CN220359030U

CN220359030U - Precharge circuit, power conversion device, and electronic apparatus

Info

Publication number: CN220359030U
Application number: CN202321686322.7U
Authority: CN
Inventors: 童文平; 黑超; 吴东; 陈熙; 王雷
Original assignee: Ecoflow Technology Ltd
Current assignee: Ecoflow Technology Ltd
Priority date: 2023-06-29
Filing date: 2023-06-29
Publication date: 2024-01-16
Anticipated expiration: 2033-06-29

Abstract

The utility model relates to the technical field of electronics, a precharge circuit, power conversion equipment and electronic equipment is provided, precharge circuit has set up the charging route of many adaptation different charging voltages, detects the size of input voltage through detection circuit, and gating circuit is according to the charging route output gating signal of the size of this output voltage of input voltage to the adaptation for this charging route switches on in order to charge for power module's busbar electric capacity based on input voltage. Therefore, corresponding pre-charging circuits are not required to be arranged for different input voltages, so that the circuit structure is simple, and the cost is reduced.

Description

Precharge circuit, power conversion device, and electronic apparatus

Technical Field

The application belongs to the technical field of electronics, and particularly relates to a precharge circuit, a power conversion device and electronic equipment.

Background

In a device with multiple inputs, a corresponding precharge circuit is usually required to be arranged on each input, and the precharge circuit is used for precharging voltages at two ends of a capacitor on a power supply bus to a preset voltage so as to avoid damage to the device caused by large current in a starting process, but in the related art, different precharge circuits are required to be designed for different input voltages, so that the circuit structure is complex and the cost is high.

Disclosure of Invention

The purpose of the application is to provide a precharge circuit, a power conversion device and an electronic device, and aims to solve the problems that different precharge circuits are required to be designed aiming at different input voltages, so that the circuit structure is complex and the cost is high.

In a first aspect, embodiments of the present application provide a precharge circuit connected to an input interface of a power circuit and a bus capacitor, the bus capacitor including a first bus capacitor and a second bus capacitor connected in series between positive and negative dc buses of the power circuit, the precharge circuit including:

the detection circuit is connected with the input interface and used for detecting the input voltage of the input interface;

the charging circuit is provided with a plurality of on-off charging paths which are applicable to different charging voltages, each charging path is connected between the input interface and the bus capacitor, and each charging path is used for being conducted under the drive of a gating signal so as to charge the bus capacitor based on the input voltage;

and the gating circuit is connected with the detection circuit and the charging circuit and is used for outputting the gating signal to the corresponding charging path according to the magnitude of the input voltage.

In some embodiments, the charging circuit comprises:

a first charging path connected with the input interface, the positive and negative direct current buses and a series node of the first bus capacitor and the second bus capacitor respectively, and used for conducting when the input voltage is in a first voltage range, and charging the first bus capacitor or the second bus capacitor based on the input voltage;

and the second charging path is respectively connected with the input interface and the positive and negative direct current buses and is used for conducting under the condition that the input voltage is in a second voltage range, and charging the bus capacitance between the positive and negative direct current buses based on the input voltage.

In some embodiments, the first charging path is configured to charge the first bus capacitor based on the input voltage if the input voltage is in a positive half-cycle, and to charge the second bus capacitor based on the input voltage if the input voltage is in a negative half-cycle;

the second charging path is used for simultaneously charging the first bus capacitor and the second bus capacitor based on the input voltage.

In some embodiments, the charging circuit includes a first switch assembly and a full bridge circuit, the full bridge circuit having a first input, a second input, and two outputs respectively connected to the positive and negative dc buses, the first switch assembly respectively connected to the input interface, the first input, the second input, and a series node of the first bus capacitor and the second bus capacitor; the first switch assembly is used for being partially conducted under the drive of a gating signal and forming the charging path through the full-bridge circuit.

In some embodiments, the first switch assembly comprises:

the first switch group is provided with a first switch and a second switch which are synchronously switched on and off, the first switch is connected between a first terminal of the input interface and the first input end, the first end of the second switch is connected with a second terminal of the input interface, and the second end of the second switch is connected with a series node of the first bus capacitor and the second bus capacitor;

the second switch group is provided with a third switch and a fourth switch which are synchronously switched on and off, the third switch is connected between the first terminal of the input interface and the first input end, and the fourth switch is connected between the second terminal of the input interface and the second input end.

