Inverter circuit for repairing potential-induced degradation

Abstract

The utility model provides an inverter circuit for repairing potential-induced degradation, and the circuit comprises a maximum power point tracking circuit, one end of which is used for connecting a photovoltaic cell panel, and the other end of which is used for connecting a battery pack; the first switch is arranged between a photovoltaic cell panel and one end of the maximum power point tracking circuit, the on-off state of the first switch is used for indicating whether the photovoltaic cell panel charges the battery pack or not, and the on-off state comprises an off state; and a coupling sub-circuit, one end of the coupling sub-circuit is connected with the negative electrode of the photovoltaic cell panel, the other end of the coupling sub-circuit is connected with a grounding end, and when the on-off state of the first switch is in an off state, the coupling sub-circuit and the maximum power point tracking circuit are inductively coupled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic power generation, and particularly relates to an inverter circuit for repairing potential induced degradation. BACKGROUND

[0002] During the process of charging the battery pack by the photovoltaic panel, the voltage released by the photovoltaic panel is high, which causes a high electric field between the pole piece of the photovoltaic panel and the ground, and causes the cations in the photovoltaic panel to be enriched on the surface of the pole piece, pollute the pole piece, form the PID phenomenon (Potential Induced Degradation), and affect the discharging efficiency of the photovoltaic panel. In the prior art, a special PID repair module is added, or the power of the power grid is provided to the pole piece of the panel through the added DC / DC converter (DC / DC) to eliminate the positive ions adsorbed on the pole piece. The above-mentioned method has a high cost. CONTENT OF THE UTILITY MODEL

[0003] Therefore, the purpose of the present application is to provide an inverter circuit for repairing potential induced degradation, which can set a first switch between the maximum power point tracking circuit and the photovoltaic panel, determine whether to supply power to the battery pack by the photovoltaic panel through the on-off state of the first switch, set a coupling sub-circuit which forms inductive coupling with the maximum power point tracking circuit when the on-off state of the first switch is in the off state, connect one end of the coupling sub-circuit to the negative electrode of the photovoltaic panel, and connect the other end of the coupling sub-circuit to the ground terminal, so as to provide a voltage difference between the electrode of the photovoltaic panel and the ground terminal through the coupling sub-circuit when the photovoltaic panel does not supply power to the battery pack, solve the technical problem that the cost of repairing potential induced degradation is high in the prior art, and achieve the technical effect of reducing the cost of repairing potential induced degradation.

[0004] In a first aspect, an embodiment of the present application provides an inverter circuit for repairing potential induced degradation, which comprises: a maximum power point tracking circuit, one end of the maximum power point tracking circuit being used for connecting a photovoltaic panel, and the other end of the maximum power point tracking circuit being used for connecting a battery pack; a first switch, the first switch being arranged between the photovoltaic panel and one end of the maximum power point tracking circuit, and the on-off state of the first switch being used for indicating whether the photovoltaic panel charges the battery pack, the on-off state including an off state; and a coupling sub-circuit, one end of the coupling sub-circuit being connected to the negative electrode of the photovoltaic panel, and the other end of the coupling sub-circuit being connected to a ground terminal, the coupling sub-circuit being inductively coupled with the maximum power point tracking circuit when the on-off state of the first switch is in the off state.

[0005] Optionally, the coupling sub-circuit comprises a target inductor, and the maximum power point tracking circuit comprises a power inductor, wherein the target inductor and the power inductor are inductively coupled.

[0006] Optionally, the coupling sub-circuit further comprises a diode, a first capacitor and a second switch, the target inductor, the diode, the first capacitor and the second switch are connected in series, wherein the diode is configured to limit the current direction of the coupling sub-circuit to flow from the negative electrode of the photovoltaic panel to the ground terminal, the first capacitor is arranged between the negative electrode of the photovoltaic panel and the ground terminal, and is configured to provide a potential difference between the negative electrode and the ground terminal, the first switch and the second switch are in different on-off states, and the second switch is configured to control whether the target inductor and the power inductor are inductively coupled.

[0007] Optionally, one end of the target inductor is connected to the anode of the diode, the cathode of the diode is connected to one end of the first capacitor, the other end of the first capacitor is connected to the other end of the target inductor, the connection between the diode and the first capacitor is used to connect the negative electrode of the photovoltaic panel, the connection between the target inductor and the first capacitor is used to connect the ground terminal, and the second switch is arranged between the other end of the target inductor and the ground terminal.

