CN107196597B

CN107196597B - photovoltaic power generation system

Info

Publication number: CN107196597B
Application number: CN201710344394.6A
Authority: CN
Inventors: 高拥兵; 李彦锋; 王勋
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2017-05-16
Filing date: 2017-05-16
Publication date: 2019-12-13
Anticipated expiration: 2037-05-16
Also published as: CN107196597A

Abstract

the application discloses photovoltaic power generation system belongs to the photoelectricity field, includes: the photovoltaic inverter comprises a photovoltaic array, a photovoltaic inverter module, an isolation module and a PID (proportion integration differentiation) resistant voltage regulation module; the isolation module is connected with the photovoltaic array and the photovoltaic inversion module, one end of the PID resistant voltage regulation module is connected with a positive terminal of a bus capacitor of the photovoltaic inversion module, and the other end of the PID resistant voltage regulation module is connected with a positive terminal or a negative terminal of the photovoltaic array or the isolation module; the isolation module is used for separating a positive terminal of a bus capacitor of the photovoltaic inversion module from a positive terminal of the photovoltaic array and separating a negative terminal of the bus capacitor of the photovoltaic inversion module from a negative terminal of the photovoltaic array; when the photovoltaic array is not illuminated, the PID resistant voltage regulation module realizes the electrical connection between the positive terminal of the bus capacitor of the photovoltaic inversion module and the positive terminal or the negative terminal of the photovoltaic array or the isolation module. The PID effect can be avoided.

Description

photovoltaic power generation system

Technical Field

The application relates to the field of photoelectricity, in particular to a photovoltaic power generation system.

Background

at present, fossil energy reserves on the earth are becoming smaller and smaller, so that other new energy sources, such as wind energy or solar energy, are beginning to be used by human beings. For solar energy, humans can use photovoltaic power generation systems to convert solar energy into electrical energy, which is then transmitted to the power grid for human use.

the photovoltaic power generation system comprises components such as a photovoltaic cell panel and an inverter, sunlight irradiates on the photovoltaic cell panel, and the photovoltaic cell panel converts the sunlight into a direct-current voltage signal; the inverter converts the dc voltage signal into an ac voltage signal, and transmits the ac voltage signal to an ac power grid.

in the process of implementing the present application, the inventor finds that the prior art has at least the following problems:

Under the condition that a photovoltaic power generation system is connected to the grid at night, due to the electrical structure of the inverter, bias voltage may exist between two ends of the photovoltaic cell panel relative to the ground, so that a Potential Induced Degradation (PID) effect occurs in the photovoltaic cell panel, and the output power of the photovoltaic cell panel is attenuated. Such as: when the bias voltage is a negative voltage, the P-type photovoltaic cell panel is caused to have a PID effect.

disclosure of Invention

in order to avoid the PID effect and realize the restoration of the photovoltaic array power attenuation caused by the PID effect, the application provides a photovoltaic power generation system. The technical scheme is as follows:

in a first aspect, an example of the present application provides a photovoltaic power generation system, comprising: the photovoltaic inverter comprises a photovoltaic array, a photovoltaic inverter module, an isolation module and a PID (proportion integration differentiation) resistant voltage regulation module; the isolation module is connected with the photovoltaic array and the photovoltaic inversion module, one end of the PID resistant voltage regulation module is connected with a positive terminal of a bus capacitor of the photovoltaic inversion module, and the other end of the PID resistant voltage regulation module is connected with a positive terminal or a negative terminal of the photovoltaic array or the isolation module; the isolation module is used for separating a positive terminal of a bus capacitor of the photovoltaic inversion module from a positive terminal of the photovoltaic array and separating a negative terminal of the bus capacitor of the photovoltaic inversion module from a negative terminal of the photovoltaic array; when the photovoltaic array is not illuminated, the PID resistant voltage regulation module realizes the electrical connection between the positive terminal of the bus capacitor of the photovoltaic inversion module and the positive terminal or the negative terminal of the photovoltaic array or the input end of the isolation module. The isolation module is used for separating the positive end of the bus capacitor of the photovoltaic inversion module from the positive end of the photovoltaic array and separating the negative end of the bus capacitor of the photovoltaic inversion module from the negative end of the photovoltaic array, so that the photovoltaic inversion module is prevented from lowering the voltage of the two ends of the photovoltaic array to the ground under the condition that the photovoltaic inversion module is connected to the grid at night, and the PID effect of the photovoltaic array is avoided; and when the photovoltaic array is not illuminated, the anti-PID voltage regulation module realizes the electrical connection between the positive terminal of the bus capacitor of the photovoltaic inverter module and the positive terminal or the negative terminal of the photovoltaic array or the isolation module, so that the photovoltaic inverter module can pull up the voltage to ground at the two ends of the photovoltaic array through the electrical connection, and the photovoltaic array can be repaired.

in a possible implementation manner of the first aspect, the isolation module includes: the positive isolation device is used for separating a positive end of a bus capacitor of the photovoltaic inversion module from a positive end of the photovoltaic array, and the negative isolation device is used for separating a negative end of the bus capacitor of the photovoltaic inversion module from a negative end of the photovoltaic array; one end of the anti-PID voltage regulation module is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the anti-PID voltage regulation module is electrically connected with the positive end or the negative end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

In one possible implementation manner of the first aspect, the anti-PID voltage regulation module includes: and one end of the switch tube is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the switch tube is electrically connected with the positive end or the negative end of the photovoltaic array or electrically connected with the input end of the positive isolation device or electrically connected with the output end of the negative isolation device. The switch tube can realize the electrical connection between the positive terminal of the bus capacitor of the photovoltaic inversion module and the positive terminal or the negative terminal of the photovoltaic array or the input end of the isolation module.

in a possible implementation manner of the first aspect, the anti-PID voltage regulation module further includes: the first resistor is connected with the switching tube in series to form a first series circuit; one end of the first series circuit is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the first series circuit is electrically connected with the positive end or the negative end of the photovoltaic array or electrically connected with the input end of the positive isolation device or electrically connected with the output end of the negative isolation device. The first resistor is connected in series to limit the magnitude of the fault current in the event of a fault.