In some embodiments, the charging circuit comprises a second switching assembly connected between the input interface and the power circuit, the second switching assembly being for gating the input voltage to the or each charging path.

In some embodiments, the input interface includes the first terminal, the second terminal, and a ground terminal for ground, the second switch assembly includes:

the third switch group is provided with a fifth switch and a sixth switch which are synchronously switched on and off;

the fourth switch group is provided with a seventh switch and an eighth switch which are synchronously switched on and off;

a fifth switch group, which is provided with a ninth switch and a tenth switch which are synchronously switched on and off; and

a sixth switch group, which is provided with an eleventh switch and a twelfth switch which are synchronously switched on and off;

wherein the fifth switch and the seventh switch Guan Chuanlian are between the second terminal and a zero line end of the power circuit, a first end of the second switch being connected to a series node of the fifth switch and the seventh switch; the sixth switch and the eighth switch Guan Chuanlian are between the first terminal and a first hot terminal of the power circuit, the first terminal of the first switch being connected to a series node of the sixth switch and the eighth switch; the ninth switch and the eleventh switch are connected in series between the first terminal and a first live end of the power circuit, and a first end of the third switch is connected with a series node of the ninth switch and the eleventh switch; the tenth switch and the twelfth switch are connected in series between the second terminal and the second live wire end of the power circuit, and the first end of the fourth switch is connected with a series node of the tenth switch and the twelfth switch.

In some embodiments, the input interface includes the first terminal, the second terminal, a neutral terminal, and a ground terminal for ground, the second switch assembly includes a thirteenth switch, a fourteenth switch, a fifteenth switch, a sixteenth switch, a seventeenth switch, an eighteenth switch, a nineteenth switch, and a twentieth switch;

wherein the thirteenth switch and the fourteenth switch are connected in series between the first terminal and a first live wire end of the power circuit, and a first end of the first switch and a first end of the third switch are connected with a series node of the thirteenth switch and the fourteenth switch; the fifteenth switch and the sixteenth switch are connected in series between the second terminal and a second live wire end of the power circuit, and a first end of the fourth switch is connected with a series node of the fifteenth switch and the sixteenth switch; the seventeenth switch and the eighteenth switch are connected in series between the second terminal and a zero line end of the power circuit, and a first end of the second switch is connected with a series node of the seventeenth switch and the eighteenth switch; the nineteenth switch and the twentieth switch are connected in series between the neutral terminal and a neutral terminal of the power circuit.

In a second aspect, embodiments of the present application provide a power conversion device including a power circuit having an input interface and a bus capacitor including a first bus capacitor and a second bus capacitor connected in series between positive and negative dc buses of the power circuit, the power conversion device further including a precharge circuit as described above.

In a third aspect, embodiments of the present application provide an electronic device including a precharge circuit as described above, or a power conversion apparatus as described above.

Compared with the traditional technology, the embodiment of the application has the beneficial effects that: the precharge circuit, the power conversion device and the electronic equipment are provided with a plurality of charging paths adapting to different charging voltages, the detection circuit is used for detecting the magnitude of the input voltage, and the gating circuit outputs gating signals to the charging paths adapting to the magnitude of the output voltage according to the magnitude of the input voltage, so that the charging paths are conducted to charge the bus capacitors of the power module based on the input voltage, and therefore, the corresponding precharge circuits are not required to be arranged for different input voltages, the circuit structure is simple, and the cost is reduced.

Drawings

FIG. 1 is a schematic block diagram of a precharge circuit according to an embodiment of the present disclosure;

FIG. 2 is a circuit diagram of a first embodiment of the precharge circuit shown in FIG. 1;

fig. 3 is a circuit diagram of a second embodiment of the precharge circuit shown in fig. 1.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved by the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Referring to fig. 1, an embodiment of the present application provides a precharge circuit, which is connected to an input interface 101 of a power circuit 100 and a bus capacitor. The power circuit 100 is, for example, an AC-DC converter having an AC-DC converting function and a DC-AC converting function. The BUS capacitance includes a first BUS capacitance C1 and a second BUS capacitance C2 connected in series between positive and negative DC buses BUS+/BUS of the power circuit 100, and the precharge circuit includes a detection circuit 210, a charging circuit 220, and a gating circuit 230.