[0008] Optionally, the maximum power point tracking circuit comprises a power inductor, and the target inductor and the power inductor are inductively coupled, wherein the power inductor refers to an inductor formed by winding a first coil on a magnetic ring, and the target inductor refers to an inductor formed by winding a second coil on the magnetic ring.

[0009] Optionally, the maximum power point tracking circuit further comprises a first bridge arm and a second bridge arm, wherein one end of the first bridge arm is used to connect the photovoltaic panel as one end of the maximum power point tracking circuit, the other end of the first bridge arm is used to connect one end of the power inductor, the other end of the power inductor is used to connect one end of the second bridge arm, and the other end of the second bridge arm is used to connect the battery pack as the other end of the maximum power point tracking circuit.

[0010] Optionally, the first bridge arm comprises a first control switch, a second control switch and a second capacitor, wherein one end of the first control switch is connected to one end of the second capacitor, the other end of the first control switch is connected to one end of the second control switch, the other end of the second control switch is connected to the other end of the second capacitor, the connection between the first control switch and the first capacitor and the connection between the second control switch and the first capacitor serve as one end of the first bridge arm, and the connection between the first control switch and the second control switch serves as the other end of the first bridge arm.

[0011] Optionally, the second bridge arm comprises a third control switch, a fourth control switch and a third capacitor, wherein one end of the third control switch is connected to one end of the third capacitor, the other end of the third control switch is connected to one end of the fourth control switch, the other end of the fourth control switch is connected to the other end of the third capacitor, the connection between the third control switch and the fourth control switch serves as one end of the second bridge arm, and the connection between the third control switch and the third capacitor and the connection between the fourth control switch and the third capacitor serve as the other end of the second bridge arm.

[0012] Optionally, the circuit further comprises a grid interface for connecting to a power grid, and a conversion module, one end of the conversion module is connected to the other end of the maximum power point tracking circuit, and the other end of the conversion module is connected to the grid interface, and whether the conversion module is in working state is used to indicate whether the power grid charges the battery pack.

[0013] Optionally, the conversion module comprises an alternating current-direct current converter and a direct current-direct current converter, wherein one end of the direct current-direct current converter serves as one end of the conversion module for connecting to the other end of the maximum power point tracking circuit, the other end of the direct current-direct current converter is connected to one end of the alternating current-direct current converter, and the other end of the alternating current-direct current converter serves as the other end of the conversion module for connecting to the grid interface.

[0014] Optionally, the on-off state further comprises a conducting state, wherein when the first switch is in the conducting state, the conversion module is in non-working state, and the battery pack is charged only by the photovoltaic panel, and when the first switch is in the off state, if the conversion module is in non-working state, the maximum power point tracking circuit is powered by the battery pack, and if the conversion module is in working state, the maximum power point tracking circuit is powered by the power grid.

[0015] The embodiment of the present application provides a kind of repair potential induced attenuation inverter circuit, the circuit includes: maximum power point tracking circuit, one end of the maximum power point tracking circuit is used to connect photovoltaic cell panel, the other end of the maximum power point tracking circuit is used to connect battery pack;First switch, the first switch is arranged between photovoltaic cell panel and one end of the maximum power point tracking circuit, the on-off state of the first switch is used to indicate whether the photovoltaic cell panel charges the battery pack, and the on-off state includes the off state;Coupling subcircuit, one end of the coupling subcircuit is connected to the negative pole of the photovoltaic cell panel, and the other end of the coupling subcircuit is connected to the ground terminal, when the on-off state of the first switch is in the off state, the coupling subcircuit is inductively coupled between the coupling subcircuit and the maximum power point tracking circuit.It can be determined whether the photovoltaic cell panel supplies power to the battery pack by setting the first switch between the maximum power point tracking circuit and the photovoltaic cell panel, by the on-off state of the first switch, and setting the on-off state of the first switch to be in the off state when the coupling subcircuit is formed inductively coupled with the maximum power point tracking circuit, one end of the coupling subcircuit is connected to the negative pole of the photovoltaic cell panel, the other end of the coupling subcircuit is connected to the ground terminal, to provide a voltage difference between the electrode of the photovoltaic cell panel and the ground terminal through the coupling subcircuit when the photovoltaic cell panel does not supply power to the battery pack, solve the technical problem that the cost of repairing potential induced attenuation in the prior art is higher, and achieve the technical effect of reducing the cost of repairing potential induced attenuation.