In a possible implementation manner of the first aspect, the anti-PID voltage regulation module further includes: the first unidirectional conducting device, the first resistor and the switching tube are connected in series to form a second series circuit; one end of the second series circuit is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the second series circuit is electrically connected with the positive end or the negative end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device; and the current of the second series circuit flows from the positive terminal of the bus capacitor of the photovoltaic inversion module to the positive terminal or the negative terminal of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device. The string uses the unidirectional effect of the first unidirectional conductive device to limit the magnitude of further fault current during fault, and the circuit structure can be simplified.

In one possible implementation manner of the first aspect, the anti-PID voltage regulation module includes: and the input end of the second one-way conduction device is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the output end of the second one-way conduction device is electrically connected with the positive end or the negative end of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device. The second unidirectional conducting device can realize the electrical connection between the positive end of the bus capacitor of the photovoltaic inversion module and the positive end or the negative end of the photovoltaic array or the input end of the positive isolating device or the output end of the negative isolating device.

In a possible implementation manner of the first aspect, the anti-PID voltage regulation module further includes: the second resistor and the second one-way conduction device are connected in series to form a third series circuit; one end of the third series circuit is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the third series circuit is electrically connected with the positive end or the negative end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device; and the current of the third series circuit flows from the positive terminal of the bus capacitor of the photovoltaic inversion module to the positive terminal or the negative terminal of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device. The second resistor is connected in series to limit the magnitude of the fault current in the event of a fault.

In one possible implementation manner of the first aspect, the photovoltaic power generation system further includes: one end of the detection module is electrically connected with the positive electrode end and/or the negative electrode end of the photovoltaic array, and the other end of the detection module is electrically connected with the photovoltaic inversion module; the detection module is used for detecting the voltage to earth of the positive terminal and/or the negative terminal of the photovoltaic array, and adjusting the voltage to earth of the positive terminal and/or the negative terminal of the photovoltaic array by controlling the voltage on the bus capacitor of the photovoltaic inversion module according to the voltage to earth. The bus voltage is controlled through the detection module, and finally the voltage of the photovoltaic array to the ground is adjusted.

In a second aspect, an example of the present application provides a photovoltaic power generation system, comprising: the photovoltaic inverter comprises a photovoltaic array, a photovoltaic inverter module, an isolation module and a PID (proportion integration differentiation) resistant voltage regulation module; the isolation module is connected with the photovoltaic array and the photovoltaic inversion module, one end of the PID resistant voltage regulation module is connected with a negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the PID resistant voltage regulation module is connected with a positive end or a negative end of the photovoltaic array or the isolation module; the isolation module is used for separating a positive terminal of a bus capacitor of the photovoltaic inversion module from a positive terminal of the photovoltaic array and separating a negative terminal of the bus capacitor of the photovoltaic inversion module from a negative terminal of the photovoltaic array; when the photovoltaic array is not illuminated, the PID resistant voltage regulation module realizes the electrical connection between the negative end of the bus capacitor of the photovoltaic inversion module and the positive end or the negative end of the photovoltaic array or the isolation module. The isolation module is used for separating the positive end of the bus capacitor of the photovoltaic inversion module from the positive end of the photovoltaic array and separating the negative end of the bus capacitor of the photovoltaic inversion module from the negative end of the photovoltaic array, so that the photovoltaic inversion module is prevented from raising the voltage of the two ends of the photovoltaic array to the ground under the condition that the photovoltaic inversion module is connected to the grid at night, and the PID effect of the photovoltaic array is avoided; and when the photovoltaic array is not illuminated, the anti-PID voltage regulation module realizes the electrical connection between the negative end of the bus capacitor of the photovoltaic inverter module and the positive end or the negative end of the photovoltaic array or the isolation module, so that the photovoltaic inverter module can pull down the voltage to ground at the two ends of the photovoltaic array through the electrical connection, and the photovoltaic array can be repaired.

in one possible implementation manner of the second aspect, the isolation module includes: the positive isolation device is used for separating a positive end of a bus capacitor of the photovoltaic inversion module from a positive end of the photovoltaic array, and the negative isolation device is used for separating a negative end of the bus capacitor of the photovoltaic inversion module from a negative end of the photovoltaic array; one end of the anti-PID voltage regulation module is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the anti-PID voltage regulation module is electrically connected with the positive end or the negative end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

In one possible implementation manner of the second aspect, the anti-PID voltage regulation module includes: and one end of the switch tube is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the switch tube is electrically connected with the negative end or the positive end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device. And the switch tube is used for realizing the electrical connection between the negative end of the bus capacitor of the photovoltaic inversion module and the positive end or the negative end of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device.

in a possible implementation manner of the second aspect, the anti-PID voltage regulation module further includes: the first resistor and the switching tube are connected in series to form a first series circuit; one end of the first series circuit is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the first series circuit is electrically connected with the negative end or the positive end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device. The first resistor is connected in series to limit the magnitude of the fault current in the event of a fault.

In a possible implementation manner of the second aspect, the anti-PID voltage regulation module further includes: the first unidirectional conducting device, the first resistor and the switching tube are connected in series to form a second series circuit; one end of the second series circuit is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the second series circuit is electrically connected with the negative end or the positive end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device; the current of the second series circuit flows from the negative end or the positive end of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device to the negative end of the bus capacitor of the photovoltaic inversion module. The string uses the unidirectional effect of the first unidirectional conductive device to limit the magnitude of further fault current during fault, and the circuit structure can be simplified.

