the control mode. That is to say, the control mode of each switch tube in the three-arm topology device provided by the embodiment of the present application includes but is not limited to the method listed in the above-mentioned embodiment, and can also be implemented in other ways, which is not performed in the embodiment of the present application. limited.

On the other hand, an embodiment of the present application also provides an uninterruptible power supply system, which includes: an external power supply, a load, and the three-leg topology device shown in the foregoing embodiment (for example, FIG. 2, FIG. 4 to FIG. 7, and, the three-leg topology device shown in any one of Figs. 14 to 23 and Figs. 24 to 61). The first end of the external power supply is connected to the positive voltage input terminal AC_L of the three-leg topology device, and the second end of the external power supply is connected to the negative voltage input terminal AC_N of the three-leg topology device. The first output terminal and the second output terminal are connected to the load. The external power supply mentioned here can be, for example, a commercial AC power supply AC or a photovoltaic PV DC power supply.

In another aspect, an embodiment of the present application also provides an uninterruptible power supply system, which includes: a first external power supply, a second external power supply, a load, and the three-arm topology device ( For example, the three-arm topology shown in Figure 62). Wherein, the first terminal of the first external power supply is connected to the first positive voltage input terminal of the three-leg topology device, and the second terminal of the first external power supply is connected to the first negative voltage input terminal of the three-leg topology device, The first terminal of the second external power supply is connected with the second positive voltage input terminal of the three-leg topology device, and the second terminal of the second external power supply is connected with the second negative voltage input terminal of the three-bridge topology device. Both the first output terminal and the second output terminal of the arm topology device are connected to the load.

The first external power supply and the second external power supply mentioned here can be two different supply sources. For example, the first external power supply may be a commercial AC power supply AC, and the second external power supply may be a photovoltaic PV DC power supply, for example. In this example, the live wire of the AC power source AC is connected to the first positive voltage input terminal AC_L of the three-legged topology device, and the neutral wire of the AC power source AC is connected to the first negative voltage input terminal AC_N of the three-legged topology device. Connected, the positive pole of the photovoltaic PV DC power supply is connected to the second positive voltage input terminal PV+ of the three-leg topology device, and the negative pole of the photovoltaic PV DC power supply is connected to the second negative voltage input terminal PV- of the three-leg topology device.

Alternatively, the first external power source may be, for example, a photovoltaic PV direct current power source, and the second external power source may be, for example, a commercial AC power source AC. In this example, the live wire of the AC power source AC is connected to the second positive voltage input terminal AC_L of the three-leg topology device, and the neutral wire of the AC power source AC is connected to the second negative voltage input terminal AC_N of the three-leg topology device. The positive pole of the photovoltaic PV DC power supply is connected to the first positive voltage input terminal PV+ of the three-leg topology device, and the negative pole of the photovoltaic PV DC power supply is connected to the first negative voltage input terminal PV- of the three-leg topology device.

The uninterruptible power supply system provided by the embodiment of the present application may be, for example, a battery low-voltage high-current UPS system, or an online medium and small power UPS system.

The implementation principle and technical effect of the UPS system provided by the embodiment of the present application are similar to the aforementioned three-leg topology device applied to the battery low-voltage high-current UPS system, and will not be repeated here.

In another aspect, an embodiment of the present application also provides an inverter system, which includes a load, and the three-leg topology device shown in the foregoing embodiment (for example, any one of FIGS. 63 to 68 and 70 to 85). The three-arm topology device shown).

In the battery power supply mode, the first external connection terminal and the second external connection terminal of the three-arm topology device are both connected to the load.

Optionally, the inverter system may further include: an external power supply; in the battery charging mode, the first external connection terminal and the second external connection terminal of the three-leg topology device are both connected to the external power supply.

The inverter system provided by the embodiment of the present application may be, for example, a battery low-voltage and high-current inverter system, or an online medium and small power inverter system. The implementation principles and technical effects of the inverter system provided by the embodiments of the present application are similar to the aforementioned three-leg topology device applied to the battery low-voltage high-current inverter system, and will not be repeated here.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, not to limit them; although the embodiments of the present application are described in detail with reference to the foregoing embodiments, those of ordinary skill in the art It should be understood that: it can still modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the embodiments of this application. The scope of the technical solution of each embodiment.

Claims

A three-leg topology device, characterized in that the three-leg topology device includes: a battery pack, a voltage conversion circuit, and a three-leg circuit;

The three bridge arm circuit includes: a first bridge arm, a second bridge arm, a third bridge arm, a first inductor, a second inductor, a DC bus capacitor, and a first capacitor;

The first bridge arm includes a first switch tube and a second switch tube connected in series;

The second bridge arm includes a third switch tube and a fourth switch tube connected in series;

The third bridge arm includes a fifth switch tube and a sixth switch tube connected in series;

The first bridge arm, the second bridge arm, the third bridge arm, and the DC bus capacitor are connected in parallel between the positive output end of the bus and the negative output end of the bus; the midpoint of the first bridge arm Connected to the first end of the first inductor, and the second end of the first inductor is used as the positive voltage input end of the three-leg topology device; the midpoint of the second bridge arm or the negative output of the bus Terminal is used as the negative voltage input terminal of the three-leg topology device; the midpoint of the third bridge arm is connected to the first terminal of the second inductor, and the second terminal of the second inductor is connected to the first terminal of the second inductor. The first end of the capacitor is connected, the second end of the first capacitor is connected to the midpoint of the second bridge arm, and the first end of the first capacitor is the first output end of the three bridge arm topology device , The second end of the first capacitor is the second output end of the three-leg topology device, and both the first output end and the second output end are connected to a load;