[0016] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 A circuit diagram of an inverter circuit for repairing potential induced attenuation is shown.

[0019] Figure 2 A circuit diagram of another inverter circuit for repairing potential induced attenuation is shown. DETAILED DESCRIPTION

[0020] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, every other embodiment obtained by a person skilled in the art without creative work falls within the scope of the present application.

[0021] In the prior art, in order to repair the potential induced degradation phenomenon of the photovoltaic cell panel, a special PID repair module needs to be arranged between the pole plate and the ground of the photovoltaic cell panel, or a DC / DC converter (DC / DC) is added to the pole plate of the cell panel to provide a DC power source to eliminate the positive ions adsorbed on the pole plate. Both of the two schemes result in high cost of repairing PID.

[0022] In view of the above problems, the embodiments of the present application provide an inverter circuit for repairing potential induced degradation. A first switch is arranged between the maximum power point tracking circuit and the photovoltaic cell panel. Whether the photovoltaic cell panel supplies power to the battery pack is determined by the on-off state of the first switch. When the on-off state of the first switch is in the off state, a coupling sub-circuit is formed between the maximum power point tracking circuit and the first switch. One end of the coupling sub-circuit is connected to the negative electrode of the photovoltaic cell panel, and the other end of the coupling sub-circuit is connected to the ground terminal. When the photovoltaic cell panel does not supply power to the battery pack, the coupling sub-circuit provides a voltage difference between the electrode of the photovoltaic cell panel and the ground terminal. The technical problem of high cost of repairing potential induced degradation in the prior art is solved, and the technical effect of reducing the cost of repairing potential induced degradation is achieved. Specifically, the following is achieved:

[0023] Please refer to Figure 1 , Figure 1 A circuit diagram of an inverter circuit for repairing potential induced degradation provided by the embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the inverter circuit for repairing potential induced degradation includes a maximum power point tracking circuit 1, a first switch 2, a coupling sub-circuit 3, a photovoltaic cell panel 4, a battery pack 5, a ground terminal 6 and a DC / DC converter 7. Figure 1As shown, the inverter circuit for repairing potential induction attenuation provided by the embodiment of the present application comprises: a maximum power point tracking circuit 101, one end of the maximum power point tracking circuit is used for connecting a photovoltaic panel PV, and the other end of the maximum power point tracking circuit is used for connecting a battery pack BAT; a first switch S1, the first switch is arranged between the photovoltaic panel and one end of the maximum power point tracking circuit, and the on-off state of the first switch is used for indicating whether the photovoltaic panel charges the battery pack, and the on-off state comprises an off state; a coupling sub-circuit 102, one end of the coupling sub-circuit is connected to the negative electrode of the photovoltaic panel, and the other end of the coupling sub-circuit is connected to a ground end, and when the on-off state of the first switch is in the off state, the coupling sub-circuit is inductively coupled with the maximum power point tracking circuit.

[0024] That is, the on-off state comprises a conduction state and an off state, when the conduction state of the first switch is in the conduction state, the power transmission direction of the inverter circuit is from the photovoltaic panel to the battery pack, and the photovoltaic panel charges the battery pack, at this time, the coupling sub-circuit does not work, and cannot form a coupling inductor between the coupling sub-circuit and the maximum power point tracking circuit, so that the potential induction attenuation of the photovoltaic panel is not repaired; when the conduction state of the first switch is in the off state, the photovoltaic panel does not charge the battery pack, and the battery pack can be discharged, and the power transmission direction of the inverter circuit is from the battery pack to the maximum power point tracking circuit, in this way, the coupling sub-circuit works, and forms a coupling inductor between the coupling sub-circuit and the maximum power point tracking circuit, so that the coupling sub-circuit transmits current through inductive coupling, forms a potential difference between the negative electrode of the photovoltaic panel and the ground end, and thus the potential induction attenuation of the photovoltaic panel can be repaired.

[0025] Therefore, by the method of the present application, the PID repair can be realized without additionally setting a high-cost PID repair module or a direct-current direct-current converter, thereby reducing the cost.

[0026] The maximum power point tracking circuit can be a buck / boost circuit, the first switch is in the conduction state, the photovoltaic panel supplies power to the battery pack, at this time, the photovoltaic panel is in an MPPT (maximum power point tracking) mode.