In one possible implementation manner of the second aspect, the anti-PID voltage regulation module includes: and the input end of the second one-way conduction device is electrically connected with the negative electrode end or the positive electrode end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device, and the output end of the second one-way conduction device is electrically connected with the negative electrode end of the bus capacitor of the photovoltaic inversion module.

in a possible implementation manner of the second aspect, the anti-PID voltage regulation module further includes: the second resistor and the second one-way conduction device are connected in series to form a third series circuit; one end of the third series circuit is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the third series circuit is electrically connected with the negative end or the positive end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device; and the current of the third series circuit flows from the negative end or the positive end of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device to the negative end of the bus capacitor of the photovoltaic inversion module. The second resistor is connected in series to limit the magnitude of the fault current in the event of a fault.

in one possible implementation manner of the second aspect, the photovoltaic power generation system further includes: one end of the detection module is electrically connected with the positive electrode end and/or the negative electrode end of the photovoltaic array, and the other end of the detection module is electrically connected with the photovoltaic inversion module; the detection module is used for detecting the voltage to earth of the positive terminal and/or the negative terminal of the photovoltaic array, and adjusting the voltage to earth of the positive terminal and/or the negative terminal of the photovoltaic array by controlling the voltage on the bus capacitor of the photovoltaic inversion module according to the voltage to earth. The bus voltage is controlled through the detection module, and finally the voltage of the photovoltaic array to the ground is adjusted.

drawings

fig. 1 is a schematic structural diagram of a photovoltaic power generation system provided by an embodiment of the present application;

FIG. 2 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 3 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 4 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 5 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 6 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 7 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 8 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 9 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 10 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 11 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 12 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 13 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 14 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 15 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 16 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 17 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

FIG. 18 is a schematic block diagram of another photovoltaic power generation system provided by an embodiment of the present application;

Fig. 19 is a schematic structural diagram of another photovoltaic power generation system provided by an embodiment of the present application.

Detailed Description

referring to fig. 1, an embodiment of the present application provides a photovoltaic power generation system including a P-type photovoltaic array, including:

The photovoltaic inverter comprises a photovoltaic array 1, a photovoltaic inverter module 2, an isolation module 3 and an anti-PID voltage regulation module 4;

the isolation module 3 is connected with the photovoltaic array 1 and the photovoltaic inversion module 2, one end of the PID resistant voltage regulation module 4 is connected with a bus capacitor positive end 2a of the photovoltaic inversion module 2, and the other end of the PID resistant voltage regulation module is connected with a positive end PV + or a negative end PV-of the photovoltaic array 1 or the isolation module 3;

The isolation module 3 is used for separating a bus capacitor positive end 2a of the photovoltaic inversion module 2 from a positive end PV + of the photovoltaic array 1 and separating a bus capacitor negative end 2b of the photovoltaic inversion module 2 from a negative end PV-of the photovoltaic array 1;

When the photovoltaic array 1 is not illuminated, the PID resistant voltage regulating module 4 realizes the electrical connection between the bus capacitor positive end 2a of the photovoltaic inverter module 2 and the positive end PV + or the negative end PV-or the isolation module 3 of the photovoltaic array 1.

the photovoltaic inversion module 2 is connected with a power grid, when the photovoltaic array 1 is not illuminated, the photovoltaic inversion module 2 obtains electric energy from the power grid, and the voltage to ground of the photovoltaic array 1, namely the voltage between the photovoltaic inversion module and the ground end, can be increased through the anti-PID voltage regulation module 4.

The photovoltaic array 1 may be a P-type photovoltaic array comprising a plurality of P-type photovoltaic panels connected in series. Photovoltaic array 1 is receiving when illumination to convert light energy into first direct current voltage signal, carries first direct current voltage signal to isolation module 3. The photovoltaic array 1 stops delivering the first direct voltage signal to the isolation module 3 when there is no illumination.

The isolation module 3 realizes that the photovoltaic array 1 and the photovoltaic inverter module 2 are isolated in a single direction, and when the isolation module 3 is realized, the current signal on the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2 can be prevented from flowing into the positive terminal PV + of the photovoltaic array 1 by the isolation module 3, but the current signal on the positive terminal PV + of the photovoltaic array 1 is allowed to flow into the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2; and, the current signal on the negative terminal PV-of the photovoltaic array 1 may be prevented from flowing into the bus capacitor negative terminal 2b of the photovoltaic inverter module 2, but the current signal on the bus capacitor negative terminal 2b of the photovoltaic inverter module 2 is allowed to flow into the negative terminal PV-of the photovoltaic array 1.

therefore, when the photovoltaic array 1 transmits the first direct-current voltage signal to the isolation module 3, the isolation module 3 transmits a second direct-current voltage signal to the photovoltaic inverter module 2, where the second direct-current voltage signal may be the first direct-current voltage signal or a voltage signal obtained by transforming the first direct-current voltage signal by the isolation module 3; the photovoltaic inversion module 2 is further connected with a power grid, converts the second direct-current voltage signal into an alternating-current voltage signal, and transmits the alternating-current voltage signal to the power grid.

When the photovoltaic array 1 is not illuminated, the photovoltaic inverter module 2 may be further connected to a power grid, and at this time, a bus voltage exists between the bus capacitor positive terminal 2a and the bus capacitor negative terminal 2b of the photovoltaic inverter module 2, a voltage value of the voltage at the bus capacitor positive terminal 2a is a positive half bus voltage, and a voltage value of the voltage at the bus capacitor negative terminal 2b is a negative half bus voltage.

Under the condition that the photovoltaic inverter module 2 is connected to the grid, the alternating-current side neutral point voltage, the grid side neutral point voltage and the panel group string midpoint voltage of the photovoltaic inverter module 2 are the same, and at this time, the potential of the bus midpoint of the photovoltaic inverter module 2 and the alternating-current side neutral point of the photovoltaic inverter module 2 are equal in potential. At night, due to the existence of the isolation module 3, a loop from a bus midpoint 0 of the photovoltaic inversion module 2 to the earth to a positive terminal PV + a negative terminal PV-of the battery panel and then to a bus capacitor negative terminal 2b of the photovoltaic inversion module 2 can be blocked, and therefore the situation that the voltage between the positive terminal PV + and the grounding terminal of the photovoltaic array 1 and the voltage between the negative terminal PV-and the grounding terminal of the photovoltaic array 1 are both negative voltage is avoided. The PID effect of the photovoltaic array 1 is avoided.