The positive pole of the battery pack is connected to the first end of the voltage conversion circuit, the negative pole of the battery pack is connected to the second end of the voltage conversion circuit, and the third end of the voltage conversion circuit is connected to the bus positive. The output terminal is connected, the fourth terminal of the voltage conversion circuit is connected with the negative output terminal of the bus, the first terminal of the external power supply is connected with the positive voltage input terminal, and the second terminal of the external power supply is connected with the Negative voltage input terminal connection;

The voltage conversion circuit is used for charging the battery pack in the external power supply mode; and discharging the battery pack in the battery power supply mode.
The device according to claim 1, wherein the voltage conversion circuit comprises: a first voltage conversion unit, a second voltage conversion unit, a transformer, and an LC resonant cavity; the LC resonant cavity includes: a fifth inductor, a first Three capacitors;

Wherein, the first voltage conversion unit is connected to the low voltage side of the transformer, and the high voltage side of the transformer is connected to the resonant cavity and the second voltage conversion unit.
The device according to claim 2, wherein the first voltage conversion unit comprises: a fourth bridge arm and a fifth bridge arm; the fourth bridge arm comprises: a seventh switch tube and an eighth switch tube; The fifth bridge arm includes a ninth switch tube and a tenth switch tube;

The first end of the seventh switch tube is connected to the first end of the eighth switch tube, the first end of the ninth switch tube is connected to the first end of the tenth switch tube, and the seventh The second end of the switching tube is connected to the second end of the ninth switching tube, and the second end of the eighth switching tube is connected to the second end of the tenth switching tube;

The midpoint of the fourth bridge arm is connected to the opposite end of the low voltage side of the transformer, and the midpoint of the fifth bridge arm is connected to the same end of the low voltage side of the transformer;

The second terminal of the seventh switch tube is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube is the second terminal of the voltage conversion circuit.
The device according to claim 2, wherein the first voltage conversion unit comprises: a seventh switch tube and an eighth switch tube;

The first end of the seventh switch tube is connected to the first end of the transformer low-voltage side with the same name, the first end of the eighth switch tube is connected to the different end of the low-voltage side of the transformer, and the seventh switch The second end of the tube is connected to the second end of the eighth switch tube;

The second end of the seventh switch tube is the second end of the voltage conversion circuit.
The device according to claim 4, wherein the second terminal with the same name on the low-voltage side of the transformer is the first terminal of the voltage conversion circuit;

Alternatively, the first voltage conversion unit further includes: a ninth switch tube; a first end of the ninth switch tube is connected to a second end of the same name on the low-voltage side of the transformer, and a second end of the ninth switch tube Is the first terminal of the voltage conversion circuit.
The device according to claim 2, wherein the first voltage conversion unit comprises: a fourth bridge arm, a fifth bridge arm and a fourth capacitor;

The fourth bridge arm includes: a seventh switching tube and an eighth switching tube; the fifth bridge arm includes a ninth switching tube and a tenth switching tube; the first end of the seventh switching tube is connected to the eighth switching tube. The first end of the switching tube is connected, and the first end of the ninth switching tube is connected to the first end of the tenth switching tube;

The second end of the seventh switch tube is connected to the first synonymous end of the low-voltage side of the transformer, and the second end of the eighth switch tube is connected to the second synonymous end of the low-voltage side of the transformer. The second terminal of the ninth switch tube and the first terminal of the fourth capacitor are both connected to the first terminal with the same name on the low-voltage side of the transformer. The second terminal of the tenth switch tube and the first terminal of the fourth capacitor are Both ends are connected to the second end of the same name on the low-voltage side of the transformer, and the midpoint of the fourth bridge arm is connected to the midpoint of the fifth bridge arm;

The second terminal of the seventh switch tube is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube is the second terminal of the voltage conversion circuit.
The device according to claim 2, wherein the battery pack comprises a first battery sub-group and a second battery sub-group connected in series, and the negative electrode of the first battery sub-group is connected to the positive electrode of the second battery sub-group, The positive electrode of the first battery subgroup is the positive electrode of the battery group, and the negative electrode of the second battery subgroup is the negative electrode of the battery group;

The first voltage conversion unit includes: a fourth bridge arm, the fourth bridge arm includes: a seventh switching tube and an eighth switching tube; the first end of the seventh switching tube is connected to the eighth switching tube The first end connection;

The negative electrode of the first battery sub-group is connected to the opposite end of the low voltage side of the transformer, and the midpoint of the fourth bridge arm is connected to the same end of the low voltage side of the transformer;

The second terminal of the seventh switch tube is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube is the second terminal of the voltage conversion circuit.
The device according to any one of claims 2-7, wherein the second voltage conversion unit comprises: a sixth bridge arm and a seventh bridge arm;

The sixth bridge arm includes: an eleventh switch tube and a twelfth switch tube; the seventh bridge arm includes a thirteenth switch tube and a fourteenth switch tube;

The first end of the eleventh switch tube is connected to the first end of the twelfth switch tube, and the first end of the thirteenth switch tube is connected to the first end of the fourteenth switch tube, The second end of the eleventh switch tube is connected to the second end of the thirteenth switch tube, and the second end of the twelfth switch tube is connected to the second end of the fourteenth switch tube;

