WO2016197976A1

WO2016197976A1 - Multi-level inverter topology circuit

Info

Publication number: WO2016197976A1
Application number: PCT/CN2016/085453
Authority: WO
Inventors: 汪洪亮
Original assignee: 汪洪亮
Priority date: 2015-06-12
Filing date: 2016-06-12
Publication date: 2016-12-15
Also published as: CN107925361B; CN107925361A

Abstract

Disclosed is a multi-level inverter topology circuit. Three-level and five-level inverter topology circuits can still operate normally under the condition where an alternating-current output end of an inverter part is connected to the cathode of a direct-current power supply via an alternating-current grid. Thus, a direct-current power supply can always keep a potential to ground greater than or equal to zero, thereby effectively inhibiting a PID effect; moreover, a high-frequency leakage current of an inverter topology can be eliminated completely.

Description

Multilevel inverter topology circuit

Cross-reference to related applications

The present application claims priority to US Provisional Patent Application No. 62/174,620, filed on Jun.

Technical field

The present application relates to multilevel inverter topology circuits, and more particularly to single phase, three phase three level and five level inverter topology circuits.

Background technique

As global energy and environmental issues intensify, renewable energy is growing rapidly. Photovoltaic power generation has a good development prospect because of its abundant resources and wide distribution. For photovoltaic power generation systems, how to reduce costs and improve efficiency has become an important issue for photovoltaic power generation.

In photovoltaic power generation systems, photovoltaic arrays are used to convert solar energy into electrical energy. However, the PV array outputs DC power, but the grid is AC. Therefore, the grid-connected photovoltaic system requires at least one inverter to convert the direct current output from the photovoltaic array into alternating current.

The photovoltaic array has a Potential Induced Degradation (PID). Potential induced attenuation, as the name implies, occurs when the potential and leakage current of the photovoltaic array cause ions to flow between the semiconductor material of the photovoltaic array and other materials. The PID effect reduces the output performance of the photovoltaic array. Therefore, the PID effect is an undesirable feature of photovoltaic arrays. The PID effect can cause up to 40% power loss. The PID effect often occurs when the PV array is negative to ground potential. Maintaining the positive voltage of the PV array to ground is an effective way to suppress the PID effect.

In addition, there is a common mode loop in a transformerless photovoltaic inverter system. High-frequency leakage currents in the common-mode loop cause electromagnetic interference and endanger equipment and personal safety. Therefore, high-frequency leakage current becomes an important problem that must be solved in a transformerless inverter system.

Summary of the invention

To solve the above technical problem, the present application provides a multilevel inverter topology circuit including single-phase three-level and five-level inverter topology circuits and three-phase three-level and five-level inverter topologies. Circuitry to effectively suppress the PID effect.

In a first aspect, the present invention provides a single-phase three-level inverter topology circuit, including: a floating capacitor, a charge and discharge module, and an inverter module;

The charge and discharge module includes at least a first inductor and a charge and discharge control unit;

The charge and discharge control unit includes a first end, a second end, a third end, and at least one charge and discharge control end; a connection suitable for the connection from the third end to the first end of the single-conductor charge and discharge control unit; and the charge and discharge control When the terminal is the first charge and discharge control signal, the connection between the first end and the second end of the charge and discharge control unit is turned on, and when the charge and discharge control terminal is connected to the second charge and discharge control signal, the charge and discharge control unit is turned off. a connection between one end and the second end;

The inverter module includes a first end, a second end, a third end, a fourth end, an AC output end, and a plurality of inverter control ends; and is adapted to be applicable to the first end, the second end, and the third end of the inverter module, Five terminals of the AC output end and the fourth end, when the inverter control terminal is connected to the first inverter control signal, only the connection between the second end and the third end of the inverter module and the AC output end and the fourth end are turned on The connection between the terminals; when the second inverter control signal is connected to the inverter control terminal, only the connection between the second end and the third end of the inverter module and the connection between the third end and the AC output end are turned on. When the third inverter control signal is connected to the inverter control end, only the connection between the first end and the second end of the inverter module and the connection between the third end and the AC output end are turned on;

The first inductor is connected between the second end of the charging and discharging control unit and the first end of the inverter module; one end of the floating capacitor is connected to the first end of the inverter module, and the other end of the floating capacitor is connected. a third end of the inverter module;

The third end of the charging and discharging control unit is connected to the second end or the third end of the inverter module;

The fourth end of the inverter module is connected to the first end of the charging and discharging control unit or The fourth end of the inverter module is connected to the first end of the inverter module.

In a second aspect, the present invention provides a single-phase five-level inverter topology circuit, including:

a first floating capacitor, a second floating capacitor, a charge and discharge module, and a five-level inverter module;

The charge and discharge control unit includes a first end, a second end, a third end, and at least one charge and discharge control end; a connection suitable for the connection from the third end to the first end of the single-conductor charge and discharge control unit; and the charge and discharge control When the terminal is the first charging and discharging control signal, the connection between the first end and the second end of the charging and discharging control unit is turned on, and when the second charging and discharging control signal is connected to the control end thereof, the charging and discharging control unit is turned off first a connection between the end and the second end;

The five-level inverter module includes a first inverter unit and a second inverter unit; the first inverter unit includes a first end, a second end, a third end, and a plurality of inverter control ends; The different control signals provided by the inverter control terminal provide at least two working modes: for the first terminal, the second terminal, and the third terminal of the first inverter unit, only the first end of the first inverter unit is turned on a connection between the two ends; for the first terminal, the second end, and the third end of the first inverter unit, only the connection between the second end and the third end of the first inverter unit is turned on;

The second inverter unit includes a first input end, a second input end, a third input end, an AC output end, and a plurality of inverter control ends; and is adapted to provide at least three types of work according to different control signals provided by the inverter control end Mode: for the first input end, the second input end, the third input end, and the AC output end of the second inverter unit, only the connection between the first input end and the AC output end of the second inverter unit is turned on For the first input end, the second input end, the third input end, and the AC output end of the second inverter unit, only the connection between the second input end of the second inverter unit and the AC output end is turned on; For the first input end, the second input end, the third input end, and the AC output end of the second inverter unit, Only connecting the connection between the third input end of the second inverter unit and the AC output terminal;

The first inductor is connected between the second end of the charging and discharging control unit and the first end of the first inverter unit; one end of the first floating capacitor is connected to the first end of the first inverter unit, The other end of the first floating capacitor is connected to the second input end of the second inverter unit; one end of the second floating capacitor is connected to the third end of the first inverter unit and the third input end of the second inverter unit The other end of the second floating capacitor is connected to the second input end of the second inverter unit;

The third end of the charging/discharging control unit is connected to the second end or the third end of the first inverter unit;

The first input end of the second inverter unit is connected to the first end of the charge and discharge control unit or the first input end of the second inverter unit is connected to the first end of the first inverter unit.

In a third aspect, the present invention provides a three-phase three-level inverter topology circuit, including: a charging and discharging module, a floating capacitor, and a three-phase inverter module;

The charge and discharge control unit includes a first end, a second end, a third end, and at least one charge and discharge control end; a connection suitable for the one-way connection from the third end to the first end; and the first at the charge and discharge control end When the charge and discharge control signal is turned on, the connection between the first end and the second end is turned on, and when the second charge and discharge control signal is connected to the charge and discharge control end, the connection between the first end and the second end is turned off;

The three-phase inverter module includes a first inverter unit and three second inverter units; the first inverter unit includes a first end, a second end, a third end, and a plurality of inverter control ends; Providing at least two working modes according to different control signals provided by the inverter control terminal: for the first terminal, the second terminal, and the third terminal of the first inverter unit, only the first end of the first inverter unit is turned on a connection with the second end; for the first terminal, the second end, and the third end of the first inverter unit, only the connection between the second end and the third end is turned on Connect

Each of the second inverter units includes a first input end, a second input end, a third input end, an AC output end, and a plurality of inverter control ends; and is adapted to provide at least three types of work according to different control signals provided by the inverter control end Mode: for the first input end, the second input end, the third input end, and the AC output end, only the connection between the first input end and the AC output end is turned on; for the first input end, the second input Four terminals of the end, the third input end and the AC output end, only the connection between the second input end and the AC output end is turned on; for the first input end, the second input end, the third input end, and the AC output end four Terminals, only connecting the connection between the third input end and the AC output end;

The first inductor is connected between the second end of the charge and discharge control unit and the first end of the first inverter unit; one end of the floating capacitor is connected to the first end of the first inverter unit, The other end of the floating capacitor is connected to the third end of the first inverter unit;

a first input end of each of the second inverter units is connected to a first end of the charge and discharge control unit or a first end connected to the first inverter unit; and a second input end is connected to a second end of the first inverter unit The third input is connected to the third end of the first inverter unit.

In a fourth aspect, the present invention provides a three-phase three-level inverter topology circuit, comprising: three single-phase three-level inverter topology circuits according to the first aspect; three said single-phase three-electric The first end of the charging and discharging module in the flat inverter topology circuit is connected; the third ends of the charging and discharging modules in the three single-phase three-level inverter topological circuits are connected.