Because when the photovoltaic array 1 is not illuminated, the anti-PID voltage regulation module 4 realizes the electrical connection between the bus capacitor positive terminal 2a of the photovoltaic inverter module 2 and the positive terminal PV + of the photovoltaic array 1, so that the current signal on the bus capacitor positive terminal 2a of the photovoltaic inverter module 2 flows into the photovoltaic array 1 through the anti-PID voltage regulation module 4, the voltage to ground of the positive terminal PV + and the voltage to ground of the negative terminal PV-of the photovoltaic array 1 can be both pulled up to positive voltage, the positive voltage to ground value of the positive terminal PV + and the negative terminal PV-voltage to ground value of the positive terminal PV + of the photovoltaic array 1 can be regulated by controlling the bus voltage of the photovoltaic inverter module 2, and the output power attenuated by the photovoltaic array 1 can be restored.

the isolation module 3 can be implemented in various ways, for example, the isolation module 3 includes a plurality of unidirectional conductors or is a dc transformer module with an isolation function, or the isolation module 3 includes a unidirectional conductor and a dc transformer module.

the direct current voltage transformation module is used for converting a first direct current voltage signal transmitted by the photovoltaic array 1 into a second direct current voltage signal, and the voltage value of the first direct current voltage signal can be different from that of the second direct current voltage signal.

Next, the isolation module 3 is illustrated by way of example, for example, when the isolation module 3 includes a plurality of unidirectional conducting devices, referring to fig. 2, the isolation module 3 includes a third unidirectional conducting device 31 and a fourth unidirectional conducting device 32, an input end of the third unidirectional conducting device 31 is electrically connected to the positive terminal PV + of the photovoltaic array 1, an output end of the third unidirectional conducting device is electrically connected to the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2, an input end of the fourth unidirectional conducting device 32 is electrically connected to the negative terminal 2b of the bus capacitor of the photovoltaic inverter module 2, and an output end of the fourth unidirectional conducting device is electrically connected to the negative terminal PV-of the photovoltaic array 1. The third unidirectional conducting device 31 and the fourth unidirectional conducting device 32 may be a positive isolating device and a negative isolating device in the isolating module 3, respectively.

the unidirectional conducting device may be a diode, a switching tube, or the like, and when the unidirectional conducting device is a diode, the input end of the unidirectional conducting device may be an anode of the diode, and the output end may be a cathode of the diode. The switch tube can be a mechanical switch or a semiconductor switch, the mechanical switch can be a relay, and the semiconductor switch can be a Mos tube.

as another example, the isolation module 3 may include a dc transformer module and a unidirectional conducting device, referring to fig. 3, the isolation module 3 may include an inductor L, a switch 33, a third unidirectional conducting device 31, and a fourth unidirectional conducting device 32; the inductor L, the switch 33 and the third unidirectional conducting device 31 form a direct current transformation module, the positive terminal PV + of the photovoltaic array 1 is electrically connected with one end of the inductor L, the other end of the inductor L is electrically connected with one end of the switch 33 and the input end of the third unidirectional conducting device 31, and the output end of the third unidirectional conducting device 31 is electrically connected with the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2; the negative end PV-of the photovoltaic array 1 is electrically connected with the output end of the fourth unidirectional conducting device 32, and the input end of the fourth unidirectional conducting device 32 is electrically connected with the negative end 2b of the bus capacitor of the photovoltaic inverter module 2 and the other end of the switch 33.

Referring to fig. 2 to 4, one end of the anti-PID voltage regulation module 4 is electrically connected to the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2, and the other end thereof may be electrically connected to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1 or to the input terminal of the third unidirectional conducting device 31 or the output terminal of the fourth unidirectional conducting device 32 in the isolation module 3. That is, the other end may be electrically connected to the input of the positive isolation device or to the output of the negative isolation device.

Referring to fig. 2, the photovoltaic inverter module 2 includes a first bus capacitor C1, a second bus capacitor C2, and an inverter circuit 21, wherein one end of the first bus capacitor C1 is electrically connected to a first input terminal of the inverter circuit 21, and the other end is electrically connected to one end of the second bus capacitor C2; the other end of the second bus capacitor C2 is electrically connected to a second input terminal of the inverter circuit 21.

The connection point O of the first bus capacitor C1 and the second bus capacitor C2 is referred to as a bus midpoint. A connection point of one end of the first bus capacitor C1 and the first input end of the inverter circuit 21 is a bus capacitor positive terminal 2a, and a connection point of the other end of the second bus capacitor C2 and the second input end of the inverter circuit 21 is a bus capacitor negative terminal 2 b.

When the photovoltaic array 1 is illuminated, the isolation module 3 transmits the second direct-current voltage signal to the inverter circuit 21, and the inverter circuit 21 is connected to the power grid and is configured to convert the second direct-current voltage signal into an alternating-current voltage signal and transmit the alternating-current voltage signal to the power grid.

when the photovoltaic array 1 is not illuminated, the inverter circuit 21 can convert the alternating current voltage signal of the power grid into a direct current voltage signal, a bus voltage is formed between the bus capacitor positive terminal 2a and the bus capacitor negative terminal 2b, the bus voltage value is controllable, the voltage value at the bus midpoint O is 0V, the voltage values of the two ends of the first bus capacitor C1 and the two ends of the second bus capacitor C2 are equal and equal to one-half of the bus voltage, therefore, the end of the first bus capacitor C1 connected to the first input end of the inverter circuit 21, i.e. the end of the bus capacitor at the positive terminal 2a, is a positive voltage and has a magnitude equal to one-half of the positive bus voltage, the end of the second bus capacitor C2 connected to the second input end of the inverter circuit 21, namely, the voltage of the negative terminal 2b of the bus capacitor is a negative voltage and is equal to the bus voltage of negative one-half.

in the present embodiment, there are multiple implementations of the anti-PID voltage regulation module 4, and in the present embodiment, the following first and second implementations are listed, including:

firstly, referring to fig. 5, the anti-PID voltage regulation module 4 includes a switch tube S, one end of the switch tube S is electrically connected to the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2, and the other end is electrically connected to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1, or electrically connected to the input terminal of the positive isolation device, or electrically connected to the output terminal of the negative isolation device. For example, the other end of the switching tube S may be electrically connected to the input terminal of the third unidirectional conducting device 31 or the output terminal of the fourth unidirectional conducting device 32 or the negative terminal PV-or the positive terminal PV + of the photovoltaic array 1.