The second terminal of the thirteenth switch tube is the third terminal of the voltage conversion circuit, and the second terminal of the fourteenth switch tube is the fourth terminal of the voltage conversion circuit.
8. The device according to claim 8, wherein the second voltage conversion unit further comprises: a second capacitor, a first end of the second capacitor is connected to a second end of the thirteen switch tube, so The second end of the second capacitor is connected to the second end of the fourteenth switch tube.
The device according to claim 8 or 9, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the sixth bridge The midpoint of the arm is connected, the different-named end of the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the midpoint of the seventh bridge arm.
The device according to claim 8 or 9, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the sixth bridge. The midpoint of the arm is connected, the different-named end of the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the midpoint of the seventh bridge arm.
The device according to claim 8 or 9, wherein the end with the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the fifth inductor. The first end of the fifth inductor is connected to the midpoint of the sixth bridge arm, and the opposite end of the transformer high-voltage side is connected to the midpoint of the seventh bridge arm.
The device according to claim 8 or 9, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the third capacitor. The first end of the third capacitor is connected to the midpoint of the sixth bridge arm, and the other end of the transformer high voltage side is connected to the midpoint of the seventh bridge arm.
The device according to claim 8 or 9, wherein the end of the same name on the high voltage side of the transformer is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the third capacitor The first end of the third capacitor is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the midpoint of the seventh bridge arm.
The device according to claim 8 or 9, wherein the end of the same name on the high voltage side of the transformer is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the fifth inductor. The first end of the fifth inductor is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the midpoint of the seventh bridge arm.
The device according to claim 8 or 9, wherein the second end of the eleventh switch tube is connected to the first synonymous end of the high voltage side of the transformer, and the second end of the twelfth switch tube is The second end of the thirteenth switch tube is connected to the first end of the same name on the high voltage side of the transformer, and the second end of the fourteenth switch tube is connected to the second end of the transformer high voltage side. It is connected to the second end of the same name on the high voltage side of the transformer, the midpoint of the sixth bridge arm is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the first end of the third capacitor. The second end of the third capacitor is connected to the midpoint of the seventh bridge arm.
The device according to claim 8 or 9, wherein the second end of the eleventh switch tube is connected to the first synonymous end of the high voltage side of the transformer, and the second end of the twelfth switch tube is The second end of the thirteenth switch tube is connected to the first end of the same name on the high voltage side of the transformer, and the second end of the fourteenth switch tube is connected to the second end of the transformer high voltage side. Is connected to the second end of the transformer with the same name on the high voltage side, the midpoint of the sixth bridge arm is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the fifth inductor The first end is connected, and the second end of the fifth inductor is connected to the midpoint of the seventh bridge arm.
7. The device according to any one of claims 2-7, wherein the second voltage conversion unit comprises: a sixth bridge arm; the sixth bridge arm comprises: an eleventh switch tube and a twelfth switch Tube;

The first terminal of the eleventh switch tube is connected to the first terminal of the twelfth switch tube, the second terminal of the eleventh switch tube is the third terminal of the voltage conversion circuit, and the first terminal The second end of the twelve switch tube is the fourth end of the voltage conversion circuit;

The voltage conversion circuit further includes a fifth terminal, and the fifth terminal of the voltage conversion circuit is connected to the midpoint of the second bridge arm.
The device according to claim 18, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the second end of the sixth bridge arm. Mid-point connection, the different-named end of the high-voltage side of the transformer is connected to the first end of the third capacitor;

The second terminal of the third capacitor is the fifth terminal of the voltage conversion circuit.
The device according to claim 18, wherein the end with the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the sixth bridge arm. Mid-point connection, the different-named end of the high-voltage side of the transformer is connected to the first end of the fifth inductor;

The second terminal of the fifth inductor is the fifth terminal of the voltage conversion circuit.
The device according to claim 18, wherein the end with the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the first end of the fifth inductor. One end is connected, and the second end of the fifth inductor is connected to the midpoint of the sixth bridge arm;

The synonymous terminal on the high voltage side of the transformer is the fifth terminal of the voltage conversion circuit.
The device according to claim 18, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the first end of the third capacitor. One end is connected, and the second end of the third capacitor is connected to the midpoint of the sixth bridge arm;

The synonymous terminal on the high voltage side of the transformer is the fifth terminal of the voltage conversion circuit.
The device according to claim 18, wherein the end of the same name on the high voltage side of the transformer is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the second end of the third capacitor. One end is connected, and the second end of the third capacitor is connected to the first end of the fifth inductor;

The second terminal of the fifth inductor is the fifth terminal of the voltage conversion circuit.
The device according to claim 18, wherein the end of the same name on the high voltage side of the transformer is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor. One end is connected, and the second end of the fifth inductor is connected to the first end of the third capacitor;

The second terminal of the third capacitor is the fifth terminal of the voltage conversion circuit.
7. The device according to any one of claims 2-7, wherein the second voltage conversion unit comprises: a sixth bridge arm; the sixth bridge arm comprises: an eleventh switch tube and a twelfth switch Tube;

The first end of the eleventh switch tube is connected to the first end of the twelfth switch tube, and the second end of the eleventh switch tube is connected to the first synonymous end of the high voltage side of the transformer, The second end of the twelfth switch tube is connected to the second synonymous end of the high voltage side of the transformer;

The first end with the same name on the high voltage side of the transformer is the third end of the voltage conversion circuit, and the second end with the same name on the high voltage side of the transformer is the fourth end of the voltage conversion circuit;

The fifth terminal of the voltage conversion circuit is connected to the midpoint of the second bridge arm.
The device according to claim 25, wherein the midpoint of the sixth bridge arm is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the first end of the third capacitor. End connection

The second terminal of the third capacitor is the fifth terminal of the voltage conversion circuit.
The device according to claim 25, wherein the midpoint of the sixth bridge arm is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the fifth inductor. The first end connection;

The second terminal of the fifth inductor is the fifth terminal of the voltage conversion circuit.
The device according to any one of claims 1-7, 9, wherein the midpoint of the second bridge arm serves as the negative voltage input terminal of the three-bridge arm topology device;

The three-arm topology device further includes: a switch;

The third terminal of the voltage conversion circuit is respectively connected to the positive output terminal of the bus bar and the positive voltage input terminal through the switch;