In a fifth aspect, the present invention provides a three-phase five-level inverter topology circuit, including:

The single-phase five-level inverter topology circuit according to the third aspect; the first ends of the charging and discharging modules in the three single-phase five-level inverter topology circuits are connected; three of the single phases The third end of the charge and discharge module in the three-level inverter topology circuit is connected.

In the three-level and five-level inverter topology circuit provided by the present invention, in the case where the AC output terminal of the inverter portion is connected to the negative pole of the DC power source through the AC power grid, the normal operation can still be performed. This enables the DC power supply to always maintain a ground potential greater than or equal to zero, thus effectively suppressing the PID effect; and completely eliminating the high frequency leakage current of the inverter topology.

DRAWINGS

In order to more fully understand the technical solution of the present invention, the drawings to be used in the following embodiments or the description of the prior art are described below. The features and advantages of the present invention will become more apparent from the understanding of the appended claims.

1 is a schematic circuit diagram of a first single-phase three-level inverter topology according to an embodiment of the present invention;

2 is a schematic circuit diagram of a second single-phase three-level inverter topology according to an embodiment of the present invention;

3 is a schematic circuit diagram of a third single-phase three-level inverter topology according to an embodiment of the present invention;

4 is a schematic circuit diagram of a fourth single-phase three-level inverter topology according to an embodiment of the present invention;

FIG. 5 is a partial block diagram of a first single-phase five-level inverter topology according to an embodiment of the present invention; FIG.

6 is a partial block diagram of a second single-phase five-level inverter topology according to an embodiment of the present invention;

7 is a partial block diagram of a third single-phase five-level inverter topology according to an embodiment of the present invention;

8 is a partial block diagram of a fourth single-phase five-level inverter topology according to an embodiment of the present invention;

FIG. 9 is a circuit diagram of a first type of second inverter unit M2 according to an embodiment of the present invention. schematic diagram;

FIG. 10 is a schematic diagram of a circuit principle of a second second inverting unit M2 according to an embodiment of the present disclosure;

FIG. 11 is a schematic diagram of a circuit principle of a third second inverting unit M2 according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram of a circuit principle of a fourth second inverting unit M2 according to an embodiment of the present disclosure;

FIG. 13 is a schematic diagram of a circuit principle of a fifth second inverting unit M2 according to an embodiment of the present disclosure;

14 is a schematic circuit diagram of a first single-phase five-level inverter with a second inverting unit M2 shown in FIG. 9 according to an embodiment of the present invention;

15 is a partial block diagram of a first three-phase three-level inverter topology according to an embodiment of the present invention;

16 is a partial block diagram of a second three-phase three-level inverter topology according to an embodiment of the present invention;

17 is a partial block diagram of a third three-phase three-level inverter topology according to an embodiment of the present invention;

18 is a partial block diagram of a fourth three-phase three-level inverter topology according to an embodiment of the present invention;

19(a) is an equivalent block diagram of a first single-phase three-level inverter topology according to an embodiment of the present invention;

19(b) is a partial block diagram showing a fifth three-phase three-level inverter topology according to an embodiment of the present invention;

20(a) is an equivalent block diagram of a third single-phase five-level inverter topology according to an embodiment of the present invention;

20(b) is a partial block diagram showing a three-phase five-level inverter topology according to an embodiment of the present invention;

For the convenience of description, the same components are denoted by the same reference numerals throughout the drawings.

detailed description

The present invention provides a multilevel inverter topology circuit comprising single phase three level and five level inverter topology circuits and three phase three level and five level inverter topology circuits. The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the drawings in the embodiments of the present invention. It is apparent that the described embodiments are only a part of the embodiments of the invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

As shown in the drawings, the term "PV" as used in the present invention denotes a photovoltaic array (that is, a direct current power source), U _PV denotes an output voltage of a direct current power source, M1 denotes a charge and discharge module, and M2 denotes a second inverter unit, C _s Indicates the floating capacitor, C _s1 represents the first floating capacitor, C _s2 represents the second floating capacitor, and G represents the AC grid.

Obviously, the PV can be replaced by other DC power sources, that is, the DC power source in the present invention is not limited to PV. Similarly, the AC grid G can be replaced with other AC loads, that is, the AC load in the present invention is not limited to the AC grid.

Note that the diode is used to represent a unidirectional conduction element, but the unidirectional conduction element in the present invention is not limited to the diode, and other unidirectional conduction elements may be employed. The anode of the diode refers to the anode and the cathode refers to the cathode.

The switching MOSFET is used to represent a controllable (on and off) semiconductor switch in the present invention, but the controllable semiconductor switch in the present invention is not limited to the MOSFET, that is, other controllable semiconductor switches can also be used. Such as IGBT. An N-channel MOSFET will be described as an example. The first end of the N-channel MOSFET is the drain, the second end is the source, and the control is the gate. A drive control signal is applied to each semiconductor switch control terminal in the multilevel inverter topology circuit of the present invention. For the sake of brevity, we will not repeat them later.

In order to ensure bidirectional flow of current in each semiconductor switch, each half of the present invention The conductor switch is connected in parallel with a diode. For the sake of brevity, the term "bidirectional switch" as used in the present invention refers to a semiconductor switch with an anti-parallel diode, such as an IGBT with an anti-parallel diode, or a MOSFET with a parallel diode.

The multilevel inverter topology circuit provided by the invention mainly comprises a charging and discharging module, at least one floating capacitor and one inverter circuit. In order to eliminate the PID, a DC power source (a photovoltaic array in this embodiment) is required to maintain a ground potential greater than or equal to zero. In order to achieve the above purpose, the negative pole of the inverter DC power supply is connected to the ground of the AC grid. For a three-phase inverter topology, the negative pole of the DC power supply can be connected to the ground of the AC power grid. Of course, the negative pole of the DC power supply can also be connected to the ground of the AC power grid. The charging and discharging module is used for charging the floating capacitor, so that the floating capacitor can provide the DC negative voltage required for the inverter circuit for a certain period of time. The DC forward voltage required for the inverter circuit can be obtained from the positive pole of the DC power supply or from the positive pole of the floating capacitor. Correspondingly, the positive input of the inverter circuit has two connection modes. The charge and discharge module has two freewheeling circuits. Therefore, the charge and discharge module has two connection modes (that is, the diode D _f in the present invention has two connection modes).

For the inverter circuit, an output three-level inverter circuit (referred to as a three-level inverter circuit) or an output five-level inverter circuit (referred to as a five-level inverter circuit) may be employed. For a single-phase three-level inverter topology, an embodiment of the present invention provides an inverter circuit. For the three-phase inverter topology including a three-phase three-level inverter topology circuit and a three-phase five-level inverter topology circuit, and a single-phase five-level inverter topology circuit, the embodiment of the present invention provides five inverses Variable circuit.

The above is the core idea of the present invention. For a better understanding of the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

FIG. 1 is a schematic diagram showing the circuit principle of a first single-phase three-level inverter topology provided by an embodiment of the present application. As shown in FIG. 1 , the inverter topology circuit includes: a floating capacitor C _s , a charging and discharging module M1 , and an inverter module, and the inverter module is specifically a full bridge inverter circuit.

The charge and discharge module M1 includes a first bidirectional switch T ₁₁ , a first inductor L _{11 ,} and a first diode D _f . The first inductor L ₁₁ and the first diode D _{f are} for suppressing an inrush current when charging the floating capacitor C _s .

As shown in FIG. 1, the full bridge inverter circuit includes a second bidirectional switch T ₁₂ , a third bidirectional switch T ₁₃ , a fourth bidirectional switch T ₁₄ , and a fifth bidirectional switch T ₁₅ .

The capacitor C _in parallel is connected across the DC power supply PV, and the capacitor C _in acts as a voltage regulator.

PV positive DC power source is connected to a first end of the first bidirectional switch T _11, T a second end of the first bidirectional switch ₁₁ is connected to a first end of a first inductor L _11, a first end of the inductor L ₁₁ is connected to a second capacitor suspension The positive pole of C _s .

The negative pole of the first diode D _f is connected to the common end of the first bidirectional switch T ₁₁ and the first inductor L _{11 (} the common end here refers to the end where the first bidirectional switch T ₁₁ and the first inductor L _{11 are} connected, specifically Referring to the second end of the first bidirectional switch T ₁₁ and the first end of the first inductor L ₁₁ ), the anode of the first diode D _f is connected to the cathode of the DC power source PV.

The first end of the second bidirectional switch T ₁₂ is connected to the positive terminal of the floating capacitor C _s , and the second end of the second bidirectional switch T ₁₂ is connected to the first end of the third bidirectional switch T ₁₃ . The common ends of the second bidirectional switch T ₁₂ and the third bidirectional switch T ₁₃ are simultaneously connected to the negative pole of the direct current power source PV and the first end of the alternating current grid. The second end of the third bidirectional switch T ₁₃ is connected to the negative terminal of the floating capacitor C _s .