[0027] Specifically, the coupling sub-circuit comprises a target inductor, and the maximum power point tracking circuit comprises a power inductor, wherein the target inductor is inductively coupled with the power inductor. That is, since the maximum power point tracking circuit needs to be directly boosted or stepped down to adjust, a power inductor is necessarily arranged, therefore, a target inductor is arranged in the coupling sub-circuit, and the target inductor is inductively coupled with the power inductor of the maximum power point tracking circuit, so that the inductive coupling between the coupling sub-circuit and the maximum power point tracking circuit is realized.

[0028] As Figure 1 shown, the coupling sub-circuit 102 includes a target inductor L2, a diode D1, a first capacitor C1 and a second switch S2, which are connected in series. Wherein, the diode is used to limit the current direction of the coupling sub-circuit to flow from the negative electrode of the photovoltaic panel to the ground terminal, the first capacitor is arranged between the negative electrode of the photovoltaic panel and the ground terminal, and the first capacitor is used to provide a potential difference between the negative electrode and the ground terminal. The first switch and the second switch are in different on-off states, respectively, and the second switch is used to control whether the target inductor and the power inductor are inductively coupled.

[0029] That is, the connection mode of the anode and the cathode of the diode needs to control the current in the coupling sub-circuit to flow from the negative electrode of the photovoltaic panel to the ground terminal, and the first capacitor is arranged between the negative electrode of the photovoltaic panel and the ground terminal, so that a potential difference is formed between the negative electrode of the photovoltaic panel and the ground terminal. Therefore, the current flowing from the negative electrode of the photovoltaic panel to the ground terminal can eliminate the positive ions adsorbed on the electrode of the photovoltaic panel, and by changing the on-off state of the second switch, whether the coupling sub-circuit works, that is, whether the target inductor of the coupling sub-circuit and the power inductor of the maximum power point tracking circuit are inductively coupled, is controlled, so as to control whether there is current flowing in the coupling sub-circuit.

[0030] As Figure 1 shown, one end of the target inductor is connected to the anode of the diode, the cathode of the diode is connected to one end of the first capacitor, the other end of the first capacitor is connected to the other end of the target inductor, and the connection between the diode and the first capacitor is used as one end of the coupling sub-circuit for connecting the negative electrode of the photovoltaic panel. The connection between the target inductor and the first capacitor is used as the other end of the coupling sub-circuit for connecting the ground terminal.

[0031] For example, as Figure 1As shown, the connection between the diode and the first capacitor in the embodiment of the present application is connected to the negative electrode of the photovoltaic cell panel, that is, in the coupling sub-circuit, a loop is formed by the target inductor L2, the diode D1 and the first capacitor connected in series, the connection between the diode and the first capacitor is connected to the negative electrode of the photovoltaic cell panel, the connection between the first capacitor and the target inductor is connected to the ground terminal, and the negative electrode of the photovoltaic cell panel and the ground terminal are connected through the first capacitor. Further, when the first switch is in the off state and the battery pack supplies power to the maximum power point tracking circuit, inductive coupling is performed between the target inductor in the maximum power point tracking circuit and the coupling sub-circuit, causing the electrical energy transmitted by the target inductor to flow to the first capacitor through the diode, and then the voltage between the negative electrode of the photovoltaic cell panel and the ground terminal is raised through the first capacitor to realize the function of repairing the PID.

[0032] As shown in the example, Figure 1 As shown, the same terminals of the target inductor and the power inductor are in the same direction, the same terminals of the power inductor are connected to the second bridge arm of the maximum power point tracking circuit, and the same terminals of the target inductor are connected to the second switch. In the absence of a diode, the current direction on the coupling sub-circuit is uncertain, and thus the transmission direction of the current needs to be set through the diode, that is, the single-phase conduction of the diode is used to limit the current direction of the coupling sub-circuit.

[0033] As shown in the example, Figure 1 The second switch is arranged between the other end of the target inductor and the ground terminal, and the first switch and the second switch are in different on-off states.

[0034] That is, when the first switch is in the on state, the photovoltaic cell panel charges the battery pack, at which time PID repair cannot be performed, and thus the second switch needs to be in the off state to cut off the loop of the coupling sub-circuit to protect the photovoltaic cell panel; when the first switch is in the off state, the battery pack supplies power to the maximum power point tracking circuit, at which time PID repair needs to be performed, and thus the second switch needs to be in the on state to turn on the coupling sub-circuit. Further, the first switch and the second switch are in different on-off states.