The switch is used to control the voltage conversion circuit to charge the battery pack in the external power supply mode; and to control the voltage conversion circuit to discharge the battery pack in the battery power supply mode.
The device according to claim 28, wherein the switch comprises: a first switch, a second switch, and balance components;

The third terminal of the voltage conversion circuit is connected to the fixed terminal of the first switch, the first selection terminal of the first switch is connected to the first terminal of the balance component, and the second terminal of the balance component is connected. Terminal is connected to the positive output terminal of the bus, the second selection terminal of the first switch is connected to the positive voltage input terminal, the first terminal of the second switch is connected to the first terminal of the external power supply, The second terminal of the second switch is connected to the positive voltage input terminal, and the fourth terminal of the voltage conversion circuit is connected to the negative output terminal of the bus;

The balance component is used to balance the voltage between the bus bar and the voltage conversion circuit.
The device according to claim 29, wherein the balance element is a resistor, and the switch further comprises: a third switch;

The third terminal of the voltage conversion circuit is connected to the first terminal of the third switch, and the second terminal of the third switch is connected to the positive output terminal of the bus; or, the third switch is connected to the resistor Connected in parallel.
The device according to claim 28, wherein the switch comprises: a first switch, a second switch, and balance components;

The third terminal of the voltage conversion circuit is respectively connected to the first terminal of the first switch and the first selection terminal of the second switch, and the second terminal of the first switch is connected to the balance component The first end of the balance element is connected to the positive output end of the bus bar, the second selection end of the second switch is connected to the first end of the external power supply, and the second end of the second switch is connected to the first end of the external power supply. The fixed terminal of the switch is connected to the positive voltage input terminal, and the fourth terminal of the voltage conversion circuit is connected to the negative output terminal of the bus;

The balance component is used to balance the voltage between the bus bar and the voltage conversion circuit.
The device according to claim 31, wherein the balance element is a resistor, and the switch further comprises: a third switch;

The third terminal of the voltage conversion circuit is connected to the first terminal of the third switch, and the second terminal of the third switch is connected to the positive output terminal of the bus; or, the third switch is connected to the resistor Connected in parallel.
The device according to claim 28, wherein the switch comprises: a first switch, a second switch, a third switch, and balance components;

The third terminal of the voltage conversion circuit is respectively connected to the first terminal of the first switch and the first terminal of the third switch, and the second terminal of the first switch is connected to the positive voltage input terminal, The first terminal of the second switch is connected to the first terminal of the external power supply, the second terminal of the second switch is connected to the positive voltage input terminal, and the second terminal of the third switch is connected to the The first end of the balance component is connected, the second end of the balance component is connected to the positive output end of the bus, and the fourth end of the voltage conversion circuit is connected to the negative output end of the bus;

The balance component is used to balance the voltage between the bus bar and the voltage conversion circuit.
The device according to claim 33, wherein the balance element is a resistor, and the switch further comprises: a fourth switch;

The third terminal of the voltage conversion circuit is connected to the first terminal of the fourth switch, and the second terminal of the fourth switch is connected to the positive output terminal of the bus; or, the fourth switch is connected to the resistor Connected in parallel.
The device according to any one of claims 29, 31, 33, wherein the balance component is any one of the following: a varistor, a thermistor with a negative temperature coefficient, and a third inductor.
The device according to any one of claims 28-35, wherein the external power supply is a commercial AC power supply;

The first end of the external power supply is the live wire of the mains AC power supply, and the second end of the external power supply is the neutral wire of the mains AC power supply.
The device according to any one of claims 1-8, 18-27, wherein the midpoint of the second bridge arm is used as the negative voltage input terminal of the three bridge arm topology device, and the external power supply Is a mains AC power supply; the first end of the external power supply is the live wire of the mains AC power supply, and the second end of the external power supply is the neutral wire of the mains AC power;

Alternatively, the negative output end of the busbar serves as the negative voltage input end of the three-arm topology device, the external power supply is a photovoltaic direct current power supply, and the first end of the external power supply is the positive pole of the photovoltaic direct current power supply, The second end of the external power supply is the negative electrode of the photovoltaic DC power supply.
The device according to any one of claims 1-8, 18-27, wherein the second terminal of the first inductor serves as the first positive voltage input terminal of the three-leg topology device, and the first The midpoint of the second bridge arm is used as the first negative voltage input terminal of the three bridge arm topology device, the external power supply is a mains AC power supply, and the first end of the external power supply is the mains AC power supply. Live wire, the second end of the external power supply is the neutral wire of the mains AC power supply;

The device further includes: an eighth bridge arm and a sixth inductor;

The eighth bridge arm includes a seventeenth switching tube and an eighteenth switching tube. The seventeenth switching tube and the eighteenth switching tube are connected in series to the positive output end of the bus and the negative output end of the bus between;

The midpoint of the eighth bridge arm is connected to the first end of the sixth inductor, and the second end of the sixth inductor is used as the second positive voltage input end of the three bridge arm topology device, and the bus bar is negative. The output terminal is used as the second negative voltage input terminal of the three-bridge arm topology device; the positive electrode of the photovoltaic direct current power supply is connected to the second positive voltage input terminal, and the negative electrode of the photovoltaic direct current power supply is connected to the second negative voltage input terminal.
An uninterruptible power supply system, characterized in that the system comprises: an external power supply, a load, and the three-leg topology device according to any one of claims 1 to 37;

Wherein, the first end of the external power supply is connected to the positive voltage input end of the three-leg topology device, and the second end of the external power supply is connected to the negative voltage input end of the three-leg topology device, Both the first output terminal and the second output terminal of the three-arm topology device are connected to the load.
An uninterruptible power supply system, characterized in that the system comprises: a first external power supply, a second external power supply, a load, and the three-leg topology device according to claim 38;