The first end of the fourth bidirectional switch T ₁₄ is connected to the positive pole of the floating capacitor C _s , and the second end of the fourth bidirectional switch T ₁₄ is connected to the first end of the fifth bidirectional switch T ₁₅ . The second end of the fifth bidirectional switch T ₁₅ is connected to the negative terminal of the floating capacitor C _s . The common ends of the fourth bidirectional switch T ₁₄ and the fifth bidirectional switch T ₁₅ are connected to the second end of the AC grid through the second inductor L ₁₂ . Therefore, the common ends defining the fourth bidirectional switch T ₁₄ and the fifth bidirectional switch T ₁₅ are the alternating current terminals.

The second inductor L _{12 is} used to filter out ripple in the output current to improve the quality of the output current.

The floating capacitor C _s is charged by the DC power source PV, so it is assumed that the floating capacitor C _s voltage is equal to the DC power supply voltage U _PV . The current defining the second inductance L ₁₂ in the drawing is a forward current from left to right and a negative current from the opposite.

In order to understand the first single-phase three-level inverter topology circuit (as shown in Figure 1) Working principle, this embodiment provides three working modes as follows:

The first mode: the forward current path is: N→T ₁₃ →C _s →T ₁₄ →L ₁₂ →G→N; the negative current path is: N→G→L ₁₂ →T ₁₄ →C _s →T ₁₃ →N. The inverter output voltage is equal to the floating capacitor voltage U _PV . In this mode, the DC forward voltage required by the inverter module is obtained from the positive electrode of the floating capacitor.

The second mode: the forward current path is: N→T ₁₃ →T ₁₅ →L ₁₂ →G→N; the negative current path is: N→G→L ₁₂ →T ₁₅ →T ₁₃ →N. The inverter output voltage is equal to zero.

A first mode and a second mode, suspended capacitance C _s is charged or discharged. Among them, the charging circuit: P → T ₁₁ → L ₁₁ → C _s → T ₁₃ → N; discharge circuit: N → T ₁₃ → C _s → L ₁₁ → T ₁₁ → P.

The third mode: the forward current path is: N→T ₁₂ →C _s →T ₁₅ →L ₁₂ →G→N; the negative current path is: N→G→L ₁₂ →T ₁₅ →C _s →T ₁₂ →N. The inverter output voltage is equal to the negative floating capacitor voltage -U _PV . In this mode, the second bidirectional switch T ₁₂ and the first diode D _f provide a freewheeling path for the inductor L ₁₁ : L ₁₁ → T ₁₂ → D _f → L ₁₁ .

The modulation strategy of the single-phase three-level inverter topology circuit provided in this embodiment is: in the positive half cycle of the AC grid voltage, the first mode and the second mode alternately work; in the negative half cycle of the AC grid voltage, the third mode The state and the second mode alternately work.

It should be noted that the semiconductor switches in the present application can be implemented by using MOSFETs or IGBTs. Taking an N-channel MOSFET as an example, the drain is the first end, the source is the second end, and the gate is the control terminal. The control terminals of each of the semiconductor switches in the single-phase three-level inverter topology circuit input corresponding driving control signals. For the sake of brevity, the description will not be repeated later.

In the single-phase three-level inverter topology circuit provided in this embodiment, the AC output can be normally operated when the AC power supply is connected to the negative pole of the DC power supply, and the DC power supply can always maintain the ground potential greater than or equal to zero. It can effectively suppress the PID effect; and can completely eliminate the high-frequency leakage current of the inverter topology circuit. Since the DC power supply side is not connected to the voltage dividing capacitor, there is no voltage balance at the midpoint of the voltage dividing capacitor. problem.

It is not difficult to understand that in the above embodiment, the first bidirectional switch T ₁₁ and the first diode D _{f function} together to connect the positive pole of the DC power source PV when the first bidirectional switch T _{11 is} turned on. The left end of the first inductor L ₁₁ is connected; and when the first bidirectional switch T _{11 is} turned off, the connection between the anode of the PV and the first inductor L ₁₁ is disconnected; and the cathode of the DC power source PV and the first inductor L _{11 are additionally} The left end is single-pass; it functions as a charging control unit. Of course, in a specific embodiment, other structures capable of performing the same or similar functions may be used instead of the first bidirectional switch T ₁₁ and the first diode D _f , and the corresponding technical solutions should fall within the scope of the present invention. protected range.

In addition, the above-mentioned inverter module functions to make the corresponding devices electrically or not connected to each other in the above three modes. Of course, those skilled in the art can also design the above-mentioned inverter module as another structure to replace the second bidirectional switch T ₁₂ , the third bidirectional switch T ₁₃ , the fourth bidirectional switch T ₁₄ and the fifth bidirectional switch in FIG. 1 . The T ₁₅ implements the corresponding functions, and the corresponding solutions do not affect the implementation of the present invention, and should also fall within the scope of the present invention.

In this embodiment and the following embodiments, each bidirectional switch is connected to a corresponding control end, and each control end is used to access a corresponding control signal. In a specific implementation, each of the bidirectional switches may be connected to the respective control terminals one-to-one, or a plurality of bidirectional switches whose working states are always the same may be connected to the same control terminal.

In this embodiment and in the following embodiments, each of the diodes may be replaced with other unidirectional conduction elements capable of achieving a single conduction. Under the premise that the same function can be achieved, what kind of structure is specifically selected as a one-way conduction element does not affect the protection scope of the present invention.

FIG. 2 is a schematic diagram showing the circuit principle of a second single-phase three-level inverter topology according to an embodiment of the present invention. Unlike the single-phase three-level inverter topology shown in FIG. 1, the first in FIG. The anode of the diode D _f is connected to the cathode of the suspension capacitor C _s and the freewheeling path of the inductor L ₁₁ is: L ₁₁ → T ₁₂ → T ₁₃ → D _f → L ₁₁ .

FIG. 3 is a schematic diagram showing the circuit principle of a third single-phase three-level inverter topology according to an embodiment of the present invention. Unlike the topology shown in FIG. 1, the first of the fourth bidirectional switch T ₁₄ in FIG. The terminal is connected to the first end of the first bidirectional switch T ₁₁ and the positive pole of the DC power supply PV, that is, the DC forward voltage required by the inverter module is directly obtained from the positive pole of the DC power supply.

FIG. 4 is a schematic diagram showing the circuit principle of a fourth single-phase three-level inverter topology according to an embodiment of the present invention. Unlike FIG. 3, the anode of the first diode D _f in FIG. The negative pole of the capacitor C _{s has} the same structure and will not be described here.

The second, third, and fourth single-phase three-level inverter topologies operate in the same manner as the first single-phase three-level inverter topology. Referring to the working principle analysis of the first single-phase three-level inverter topology described above, a similar working modal analysis can be performed for the second, third, and fourth single-phase three-level inverter topologies. Let me repeat.

FIG. 5 is a schematic diagram showing the circuit principle of a first single-phase five-level inverter topology according to an embodiment of the present invention. As shown in FIG. 5, the single-phase five-level inverter topology circuit includes: a first floating capacitor C _s1 , a second floating capacitor C _s2 , a charging and discharging module M1 , and a five-level inverter module. The five-level inverter module includes a first inverter unit and a second inverter unit M2. The first inverting unit includes a first switching circuit branch and a second switching circuit branch. The first switching circuit branch includes a second bidirectional switch T ₅₂ and the second switching circuit branch includes a third bidirectional switch T ₅₃ .

The charging and discharging module M1 includes a first bidirectional switch T ₁₁ , a first inductor L _{11 ,} and a first diode D _f .

The second inverter unit M2 includes a first input terminal I ₁ , a second input terminal I ₀ , a third input terminal I _{−1 ,} and an AC output terminal I _out .

The first end of the first bidirectional switch T ₁₁ is connected to the positive end of the DC power source PV, and the second end of the first bidirectional switch T ₁₁ is connected to the first end of the first inductor L ₁₁ . The second end of the first inductor L ₁₁ is connected to the anode of the first floating capacitor C _s1 .

The cathode of the first diode D _f is connected to the common terminal of the first bidirectional switch T ₁₁ and the first inductor L ₁₁ , and the anode of the first diode D _f is connected to the cathode of the DC power source PV. The first inductor L ₁₁ and the first diode D _{f are} for suppressing an inrush current when the first floating capacitor C _s1 and the second floating capacitor C _{s2 are} charged. The freewheeling path of the first inductor L ₁₁ is: L ₁₁ → C _s1 → C _s2 → T ₅₃ → D _f → L ₁₁ .

The cathode of the first floating capacitor C _s1 is connected to the anode of the second suspension capacitor C _s2 . The cathode of the second suspension capacitor C _s2 is connected to the third input terminal I _{-1 of the} second inverter unit M2.

The first end of the second bidirectional switch T ₅₂ is connected to the positive terminal of the first floating capacitor C _s1 , and the second end of the second bidirectional switch T ₅₂ is connected to the first end of the third bidirectional switch T ₅₃ . The common ends of the second bidirectional switch T ₅₂ and the third bidirectional switch T ₅₃ are simultaneously connected to the negative pole of the direct current power source PV and the first end of the alternating current grid. The second end of the third bidirectional switch T ₅₃ is connected to the negative pole of the second floating capacitor C _s2 .