The detection circuit 210 is connected to the input interface 101, and is configured to detect a magnitude of an input voltage Vin of the input interface 101; the charging circuit 220 has a plurality of switchable charging paths #1 … … #n adapted to different charging voltages, each charging path #1 … … #n is connected between the input interface 101 and the bus capacitors C1, C2, and each charging path #1 … … #n is used for being turned on under the driving of the strobe signal to charge the bus capacitors C1, C2 based on the input voltage Vin; the gate circuit 230 is connected to the detection circuit 210 and the charging circuit 220, and outputs a gate signal to the corresponding charging path #1 … … #n according to the magnitude of the input voltage Vin.

The detection circuit 210 may be implemented in the form of a voltage division network, and divides the input voltage Vin to obtain a voltage component, and the voltage component is sent to the gate circuit 230, where the gate circuit 230 may be implemented by, for example, a controller, and performs analog-to-digital conversion according to the voltage component, so as to determine the magnitude of the input voltage Vin. Since the charging circuit 220 has the charging paths #1 … … #n capable of adapting to different charging voltages, when the input voltage Vin is inputted to the charging circuit 220 as the charging voltage, the gate circuit 230 may select the charging path adapted to the magnitude of the input voltage Vin to output the gate signal according to the magnitude of the determined input voltage Vin, and turn on the charging paths to charge the bus capacitors C1 and C2 of the power circuit 100 based on the input voltage Vin. Therefore, corresponding pre-charging circuits are not required to be arranged for different input voltages Vin, so that the circuit structure is simple, and the cost is reduced.

Referring to fig. 2 and 3, in some embodiments, the charging circuit 220 includes: a first charging path #1 and a second charging path #2. The first charging path #1 is connected to the input interface 101, the positive and negative dc BUS bus+/BUS-, and the serial node of the first BUS capacitor C1 and the second BUS capacitor C2, respectively, for conducting in the first voltage range of the input voltage Vin, and charging the BUS capacitor C1 or the BUS capacitor C2 based on the input voltage Vin. The second charging path #2 is connected to the input interface 101 and the positive and negative dc BUS bus+/BUS, respectively, for conducting when the input voltage Vin is within the second voltage range, and charging the BUS capacitors C1, C2 based on the input voltage Vin.

In one example, a maximum boundary value of the first voltage range is less than a minimum boundary value of the second voltage range. Therefore, in the case where the input voltage Vin is within the first voltage range, the charging power provided by the input voltage Vin is low, and thus the first charging path #1 is configured to alternately charge the first bus capacitor C1 and the second bus capacitor C2 based on the input voltage Vin, and the alternate transition timing may be a transition timing of the input voltage Vin of alternating current between the positive half cycle and the negative half cycle.

In one embodiment, the first charging path #1 charges the first bus capacitor C1 based on the input voltage Vin in a case where the input voltage Vin is in a positive half cycle, and charges the second bus capacitor C2 based on the input voltage Vin in a case where the input voltage Vin is in a negative half cycle. So that the charging circuit 220 can be adapted to a low charging voltage while being able to precharge the first bus capacitor C1 and the second bus capacitor C2, respectively.

And in the case where the input voltage Vin is within the second voltage range, the charging power provided by the input voltage Vin is high, so that the second charging path #2 can charge the first bus capacitor C1 and the second bus capacitor C2 at the same time based on the input voltage Vin. So that the charging circuit 220 can be adapted to a higher charging voltage while being able to precharge the first bus capacitor C1 and the second bus capacitor C2.

Referring to fig. 2, in some embodiments, the charging circuit 220 includes a first switch component 221 and a full-bridge circuit BR, the full-bridge circuit BR has a first input terminal, a second input terminal, and two output terminals connected to positive and negative dc BUS +/BUS-, respectively, that is, the two output terminals are also connected to a first BUS capacitor C1 and a second BUS capacitor C2, the first switch component 221 is connected to the input interface 101, the first input terminal of the full-bridge circuit BR, the second input terminal of the full-bridge circuit BR, and the series node of the first BUS capacitor C1 and the second BUS capacitor C2; the first switching element 221 is used to be partially turned on by the gate signal and form a charging path #1 … … #n through the full-bridge circuit BR.