Wherein, the first terminal of the first external power supply is connected to the first positive voltage input terminal of the three-leg topology device, and the second terminal of the first external power supply is connected to the first positive voltage input terminal of the three-leg topology device. The first negative voltage input terminal is connected, the first terminal of the second external power supply is connected to the second positive voltage input terminal of the three-leg topology device, and the second terminal of the second external power supply is connected to the The second negative voltage input terminal of the three-leg topology device is connected, and the first output terminal and the second output terminal of the three-leg topology device are both connected to the load.
A method for controlling a three-arm topology device, wherein the method is used to control the three-arm topology device according to claim 29, and the method comprises:

In the external power supply mode, controlling the fixed terminal of the first switch to communicate with the first selection terminal of the first switch, and the second switch is closed;

In the battery power supply mode, the fixed terminal of the first switch is controlled to communicate with the second selection terminal of the first switch, and the second switch is turned off.
A method for controlling a three-arm topology device, wherein the method is used to control the three-arm topology device according to claim 30, and the method comprises:

In the external power supply mode, the fixed terminal of the first switch is controlled to be connected to the first selection terminal of the first switch, the second switch is closed, and the voltage between the bus bar and the voltage conversion circuit of the three-leg topology device When the difference is less than or equal to the preset threshold, control the third switch to close;

In the battery power supply mode, the fixed terminal of the first switch is controlled to communicate with the second selection terminal of the first switch, and the second switch and the third switch are disconnected.
A method for controlling a three-arm topology device, wherein the method is used to control the three-arm topology device according to claim 31, and the method comprises:

In the external power supply mode, controlling the first switch to close, and the fixed end of the second switch is connected to the second selection end of the second switch;

In the battery power supply mode, the first switch is controlled to be turned off, and the fixed end of the second switch is connected to the first selection end of the second switch.
A method for controlling a three-arm topology device, characterized in that the method is used to control the three-arm topology device according to claim 32, and the method comprises:

In the external power supply mode, the first switch is controlled to be closed, the fixed end of the second switch is connected to the second selection end of the second switch, and the voltage between the bus bar and the voltage conversion circuit of the three-leg topology device When the difference is less than or equal to the preset threshold, control the third switch to close;

In the battery power supply mode, the third switch and the first switch are controlled to be turned off, and the fixed end of the second switch is connected to the first selection end of the second switch.
A method for controlling a three-arm topology device, wherein the method is used to control the three-arm topology device according to claim 33, and the method comprises:

In the external power supply mode, control the first switch to open, and the second switch and the third switch to close;

In the battery power supply mode, the first switch is controlled to be closed, and the second switch and the third switch are opened.
A method for controlling a three-arm topology device, wherein the method is used to control the three-arm topology device according to claim 34, and the method comprises:

In the external power supply mode, the first switch is controlled to open, the second switch and the third switch are closed, and when the voltage difference between the bus and the voltage conversion circuit of the three-leg topology device is less than or equal to the preset threshold , Control the fourth switch to close;

In the battery power supply mode, the first switch is controlled to be closed, and the second switch, the third switch and the fourth switch are opened.
A method for controlling a three-arm topology device, characterized in that the method is used to control the three-arm topology device according to any one of claims 18-27, and the method comprises:

In the first stage of the external power supply mode, control the second switching tube, the fourth switching tube, the fifth switching tube, and the eleventh switching tube to turn on;

In the second stage of the external power supply mode, controlling the second switching tube, the fourth switching tube, the fifth switching tube, and the twelfth switching tube to conduct;

In the third stage of the external power supply mode, controlling the fourth switching tube, the fifth switching tube, and the eleventh switching tube to be turned on;

In the fourth stage of the external power supply mode, controlling the fourth switching tube, the fifth switching tube, and the twelfth switching tube to be turned on;

In the fifth stage of the external power supply mode, controlling the second switching tube, the fourth switching tube, the sixth switching tube, and the eleventh switching tube to be turned on;

In the sixth stage of the external power supply mode, controlling the second switching tube, the fourth switching tube, the sixth switching tube, and the twelfth switching tube to be turned on;

In the seventh stage of the external power supply mode, controlling the fourth switching tube, the sixth switching tube, and the eleventh switching tube to be turned on;

In the eighth stage of the external power supply mode, controlling the fourth switching tube, the sixth switching tube, and the twelfth switching tube to be turned on;

In the ninth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the sixth switching tube, and the twelfth switching tube to turn on;

In the tenth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the sixth switching tube, and the eleventh switch to conduct;

In the eleventh stage of the external power supply mode, controlling the third switching tube, the sixth switching tube, and the twelfth switching tube to be turned on;

In the twelfth stage of the external power supply mode, controlling the third switching tube, the sixth switching tube, and the eleventh switching tube to be turned on;

In the thirteenth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the fifth switching tube, and the twelfth switching tube to be turned on;

In the fourteenth stage of the external power supply mode, controlling the first switching tube, the third switching tube, the fifth switching tube, and the eleventh switching tube to be turned on;

In the fifteenth stage of the external power supply mode, controlling the third switching tube, the fifth switching tube, and the twelfth switching tube to be turned on;

In the sixteenth stage of the external power supply mode, controlling the third switching tube, the fifth switching tube, and the eleventh switching tube to be turned on;

In the first stage of the battery power supply mode, controlling the fourth switching tube, the fifth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to conduct;

In the second stage of the battery power supply mode, controlling the fourth switching tube, the fifth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube to be turned on;

In the third stage of the battery power supply mode, controlling the fourth switching tube, the sixth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to conduct;

In the fourth stage of the battery power supply mode, controlling the fourth switching tube, the sixth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube to conduct;