The first input terminal I _{1 of the} second inverter unit M2 is connected to the anode of the first suspension capacitor C _s1 , and the second input terminal I _{0 of the} second inverter unit M2 is connected to the first suspension capacitor C _s1 and the second suspension capacitor C _{s2 .} the common terminal of the second inverter AC output terminal I _out cell M2 connected to the second end of the AC power grid G by a second inductor L _52. The second inductor L _{52 is} used to filter out ripple in the output current to improve current quality.

A switching circuit sub-branch is disposed between each input end of the second inverter unit M2 and the AC output terminal I _out . Corresponding to the first input end, the second input end and the third input end are respectively a first switch circuit sub-branch, a second switch circuit sub-branch and a third switch circuit sub-branch.

In this embodiment, it is assumed that the first suspension capacitor C _{s1 has a} capacitive reactance equal to the second suspension capacitor C _s2 . The DC power supply PV is commonly charged by the first floating capacitor C _s1 and the second floating capacitor C _s2 , so the first floating capacitor voltage is equal to the second floating capacitor voltage, that is, equal to half of the DC power supply voltage of 0.5 U _PV .

In the first case, the first switching circuit branch operates, that is, the second bidirectional switch T _{52 is} turned on. At this time, the first end of the AC power grid is equivalently connected to the first floating capacitor C _s1 positive terminal or the first input terminal I _{1 of the} second inverter unit M2 . Meanwhile, if the first switching circuit sub-branch operates, the inverter output voltage is equal to zero; if the second switching circuit sub-branch operates, the inverter output voltage is equal to the negative first floating capacitor voltage, ie -0.5 U _PV If the third switching circuit sub-branch operates, the inverter output voltage is equal to the sum of the negative first floating capacitor voltage and the negative second floating capacitor voltage, ie -U _PV .

In the second case, the second switching circuit branch operates, that is, the third bidirectional switch _{T53 is} turned on. At this time, the first end of the AC power grid is equivalently connected to the second floating capacitor C _s2 anode or the third input terminal I _{-1 of the} second inverter unit M2. Meanwhile, if the first switching circuit sub-branch operates, the inverter output voltage is equal to the sum of the first floating capacitor voltage and the second floating capacitor voltage, that is, U _PV ; if the second switching circuit sub-branch operates, the inverter The output voltage of the device is equal to the second floating capacitor voltage, ie 0.5 U _PV ; if the third switching circuit sub-branch is active, the inverter output voltage is equal to zero.

FIG. 6 is a schematic diagram showing the circuit principle of a second single-phase five-level inverter topology according to an embodiment of the present invention. Topology shown in Figure 5 except that the negative electrode and the first inductor L freewheel path anode of the first diode D _f in FIG 6 is connected to a second capacitance C _s2 of the suspension is _11: L ₁₁ → C _s1 →C _s2 →D _f →L ₁₁ .

FIG. 7 is a schematic diagram showing the circuit principle of a third single-phase five-level inverter topology provided by an embodiment of the present invention. Topology shown in Figure 5 except that the first input of the second inverter in FIG. 7 means M2 simultaneously connected to the terminal I ₁ of the first bidirectional switch T positive electrode terminal ₁₁ and a first DC power source PV, other The structure is the same as that of FIG. 5. The DC forward voltage required by the inverter module is directly obtained from the positive pole of the DC power supply.

FIG. 8 is a schematic diagram showing the circuit principle of a fourth single-phase five-level inverter topology according to an embodiment of the present invention. The difference from the topology shown in FIG. 7 is that the anode of the first diode D _f in FIG. 8 is connected to the cathode of the second suspension capacitor C _s2 and the freewheeling path of the first inductor L ₁₁ is: L ₁₁ → C _s1 →C _s2 →D _f →L ₁₁ .

FIG. 9 is a schematic diagram showing the circuit principle of a first type of second inverter unit M2 according to an embodiment of the present invention. As shown in FIG. 9, the second inverter unit M2 includes a fourth bidirectional switch T ₉₄ , a fifth bidirectional switch T ₉₅ , a sixth bidirectional switch T _{96 ,} and a seventh bidirectional switch T ₉₇ .

The first end of the fourth bidirectional switch T ₉₄ is connected to the first input end I _{1 of} the second inverting unit M2 , and the second end of the fourth bidirectional switch T ₉₄ is connected to the second inverting unit M2 AC output I _out . The first end of the fifth bidirectional switch T ₉₅ is connected to the second input end I _{0 of} the second inverting unit M2 , and the second end of the fifth bidirectional switch T ₉₅ is connected to the second end of the sixth bidirectional switch T ₉₆ , The first end of the six-way switch T ₉₆ is connected to the AC output terminal I _{out of} the second inverter unit M2. The first end of the seventh bidirectional switch T ₉₇ is connected to the AC output terminal I _{out of} the second inverter unit M2, and the second end of the seventh bidirectional switch T ₉₇ is connected to the third end of the second inverter unit M2 Input I-1.

FIG. 10 is a schematic diagram showing the circuit principle of a second second inverting unit M2 according to an embodiment of the present invention. As shown in FIG. 10, the second inverter unit M2 includes a fourth bidirectional switch T ₁₀₄ , a fifth bidirectional switch T ₁₀₅ , a sixth bidirectional switch T _{106 ,} and a seventh bidirectional switch T ₁₀₇ .

The first end of the fourth bidirectional switch T ₁₀₄ is connected to the first input end I _{1 of} the second inverter unit M2 , and the second end of the fourth bidirectional switch T ₁₀₄ is connected to the AC output end of the second inverter unit M2 . I _out . The second input terminal of the second T fifth bidirectional switch ₁₀₅ is connected to the second terminal M2 inverter unit I _0, T fifth bidirectional switch ₁₀₅ is connected to a first end of the second end ₁₀₆ of the sixth bidirectional switch T. The first end of the sixth bidirectional switch T ₁₀₆ is connected to the AC output end I _{out of} the second inverting unit M2. The first end of the seventh bidirectional switch T ₁₀₇ is connected to the second end of the sixth bidirectional switch T ₁₀₆ , and the second end of the seventh bidirectional switch T ₁₀₇ is connected to the third input end I _{-1 of} the second inverting unit M2 .

FIG. 11 is a schematic diagram showing the circuit principle of a third second inverting unit M2 according to an embodiment of the present invention. As shown in FIG. 11, the second inverter unit M2 includes a fourth bidirectional switch T ₁₁₄ , a fifth bidirectional switch T ₁₁₅ , a sixth bidirectional switch T _{116 ,} and a seventh bidirectional switch T ₁₁₇ .

The first end of the fourth bidirectional switch T ₁₁₄ is connected to the first end I _{1 of} the second inverting unit M2, and the second end of the fourth bidirectional switch T ₁₁₄ is connected to the first end of the sixth bidirectional switch T ₁₁₆ . The second end of the six-way switch T ₁₁₆ is connected to the AC output terminal I _{out of} the second inverter unit M2.

The first end of the fifth bidirectional switch T ₁₁₅ is connected to the first end of the sixth bidirectional switch T ₁₁₆ , and the second end of the fifth bidirectional switch T ₁₁₅ is connected to the second input end I _{0 of} the second inverting unit M2. The first end of the seventh bidirectional switch T ₁₁₇ is connected to the AC output end I _{out of} the second inverting unit M2, and the second end of the seventh bidirectional switch T ₁₁₇ is connected to the third end of the second inverting unit M2 Input I _-1 .

FIG. 12 is a schematic diagram showing the circuit principle of a fourth second inverting unit M2 according to an embodiment of the present invention. As shown in FIG. 12, the second inverter unit M2 includes: a fourth bidirectional switch T ₁₂₄ , a fifth bidirectional switch T ₁₂₅ , a sixth bidirectional switch T ₁₂₆ , a seventh bidirectional switch T ₁₂₇ , and a second diode D ₁₂₂ and a third diode D ₁₂₃ .

The first end of the fourth bidirectional switch T ₁₂₄ is connected to the first input end I _{1 of} the second inverting unit M2, and the second end of the fourth bidirectional switch T ₁₂₄ is connected to the fifth bidirectional switch T ₁₂₅ At one end, the second end of the fifth bidirectional switch T ₁₂₅ is coupled to the first end of the sixth bidirectional switch T ₁₂₆ . T sixth bidirectional switch ₁₂₆ is connected to a second terminal of the seventh end of the first bidirectional switch T _127, T seventh bidirectional switch connecting a second terminal of a third input of the second inverter unit M2 of the terminal I _-1 _127. The common ends of the fifth bidirectional switch T ₁₂₅ and the sixth bidirectional switch T ₁₂₆ are connected to the AC output terminal I _{out of} the second inverting unit M2. The cathode of the second diode D ₁₂₂ is connected to the common terminal of the fourth bidirectional switch T ₁₂₄ and the fifth bidirectional switch T ₁₂₅ , and the anode of the second diode D ₁₂₂ is connected to the cathode of the third diode D ₁₂₃ , the third two The anode of the pole tube D ₁₂₃ is connected to the common terminal of the sixth bidirectional switch T ₁₂₆ and the seventh bidirectional switch T ₁₂₇ . The common terminal of the second diode D ₁₂₂ and the anode D ₁₂₃ of the third diode is connected to the second input terminal I _{0 of} the second inverter unit M2.