In this embodiment, the charging circuit 220 is configured to access the input voltage Vin of the input interface 101 through the first switch component 221, and control the conduction of different portions of the first switch component 22 through different gate signals of the gate circuit 230, so that the full-bridge circuit BR accesses the input voltage Vin through different input ports, thereby forming different paths, i.e. charging paths # … … #n, and then provides the charging voltage to the first bus capacitor C1 and the second bus capacitor C2 for charging in different output modes.

Referring to fig. 2 and 3, in some embodiments, the first switching assembly 221 includes: a first switch group RLY5 and a second switch group RLY6.

The first switch group RLY5 has a first switch S1 and a second switch S2 that are synchronously turned on and off, the first switch S1 is connected between the first terminal L1 of the input interface 101 and the first input end of the full-bridge circuit BR, the first end of the second switch S2 is connected to the second terminal L2/N of the input interface 101, and the second end of the second switch S2 is connected to the series node of the first bus capacitor C1 and the second bus capacitor C2. In this embodiment, the first switch group rliy 5 is used for controlling the on/off of the first charging path 1 #. In one example, the first switch S1 and the second switch S2 of the first switch group RLY5 are respectively two normally open contacts of the relay, and the gating circuit 230 may enable the first switch S1 and the second switch S2 to be closed at the same time by powering up the coil that drives the relay.

The second switch group RLY6 has a third switch S3 and a fourth switch S4 that are synchronously turned on and off, the third switch S3 is connected between the first terminal L1 of the input interface 101 and the first input terminal of the full-bridge circuit BR, and the fourth switch S4 is connected between the second terminal L2/N of the input interface 101 and the second input terminal of the full-bridge circuit BR. In this embodiment, the second switch group rli 6 is used for controlling the on/off of the second charging path 2 #. In one example, the third switch S3 and the fourth switch S4 of the second switch group RLY6 are respectively two normally open contacts of the relay, and the gating circuit 230 may enable the third switch S3 and the fourth switch S4 to be closed at the same time by powering up the coil that drives the relay.

Referring to fig. 2, in some embodiments, the charging circuit 220 includes a second switching component 222, the second switching component 222 is connected between the input interface 101 and the power circuit 100, and the second switching component 222 is used to gate the input voltage Vin to the power circuit 100 or each charging path #1 … … #n.

For the safety requirements of alternating current, the terminal which can be touched by hands needs to meet the electric gap of 3.5mm, and the electric gap of the relay is 1.8mm currently, so that electric equipment such as a power conversion device, an energy storage device and the like needs to be connected with two relays in series at the input interface 101 to meet the requirements of the electric gap. In addition, the non-isolated inverter isolation is to consider the single point fault condition, consider relay adhesion, and therefore also use redundant relay design (at least two, for example, when one relay fails and adheres, and causes relay control failure, the other relay can still control circuit disconnection, which can make the circuit safer). Meanwhile, considering the failure of a relay control circuit, at least two controllers are required to independently control redundant relays, for example, a first relay in the relays with redundant design is controlled by a first controller, and a second relay is controlled by a second controller, so that when the first relay is adhered, the second controller can effectively control the second relay.

In this embodiment, the second switch assembly 222 includes at least two relays, and the gate circuit 230 includes the first controller and the second controller. Specifically, each charging path #1 … … #n is a connection node connected between the at least two relays, so that the input voltage Vin can be gated to each charging path #1 … … #n by controlling the connection node to be closed with the relay of the input interface 101 and controlling the relay between the connection node and the power circuit 100 to be opened, thereby realizing the precharge; and the relay between the connection node and the power circuit 100 is controlled to be closed, and the gating circuit 230 does not output a gating signal, so that each charging path #1 … … #n is turned off, and the input voltage Vin can be gated to the power circuit 100, thereby realizing normal power supply.

Referring to fig. 2, in some embodiments, the input interface 101 includes a first terminal L1, a second terminal L2/N, and a ground terminal PE for grounding, and the second switch assembly 222 includes:

the third switch group PLY1 is provided with a fifth switch S5 and a sixth switch S6 which are synchronously switched on and off;

a fourth switch group RLY3, which is provided with a seventh switch S7 and an eighth switch S8 which are synchronously switched on and off;

a fifth switch group RLY2 having a ninth switch S9 and a tenth switch S10 that are synchronously turned on and off; and

a sixth switch group RLY4 having an eleventh switch S11 and a twelfth switch S12 that are synchronously turned on and off;