In the fifth stage of the battery power supply mode, controlling the third switching tube, the sixth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to be turned on;

In the sixth stage of the battery power supply mode, controlling the third switching tube, the sixth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube to be turned on;

In the seventh stage of the battery power supply mode, controlling the third switching tube, the fifth switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to be turned on;

In the eighth stage of the battery power supply mode, the third switching tube, the fifth switching tube, the eighth switching tube, the ninth switching tube, and the eleventh switching tube are controlled to be turned on.
A three-leg topology device, characterized in that the three-leg topology device includes: a battery pack, a voltage conversion circuit, and a three-leg circuit;

The three bridge arm circuit includes: a first bridge arm, a second bridge arm, a third bridge arm, a DC bus capacitor, and a filter;

The first bridge arm includes a first switch tube and a second switch tube connected in series;

The second bridge arm includes a third switch tube and a fourth switch tube connected in series;

The third bridge arm includes a fifth switch tube and a sixth switch tube connected in series;

The first bridge arm, the second bridge arm, the third bridge arm and the DC bus capacitor are connected in parallel between the positive output end of the bus and the negative output end of the bus; the midpoint of the second bridge arm And the midpoint of the third bridge arm are both connected to the filter;

The positive electrode of the battery pack is connected to the first end of the voltage conversion circuit, the negative electrode of the battery pack is connected to the second end of the voltage conversion circuit, and the third and fourth ends of the voltage conversion circuit are both connected. Connected to the three-leg circuit, the filter is provided with a first external connection terminal of the three-leg topology device and a second external connection terminal of the three-leg topology device, and is connected to the load in the battery power supply mode connect;

The voltage conversion circuit discharges the battery pack in the battery power supply mode.
The device according to claim 48, wherein the voltage conversion circuit comprises: a first voltage conversion unit, a transformer, and an LC resonant cavity; the LC resonant cavity comprises: a fifth inductor and a third capacitor;

Wherein, the first voltage conversion unit is connected to the low voltage side of the transformer, and the high voltage side of the transformer is connected to the resonant cavity.
The device according to claim 49, wherein the first voltage conversion unit comprises: a fourth bridge arm and a fifth bridge arm; the fourth bridge arm comprises: a seventh switch tube and an eighth switch tube; The fifth bridge arm includes a ninth switch tube and a tenth switch tube;

The first end of the seventh switch tube is connected to the first end of the eighth switch tube, the first end of the ninth switch tube is connected to the first end of the tenth switch tube, and the seventh The second end of the switching tube is connected to the second end of the ninth switching tube, and the second end of the eighth switching tube is connected to the second end of the tenth switching tube;

The midpoint of the fourth bridge arm is connected to the opposite end of the low voltage side of the transformer, and the midpoint of the fifth bridge arm is connected to the same end of the low voltage side of the transformer;

The second terminal of the seventh switch tube is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube is the second terminal of the voltage conversion circuit.
The device according to claim 49, wherein the first voltage conversion unit comprises: a seventh switch tube and an eighth switch tube;

The first end of the seventh switch tube is connected to the first end of the transformer low-voltage side with the same name, the first end of the eighth switch tube is connected to the different end of the low-voltage side of the transformer, and the seventh switch The second end of the tube is connected to the second end of the eighth switch tube;

The second end of the seventh switch tube is the second end of the voltage conversion circuit.
The device according to claim 51, wherein the second terminal with the same name on the low-voltage side of the transformer is the first terminal of the voltage conversion circuit;

Alternatively, the first voltage conversion unit further includes: a ninth switch tube; a first end of the ninth switch tube is connected to a second end of the same name on the low-voltage side of the transformer, and a second end of the ninth switch tube Is the first terminal of the voltage conversion circuit.
The device of claim 49, wherein the first voltage conversion unit comprises: a fourth bridge arm, a fifth bridge arm, and a fourth capacitor;

The fourth bridge arm includes: a seventh switching tube and an eighth switching tube; the fifth bridge arm includes a ninth switching tube and a tenth switching tube; the first end of the seventh switching tube is connected to the eighth switching tube. The first end of the switching tube is connected, and the first end of the ninth switching tube is connected to the first end of the tenth switching tube;

The second end of the seventh switch tube is connected to the first synonymous end of the low-voltage side of the transformer, and the second end of the eighth switch tube is connected to the second synonymous end of the low-voltage side of the transformer. The second terminal of the ninth switch tube and the first terminal of the fourth capacitor are both connected to the first terminal with the same name on the low-voltage side of the transformer. The second terminal of the tenth switch tube and the first terminal of the fourth capacitor are Both ends are connected to the second end of the same name on the low-voltage side of the transformer, and the midpoint of the fourth bridge arm is connected to the midpoint of the fifth bridge arm;

The second terminal of the seventh switch tube is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube is the second terminal of the voltage conversion circuit.
The device according to claim 49, wherein the battery pack comprises a first battery sub-group and a second battery sub-group connected in series, and the negative electrode of the first battery sub-group is connected to the positive electrode of the second battery sub-group, The positive electrode of the first battery subgroup is the positive electrode of the battery group, and the negative electrode of the second battery subgroup is the negative electrode of the battery group;

The first voltage conversion unit includes: a fourth bridge arm, the fourth bridge arm includes: a seventh switching tube and an eighth switching tube; the first end of the seventh switching tube is connected to the eighth switching tube The first end connection;

The negative electrode of the first battery sub-group is connected to the opposite end of the low voltage side of the transformer, and the midpoint of the fourth bridge arm is connected to the same end of the low voltage side of the transformer;