FIG. 13 is a schematic diagram showing the circuit principle of a fifth second inverting unit M2 according to an embodiment of the present invention. As shown in FIG. 13, the second inverter unit M2 includes: a fourth bidirectional switch T ₁₃₄ , a fifth bidirectional switch T ₁₃₅ , a sixth bidirectional switch T ₁₃₆ , a second diode D ₁₃₂ , and a third diode D ₁₃₃ , fourth diode D ₁₃₄ and fifth diode D ₁₃₅ .

The first end of the fourth bidirectional switch T ₁₃₄ is connected to the first input end I _{1 of} the second inverter unit M2 , and the second end of the fourth bidirectional switch T ₁₃₄ is connected to the AC output end of the second inverter unit M2 . I _out . The first end of the sixth bidirectional switch T ₁₃₆ is connected to the AC output end I _{out of} the second inverter unit M2, and the second end of the sixth bidirectional switch T ₁₃₆ is connected to the third input end of the second inverter unit M2. I _-1 .

The cathode of the second diode D ₁₃₂ is connected to the first end of the fifth bidirectional switch T ₁₃₅ , the anode of the second diode D ₁₃₂ is connected to the cathode of the third diode D ₁₃₃ , and the anode of the third diode D ₁₃₃ The second end of the fifth bidirectional switch T ₁₃₅ is connected. The common end of the second diode D ₁₃₂ and the third diode D ₁₃₃ is connected to the second input terminal I _{0 of} the second inverter unit M2; the negative terminal of the fourth diode D ₁₃₄ is connected to the fifth bidirectional switch T The first end of the ₁₃₅ , the anode of the fourth diode D ₁₃₄ is connected to the cathode of the fifth diode D ₁₃₅ , and the anode of the fifth diode D ₁₃₅ is connected to the second end of the fifth bidirectional switch T ₁₃₅ , the fourth two The common terminal of the diode D ₁₃₄ and the fifth diode D ₁₃₅ is connected to the AC output terminal I _{out of} the second inverter unit M2.

As shown in FIG. 14, the operation principle of the first single-phase five-level inverter will be described with reference to the second inverter unit M2 shown in FIG. This embodiment provides five working modes as follows:

First working mode: forward current: N→T ₅₃ →C _s2 →C _s1 →T ₉₄ →L ₅₂ →G→N; negative current: N→G→L ₅₂ →T ₉₄ →C _s1 →C _s2 →T ₅₃ →N. The inverter output voltage is equal to the sum of the first floating capacitor voltage and the second floating capacitor voltage, ie U _PV .

Second working mode: forward current: N→T ₅₃ →C _s2 →T ₉₅ →T ₉₆ →L ₅₂ →G→N; negative current: N→G→L ₅₂ →T ₉₆ →T ₉₅ →C _s2 →T ₅₃ →N. The inverter output voltage is equal to the second floating capacitor voltage, which is 0.5U _PV .

The third working mode: forward current: N → T ₅₃ → T ₉₇ → L ₅₂ → G → N; negative current: N → G → L ₅₂ → T ₉₇ → T ₅₃ → N. The inverter output voltage is equal to zero.

Fourth working mode: Forward current: N→T ₅₂ →C _s1 →T ₉₅ →T ₉₆ →L ₅₂ →G→N; Negative current: N→G→L ₅₂ →T ₉₆ →T ₉₅ →C _s1 →T ₅₂ →N. The inverter output voltage is equal to the negative first floating capacitor voltage, which is -0.5U _PV .

Fifth working mode: forward current: N→T ₅₂ →C _s1 →C _s2 →T ₉₇ →L ₅₂ →G→N; negative current: N→G→L ₅₂ →T ₉₇ →C _s2 →C _s1 →T ₅₂ →N. The inverter output voltage is equal to the sum of the negative first floating capacitor voltage and the negative second floating capacitor voltage, ie -U _PV .

Meanwhile, when the diode in the bidirectional switch T ₅₃ operates, the first floating capacitor C _s1 and the second floating capacitor C _s2 are charged by the charge and discharge module M1. Charging circuit: N→PV→P→T ₁₁ →L ₁₁ →C _s1 →C _s2 →T ₅₃ →N.

The AC output end of the second inverter unit M2 in the single-phase five-level inverter provided in this embodiment is connected to the negative pole of the DC power source through the AC power grid, thereby ensuring that the DC power source always maintains the ground potential to be greater than or equal to zero, thereby being effective. The PID effect is suppressed; and the high-frequency leakage current of the inverter topology can be completely eliminated.

It should be noted that, for those skilled in the art, some changes made to the embodiments of the present invention, such as each of the above-mentioned inverses, without deliberate labor without departing from the principles of the present application. The dual topology of the DC power supply corresponding to the variable topology is connected to the dual topology of the AC power grid. The topology obtained by such changes should also be regarded as the protection scope of the present application.

FIG. 15 is a schematic diagram showing a partial block circuit principle of a first three-phase three-level inverter topology according to an embodiment of the present invention. As shown in FIG. 15, the three-phase three-level inverter topology comprises a discharge module M1, capacitance C _s and a suspension of a three-phase inverter circuit.

The charging and discharging module M1 includes a first bidirectional switch T ₁₁ , a first inductor L ₁₁ and a first diode D _f . The specific circuit connection and working principle are the same as those of the charging and discharging module shown in FIG. 1 . Narration.

The three-phase inverter circuit includes a first switching circuit branch, a second switching circuit branch, and three second inverter units M2. The first switching circuit branch includes a second bidirectional switch T ₁₅₂ and the second switching circuit branch includes a third bidirectional switch T ₁₅₃ . Each of the second inverter units M2 has a first input terminal, a second input terminal, a third input terminal, and an AC output terminal.

The first end of the second bidirectional switch T ₁₅₂ is connected to the positive pole of the floating capacitor C _s , the second end of the second bidirectional switch T ₁₅₂ is connected to the first end of the third bidirectional switch T ₁₅₃ , and the second bidirectional switch T ₁₅₂ and The common end of the third bidirectional switch T ₁₅₃ is connected to the negative pole of the DC power source PV. The second end of the third bidirectional switch T ₁₅₃ is connected to the negative terminal of the floating capacitor C _s .

The first input ends of the three second inverter units M2 are connected to the first end of the second bidirectional switch T ₁₅₂ ; the second input ends of the three second inverter units M2 are connected to the negative pole of the DC power supply PV; The three input terminals are connected to the negative pole of the floating capacitor C _s ; the three AC output terminals of the three second inverter units M2 are respectively connected to the three phases of the AC power grid. If the ground of the AC power grid is connected to the negative pole of the DC power supply, a three-phase four-wire system is formed; conversely, if the ground of the AC power grid is not connected to the negative pole of the DC power supply, a three-phase three-wire system is formed.

Any one of the three second inverter units M2 may adopt any one of the second inverter units shown in FIG. 9 to FIG. 13 , and details are not described herein again. Considering the ease of integration, the three second inverter units preferentially use the same second inverter unit. For example, the three second inverter units M2 all adopt the second inverter unit shown in FIG.

In the three-phase three-level inverter topology provided by the embodiment, the three-phase circuit part shares the charging and discharging module, the floating capacitor and the first and second switching circuit branches, thereby simplifying the circuit structure, reducing the circuit cost, and facilitating the circuit. integrated.

16 is a schematic diagram showing the principle of a partial block circuit of a second three-phase three-level inverter topology according to an embodiment of the present invention. Unlike the topology shown in FIG. 15, the three second inverters in FIG. The first input end of the unit is connected to the positive pole of the DC power supply PV, and the other parts are the same as those in FIG. 15 and will not be described again here.

FIG. 17 is a schematic diagram showing the principle of a partial block circuit of a third three-phase three-level inverter topology according to an embodiment of the present invention. Unlike the topology shown in FIG. 15, the first diode D in FIG. The anode of _f is connected to the cathode of the suspension capacitor C _s , and the other portions are the same as those of FIG. 15 and will not be described herein.

FIG. 18 is a schematic diagram showing a partial block circuit principle of a fourth three-phase three-level inverter topology according to an embodiment of the present invention. Unlike the topology shown in FIG. 17, three second inverters in FIG. 18 are shown. The first input end of the unit is connected to the positive pole of the DC power supply PV, and the other parts are the same as those in FIG. 17, and details are not described herein again.

Figure 19 (a) is a block diagram showing the equivalent circuit of the first single-phase three-level inverter topology of the embodiment of the present invention. As shown 19 (a), the discharge module defines a first end of the first bidirectional switch T ₁₁ for the single-phase three-level inverter topology positive DC input terminal, while the definition of the DC power supply is connected to the negative terminal It is its negative DC input.