wherein the fifth switch S5 and the seventh switch S7 are connected in series between the second terminal L2/N and the zero line terminal N of the power circuit 100, and the first terminal of the second switch S2 is connected to a series node of the fifth switch S5 and the seventh switch S7; the sixth switch S6 and the eighth switch S8 are connected in series between the first terminal L1 of the input interface 101 and the first hot terminal L1 of the power circuit 100, and the first terminal of the first switch S1 is connected to a series node of the sixth switch S6 and the eighth switch S8; the ninth switch S9 and the eleventh switch S11 are connected in series between the first terminal L1 and the first hot terminal L1 of the power circuit 100, and the first terminal of the third switch S3 is connected to a series node of the ninth switch S9 and the eleventh switch S11; the tenth switch S10 and the twelfth switch S12 are connected in series between the second terminal L2/N and the second live terminal L2 of the power circuit 100, and the first terminal of the fourth switch S4 is connected to the series node of the tenth switch S10 and the twelfth switch S12.

In one example, the switches of each switch group rli 6 are respectively two normally open contacts of the relay, and the gating circuit 230 can enable the two normally open contacts to be closed at the same time by driving the coil of the relay to be electrified. The third switch group RLY1 and the fifth switch group RLY2 are controlled by the first controller of the gate circuit 230, and the fourth switch group RLY3, the sixth switch group RLY4, the first switch group RLY5, and the second switch group RLY6 are controlled by the second controller of the gate circuit 230. The input interface 101 is a C20 interface for receiving an ac input of about 120V or 240V.

When the input interface 101 is connected to 120V ac voltage, the first terminal L1 and the second terminal L2/N are connected by ac, where the first terminal L is a live wire, the second terminal L2/N is a zero line, and the adaptive charging voltage corresponds to the first voltage range: and 85V-145V, controlling the third switch group RLY1 to be closed, and controlling the first switch group RLY5 to be closed to precharge the busbar capacitors C1 and C2.

When the alternating current of the input voltage Vin is in a positive half cycle, the first bus capacitor C1 is precharged. When the alternating current of the input voltage Vin is in the negative half cycle, the capacitor C2 on the second bus is precharged.

After detecting that the voltage on the bus capacitors C1, C2 is pre-charged to a preset voltage value (e.g. 240v×1.414), the first switch group rliy 5 is controlled to be opened, the fourth switch group rliy 3 is controlled to be closed, and at this time, the pre-charging is completed, and the power circuit 100 is started.

When the input interface 101 is connected to 240V, the first terminal L1 and the second terminal L2/N are connected by ac, and are live wires, the voltages are the same, the phases are opposite, and the adaptive charging voltage corresponds to the second voltage range: 170V-290V. The fifth switch group rle 2 is closed, the second switch group rle 6 is closed, the busbar capacitors C1 and C2 are precharged, at the same time, the first busbar capacitor C1 and the second busbar capacitor C2 are precharged, after the precharge is judged to be completed, the second switch group rle 6 is controlled to be opened, the sixth switch group rle 4 is closed, and the power circuit 100 is started.

In the above example, the input voltage is: vin <85v,145v < Vin <170v, vin >290v is not able to adapt the power supply range of the power circuit 100 or the charging voltage of the first bus capacitor C1 and the second bus capacitor C2, and therefore the gating circuit 230 controls all relays to be inactive.

Referring to fig. 3, in some embodiments, the input interface 101 includes a first terminal L1, a second terminal L2, a neutral terminal N, and a ground terminal PE for grounding, and the second switch assembly 222 includes a thirteenth switch K1, a fourteenth switch K5, a fifteenth switch K2, a sixteenth switch K6, a seventeenth switch K3, an eighteenth switch K7, a nineteenth switch K4, and a twentieth switch K8;

wherein the thirteenth switch K1 and the fourteenth switch K5 are connected in series between the first terminal L1 of the input interface 101 and the first fire line terminal L1 of the power circuit 100, and the first terminal of the first switch S1 and the first terminal of the third switch S3 are connected to a series node of the thirteenth switch K1 and the fourteenth switch K5; the fifteenth switch K2 and the sixteenth switch K6 are connected in series between the second terminal L2 and the second live terminal L2 of the power circuit 100, and the first terminal of the fourth switch S4 is connected to a series node of the fifteenth switch K2 and the sixteenth switch K6; the seventeenth switch K3 and the eighteenth switch K7 are connected in series between the second terminal L2 and the zero line terminal N of the power circuit 100, and the first terminal of the second switch S2 is connected to a series node of the seventeenth switch K3 and the eighteenth switch K7; the nineteenth switch K4 and the twentieth switch K8 are connected in series between the neutral terminal N and the neutral terminal N of the power circuit 100.