When the photovoltaic array 1 is not illuminated, the switch tube S is closed to conduct the positive terminal 2a of the bus capacitor of the photovoltaic inversion module 2 with the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1 or the input terminal of the positive isolation device or the output terminal of the negative isolation device; the positive current signal on the positive terminal 2a of the bus capacitor flows into the photovoltaic array 1 through the switching tube S. When the photovoltaic array 1 is illuminated, the switching tube S is disconnected to disconnect the positive terminal 2a of the bus capacitor from the photovoltaic array 1.

referring to fig. 6, in a first implementation manner of the anti-PID voltage regulation module 4, the anti-PID voltage regulation module 4 further includes a first resistor R1; the first resistor R1 and the switching tube S are connected in series to form a first series circuit;

One end of the first series circuit is electrically connected with the positive end 2a of the bus capacitor of the photovoltaic inversion module 2, and the other end of the first series circuit is electrically connected with the positive end PV + or the negative end PV-of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

For example, the other end of the switch tube S is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1 or electrically connected to the input terminal of the third unidirectional conducting device 31 or electrically connected to the output terminal of the fourth unidirectional conducting device 32.

thus, when the switch tube S is closed, a positive current signal on the positive terminal 2a of the bus capacitor flows into the photovoltaic array 1 through the switch tube S and the first resistor R1.

referring to fig. 7, in a first implementation manner of the anti-PID voltage regulation module 4, the anti-PID voltage regulation module 4 further includes a first one-way conduction device 41, and the first one-way conduction device 41, a first resistor R1 and a switching tube S are connected in series to form a second series circuit;

one end of the second series circuit is electrically connected with the positive end 2a of the bus capacitor of the photovoltaic inversion module 2, and the other end of the second series circuit is electrically connected with the positive end PV + or the negative end PV-of the photovoltaic array 1 or electrically connected with the input end of the positive isolation device or electrically connected with the output end of the negative isolation device;

the current of the second series circuit flows from the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2 to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1 or the input terminal of the positive isolation device or the output terminal of the negative isolation device.

For example, referring to fig. 7, the first unidirectional conducting device 41 is a diode, an anode of which is connected to the other end of the first resistor R1, and a cathode of which is electrically connected to the positive terminal PV + of the photovoltaic array 1.

thus, when the switch tube S is closed, a positive current signal on the positive terminal 2a of the bus capacitor flows into the photovoltaic array 1 through the switch tube S, the first resistor R1 and the first unidirectional flux device 41.

Secondly, referring to fig. 8, the anti-PID voltage regulation module 4 includes a second unidirectional conducting device 42, an input end of the second unidirectional conducting device 42 is electrically connected to the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2, and an output end is electrically connected to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1 or to an input end of the positive isolation device or to an output end of the negative isolation device.

when the photovoltaic array 1 is not illuminated, the voltage to ground at the positive terminal PV + of the photovoltaic array 1 is 0, the voltage to ground at the positive terminal 2a of the bus capacitor is a positive voltage signal, and the second unidirectional conducting device 42 conducts the positive terminal 2a of the bus capacitor and the photovoltaic array 1; the positive current signal on the positive terminal 2a of the bus capacitor flows through the second unidirectional conducting device 42 into the photovoltaic array 1. When the photovoltaic array 1 is illuminated, the second unidirectional conducting device 42 may prevent the positive current signal output from the positive terminal PV + of the photovoltaic array 1 from flowing into the positive terminal 2a of the bus capacitor.

referring to fig. 9, in a second implementation manner of the anti-PID voltage regulation module 4, the anti-PID voltage regulation module 5 further includes a second resistor R2; the second resistor R2 and the second one-way conduction device 42 are connected in series to form a third series circuit;

one end of the third series circuit is electrically connected with the positive end 2a of the bus capacitor of the photovoltaic inversion module 2, and the other end of the third series circuit is electrically connected with the positive end PV + or the negative end PV-of the photovoltaic array 1 or electrically connected with the input end of the positive isolation device or electrically connected with the output end of the negative isolation device;

the current of the third series circuit flows from the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2 to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1 or the input terminal of the positive isolation device or the output terminal of the negative isolation device.

referring to fig. 10, the photovoltaic power generation system further includes:

one end of the detection module 4 is electrically connected with the positive electrode end PV + and/or the negative electrode end PV-of the photovoltaic array 1, and the other end of the detection module is electrically connected with the photovoltaic inverter module 2;

and the detection module 5 is used for detecting the voltage to ground of the positive electrode end PV + and/or the negative electrode end PV-of the photovoltaic array 1, and adjusting the voltage to ground of the positive electrode end PV + and/or the negative electrode end PV-of the photovoltaic array 1 by controlling the voltage on the bus capacitor of the photovoltaic inverter module 2 according to the voltage to ground.

The detection module 5 may be directly integrated on the photovoltaic inverter module 2, or may be an independent module.

In an embodiment of the application, when the photovoltaic array is not illuminated, the anti-PID voltage regulation module realizes the electrical connection between the positive terminal 2a of the bus capacitor of the photovoltaic inverter module and the positive terminal PV + or the negative terminal PV-or the isolation module 3 of the photovoltaic array, and the photovoltaic inverter module pulls up the positive terminal PV + and the negative terminal PV-to-ground voltages of the photovoltaic array through the anti-PID voltage regulation module, so that the voltages between the positive terminal PV + and the ground terminal of the photovoltaic array and the voltages between the negative terminal PV-and the ground terminal of the photovoltaic array are both greater than 0, thereby avoiding the occurrence of the PID effect of the photovoltaic array, and also repairing the output power of the photovoltaic array.

Referring to fig. 11, an embodiment of the present application provides a photovoltaic power generation system including a photovoltaic array that is an N-type photovoltaic array, including:

The isolation module 3 is connected with the photovoltaic array 1 and the photovoltaic inversion module 2, one end of the PID resistant voltage regulation module 4 is connected with the negative end 2b of the bus capacitor of the photovoltaic inversion module 2, and the other end is connected with the positive end PV + or the negative end PV-of the photovoltaic array 1 or the isolation module 3;

When the photovoltaic array 1 is not illuminated, the anti-PID voltage regulation module 4 realizes the electrical connection between the bus capacitor negative end 2b of the photovoltaic inverter module 2 and the positive end PV + or the negative end PV-or the isolation module 3 of the photovoltaic array 1.