[0035] Please refer to Figure 2 , Figure 2 Another circuit diagram of an inverter circuit for repairing potential induced degradation provided by the embodiment of the present application is provided. As shown in the example, Figure 2 The maximum power point tracking circuit 101 includes a power inductor L2, and the target inductor and the power inductor are inductively coupled, wherein the power inductor refers to an inductor formed by winding a first coil on a magnetic ring, and the target inductor refers to an inductor formed by winding a second coil on the magnetic ring.

[0036] As shown in Figure 2 The power inductance of the maximum power point tracking circuit is originally an inductance formed by winding a first coil on a magnetic ring, and then a second coil is additionally wound on the same magnetic ring as a target inductance of the coupled sub-circuit, and inductance coupling is achieved so that the target inductance can have current flowing through when the power inductance has current flowing through.

[0037] As shown in Figure 2 The maximum power point tracking circuit further includes a first bridge arm and a second bridge arm, wherein one end of the first bridge arm is used as one end of the maximum power point tracking circuit for connecting a photovoltaic panel, the other end of the first bridge arm is used for connecting one end of the power inductance, the other end of the power inductance is used for connecting one end of the second bridge arm, and the other end of the second bridge arm is used as the other end of the maximum power point tracking circuit for connecting a battery pack.

[0038] That is, the power inductance in the maximum power point tracking circuit is arranged between the first bridge arm and the second bridge arm, and since the maximum power point tracking circuit has the power inductance, only a coil wound on the magnetic ring of the power inductance is needed as the target inductance of the coupled sub-circuit, thereby saving the cost of the circuit.

[0039] As shown in Figure 2 The first bridge arm includes a first control switch Q1, a second control switch Q2, and a second capacitor C2, wherein one end of the first control switch is connected to one end of the second capacitor, the other end of the first control switch is connected to one end of the second control switch, the other end of the second control switch is connected to the other end of the second capacitor, and the connection between the first control switch and the first capacitor and the connection between the second control switch and the first capacitor are used as one end of the first bridge arm, and the connection between the first control switch and the second control switch is used as the other end of the first bridge arm.

[0040] The second bridge arm includes a third control switch Q3, a fourth control switch Q4, and a third capacitor C3, wherein one end of the third control switch is connected to one end of the third capacitor, the other end of the third control switch is connected to one end of the fourth control switch, the other end of the fourth control switch is connected to the other end of the third capacitor, and the connection between the third control switch and the fourth control switch is used as one end of the second bridge arm, and the connection between the third control switch and the third capacitor and the connection between the fourth control switch and the third capacitor are used as the other end of the second bridge arm.

[0041] The power transmission on the maximum power point tracking circuit is realized by the on-off state of the control switch arranged on the first bridge arm and the second bridge arm. Exemplarily, the control switch can be a transistor, including a MOS tube (insulated gate field effect tube) and an IGBT (insulated gate bipolar transistor).

[0042] Exemplarily, as shown in Figure 2 If the first switch is in the on state and the second switch is in the off state, the respective control switches on the first bridge arm and the second bridge arm are controlled according to the size relationship between the battery pack voltage and the photovoltaic cell panel voltage. When the battery pack voltage is less than the photovoltaic cell panel voltage, the third control switch is controlled to be always on, the fourth control switch is controlled to be off, and the first control switch and the second control switch are controlled to be complementary on. When the battery pack voltage is greater than the photovoltaic cell panel voltage, the first control switch is controlled to be always on, the second control switch is controlled to be off, and the third control switch and the fourth control switch are controlled to be complementary on, so as to realize the charging of the photovoltaic cell panel to the battery pack.

[0043] Exemplarily, if the first switch is in the off state and the second switch is in the closed state, the third control switch is controlled to be on, the first control switch and the fourth control switch are controlled to be off, and the second control switch is controlled to be frequently switched between the on state and the off state. At this time, the power of the battery pack forms a loop through the third control switch, the power inductor and the second control switch, a coupling inductor is formed between the target inductor and the power inductor, and a current also flows through the target inductor. The charging and discharging of the first capacitor is realized by frequently switching the on-off of the second control switch, so as to control the potential difference between the negative electrode of the photovoltaic cell panel in the coupling sub-circuit and the ground end, and perform PID repair.

[0044] The second capacitor and the third capacitor play a voltage stabilizing role.