In one example, the switches are normally open contacts of the relay, and the gating circuit 230 may cause the normally open contacts to be closed simultaneously by powering up the coil of the relay. The thirteenth, fifteenth, seventeenth, and nineteenth switches K1, K2, K3, and K4 are controlled by the first controller of the gate circuit 230, and the fourteenth, sixteenth, eighteenth, and twentieth switches K5, K6, K7, K8, the first and second switch groups rliy 5, rliy 6 are controlled by the second controller of the gate circuit 230. The input interface 101 is a 5+8 interface for receiving an ac input of about 120V or 240V.

When the first terminal L1 and the second terminal L2 of the input interface 101 are connected with the low-voltage charging pile to access 120V voltage, the thirteenth switch K1, the seventeenth switch K3 and the first switch group rliy 5 are controlled to be closed, the busbar capacitors C1 and C2 are precharged, after the precharge is judged to be completed, the first switch group rliy 5 is controlled to be opened, the 2#mcu controls the fourteenth switch K5 and the eighteenth switch K7 to be closed, and the power circuit 100 starts to operate;

After detecting that the voltages on the bus capacitors C1 and C2 are pre-charged to the preset voltage value (e.g. 240v×1.414), the first switch group RLY5 is controlled to be opened, the fourteenth switch K5 and the eighteenth switch K7 are closed, and at this time, the pre-charging is completed, and the power circuit 100 is started.

When the first terminal L1 and the zero line terminal N of the input interface 101 are connected with 120V, the system prompts a fault and does not work as the scene does not have the working condition;

when the first terminal L1, the second terminal L2, and the neutral line terminal N of the input interface 101 are connected to a 240V voltage, such as a high-voltage charging pile, the north american parallel network split phase is connected to the first terminal L1 and the second terminal L2, the neutral line terminal N is not connected to the first switch K1, the fifteenth switch K2, the nineteenth switch K4, and the second switch group rli 6 are controlled to be closed, the busbar capacitors C1 and C2 are precharged, the second switch group rli 6 is controlled to be opened after the precharge is determined, the fourteenth switch K5, the sixteenth switch K6, and the twentieth switch K8 are controlled to be closed, and the main power circuit 100 starts to operate.

In one embodiment, when the precharge is determined to be completed, the detection circuit 210 may detect the voltages across the bus capacitors C1, C2 and output the detection results to the gate circuit 230 to implement the corresponding relay control after the precharge is completed.

In addition, the effect of precharging the bus bar capacitor will be described:

for example, in one example, the voltage of the bus capacitors C1, C2 is to be pre-charged to 1.414 times the input voltage Vin, for example, when the input voltage Vin is 240V, the voltage of the bus capacitors C1, C2 needs to be controlled to be 240v×1.414=340V, when the input voltage Vin is 120V, the voltage of the bus capacitors C1, C2 needs to be controlled to be 2×120v×1.414=340V, so when the input voltage Vin is 120V or 240V, the pre-charging circuit charges the bus capacitors to 240v×1.414 first, and then the power circuit 100 starts to operate.

In a second aspect, embodiments of the present application provide a power conversion device, including a power circuit 100, where the power circuit 100 has an input interface 101 and BUS capacitors C1, C2, where the BUS capacitors C1, C2 include a first BUS capacitor C1 and a second BUS capacitor C2 connected in series between positive and negative dc buses bus+/BUS of the power circuit 100, and the power conversion device further includes a precharge circuit 220 as above.

For example, when the power conversion device is used in a photovoltaic system, the power circuit 100 includes a boost circuit and an AC-DC circuit, and the bus capacitors C1 and C2 are connected between the boost circuit and the AC-DC circuit.

In a third aspect, embodiments of the present application provide an electronic device including the precharge circuit 220 described above, or the power conversion apparatus described above. The electronic device is for example an energy storage device.