The photovoltaic inversion module 2 is connected with a power grid, when the photovoltaic array 1 is not illuminated, the photovoltaic inversion module 2 obtains electric energy from the power grid, the voltage on a bus capacitor of the photovoltaic inversion module 2 is controlled by detecting the voltage value to the ground of the positive terminal PV + and/or the voltage value to the ground of the negative terminal PV-of the photovoltaic array 1, and the voltage value to the ground of the positive terminal PV + and the voltage value to the ground of the negative terminal PV-of the photovoltaic array 1 is adjusted.

The photovoltaic array 1 may be an N-type photovoltaic array comprising a plurality of N-type photovoltaic panels connected in series. Photovoltaic array 1 is receiving when illumination to convert light energy into first direct current voltage signal, carries first direct current voltage signal to isolation module 3. The photovoltaic array 1 stops delivering the first direct voltage signal to the isolation module 3 when there is no illumination.

because the isolation module 3 can prevent the bus capacitor positive terminal 2a of the photovoltaic inverter module 2 from pulling up the voltage to the ground at the two ends of the photovoltaic array 1, the voltage between the positive terminal PV + of the photovoltaic array 1 and the grounding terminal and the voltage between the negative terminal PV-and the grounding terminal are both prevented from becoming positive voltages, and thus the PID effect and the output power attenuation of the photovoltaic array 1 are prevented.

when the photovoltaic array 1 is not illuminated, the anti-PID voltage regulation module 4 realizes the electrical connection between the bus capacitor negative end 2b of the photovoltaic inverter module 2 and the positive end PV + or the negative end PV-of the photovoltaic array 1 or the input end of the isolation device of the isolation module 3, and the bus capacitor energy of the photovoltaic inverter module 2 flows to the ground through the bus midpoint O, and flows into the bus capacitor negative end 2b from the photovoltaic array 1 to the anti-PID voltage regulation module 4 through the ground. Therefore, the voltage to ground of the positive electrode end PV + and the voltage to ground of the negative electrode end PV-of the photovoltaic array 1 can be pulled down to be negative voltage, and the output power attenuated by the photovoltaic array 1 can be repaired.

next, the isolation module 3 is illustrated by way of example, for example, when the isolation module 3 includes a plurality of unidirectional conducting devices, referring to fig. 12, the isolation module 3 includes a third unidirectional conducting device 31 and a fourth unidirectional conducting device 32, an input end of the third unidirectional conducting device 31 is electrically connected to the positive terminal PV + of the photovoltaic array 1, an output end of the third unidirectional conducting device is electrically connected to the positive terminal 2a of the bus capacitor of the photovoltaic inverter module 2, an input end of the fourth unidirectional conducting device 32 is electrically connected to the negative terminal 2b of the bus capacitor of the photovoltaic inverter module 2, and an output end of the fourth unidirectional conducting device is electrically connected to the negative terminal PV-of the photovoltaic array 1. The third unidirectional conducting device 31 and the fourth unidirectional conducting device 32 may be a positive isolating device and a negative isolating device in the isolating module 3, respectively.

As another example, the isolation module 3 may include a dc transformer module and a unidirectional conducting device, referring to fig. 13, the isolation module 3 may include an inductor L, a switch 33, a third unidirectional conducting device 31, and a fourth unidirectional conducting device 32; the inductor L, the switch 33 and the fourth unidirectional conducting device 32 form a direct current transformation module, a negative electrode end PV-of the photovoltaic array 1 is electrically connected with one end of the inductor L, the other end of the inductor L is electrically connected with one end of the switch 33 and the output end of the fourth unidirectional conducting device 32, and the input end of the fourth unidirectional conducting device 32 is electrically connected with a negative electrode end 2b of a bus capacitor of the photovoltaic inverter module 2; the positive end PV + of the photovoltaic array 1 is electrically connected with the input end of the third unidirectional conducting device 31, and the output end of the third unidirectional conducting device 31 is electrically connected with the positive end 2a of the bus capacitor of the photovoltaic inverter module 2 and the other end of the switch 33.

Referring to fig. 12 to 13, one end of the anti-PID voltage adjusting module 4 is electrically connected to the negative terminal 2b of the bus capacitor of the photovoltaic inverter module 2, and the other end may be electrically connected to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1, or electrically connected to the input terminal of the third unidirectional conducting device 31, or electrically connected to the output terminal of the fourth unidirectional conducting device 32. That is, the other end may be electrically connected to the input of the positive isolation device or to the output of the negative isolation device.

Referring to fig. 12, the photovoltaic inverter module 2 includes a first bus capacitor C1, a second bus capacitor C2, and an inverter circuit 21, wherein one end of the first bus capacitor C1 is electrically connected to a first input terminal of the inverter circuit 21, and the other end is electrically connected to one end of the second bus capacitor C2; the other end of the second bus capacitor C2 is electrically connected to a second input terminal of the inverter circuit 21.

when the photovoltaic array 1 is not illuminated, the inverter circuit 21 may convert an ac voltage signal of a power grid into a dc voltage signal, a bus voltage is formed between the bus capacitor positive terminal 2a and the bus capacitor negative terminal 2b, and a voltage value at the bus midpoint O is 0V, a voltage value at two ends of the first bus capacitor C1 and a voltage value at two ends of the second bus capacitor C2 are equal to and equal to one-half of the bus voltage, so that the first bus capacitor C1 is connected to the first input terminal of the inverter circuit 21, the bus capacitor positive terminal 2a has a positive voltage and a magnitude equal to one-half of the positive bus voltage, and the second bus capacitor C2 is connected to the second input terminal of the inverter circuit 21, that is, the bus capacitor negative terminal 2b has a negative voltage and a magnitude equal to one-half of the negative bus voltage.

the isolation module 3 can block positive current signals on the positive terminal 2a of the bus capacitor from flowing into the photovoltaic array 1, and the voltage between the positive terminal PV + of the photovoltaic array 1 and the grounding terminal and the voltage between the negative terminal PV-and the grounding terminal are prevented from being pulled down to be high voltage, so that the PID effect of the photovoltaic array 1 is prevented.