Figure 19(b) shows the single-phase three-level inverter topology shown in Figure 19(a). A schematic diagram of a partial block circuit schematic of the fifth three-phase three-level inverter topology.

As shown in FIG. 19(b), the fifth three-phase three-level inverter topology includes three single-phase three-level inverter topologies in which three input sides are connected in parallel. The two DC input terminals of each single-phase three-level inverter topology are connected in parallel at both ends of the DC power supply. Specifically, the positive DC input terminals of the three single-phase three-level inverter topologies are connected to the positive pole of the DC power supply, and the negative DC input terminals are connected to the negative pole of the DC power supply. The three AC outputs of the three single-phase three-level inverter topologies are respectively connected to the three phases of the AC grid (A phase, B phase, C phase).

Any of the three single-phase three-level inverter topologies may employ any of the single-phase three-level inverter topologies illustrated in Figures 1 through 4.

Figure 20 (a) is a block diagram showing an equivalent circuit of a single-phase five-level inverter topology in accordance with an embodiment of the present invention. Fig. 20(b) is a partial block circuit schematic diagram showing a three-phase five-level inverter topology obtained by using the single-phase five-level inverter topology shown in Fig. 20(a).

The three-phase five-level inverter topology includes a single-phase five-level inverter topology in which three input sides are connected in parallel. Wherein, two DC input ends of each single-phase five-level inverter topology are connected in parallel to both ends of the DC power supply. Specifically, the positive DC input terminals of the three single-phase three-level inverter topologies are connected to the positive pole of the DC power supply, and the negative DC input terminals are connected to the negative pole of the DC power supply. The three AC outputs of the three single-phase three-level inverter topologies are respectively connected to the three phases of the AC grid (A phase, B phase, C phase).

Any one of the three single-phase five-level inverter topologies may adopt any one of the single-phase five-level inverter topologies shown in FIG. 5 to FIG. 8 , and details are not described herein again. The second inverting unit M2 in each single-phase five-level inverter topology may adopt any one of the second inverting units shown in FIG. 9 to FIG. Considering the ease of integration, the three single-phase five-level inverter topologies preferentially use the same second inverter unit. For example, three single-phase five-level inverter topologies use the second inverter unit shown in FIG.

As can be seen from the foregoing various embodiments, the AC output terminals of the inverter circuit in the single-phase three-level inverter topology and the single-phase five-level inverter topology provided by the present invention are all exchanged. The grid is connected to the negative pole of the DC power supply, so that the DC power supply always maintains the ground potential greater than or equal to zero. Therefore, the PID effect can be effectively suppressed; and the high-frequency leakage current of the inverter topology can be completely eliminated.

The various embodiments in the specification are described in a progressive manner, and the same or similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments.

It should be noted that, in this context, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these There is any such actual relationship or order between entities or operations. Furthermore, the terms "comprises," "comprising," or "includes" or "includes" or "includes" or "includes" or "includes" or "includes" Other elements, or elements that are inherent to such a process, method, item, or device. An element that is defined by the phrase "comprising a ..." does not exclude the presence of additional equivalent elements in the process, method, item, or device that comprises the element.

The above is only a specific embodiment of the present invention, and it should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the present invention, for example, according to the present embodiment. The topological circuit in the example utilizes the topology obtained by the symmetry characteristic, and these improvements and retouchings should also be regarded as the protection scope of the present invention.

Claims

A single-phase three-level inverter topology circuit, comprising: a suspension capacitor, a charge and discharge module and an inverter module;

The charge and discharge module includes at least a first inductor and a charge and discharge control unit;

The charge and discharge control unit includes a first end, a second end, a third end, and at least one charge and discharge control end; a connection suitable for the connection from the third end to the first end of the single-conductor charge and discharge control unit; and the charge and discharge control When the terminal is the first charge and discharge control signal, the connection between the first end and the second end of the charge and discharge control unit is turned on, and when the charge and discharge control terminal is connected to the second charge and discharge control signal, the charge and discharge control unit is turned off. a connection between one end and the second end;

The inverter module includes a first end, a second end, a third end, a fourth end, an AC output end, and a plurality of inverter control ends; and is adapted to be applicable to the first end, the second end, and the third end of the inverter module, Five terminals of the AC output end and the fourth end, when the inverter control terminal is connected to the first inverter control signal, only the connection between the second end and the third end of the inverter module and the AC output end and the fourth end are turned on The connection between the terminals; when the second inverter control signal is connected to the inverter control terminal, only the connection between the second end and the third end of the inverter module and the connection between the third end and the AC output end are turned on. When the third inverter control signal is connected to the inverter control end, only the connection between the first end and the second end of the inverter module and the connection between the third end and the AC output end are turned on;

The first inductor is connected between the second end of the charging and discharging control unit and the first end of the inverter module; one end of the floating capacitor is connected to the first end of the inverter module, and the other end of the floating capacitor is connected. a third end of the inverter module;

The third end of the charging and discharging control unit is connected to the second end or the third end of the inverter module;

The fourth end of the inverter module is connected to the first end of the charging and discharging control unit or the fourth end of the inverter module is connected to the first end of the inverter module.
The single-phase three-level inverter topology circuit according to claim 1, wherein the charge and discharge control unit comprises a first bidirectional switch and a first unidirectional conduction element; The first end of the first bidirectional switch is connected to the first end of the charging and discharging control unit, and the second end of the first bidirectional switch is connected to the second end of the charging and discharging control unit, the first bidirectional switch The control end is connected to the charge and discharge control end; the first end of the first unidirectional conduction element is connected to the second end of the charge and discharge control unit, and the second end of the first unidirectional conduction element is connected to the charge and discharge The third end of the control unit has a conduction direction directed from the second end of the first one-way conducting element to the first end of the first one-way conducting element.
The single-phase three-level inverter topology circuit according to claim 1 or 2, wherein the inverter module comprises a second bidirectional switch, a third bidirectional switch, a fourth bidirectional switch and a fifth bidirectional switch, The control ends of the respective bidirectional switches are respectively connected to the inverter control end; in the inverter module, the first end of the second bidirectional switch is connected to the first end of the inverter module, and the second end of the second bidirectional switch is connected to the a second end of the inverter module; a first end of the third bidirectional switch is connected to the second end of the inverter module, and a second end of the third bidirectional switch is connected to the third end of the inverter module; the fourth bidirectional switch The first end of the fourth bidirectional switch is connected to the fourth end of the inverter module, and the second end of the fourth bidirectional switch is connected to the AC output end of the inverter module; the first end of the fifth bidirectional switch is connected to the alternating current of the inverter module The output end, the second end of the fifth bidirectional switch is connected to the third end of the inverter module.
The single-phase three-level inverter topology circuit according to claim 1 or 2, further comprising a charging capacitor and/or a second inductor;

The first end of the charging capacitor is connected to the first end of the charging and discharging control unit, the second end of the charging capacitor is connected to the third end of the charging and discharging control unit, or the second end of the charging capacitor is connected a second end of the inverter module;

One end of the second inductor is connected to the AC output end of the inverter module, and the other end is used to access an AC load.
The single-phase three-level inverter topology circuit according to claim 1 or 2, further comprising a DC power source;

a positive pole of the DC power source is connected to a first end of the charge and discharge control unit, a cathode of the DC power source is connected to a third end of the charge and discharge control unit, or the DC The negative pole of the power supply is connected to the second end of the inverter module.
The single-phase three-level inverter topology circuit according to claim 5, wherein the AC output end of the inverter module is connected to the negative pole of the DC power source through an AC load.
A single-phase five-level inverter topology circuit, comprising: a first floating capacitor, a second floating capacitor, a charging and discharging module and a five-level inverter module;

The charge and discharge module includes at least a first inductor and a charge and discharge control unit;

The charge and discharge control unit includes a first end, a second end, a third end, and at least one charge and discharge control end; a connection suitable for the connection from the third end to the first end of the single-conductor charge and discharge control unit; and the charge and discharge control When the terminal is the first charging and discharging control signal, the connection between the first end and the second end of the charging and discharging control unit is turned on, and when the second charging and discharging control signal is connected to the control end thereof, the charging and discharging control unit is turned off first a connection between the end and the second end;

The five-level inverter module includes a first inverter unit and a second inverter unit; the first inverter unit includes a first end, a second end, a third end, and a plurality of inverter control ends; The different control signals provided by the inverter control terminal provide at least two working modes: for the first terminal, the second terminal, and the third terminal of the first inverter unit, only the first end of the first inverter unit is turned on a connection between the two ends; for the first terminal, the second end, and the third end of the first inverter unit, only the connection between the second end and the third end of the first inverter unit is turned on;