The second terminal of the seventh switch tube is the first terminal of the voltage conversion circuit, and the second terminal of the eighth switch tube is the second terminal of the voltage conversion circuit.
The device according to any one of claims 49-54, wherein the voltage conversion circuit comprises: a second voltage conversion unit, and the second voltage conversion unit comprises: a sixth bridge arm; and the sixth bridge The arm includes: the eleventh switch tube and the twelfth switch tube;

The first terminal of the eleventh switch tube is connected to the first terminal of the twelfth switch tube, the second terminal of the eleventh switch tube is the third terminal of the voltage conversion circuit, and the first terminal The second end of the twelve switch tube is the fourth end of the voltage conversion circuit; the third end of the voltage conversion circuit is connected to the positive output end of the bus, and the fourth end of the voltage conversion circuit is connected to the bus Negative output terminal connection;

The voltage conversion circuit further includes a fifth terminal, and the fifth terminal of the voltage conversion circuit is connected to the midpoint of the first bridge arm.
The device according to claim 55, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the second end of the sixth bridge arm. Mid-point connection, the different-named end of the high-voltage side of the transformer is connected to the first end of the third capacitor;

The second terminal of the third capacitor is the fifth terminal of the voltage conversion circuit.
The device according to claim 55, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the sixth bridge arm. Mid-point connection, the different-named end of the high-voltage side of the transformer is connected to the first end of the fifth inductor;

The second terminal of the fifth inductor is the fifth terminal of the voltage conversion circuit.
The device according to claim 55, wherein the end with the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the first end of the fifth inductor. One end is connected, and the second end of the fifth inductor is connected to the midpoint of the sixth bridge arm;

The synonymous terminal on the high voltage side of the transformer is the fifth terminal of the voltage conversion circuit.
The device according to claim 55, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the first end of the third capacitor. One end is connected, and the second end of the third capacitor is connected to the midpoint of the sixth bridge arm;

The synonymous terminal on the high voltage side of the transformer is the fifth terminal of the voltage conversion circuit.
The device according to claim 55, wherein the end of the same name on the high voltage side of the transformer is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high voltage side of the transformer is connected to the second end of the third capacitor. One end is connected, and the second end of the third capacitor is connected to the first end of the fifth inductor;

The second terminal of the fifth inductor is the fifth terminal of the voltage conversion circuit.
The device according to claim 55, wherein the end of the same name on the high-voltage side of the transformer is connected to the midpoint of the sixth bridge arm, and the end of the same name on the high-voltage side of the transformer is connected to the first end of the fifth inductor. One end is connected, and the second end of the fifth inductor is connected to the first end of the third capacitor;

The second terminal of the third capacitor is the fifth terminal of the voltage conversion circuit.
The device according to any one of claims 49-54, wherein the second voltage conversion unit comprises: a sixth bridge arm; the sixth bridge arm comprises: an eleventh switch tube and a twelfth switch Tube;

The first end of the eleventh switch tube is connected to the first end of the twelfth switch tube, and the second end of the eleventh switch tube is connected to the first synonymous end of the high voltage side of the transformer, The second end of the twelfth switch tube is connected to the second synonymous end of the high voltage side of the transformer;

The first terminal with the same name on the high voltage side of the transformer is the third terminal of the voltage conversion circuit, the second terminal with the same name on the high voltage side of the transformer is the fourth terminal of the voltage conversion circuit; the third terminal of the voltage conversion circuit Terminal is connected to the positive output terminal of the bus, and the fourth terminal of the voltage conversion circuit is connected to the negative output terminal of the bus;

The voltage conversion circuit further includes a fifth terminal, and the fifth terminal of the voltage conversion circuit is connected to the midpoint of the first bridge arm.
The device of claim 62, wherein the midpoint of the sixth bridge arm is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the first end of the third capacitor. End connection

The second terminal of the third capacitor is the fifth terminal of the voltage conversion circuit.
The device of claim 62, wherein the midpoint of the sixth bridge arm is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the fifth inductor. The first end connection;

The second terminal of the fifth inductor is the fifth terminal of the voltage conversion circuit.
The device according to any one of claims 49-54, wherein the third end of the voltage conversion circuit is connected to the midpoint of the first bridge arm, and the fourth end of the voltage conversion circuit is connected to the midpoint of the first bridge arm. The midpoint of the second bridge arm is connected.
The device according to claim 65, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor. One end connected

The second terminal of the fifth inductor is the third terminal of the voltage conversion circuit, and the second terminal of the third capacitor is the fourth terminal of the voltage conversion circuit.
The device according to claim 65, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor. One end connected

The second terminal of the third capacitor is the third terminal of the voltage conversion circuit, and the second terminal of the fifth inductor is the fourth terminal of the voltage conversion circuit.
The device according to claim 65, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the first end of the fifth inductor. One end connected

The second terminal of the fifth inductor is the third terminal of the voltage conversion circuit, and the synonymous terminal of the high voltage side of the transformer is the fourth terminal of the voltage conversion circuit.
The device according to claim 65, wherein the end of the same name on the high voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the first end of the third capacitor. One end connected

The second terminal of the third capacitor is the third terminal of the voltage conversion circuit, and the synonymous terminal of the high voltage side of the transformer is the fourth terminal of the voltage conversion circuit.
The device according to claim 65, wherein the different-named end of the high-voltage side of the transformer is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the fifth inductor. The first end connection;

The terminal with the same name on the high voltage side of the transformer is the third terminal of the voltage conversion circuit, and the second terminal of the fifth inductor is the fourth terminal of the voltage conversion circuit.
The device according to claim 65, wherein the different-named end of the high-voltage side of the transformer is connected to the first end of the fifth inductor, and the second end of the fifth inductor is connected to the second end of the third capacitor. The first end connection;