[0045] The circuit further comprises a grid-connected interface for connecting a power grid, and a conversion module, one end of the conversion module being connected to the other end of the maximum power point tracking circuit, and the other end of the conversion module being connected to the grid-connected interface. Whether the conversion module is in a working state is used to indicate whether the power grid charges the battery pack.

[0046] That is, the power grid is connected through the grid-connected interface led out by the conversion module, and then the battery pack is charged by the power grid when the conversion module is in the working state. In addition, since the conversion module is also connected to the maximum power point tracking circuit, the power of the power grid can also be transmitted to the maximum power point tracking circuit through the conversion module, and the on-off state of the control switch of the maximum power point tracking circuit is controlled to realize the current passing through the power inductor, so that the target inductor of the coupling sub-circuit also has a current flowing through it, and PID repair is realized.

[0047] When the first switch is in the on state, the conversion module is in a non-working state, and only the photovoltaic cell panel charges the battery pack; when the first switch is in the off state, if the conversion module is in a non-working state, the battery pack supplies power to the maximum power point tracking circuit, and if the conversion module is in a working state, the power grid supplies power to the maximum power point tracking circuit.

[0048] That is, when the first switch is in the on state, the conversion module is in a non-working state, that is, there is no exchange of electrical energy between the power grid and the battery pack, and only the photovoltaic cell panel charges the battery pack through the maximum power point tracking circuit; when the first switch is in the off state, if the conversion module is in a non-working state, the battery pack supplies power to the maximum power point tracking circuit, and a coupling inductance is formed between the maximum power point tracking circuit and the coupling sub-circuit to realize PID repair; when the first switch is in the off state, if the conversion module is in a working state, the photovoltaic cell panel does not work, the conversion module rectifies the electrical energy transmitted by the power grid through PFC (power factor correction) and then charges the battery pack through the DC / DC converter, and supplies power to the maximum power point tracking circuit, and at this time, a coupling inductance is formed between the maximum power point tracking circuit and the coupling sub-circuit to realize PID repair.

[0049] As shown in Figure 2 The conversion module includes an AC / DC converter ACDC and a DC / DC converter DCDC, wherein one end of the DC / DC converter is used as one end of the conversion module for connecting the other end of the maximum power point tracking circuit, the other end of the DC / DC converter is connected to one end of the AC / DC converter, and the other end of the AC / DC converter is used as the other end of the conversion module for connecting the grid-connected interface.

[0050] That is, when the first switch is in the off state, the conversion module is in a working state, and then the AC / DC converter converts the AC power of the grid AC received by the grid-connected interface into DC power and transmits it to the DC / DC converter, the DC / DC converter converts the input DC power into electrical energy required for charging the battery pack, so as to charge the battery pack and supply power to the maximum power point tracking circuit, to realize the transmission of electrical energy between the coupling sub-circuits.

[0051] For example, the control of the on-off state of the first switch, the on-off state of the second switch, and whether the conversion module is in a working state can be realized by a control unit adjusted by the MPPT mode used by the photovoltaic cell panel.

[0052] Further, the application makes simple structure improvement to the existing inverter circuit topology, adds a coupling winding to the power inductor of the maximum power point tracking circuit to realize the voltage transformation function, generates a high-voltage DC between the negative electrode of the photovoltaic cell panel and the ground to realize the PID repair, without adding an additional PID repair module, and without designing a high-frequency transformer to adjust the mains into a DC power supply to perform the PID repair, saving the power switch tube and control chip necessary for the design of the traditional DC power supply, reducing the cost, and optimizing the complexity of the circuit design.

[0053] In the description of the present application, it should be noted that the terms "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0054] It should also be noted that unless otherwise explicitly specified and limited, the terms "provided", "connected" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] The above only describes the embodiments of the present application and is not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A repair for potential induced degradation of an inverter circuit, characterized by, The circuit comprises: a maximum power point tracking circuit, one end of the maximum power point tracking circuit being used for connecting a photovoltaic cell panel, the other end of the maximum power point tracking circuit being used for connecting a battery pack; a first switch, the first switch being arranged between the photovoltaic cell panel and one end of the maximum power point tracking circuit, the on-off state of the first switch being used for indicating whether the photovoltaic cell panel charges the battery pack, the on-off state including an off state; a coupling sub-circuit, one end of the coupling sub-circuit being connected to a negative electrode of the photovoltaic cell panel, the other end of the coupling sub-circuit being connected to a ground terminal, the coupling sub-circuit being inductively coupled with the maximum power point tracking circuit when the on-off state of the first switch is in the off state.