The second inverter unit includes a first input end, a second input end, a third input end, an AC output end, and a plurality of inverter control ends; and is adapted to provide at least three types of work according to different control signals provided by the inverter control end Mode: for the first input end, the second input end, the third input end, and the AC output end of the second inverter unit, only the connection between the first input end and the AC output end of the second inverter unit is turned on For the first input end, the second input end, the third input end, and the AC output end of the second inverter unit, only the connection between the second input end of the second inverter unit and the AC output end is turned on; For the first input end, the second input end, the third input end, and the AC output end of the second inverter unit, Only connecting the connection between the third input end of the second inverter unit and the AC output terminal;

The first inductor is connected between the second end of the charging and discharging control unit and the first end of the first inverter unit; one end of the first floating capacitor is connected to the first end of the first inverter unit, The other end of the first floating capacitor is connected to the second input end of the second inverter unit; one end of the second floating capacitor is connected to the third end of the first inverter unit and the third input end of the second inverter unit The other end of the second floating capacitor is connected to the second input end of the second inverter unit;

The third end of the charging/discharging control unit is connected to the second end or the third end of the first inverter unit;

The first input end of the second inverter unit is connected to the first end of the charge and discharge control unit or the first input end of the second inverter unit is connected to the first end of the first inverter unit.
The single-phase five-level inverter topology circuit according to claim 7, wherein said charge and discharge control unit comprises a first bidirectional switch and a first unidirectional conduction element; and said first bidirectional switch is first The first end of the first bidirectional switch is connected to the second end of the charge and discharge control unit, and the control end of the first bidirectional switch is connected to the charge and discharge control end; a first end of the first unidirectional conduction element is connected to a second end of the charge and discharge control unit, and a second end of the first unidirectional conduction element is connected to a third end of the charge and discharge control unit, and is turned on The direction is directed by the second end of the first one-way element toward the first end of the first one-way element.
The single-phase five-level inverter topology circuit according to claim 7 or 8, wherein the first inverter unit comprises a second bidirectional switch and a third bidirectional switch, and the control ends of the respective bidirectional switches are correspondingly connected to the a first end of the second bidirectional switch is connected to the first end of the first inverting unit, and a second end of the second bidirectional switch is connected to the second end of the first inverting unit The first end of the third bidirectional switch is connected to the second end of the first inverting unit, and the second end of the third bidirectional switch is connected to the third end of the first inverting unit.
The single-phase five-level inverter topology circuit according to claim 7 or 8, wherein the second inverter unit further comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a a seven-way switch, wherein the control ends of the two-way switches are respectively connected to the respective inverter control ends of the second inverter unit; wherein the first end of the fourth bidirectional switch is connected to the first input end of the second inverter unit, The second end of the fourth bidirectional switch is connected to the AC output end of the second inverter unit; the first end of the fifth bidirectional switch is connected to the second input end of the second inverter unit, a second end of the fifth bidirectional switch is connected to the second end of the sixth bidirectional switch; a first end of the sixth bidirectional switch is connected to an AC output end of the second inverting unit; One end is connected to the AC output end of the second inverter unit, and the second end of the seventh bidirectional switch is connected to the third input end of the second inverter unit.
The single-phase five-level inverter topology circuit according to claim 7 or 8, wherein the second inverter unit further comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a Seven bidirectional switches, where:

a first end of the fourth bidirectional switch is connected to the first input end of the second inverter unit, and a second end of the fourth bidirectional switch is connected to the AC output end of the second inverter unit; The second end of the switch is connected to the second input end of the second inverter unit, the first end of the fifth bidirectional switch is connected to the second end of the sixth bidirectional switch; the first end of the sixth bidirectional switch The first end of the seventh bidirectional switch is connected to the second end of the sixth bidirectional switch, and the second end of the seventh bidirectional switch is connected to the second end The third input of the second inverter unit.
The single-phase five-level inverter topology circuit according to claim 7 or 8, wherein the second inverter unit further comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a a seven-way switch, wherein the control ends of the respective two-way switches are respectively connected to respective inverter control ends of the second inverter unit; wherein:

The first end of the fourth bidirectional switch is connected to the first end of the second inverting unit, and the second end of the fourth bidirectional switch is connected to the first end of the sixth bidirectional switch; The second end of the sixth bidirectional switch is connected to the AC output end of the second inverting unit; the first end of the fifth bidirectional switch is connected to the first end of the sixth bidirectional switch, the fifth bidirectional The second end of the switch is connected to the second input end of the second inverter unit; the first end of the seventh bidirectional switch is connected to the AC output end of the second inverter unit, and the second end of the seventh bidirectional switch Connecting a third input end of the second inverter unit.
The single-phase five-level inverter topology circuit according to claim 7 or 8, wherein the second inverter unit further comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a a seven-way switch, a second one-way conducting component, and a third one-way conducting component, wherein the control ends of the respective two-way switches are respectively connected to the respective inverter control ends of the second inverter unit, and the conduction directions of the respective one-way conducting components are a second end of the one-way conducting element is directed to the first end of the one-way conducting element; wherein:

a first end of the fourth bidirectional switch is connected to a first input end of the second inverting unit, and a second end of the fourth bidirectional switch is connected to a first end of the fifth bidirectional switch; a second end of the bidirectional switch is connected to the first end of the sixth bidirectional switch end; a second end of the sixth bidirectional switch is connected to the first end of the seventh bidirectional switch, and the second end of the seventh bidirectional switch Connecting a third input end of the second inverter unit; a second end of the fifth bidirectional switch and a first end of the sixth bidirectional switch are connected to an AC output end of the second inverter unit; a first end of the second unidirectional conduction element is connected to the second end of the fourth bidirectional switch and a first end of the fifth bidirectional switch, and a second end of the second unidirectional conduction element is connected to the third end a first end of the single-way element; a second end of the third one-way element connecting the second end of the sixth bidirectional switch and the first end of the seventh bidirectional switch; the second single guide a second end of the pass element and a first end of the third one-way element are coupled to the second A second input unit becomes.
The single-phase five-level inverter topology circuit according to claim 7 or 8, wherein the second inverter unit further comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a a two-way conduction element, a third one-way conduction element, a fourth one-way conduction element, and a fifth one-way conduction element, each of the one-way conduction element conduction side Pointing to the first end of the one-way conducting element from the second end of the one-way conducting element;

a first end of the fourth bidirectional switch is connected to a first input end of the second inverting unit, and a second end of the fourth bidirectional switch is connected to an AC output end of the second inverting unit; a first end of the six-way switch is connected to the AC output end of the second inverter unit, and a second end of the sixth bidirectional switch is connected to the third input end of the second inverter unit;

a first end of the second unidirectional conduction element is connected to a first end of the fifth bidirectional switch, and a second end of the second unidirectional conduction element is connected to a first end of the third unidirectional conduction element; a second end of the third unidirectional pass element is connected to a second end of the fifth bidirectional switch, and a second end of the second unidirectional pass element is connected to a first end of the third unidirectional pass element a second input end of the second inverter unit; a first end of the fourth unidirectional conduction element is connected to a first end of the fifth bidirectional switch, and a second end of the fourth unidirectional conduction element is connected a first end of the fifth unidirectional pass element; a second end of the fifth unidirectional pass element connected to a second end of the fifth bidirectional switch; a second end of the fourth unidirectional pass element The first end of the fifth unidirectional conduction element is connected to the AC output end of the second inverter unit.
The single-phase five-level inverter topology circuit according to claim 7 or 8, further comprising a charging capacitor and/or a second inductor;

The first end of the charging capacitor is connected to the first end of the charging and discharging control unit, the second end of the charging capacitor is connected to the third end of the charging and discharging control unit, or the second end of the charging capacitor is connected to the first end a second end of the inverter unit;

One end of the second inductor is connected to the AC output end of the second inverter unit, and the other end is used to access the AC load.
The single-phase five-level inverter topology circuit according to claim 7 or 8, further comprising a DC power source;

a positive pole of the DC power source is connected to a first end of the charge and discharge control unit, a cathode of the DC power source is connected to a third end of the charge and discharge control unit, or the DC The negative pole of the power source is connected to the second end of the first inverter module.
The single-phase five-level inverter topology circuit according to claim 16, wherein the AC output end of the second inverter module is connected to the negative pole of the DC power source through an AC load.
A three-phase three-level inverter topology circuit, comprising: a charging and discharging module, a floating capacitor and a three-phase inverter module; wherein

The charge and discharge module includes at least a first inductor and a charge and discharge control unit;

The charge and discharge control unit includes a first end, a second end, a third end, and at least one charge and discharge control end; a connection suitable for the one-way connection from the third end to the first end; and the first at the charge and discharge control end When the charge and discharge control signal is turned on, the connection between the first end and the second end is turned on, and when the second charge and discharge control signal is connected to the charge and discharge control end, the connection between the first end and the second end is turned off;

The three-phase inverter module includes a first inverter unit and three second inverter units; the first inverter unit includes a first end, a second end, a third end, and a plurality of inverter control ends; Providing at least two working modes according to different control signals provided by the inverter control terminal: for the first terminal, the second terminal, and the third terminal of the first inverter unit, only the first end of the first inverter unit is turned on a connection with the second end; for the first terminal, the second end, and the third end of the first inverter unit, only the connection between the second end and the third end is turned on;