The terminal with the same name on the high voltage side of the transformer is the third terminal of the voltage conversion circuit, and the second terminal of the third capacitor is the fourth terminal of the voltage conversion circuit.
The device according to claim 65, wherein the second end of the first switch tube is connected to the first synonymous end of the high voltage side of the transformer, and the second end of the second switch tube is connected to the The second synonymous end of the high-voltage side of the transformer is connected;

The first end of the same name on the high voltage side of the transformer is connected to the positive output end of the bus, and the second end of the same name on the high voltage side of the transformer is connected to the negative output end of the bus;

The first terminal of the fifth inductor is the third terminal of the voltage conversion circuit, the second terminal of the fifth inductor is connected to the first terminal of the third capacitor, and the second terminal of the third capacitor is Is the fourth terminal of the voltage conversion circuit; or, the first terminal of the third capacitor is the third terminal of the voltage conversion circuit, and the second terminal of the third capacitor is connected to the second terminal of the fifth inductor. One end is connected, and the second end of the fifth inductor is the fourth end of the voltage conversion circuit.
The device according to any one of claims 65-72, wherein the first switch tube and the second switch tube are both diodes.
The device according to any one of claims 48-72, wherein the first external connection terminal and the second external connection terminal are connected to an external power supply in the battery charging mode;

The voltage conversion circuit is also used to charge the battery pack in the battery charging mode.
The device according to any one of claims 48-74, wherein the filter comprises: a second inductor and a first capacitor; and the first end of the first capacitor is of the three-leg topology device A first external connection terminal, and a second terminal of the first capacitor is a second external connection terminal of the three-leg topology device;

The midpoint of the third bridge arm is connected to the first end of the second inductor, the second end of the second inductor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the Connected to the midpoint of the second bridge arm;

Alternatively, the midpoint of the second bridge arm is connected to the first end of the second inductor, and the second end of the second inductor is connected to the second end of the first capacitor. The first end is connected with the midpoint of the third bridge arm.
The device according to any one of claims 48-74, wherein the filter comprises: a second inductor, a first capacitor, and a fourth inductor;

The midpoint of the third bridge arm is connected to the first end of the second inductor, the second end of the second inductor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the Terminal is connected to the first terminal of the fourth inductor, and the second terminal of the fourth inductor is connected to the midpoint of the second bridge arm;

The first terminal of the first capacitor is the first external connection terminal of the three-leg topology device, and the second terminal of the first capacitor is the second external connection terminal of the three-leg topology device.
An inverter system, characterized in that the system includes a load, and the three-leg topology device according to any one of claims 48 to 76;

In the battery power supply mode, the first external connection terminal and the second external connection terminal of the three-arm topology device are both connected to the load.
The system according to claim 77, wherein the system further comprises: an external power supply; in the battery charging mode, the first external connection terminal and the second external connection terminal of the three-leg topology device are both connected to The external power supply is connected.
A method for controlling a three-arm topology device, wherein the method is used to control the three-arm topology device according to any one of claims 55-64, and the method comprises:

In the first stage of the battery power supply mode, control the second switch tube, the eighth switch tube, the ninth switch tube, and the eleventh switch tube to turn on;

In the second stage of the battery power supply mode, controlling the first switching tube, the seventh switching tube, the tenth switching tube, and the twelfth switching tube to be turned on;

In the first stage of the battery charging mode, controlling the second switching tube and the eleventh switching tube to be turned on;

In the second stage of the battery charging mode, the first switching tube and the twelfth switching tube are controlled to be turned on.
A method for controlling a three-arm topology device, characterized in that the method is used to control the three-arm topology device according to any one of claims 65-72, and the method comprises:

In the first stage of the battery power supply mode, control the second switching tube, the fourth switching tube, the fifth switching tube, the seventh switching tube, and the tenth switching tube to conduct;

In the second stage of the battery power supply mode, controlling the first switching tube, the fourth switching tube, the fifth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the third stage of the battery power supply mode, controlling the second switching tube, the fourth switching tube, the sixth switching tube, the seventh switching tube, and the tenth switching tube to conduct;

In the fourth stage of the battery power supply mode, controlling the first switching tube, the fourth switching tube, the sixth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the fifth stage of the battery power supply mode, controlling the first switching tube, the third switching tube, the sixth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the sixth stage of the battery power supply mode, the first switching tube, the second switching tube, the third switching tube, the sixth switching tube, the seventh switching tube, and the tenth switching tube are controlled Tube conduction;

In the seventh stage of the battery power supply mode, controlling the first switching tube, the third switching tube, the fifth switching tube, the eighth switching tube, and the ninth switching tube to conduct;

In the eighth stage of the battery power supply mode, the first switching tube, the second switching tube, the third switching tube, the fifth switching tube, the seventh switching tube, and the first switching tube are controlled. Ten switch tube is turned on;

In the first stage of the battery charging mode, controlling the first switching tube, the fourth switching tube, and the sixth switching tube to conduct;

In the second stage of the battery charging mode, controlling the second switching tube, the fourth switching tube, and the sixth switching tube to conduct;

In the third stage of the battery charging mode, controlling the first switching tube, the fourth switching tube, and the fifth switching tube to conduct;

In the fourth stage of the battery charging mode, controlling the second switching tube, the fourth switching tube, and the fifth switching tube to conduct;

In the fifth stage of the battery charging mode, controlling the second switching tube, the third switching tube, and the fifth switching tube to conduct;

In the sixth stage of the battery charging mode, controlling the first switching tube, the third switching tube, and the fifth switching tube to conduct;

In the seventh stage of the battery charging mode, controlling the second switching tube, the third switching tube, and the sixth switching tube to conduct;

In the eighth stage of the battery charging mode, the first switching tube, the third switching tube, and the sixth switching tube are controlled to be turned on.