Compared with the traditional technology, the embodiment of the application has the beneficial effects that: the precharge circuit 220, the power conversion device and the electronic device set a plurality of charging paths #1 … … #n adapted to different charging voltages, the detection circuit 210 detects the magnitude of the input voltage Vin, and the gating circuit 230 outputs a gating signal to the charging path #1 … … #n adapted to the magnitude of the output voltage according to the magnitude of the input voltage Vin, so that the charging path # … … #n is turned on to charge the bus capacitors C1, C2 of the power module based on the input voltage Vin.

The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims

1. A precharge circuit connected to an input interface of a power circuit and a bus capacitor comprising a first bus capacitor and a second bus capacitor connected in series between positive and negative dc buses of the power circuit, the precharge circuit comprising:

2. The precharge circuit of claim 1, wherein the charge circuit comprises:

a first charging path connected with the input interface, the positive and negative direct current buses and a series node of the first bus capacitor and the second bus capacitor respectively, and used for conducting under the condition that the input voltage is in a first voltage range, and charging the first bus capacitor or the second bus capacitor based on the input voltage;

3. The precharge circuit of claim 2, wherein:

the first charging path is used for charging the first bus capacitor based on the input voltage when the input voltage is in a positive half cycle, and charging the second bus capacitor based on the input voltage when the input voltage is in a negative half cycle;

4. A precharge circuit as claimed in any one of claims 1 to 3, wherein said charge circuit comprises a first switch assembly and a full bridge circuit, said full bridge circuit having a first input, a second input and two outputs respectively connected to said positive and negative dc bus bars, said first switch assembly being respectively connected to said input interface, said first input, said second input and a series node of said first bus capacitor and said second bus capacitor; the first switch assembly is used for being partially conducted under the drive of a gating signal and forming the charging path through the full-bridge circuit.

5. The precharge circuit of claim 4, wherein the first switch assembly comprises:

6. A pre-charge circuit as claimed in claim 5, wherein the charging circuit comprises a second switching assembly connected between the input interface and the power circuit, the second switching assembly being operable to gate the input voltage to the or each charging path.

7. The precharge circuit of claim 6, wherein the input interface comprises the first terminal, the second terminal, and a ground terminal for ground, the second switch assembly comprising:

wherein the fifth and seventh switches Guan Chuanlian are between the second terminal and a zero line end of the power circuit, a first end of the second switch being connected to a series node of the fifth and seventh switches; the sixth switch and the eighth switch Guan Chuanlian are between the first terminal and a first hot terminal of the power circuit, the first terminal of the first switch being connected to a series node of the sixth switch and the eighth switch; the ninth switch and the eleventh switch are connected in series between the first terminal and a first live end of the power circuit, and a first end of the third switch is connected to a series node of the ninth switch and the eleventh switch; the tenth switch and the twelfth switch are connected in series between the second terminal and a second live end of the power circuit, and a first end of the fourth switch is connected to a series node of the tenth switch and the twelfth switch.

8. The precharge circuit of claim 6, wherein the input interface comprises the first terminal, the second terminal, a zero line terminal, and a ground terminal for ground, the second switch assembly comprising a thirteenth switch, a fourteenth switch, a fifteenth switch, a sixteenth switch, a seventeenth switch, an eighteenth switch, a nineteenth switch, and a twentieth switch;

wherein the thirteenth switch and the fourteenth switch are connected in series between the first terminal and a first live end of the power circuit, and a first end of the first switch and a first end of the third switch are connected to a series node of the thirteenth switch and the fourteenth switch; the fifteenth switch and the sixteenth switch are connected in series between the second terminal and a second live end of the power circuit, and a first end of the fourth switch is connected to a series node of the fifteenth switch and the sixteenth switch; the seventeenth switch and the eighteenth switch are connected in series between the second terminal and a zero line end of the power circuit, and a first end of the second switch is connected to a series node of the seventeenth switch and the eighteenth switch; the nineteenth switch and the twentieth switch are connected in series between the neutral terminal and a neutral terminal of the power circuit.

9. A power conversion device comprising a power circuit having an input interface and a bus capacitor comprising a first bus capacitor and a second bus capacitor connected in series between positive and negative dc buses of the power circuit, the power conversion device further comprising a precharge circuit according to any one of claims 1 to 8.

10. An electronic device comprising a precharge circuit as claimed in any one of claims 1 to 8, or a power conversion apparatus as claimed in claim 9.