2. The circuit of claim 1, wherein, The coupling sub-circuit comprises a target inductor, and the maximum power point tracking circuit comprises a power inductor, wherein the target inductor is inductively coupled with the power inductor.

3. The circuit of claim 2, wherein, The coupling sub-circuit further comprises a diode, a first capacitor and a second switch, the target inductor, the diode, the first capacitor and the second switch being connected in series, wherein the diode is used for limiting the current direction of the coupling sub-circuit to flow from the negative electrode of the photovoltaic cell panel to the ground terminal, the first capacitor is arranged between the negative electrode of the photovoltaic cell panel and the ground terminal, the first capacitor is used for providing a potential difference between the negative electrode and the ground terminal, the first switch and the second switch are respectively in different on-off states, and the second switch is used for controlling whether the target inductor is inductively coupled with the power inductor.

4. The circuit of claim 3, wherein, One end of the target inductor is connected to an anode of the diode, a cathode of the diode is connected to one end of the first capacitor, the other end of the first capacitor is connected to the other end of the target inductor, the connection between the diode and the first capacitor is used for connecting the negative electrode of the photovoltaic cell panel as one end of the coupling sub-circuit, the connection between the target inductor and the first capacitor is used for connecting the ground terminal as the other end of the coupling sub-circuit, and the second switch is arranged between the other end of the target inductor and the ground terminal.

5. The circuit of claim 2, wherein, The power inductor refers to an inductor formed by winding a first coil on a magnetic ring, and the target inductor refers to an inductor formed by winding a second coil on the magnetic ring.

6. The circuit of claim 5, wherein, The maximum power point tracking circuit further comprises a first bridge arm and a second bridge arm, wherein one end of the first bridge arm is used for connecting the photovoltaic cell panel as one end of the maximum power point tracking circuit, the other end of the first bridge arm is used for connecting one end of the power inductor, the other end of the power inductor is used for connecting one end of the second bridge arm, and the other end of the second bridge arm is used for connecting the battery pack as the other end of the maximum power point tracking circuit.

7. The circuit of claim 6, wherein, The first bridge arm comprises a first control switch, a second control switch and a second capacitor, wherein one end of the first control switch is connected to one end of the second capacitor, the other end of the first control switch is connected to one end of the second control switch, and the other end of the second control switch is connected to the other end of the second capacitor, The connection between the first control switch and the first capacitor and the connection between the second control switch and the first capacitor serve as one end of the first bridge arm, and the connection between the first control switch and the second control switch serves as the other end of the first bridge arm.

8. The circuit of claim 6, wherein, The second bridge arm comprises a third control switch, a fourth control switch and a third capacitor, wherein one end of the third control switch is connected to one end of the third capacitor, the other end of the third control switch is connected to one end of the fourth control switch, and the other end of the fourth control switch is connected to the other end of the third capacitor, the connection between the third control switch and the fourth control switch serves as one end of the second bridge arm, and the connection between the third control switch and the third capacitor and the connection between the fourth control switch and the third capacitor serve as the other end of the second bridge arm.

9. The circuit of claim 1, wherein, The circuit further comprises: a grid-connected interface for connecting a power grid; a conversion module, one end of the conversion module is connected to the other end of the maximum power point tracking circuit, and the other end of the conversion module is connected to the grid-connected interface, and whether the conversion module is in a working state is used to indicate whether the power grid charges the battery pack.

10. The circuit of claim 9, wherein, The conversion module comprises an AC / DC converter and a DC / DC converter, wherein one end of the DC / DC converter serves as one end of the conversion module for connecting the other end of the maximum power point tracking circuit, the other end of the DC / DC converter is connected to one end of the AC / DC converter, and the other end of the AC / DC converter serves as the other end of the conversion module for connecting the grid-connected interface.

11. The circuit of claim 9, wherein, The on-off state further comprises an on state, wherein when the first switch is in the on state, the conversion module is in a non-working state, and only the photovoltaic cell panel charges the battery pack, when the first switch is in the off state, if the conversion module is in a non-working state, the battery pack supplies power to the maximum power point tracking circuit, and if the conversion module is in a working state, the power grid supplies power to the maximum power point tracking circuit.

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