Each of the second inverter units includes a first input end, a second input end, a third input end, an AC output end, and a plurality of inverter control ends; and is adapted to provide at least three types of work according to different control signals provided by the inverter control end Mode: for the first input end, the second input end, the third input end, and the AC output end, only the connection between the first input end and the AC output end is turned on; for the first input end, the second input Four terminals of the end, the third input end and the AC output end, only the connection between the second input end and the AC output end is turned on; for the first input end, the second input end, the third input end, and the AC output end four Terminals, only connecting the connection between the third input end and the AC output end;

The first inductor is connected between the second end of the charge and discharge control unit and the first end of the first inverter unit; one end of the floating capacitor is connected to the first end of the first inverter unit, The other end of the floating capacitor is connected to the third end of the first inverter unit;

The third end of the charging/discharging control unit is connected to the second end or the third end of the first inverter unit;

a first input end of each of the second inverter units is connected to a first end of the charge and discharge control unit or a first end connected to the first inverter unit; and a second input end is connected to a second end of the first inverter unit The third input is connected to the third end of the first inverter unit.
The three-phase three-level inverter topology circuit according to claim 18, wherein said charge and discharge control unit comprises a first bidirectional switch and a first unidirectional conduction element; and said first bidirectional switch is first The first end of the first bidirectional switch is connected to the second end of the charge and discharge control unit, and the control end of the first bidirectional switch is connected to the charge and discharge control end; a first end of the first unidirectional conduction element is connected to a second end of the charge and discharge control unit, and a second end of the first unidirectional conduction element is connected to a third end of the charge and discharge control unit, and is turned on The direction is directed by the second end of the first one-way element toward the first end of the first one-way element.
The three-phase three-level inverter topology circuit according to claim 18 or 19, wherein the first inverter unit comprises a second bidirectional switch and a third bidirectional switch, and the control ends of the respective bidirectional switches are correspondingly connected to the a first end of the second bidirectional switch is connected to the first end of the first inverting unit, and a second end of the second bidirectional switch is connected to the second end of the first inverting unit The first end of the third bidirectional switch is connected to the second end of the first inverting unit, and the second end of the third bidirectional switch is connected to the third end of the first inverting unit.
The three-phase three-level inverter topology circuit according to claims 18 and 19, wherein the second inverter unit comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a seventh a bidirectional switch, wherein the control ends of the respective bidirectional switches are respectively connected to the respective inverter control ends of the second inverter unit; wherein, the fourth bidirectional switch One end of the second inverter unit is connected to the first input end of the second inverter unit, and the second end of the fourth bidirectional switch is connected to the AC output end of the second inverter unit; a second input end of the second inverter unit, the second end of the fifth bidirectional switch is connected to the second end of the sixth bidirectional switch; the first end of the sixth bidirectional switch is connected to the second reverse An AC output end of the variable unit; a first end of the seventh bidirectional switch is connected to an AC output end of the second inverter unit, and a second end of the seventh bidirectional switch is connected to the second inverter unit Three inputs.
The three-phase three-level inverter topology circuit according to claim 18 or 19, wherein the second inverter unit comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a seventh Bidirectional switch, where:

a first end of the fourth bidirectional switch is connected to the first input end of the second inverter unit, and a second end of the fourth bidirectional switch is connected to the AC output end of the second inverter unit; The second end of the switch is connected to the second input end of the second inverter unit, the first end of the fifth bidirectional switch is connected to the second end of the sixth bidirectional switch; the first end of the sixth bidirectional switch The first end of the seventh bidirectional switch is connected to the second end of the sixth bidirectional switch, and the second end of the seventh bidirectional switch is connected to the second end The third input of the second inverter unit.
The three-phase three-level inverter topology circuit according to claim 18 or 19, wherein the second inverter unit comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a seventh a bidirectional switch, wherein the control ends of the respective bidirectional switches are respectively connected to respective inverter control ends of the second inverter unit; wherein:

a first end of the fourth bidirectional switch is connected to a first input end of the second bidirectional switch, and a second end of the fourth bidirectional switch is connected to a first end of the sixth bidirectional switch; a second end of the bidirectional switch is connected to the AC output end of the second inverter unit; a first end of the fifth bidirectional switch is connected to the first end of the sixth bidirectional switch, and the second end of the fifth bidirectional switch is Connecting a second input end of the second inverter unit; the first end of the seventh bidirectional switch is connected to the AC output end of the second inverter unit, the seventh The second end of the bidirectional switch is connected to the third input end of the second inverter unit.
The three-phase three-level inverter topology circuit according to claim 18 or 19, wherein the second inverter unit comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a seventh a bidirectional switch, a second one-way conducting component, and a third one-way conducting component, wherein the control ends of the respective bidirectional switches are respectively connected to the respective inverter control ends of the second inverter unit, and the conduction directions of the respective one-way conducting components are from the single a second end of the guiding element is directed to the first end of the one-way conducting element; wherein:

a first end of the fourth bidirectional switch is connected to a first input end of the second inverting unit, and a second end of the fourth bidirectional switch is connected to a first end of the fifth bidirectional switch; a second end of the bidirectional switch is connected to the first end of the sixth bidirectional switch end; a second end of the sixth bidirectional switch is connected to the first end of the seventh bidirectional switch, and the second end of the seventh bidirectional switch Connecting a third input end of the second inverter unit; a second end of the fifth bidirectional switch and a first end of the sixth bidirectional switch are connected to an AC output end of the second inverter unit; a first end of the second unidirectional conduction element is connected to the second end of the fourth bidirectional switch and a first end of the fifth bidirectional switch, and a second end of the second unidirectional conduction element is connected to the third end a first end of the single-way element; a second end of the third one-way element connecting the second end of the sixth bidirectional switch and the first end of the seventh bidirectional switch; the second single guide a second end of the pass element and a first end of the third one-way element are coupled to the second A second input unit becomes.
The three-phase three-level inverter topology circuit according to claim 18 or 19, wherein the second inverter unit comprises: a fourth bidirectional switch, a fifth bidirectional switch, a sixth bidirectional switch, and a second a unidirectional conduction element, a third unidirectional conduction element, a fourth unidirectional conduction element, and a fifth unidirectional conduction element, wherein the unidirectional conduction element is turned in a direction from the second end of the unidirectional conduction element to the unidirectional conduction element First end;

a first end of the fourth bidirectional switch is connected to a first input end of the second inverting unit, and a second end of the fourth bidirectional switch is connected to an AC output end of the second inverting unit; The first end of the six bidirectional switch is connected to the AC output of the second inverter unit The second end of the sixth bidirectional switch is connected to the third input end of the second inverting unit;

a first end of the second unidirectional conduction element is connected to a first end of the fifth bidirectional switch, and a second end of the second unidirectional conduction element is connected to a first end of the third unidirectional conduction element; a second end of the third unidirectional pass element is connected to a second end of the fifth bidirectional switch, and a second end of the second unidirectional pass element is connected to a first end of the third unidirectional pass element a second input end of the second inverter unit; a first end of the fourth unidirectional conduction element is connected to a first end of the fifth bidirectional switch, and a second end of the fourth unidirectional conduction element is connected a first end of the fifth unidirectional pass element; a second end of the fifth unidirectional pass element connected to a second end of the fifth bidirectional switch; a second end of the fourth unidirectional pass element The first end of the fifth unidirectional conduction element is connected to the AC output end of the second inverter unit.
The three-phase three-level inverter topology circuit according to claim 18 or 19, further comprising a charging capacitor and/or three second inductors;

The first end of the charging capacitor is connected to the first end of the charging and discharging control unit, the second end of the charging capacitor is connected to the third end of the charging and discharging control unit, or the second end of the charging capacitor Connecting the second end of the first inverter unit;

Each of the second inductors corresponds to a second inverter unit, one end of which is connected to the AC output end of the second inverter unit, and the other end is used for accessing an AC load.
The three-phase three-level inverter topology circuit according to claim 18 or 19, further comprising a DC power source;

a positive pole of the DC power source is connected to a first end of the charge and discharge control unit, a cathode of the DC power source is connected to a third end of the charge and discharge control unit, or a cathode of the DC power source is connected to the first inverter The second end of the module.
The three-phase three-level inverter topology circuit according to claim 27, wherein the AC output end of the second inverter module is connected to the negative pole of the DC power source through an AC load.
A three-phase three-level inverter topology circuit, comprising: three single-phase three-level inverter topology circuits according to any one of claims 1 to 6; three said single-phase three-electricity The first ends of the charging and discharging modules in the flat inverter topology circuit are connected; the third ends of the charging and discharging modules in the three single-phase three-level inverter topology circuits are connected.
A three-phase five-level inverter topology circuit, comprising: three single-phase five-level inverter topology circuits according to any one of claims 7 to 17; three said single-phase five-electricity The first ends of the charging and discharging modules in the flat inverter topology circuit are connected; the third ends of the charging and discharging modules in the three single-phase three-level inverter topology circuits are connected.