Firstly, referring to fig. 14, the anti-PID voltage regulation module 4 includes a switch tube S, one end of the switch tube S is electrically connected to the negative terminal 2b of the bus capacitor of the photovoltaic inverter module 2, and the other end is electrically connected to the positive terminal PV + or the negative terminal PV-of the photovoltaic array 1, or the input terminal of the positive isolation device, or the output terminal of the negative isolation device.

Referring to fig. 15, in a first implementation manner of the anti-PID voltage regulation module 4, the anti-PID voltage regulation module 4 further includes a first resistor R1, and the first resistor R1 and the switching tube S are connected in series to form a first series circuit;

one end of the first series circuit is electrically connected with the negative end 2b of the bus capacitor of the photovoltaic inversion module 2, and the other end of the first series circuit is electrically connected with the positive end PV + or the negative end PV-of the photovoltaic array 1, or electrically connected with the input end of the positive isolation device or electrically connected with the output end of the negative isolation device.

referring to fig. 16, in a first implementation manner of the anti-PID voltage regulation module 4, the anti-PID voltage regulation module 4 further includes a first one-way conduction device 41, and the first one-way conduction device 41, a first resistor R1 and a switching tube S are connected in series to form a second series circuit;

one end of the second series circuit is electrically connected with the negative end 2b of the bus capacitor of the photovoltaic inversion module 2, and the other end of the second series circuit is electrically connected with the positive end PV + or the negative end PV-of the photovoltaic array 1 or electrically connected with the input end of the positive isolation device or electrically connected with the output end of the negative isolation device;

The current of the second series circuit flows from the negative end PV-or the positive end PV + of the photovoltaic array 1 or the input end of the positive isolation device or the output end of the negative isolation device to the negative end 2b of the bus capacitor of the photovoltaic inverter module 2.

thus, when the switch tube S is closed, the current signal at the bus midpoint O flows into the photovoltaic array 1 through the ground terminal, and the current signal flows into the bus capacitor negative terminal 2b through the second series circuit composed of the switch tube S, the first resistor R1 and the first unidirectional conducting device 41, so as to pull down the positive terminal PV + and the negative terminal PV-ground voltages of the photovoltaic array 1.

second, referring to fig. 17, the anti-PID voltage regulating module 4 includes a second one-way pass device 42,

the input end of the second unidirectional conducting device 42 is electrically connected with the negative electrode end PV-or the positive electrode end PV + of the photovoltaic array 1 or electrically connected with the input end of the positive isolating device or the output end of the negative isolating device, and the output end is electrically connected with the negative electrode end 2b of the bus capacitor of the photovoltaic inverter module 2.

When the photovoltaic array 1 is not illuminated, the voltage on the negative end PV-of the photovoltaic array 1 is 0, a current signal on the bus midpoint O flows into the photovoltaic array 1 through the ground end, and the current signal flows into the bus capacitor negative end 2b through the second unidirectional conducting device 42 to pull down the positive end PV + voltage to ground and the negative end PV-voltage to ground of the photovoltaic array 1.

Referring to fig. 18, in the first implementation of the anti-PID voltage regulation module 4, the regulation module 5 further includes a second resistor R2;

the second resistor R2 and the second one-way conduction device 42 are connected in series to form a third series circuit;

One end of the third series circuit is electrically connected with the negative end 2b of the bus capacitor of the photovoltaic inversion module 2, and the other end of the third series circuit is electrically connected with the negative end PV-or the positive end PV + of the photovoltaic array 1 or the input end of the positive isolation device or the output end of the negative isolation device;

the current of the third series circuit flows from the negative end PV-or the positive end PV + of the photovoltaic array 1 or the input end of the positive isolation device or the output end of the negative isolation device to the negative end 2b of the bus capacitor of the photovoltaic inverter module 2.

referring to fig. 19, the photovoltaic power generation system further includes:

in an embodiment of the application, when the photovoltaic array is not illuminated, the photovoltaic inverter module pulls down the positive terminal PV + voltage to ground and the negative terminal PV-voltage to ground of the photovoltaic array through the anti-PID voltage adjustment module, so that the voltage between the positive terminal PV + and the ground of the photovoltaic array and the voltage between the negative terminal PV-and the ground of the photovoltaic array are both less than 0, thereby avoiding the occurrence of PID effect in the photovoltaic array, and also repairing the output power of the photovoltaic array.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A photovoltaic power generation system, characterized in that the photovoltaic power generation system comprises:

The photovoltaic inversion module comprises a first bus capacitor, a second bus capacitor and an inversion circuit, wherein one end of the first bus capacitor is electrically connected with a first input end of the inversion circuit, and the other end of the first bus capacitor is electrically connected with one end of the second bus capacitor; the other end of the second bus capacitor is electrically connected with a second input end of the inverter circuit;

The connection point of the first bus capacitor and the second bus capacitor is a bus midpoint, the connection point of one end of the first bus capacitor and the first input end of the inverter circuit is a bus capacitor positive end, and the connection point of the other end of the second bus capacitor and the second input end of the inverter circuit is a bus capacitor negative end;

The isolation module is connected with the photovoltaic array and the photovoltaic inversion module, one end of the PID resistant voltage regulation module is connected with the positive terminal of the bus capacitor, and the other end of the PID resistant voltage regulation module is connected with the positive terminal or the negative terminal of the photovoltaic array or the isolation module;

The isolation module is used for realizing the separation of the positive end of the bus capacitor and the positive end of the photovoltaic array and the separation of the negative end of the bus capacitor of the photovoltaic inversion module and the negative end of the photovoltaic array;

When the photovoltaic array is not illuminated, the PID resistant voltage regulation module realizes the electrical connection between the positive terminal of the bus capacitor and the positive terminal or the negative terminal of the photovoltaic array or the isolation module, and a current signal on the positive terminal of the bus capacitor flows into the photovoltaic array through the PID resistant voltage regulation module.

2. the photovoltaic power generation system of claim 1, wherein the isolation module comprises:

the positive isolation device is used for separating a positive end of a bus capacitor of the photovoltaic inversion module from a positive end of the photovoltaic array, and the negative isolation device is used for separating a negative end of the bus capacitor of the photovoltaic inversion module from a negative end of the photovoltaic array;

One end of the anti-PID voltage regulation module is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the anti-PID voltage regulation module is electrically connected with the positive end or the negative end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

3. the photovoltaic power generation system of claim 2, wherein the anti-PID voltage regulation module comprises:

a switch tube is arranged on the upper surface of the shell,

One end of the switch tube is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the switch tube is electrically connected with the positive end or the negative end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

4. The photovoltaic power generation system of claim 3, wherein the anti-PID voltage regulation module further comprises:

the first resistor is connected with the switching tube in series to form a first series circuit;

One end of the first series circuit is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the first series circuit is electrically connected with the positive end or the negative end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

5. The photovoltaic power generation system of claim 4, wherein the anti-PID voltage regulation module further comprises:

the first unidirectional conducting device, the first resistor and the switching tube are connected in series to form a second series circuit;

One end of the second series circuit is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the second series circuit is electrically connected with the positive end or the negative end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device;

And the current of the second series circuit flows from the positive terminal of the bus capacitor of the photovoltaic inversion module to the positive terminal or the negative terminal of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device.

6. the photovoltaic power generation system of claim 2, wherein the anti-PID voltage regulation module comprises:

a second one-way conducting device for conducting,

the input end of the second one-way conduction device is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the output end of the second one-way conduction device is electrically connected with the positive end or the negative end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

7. the photovoltaic power generation system of claim 6, wherein the anti-PID voltage regulation module further comprises:

the second resistor and the second one-way conduction device are connected in series to form a third series circuit;

One end of the third series circuit is electrically connected with the positive end of a bus capacitor of the photovoltaic inversion module, and the other end of the third series circuit is electrically connected with the positive end or the negative end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device;

and the current of the third series circuit flows from the positive terminal of the bus capacitor of the photovoltaic inversion module to the positive terminal or the negative terminal of the photovoltaic array or the input end of the positive isolation device or the output end of the negative isolation device.

8. The photovoltaic power generation system of any one of claims 1 to 7, further comprising:

one end of the detection module is electrically connected with the positive electrode end and/or the negative electrode end of the photovoltaic array, and the other end of the detection module is electrically connected with the photovoltaic inversion module;

The detection module is used for detecting the voltage to earth of the positive terminal and/or the negative terminal of the photovoltaic array, and adjusting the voltage to earth of the positive terminal and/or the negative terminal of the photovoltaic array by controlling the voltage on the bus capacitor of the photovoltaic inversion module according to the voltage to earth.

9. A photovoltaic power generation system, characterized in that the photovoltaic power generation system comprises:

the isolation module is connected with the photovoltaic array and the photovoltaic inversion module, one end of the PID resistant voltage regulation module is connected with the negative end of the bus capacitor, and the other end of the PID resistant voltage regulation module is connected with the positive end or the negative end of the photovoltaic array or the isolation module;

When the photovoltaic array is not illuminated, the anti-PID voltage regulation module realizes the electrical connection between the negative end of the bus capacitor and the positive end or the negative end of the photovoltaic array or the isolation module, the bus capacitor energy goes to the ground through the bus midpoint and then goes to the photovoltaic array through the ground, and the photovoltaic array goes to the anti-PID voltage regulation module and flows into the negative end of the bus capacitor.

10. the photovoltaic power generation system of claim 9, wherein the isolation module comprises:

one end of the anti-PID voltage regulation module is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the anti-PID voltage regulation module is electrically connected with the positive end or the negative end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

11. The photovoltaic power generation system of claim 10, wherein the anti-PID voltage regulation module comprises:

A switch tube is arranged on the upper surface of the shell,

One end of the switch tube is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the switch tube is electrically connected with the negative end or the positive end of the photovoltaic array or electrically connected with the input end of the positive isolation device or the output end of the negative isolation device.

12. the photovoltaic power generation system of claim 11, wherein the anti-PID voltage regulation module further comprises:

the first resistor and the switching tube are connected in series to form a first series circuit;

One end of the first series circuit is electrically connected with a negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the first series circuit is electrically connected with a negative end or a positive end of the photovoltaic array, or is electrically connected with an input end of the positive isolation device or an output end of the negative isolation device.

13. The photovoltaic power generation system of claim 12, wherein the anti-PID voltage regulation module further comprises:

One end of the second series circuit is electrically connected with the negative end of a bus capacitor of the photovoltaic inversion module, and the other end of the second series circuit is electrically connected with the negative end or the positive end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device;

the current of the second series circuit flows from the negative end or the positive end of the photovoltaic array, or the input end of the positive isolation device or the output end of the negative isolation device to the negative end of the bus capacitor of the photovoltaic inversion module.

14. The photovoltaic power generation system of claim 10, wherein the anti-PID voltage regulation module comprises:

A second one-way conducting device for conducting,

The input end of the second one-way conduction device is electrically connected with the negative end or the positive end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or is electrically connected with the output end of the negative isolation device, and the output end of the second one-way conduction device is electrically connected with the negative end of the bus capacitor of the photovoltaic inversion module.

15. The photovoltaic power generation system of claim 14, wherein the anti-PID voltage regulation module further comprises:

One end of the third series circuit is electrically connected with the negative end of the bus capacitor of the photovoltaic inversion module, and the other end of the third series circuit is electrically connected with the negative end or the positive end of the photovoltaic array, or is electrically connected with the input end of the positive isolation device or the output end of the negative isolation device;

The current of the third series circuit flows from the negative end or the positive end of the photovoltaic array, or the input end of the positive isolation device or the output end of the negative isolation device to the negative end of the bus capacitor of the photovoltaic inversion module.

16. The photovoltaic power generation system of any one of claims 9 to 15, further comprising: