Compensation circuit, PID board and photovoltaic system

Abstract

This application provides a compensation circuit, a PID board, and a photovoltaic system. The compensation circuit is applied to a photovoltaic system, which includes photovoltaic modules and a photovoltaic inverter connected in sequence. The photovoltaic inverter is also used for connection to the power grid. The compensation circuit includes: a first voltage conversion module, a second voltage conversion module, a switching module, and a control module. The control module is used to collect the plate voltage of the photovoltaic modules and control the switching module to close or open based on the plate voltage. The second voltage conversion module is used to convert the inverter voltage into a supply voltage and supply power to both the switching module and the control module. The first voltage conversion module is used to convert the inverter voltage into a compensation voltage and perform voltage compensation to the photovoltaic modules when the switching module is closed. This application can reduce the size of the PID compensation circuit while ensuring the PID compensation effect.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a compensation circuit PID board and a photovoltaic system. Background Technology

[0002] With the development of the photovoltaic industry, photovoltaic modules are being used more and more widely. However, during long-term use, photovoltaic modules experience potential-induced degradation (PID) effects, which affect the reliability of photovoltaic power generation.

[0003] The PID effect refers to the phenomenon where high-intensity negative voltage is applied to photovoltaic (PV) modules, leading to a decline in module performance. Its main harm lies in the accumulation of a large amount of charge on the surface of the PV cells, causing surface passivation, power degradation, and affecting the reliability of the PV module. Essentially, it is the significant loss of ions from the PN junction of the PV cells during operation.

[0004] Currently, most methods for addressing the PID effect employ compensation circuits, which compensate the voltage of photovoltaic modules by introducing an additional power supply. However, existing PID compensation circuits typically use traditional power frequency transformers for voltage conversion. Power frequency transformers are bulky, and the introduction of an additional power supply both result in the PID compensation circuit requiring a significant amount of space. Summary of the Invention

[0005] This application provides a compensation circuit, a PID board, and a photovoltaic system to solve the problem that existing methods of using large-volume power frequency transformers to transform the voltage of external power sources for PID compensation may result in the PID compensation circuit requiring a large space, which is not conducive to installation.

[0006] In a first aspect, embodiments of this application provide a compensation circuit applied to a photovoltaic system. The photovoltaic system includes photovoltaic modules and a photovoltaic inverter connected in sequence. The photovoltaic inverter is also used to connect to the power grid. The compensation circuit includes: a first voltage conversion module, a second voltage conversion module, a switching module, and a control module.

[0007] The first voltage conversion module is connected to the inverter and the switching module respectively; the second voltage conversion module is connected to the inverter, the switching module, and the control module respectively; the control module is connected to the switching module and the photovoltaic module respectively; the switching module is connected to the photovoltaic module.

[0008] The control module is used to collect the plate voltage of the photovoltaic module and control the switch module to close or open based on the plate voltage;

[0009] The second voltage conversion module is used to convert the inverter voltage into the supply voltage and supply power to the switching module and the control module respectively;

[0010] The first voltage conversion module is used to convert the inverter voltage into a compensation voltage and to provide voltage compensation to the photovoltaic module when the switching module is closed.

[0011] In one possible implementation, the first voltage conversion module includes a first voltage conversion unit and a second voltage conversion unit;

[0012] When the inverter includes an AC interface, the first voltage conversion unit is connected to the AC interface and the second voltage conversion unit respectively, and the second voltage conversion unit is connected to the switching module.

[0013] When the inverter includes a DC interface, the second voltage conversion unit is connected to the DC interface and the switching module respectively;

[0014] The AC interface is used to provide AC voltage, and the DC interface is used to provide DC voltage.

[0015] The first voltage conversion unit is used to convert AC voltage into DC voltage, and the second voltage conversion unit is used to convert DC voltage into compensation voltage.

[0016] In one possible implementation, the second voltage conversion unit includes an input filter, a step-up transformer, and an output filter connected in sequence.

[0017] In one possible implementation, the compensation circuit further includes a voltage feedback module connected across the two ends of the step-up transformer, which is used to adjust the output voltage of the second voltage conversion unit.

[0018] In one possible implementation, the voltage feedback module includes a voltage acquisition unit, a voltage feedback unit, and a voltage regulation unit;

[0019] The voltage acquisition unit has its input terminal connected to the output terminal of the step-up transformer and its output terminal connected to the input terminal of the voltage feedback unit.

[0020] The output terminal of the voltage acquisition unit is connected to the adjustment terminal of the voltage regulation unit, and the output terminal of the voltage regulation unit is connected to the input terminal of the step-up transformer.

[0021] In one possible implementation, the second voltage conversion module includes a first power supply conversion circuit and a second power supply conversion circuit;

[0022] The first power conversion circuit has its input terminal connected to the output terminal of the inverter, and its output terminal connected to the input terminal of the second power conversion circuit and the power supply terminal of the control module, respectively.

[0023] The output of the second power conversion circuit is connected to the power supply terminal of the switching module;

[0024] The first power supply conversion circuit is used to convert the inverter's output voltage into a first power supply voltage and supply power to the control module. The second power supply conversion circuit is used to convert the first power supply voltage into a second power supply voltage and supply power to the switching module.

[0025] In one possible implementation, the control module is used for:

[0026] When the plate voltage is less than or equal to a first preset voltage, a first control signal is output. This first control signal is used to control the closing of the switch module; and...

[0027] When the plate voltage is greater than or equal to the second preset voltage, a second control signal is output, which is used to control the switch module to disconnect.

[0028] In one possible implementation, the control module includes a first comparator unit, a second comparator unit, and a pull-up unit, wherein the pull-up unit is used to provide a comparison voltage;

[0029] The first comparator unit has its positive input terminal connected to the positive plate of the photovoltaic module, its negative input terminal connected to the negative plate of the photovoltaic module, and its output terminal connected to the negative input terminal of the second comparator unit.

[0030] The second comparator unit has its positive input connected to the pull-up unit and its output connected to the switch module.

[0031] Secondly, embodiments of this application provide a PID board, including a circuit board and a compensation circuit as described in any of the first aspects above, the compensation circuit being disposed on the circuit board.

[0032] Thirdly, embodiments of this application provide a photovoltaic system, including the PID board as described in the second aspect above.

[0033] This application provides a compensation circuit for use in photovoltaic systems. This circuit draws power from the inverter to compensate for the photovoltaic modules, eliminating the need for an external power supply and resulting in a smaller size. The compensation circuit includes a first voltage conversion module and a second voltage conversion module. It avoids using a large power frequency transformer for voltage conversion. While compensating the photovoltaic modules through the first voltage conversion module, the second voltage conversion module can simultaneously supply power to the switching and control modules, ensuring reliable operation of the compensation circuit. Generally, the voltage conversion module in this application does not use a power frequency transformer, thus further reducing the size of the compensation circuit and making it easier to install and use. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a compensation circuit provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of another compensation circuit provided in an embodiment of this application;

[0037] Figure 3 This is a schematic diagram of the structure of a second voltage conversion unit provided in an embodiment of this application;

[0038] Figure 4 This is a circuit diagram of a second voltage conversion unit provided in an embodiment of this application;

[0039] Figure 5 This is a schematic diagram of another compensation circuit provided in an embodiment of this application;

[0040] Figure 6 This is a schematic diagram of another compensation circuit provided in an embodiment of this application. Detailed Implementation

[0041] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of this solution will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this solution, not all of them. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this solution.

[0042] The term "comprising" and any other variations thereof in the specification, claims, and accompanying drawings of this invention mean "including but not limited to," and are intended to cover a non-exclusive inclusion, not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order.

[0043] The implementation of this application will be described in detail below with reference to the specific accompanying drawings:

[0044] Figure 1 This is a schematic diagram of a compensation circuit provided in an embodiment of this application. Figure 1As shown, in some embodiments of this application, the compensation circuit 10 is applied to a photovoltaic system, which includes a photovoltaic module 21 and a photovoltaic inverter 22 connected in sequence. The photovoltaic inverter 22 is also used to connect to the power grid 30. The compensation circuit 10 includes a first voltage conversion module 11, a second voltage conversion module 12, a switching module 13, and a control module 14.

[0045] The first voltage conversion module 11 is connected to the inverter 22 and the switching module 13, respectively.

[0046] The second voltage conversion module 12 is connected to the inverter 22, the switching module 13 and the control module 14 respectively.

[0047] The control module 14 is connected to the switch module 13 and the photovoltaic module 21 respectively.

[0048] The switch module 13 is connected to the photovoltaic module 21.

[0049] The control module 14 is used to collect the plate voltage of the photovoltaic module 21 and control the switch module 13 to close or open according to the plate voltage.

[0050] The second voltage conversion module 12 is used to convert the voltage of the inverter 22 into the supply voltage and supply power to the switching module 13 and the control module 14 respectively.

[0051] The first voltage conversion module 11 is used to convert the voltage of the inverter 22 into a compensation voltage and to provide voltage compensation to the photovoltaic module 21 when the switch module 13 is closed.

[0052] In embodiments of this application, the first voltage conversion module 11 may include a forward converter circuit for drawing power from the inverter and converting the voltage of the inverter 22 into a compensation voltage. For example, the voltage of the inverter 22 may be 24VDC, and the first voltage conversion module 11 can convert 24VDC to 300VDC to compensate the voltage of the photovoltaic plates of the photovoltaic module 21. The first voltage conversion module 11 is mainly used for voltage compensation.

[0053] When using a forward converter, the first voltage conversion module 11 does not need to use a large power frequency transformer. A small transformer can be used to achieve voltage conversion, which can greatly reduce the size of the compensation circuit and facilitate installation and use.

[0054] In embodiments of this application, the second voltage conversion module 12 may include a flyback circuit for drawing power from the inverter and converting the voltage of the inverter 22 into a supply voltage. For example, the voltage of the inverter 22 may be 24VDC, and the second voltage conversion module 12 may convert 24VDC to 15VDC or 12VDC to supply power to the switching module 13 and the control module 14 respectively, ensuring the stable and reliable operation of the switching module 13 and the control module 14.

[0055] Optionally, the first voltage conversion module 11 and the second voltage conversion module 12 can draw power from the same port of the inverter 22 or from different ports, depending on the actual situation.

[0056] In the embodiments of this application, the switch module 13 can be a relay switch module. The control module 14 can output different control signals to control the switch module 13 to close or open.

[0057] Specifically, the control module 14 can obtain the plate voltage of the photovoltaic module 21.

[0058] When the plate voltage is less than or equal to a first preset voltage, a first control signal is output. This first control signal is used to control the closing of the switch module; and...

[0059] When the plate voltage is greater than or equal to the second preset voltage, a second control signal is output, which is used to control the switch module to disconnect.

[0060] The first preset voltage is less than the second preset voltage. The first preset voltage is the minimum voltage output by the photovoltaic panels of the photovoltaic module at night. The second preset voltage is the maximum voltage output by the photovoltaic panels of the photovoltaic module at night.

[0061] The first and second preset voltages can be set according to the actual situation of the photovoltaic module. For example, the first preset voltage is 50V and the second preset voltage is 150V.

[0062] Optionally, the control module 14 may include a control chip that can acquire the plate voltage of the photovoltaic module and control the switch module to close or open based on the plate voltage. Alternatively, the control module 14 may consist of hardware circuitry including a comparator, implementing the control of the switch module to close or open based on the plate voltage of the photovoltaic module in a purely hardware manner. The specific choice can be made according to the actual situation.

[0063] In this embodiment, when the control module 14 detects that the voltage of the photovoltaic module 21's plates is too low, it can control the switch module 14 to close. At this time, the first voltage conversion module 11 can convert the voltage of the inverter 22 to compensate for the voltage of the photovoltaic plates of the photovoltaic module 21. The second voltage conversion module 12 continuously supplies power to the switch module 13 and the control module 14.

[0064] In this embodiment, while compensating the photovoltaic module through the first voltage conversion module, the second voltage conversion module can simultaneously supply power to the switching module and the control module, ensuring the reliable operation of the compensation circuit. Generally, the voltage conversion module in this embodiment does not use a power frequency transformer, thus further reducing the size of the compensation circuit and making it easier to install and use.

[0065] Figure 2 This is a schematic diagram of another compensation circuit provided in an embodiment of this application, as shown below. Figure 2 As shown, in some embodiments of this application, the first voltage conversion module 11 includes a first voltage conversion unit 111 and a second voltage conversion unit 112.

[0066] When the inverter 22 includes an AC interface A, the first voltage conversion unit 111 is connected to the AC interface A and the second voltage conversion unit 112 respectively, and the second voltage conversion unit 112 is connected to the switching module 13.

[0067] When the inverter 22 includes a DC interface B, the second voltage conversion unit 112 is connected to the DC interface B and the switching module 13 respectively.

[0068] AC interface A is used to provide AC voltage, and DC interface B is used to provide DC voltage.

[0069] The first voltage conversion unit 111 is used to convert AC voltage into DC voltage, and the second voltage conversion unit 112 is used to convert DC voltage into compensation voltage.

[0070] In embodiments of this application, the inverter 22 may include two interfaces, namely AC interface A and DC interface B.

[0071] In one scenario, the inverter 22 is not directly connected to the grid and can only output DC voltage. In this case, the second voltage conversion unit 112 can convert the DC voltage of the inverter 22 into a compensation voltage to compensate the photovoltaic plates of the photovoltaic module 21 when the switch module 13 is closed.

[0072] In another scenario, the inverter 22 is directly connected to the grid and can output AC voltage. The first voltage conversion unit 111 is used to convert the AC voltage into DC voltage, and the second voltage conversion unit 112 can convert the DC voltage into a compensation voltage for voltage compensation.

[0073] The embodiments of this application are compatible with inverter 22 outputting either AC or DC, which can greatly expand the application range of compensation voltage and make the compensation circuit more compatible.

[0074] Figure 3 This is a schematic diagram of the structure of a second voltage conversion unit provided in an embodiment of this application, as shown below. Figure 3 As shown, in some embodiments of this application, the second voltage conversion unit includes an input filter, a step-up transformer, and an output filter connected in sequence.

[0075] The input filter's input terminal can be connected to either the output terminal of the first voltage conversion unit 111 or the DC interface of the inverter 22, and its output terminal is connected to the input terminal of the step-up transformer. The output terminal of the step-up transformer is connected to the input terminal of the output filter, and the output terminal of the output filter is connected to the electrode plate of the photovoltaic module 21.

[0076] For example, Figure 4 This is a circuit diagram of a second voltage conversion unit provided in an embodiment of this application, as shown below. Figure 4 As shown, the second voltage conversion unit may include an input filter consisting of multiple filter resistors and multiple filter capacitors, a boost transformer, and an output filter consisting of multiple filters and anti-reverse diodes.

[0077] like Figure 4 As shown, the switch module 13 can be composed of multiple relays. The output terminal of the switch module 13 can be connected to the positive busbar BUS+ and the negative busbar BUS- of the photovoltaic module 21 respectively through reverse connection protection diodes. In addition, the output terminal of the switch module 13 can be connected to the ground terminal through a grounding resistor.

[0078] In the embodiments of this application, the DC voltage output by the inverter can be 24VDC, and the step-up transformer can convert 24VDC to 300VDC.

[0079] Figure 4 The second voltage conversion module shown uses a forward converter to achieve voltage conversion, eliminating the need for a bulky power frequency transformer. The step-up transformer in the forward converter is very small, which can effectively reduce the size of the compensation circuit and facilitate installation and use.

[0080] The embodiments of this application can perform voltage conversion through a second voltage conversion module to compensate the voltage of the photovoltaic module, thereby improving the compensation reliability of the PID.

[0081] Figure 5 This is a schematic diagram of another compensation circuit provided in the embodiments of this application, as shown below. Figure 5As shown, in some embodiments of this application, the compensation circuit may further include a voltage feedback module 15 connected to both ends of the step-up transformer, the voltage feedback module 15 being used to adjust the output voltage of the second voltage conversion unit.

[0082] Specifically, the voltage feedback module includes a voltage acquisition unit, a voltage feedback unit, and a voltage regulation unit;

[0083] The voltage acquisition unit has its input terminal connected to the output terminal of the step-up transformer and its output terminal connected to the input terminal of the voltage feedback unit.

[0084] The output terminal of the voltage acquisition unit is connected to the adjustment terminal of the voltage regulation unit, and the output terminal of the voltage regulation unit is connected to the input terminal of the step-up transformer.

[0085] Figure 6 This is a schematic diagram of another compensation circuit provided in the embodiments of this application, as shown below. Figure 6 As shown, in some embodiments of this application, the second voltage conversion module 12 includes a first power supply conversion circuit 121 and a second power supply conversion circuit 122.

[0086] The first power conversion circuit 121 has its input terminal connected to the output terminal of the inverter 22, and its output terminal connected to the input terminal of the second power conversion circuit 122 and the power supply terminal of the control module 14, respectively.

[0087] The output terminal of the second power supply conversion circuit 122 is connected to the power supply terminal of the switching module 13;

[0088] The first power supply conversion circuit 121 is used to convert the output voltage of the inverter into a first power supply voltage and supply power to the control module 14. The second power supply conversion circuit 122 is used to convert the first power supply voltage into a second power supply voltage and supply power to the switching module 13.

[0089] In the embodiments of this application, the first power conversion circuit 121 can also convert 24VDC to 15VDC to power the voltage feedback module.

[0090] In the embodiments of this application, the first voltage conversion module and the second voltage conversion module together form a flyback circuit to power each module in the compensation circuit. This eliminates the need for an additional power supply, thereby reducing the size of the compensation circuit while ensuring its operational stability.

[0091] In some embodiments of this application, the control module may be composed of purely hardware circuitry. The control module includes a first comparator unit, a second comparator unit, and a pull-up unit, the pull-up unit being used to provide a comparison voltage;

[0092] The first comparator unit has its positive input terminal connected to the positive plate of the photovoltaic module, its negative input terminal connected to the negative plate of the photovoltaic module, and its output terminal connected to the negative input terminal of the second comparator unit.

[0093] The second comparator unit has its positive input connected to the pull-up unit and its output connected to the switch module.

[0094] This embodiment of the application achieves the control of the switching module to close or open based on the substrate voltage of the photovoltaic module by setting two comparators and pull-up units. There is no need to set up a control chip, which can greatly reduce costs and improve the working reliability of the compensation circuit.

[0095] The compensation circuit in this application is compatible with two versions:

[0096] AC version: When the inverter has no AC power source, the rated grid voltage is 400Vac, which is converted to 24VDC by the flyback circuit. The main circuit is a 24VDC to 300VDC (reinforced insulation) forward converter with a power output of approximately 2W. The auxiliary circuit is a 24VDC to 15VDC (basic insulation) flyback converter, which then converts it to 12V for regulation. The 12V supply provides power to the operational amplifiers and part of the reference voltage, and can also be converted to 5V to power the relay switches.

[0097] DC Version: When the inverter draws DC power, it is supplied with 24VDC from the inverter's AC power board. The main circuit is a 24VDC to 300VDC (reinforced insulation) forward converter with a power output of approximately 2W. The auxiliary circuit is a 24VDC to 15VDC (basic insulation) flyback converter, which then converts to 12V for regulation. The 12V supply provides power to the operational amplifiers and part of the reference voltage, and can also be converted to 5V to power the relay switches.

[0098] This application also provides a PID board, including a circuit board and a compensation circuit as described in any of the above embodiments, wherein the compensation circuit is disposed on the circuit board.

[0099] The PID version provided in this application embodiment can realize that the forward circuit, flyback circuit and control circuit are all on a single circuit board, which can greatly save space and reduce size during installation and use.

[0100] This application also provides a photovoltaic system, including the PID board as described in the above embodiment. The photovoltaic system may further include photovoltaic modules and an inverter. The PID board can draw power from the inverter and perform voltage compensation for the photovoltaic plates of the photovoltaic modules to improve the operational reliability of the photovoltaic system.

[0101] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A compensation circuit, characterized in that, The compensation circuit is applied to a photovoltaic system, which includes photovoltaic modules and an inverter connected in sequence. The inverter is also used to connect to the power grid. The compensation circuit includes: a first voltage conversion module, a second voltage conversion module, a switching module, and a control module. The first voltage conversion module is connected to both the inverter and the switching module; the second voltage conversion module is connected to the inverter, the switching module, and the control module; the control module is connected to both the switching module and the photovoltaic module; the switching module is connected to the photovoltaic module. The control module is used to collect the plate voltage of the photovoltaic module and control the switch module to close or open based on the plate voltage; The second voltage conversion module is used to convert the inverter voltage into a supply voltage and supply power to the switching module and the control module respectively; The first voltage conversion module is used to convert the inverter voltage into a compensation voltage and to provide voltage compensation to the photovoltaic module when the switch module is closed.

2. The compensation circuit as described in claim 1, characterized in that, The first voltage conversion module includes a first voltage conversion unit and a second voltage conversion unit; When the inverter includes an AC interface, the first voltage conversion unit is connected to the AC interface and the second voltage conversion unit, and the second voltage conversion unit is connected to the switching module. When the inverter includes a DC interface, the second voltage conversion unit is connected to the DC interface and the switching module respectively; The AC interface is used to provide AC voltage, and the DC interface is used to provide DC voltage; The first voltage conversion unit is used to convert AC voltage into DC voltage, and the second voltage conversion unit is used to convert DC voltage into compensation voltage.

3. The compensation circuit as described in claim 2, characterized in that, The second voltage conversion unit includes an input filter, a step-up transformer, and an output filter connected in sequence.

4. The compensation circuit as described in claim 3, characterized in that, It also includes a voltage feedback module connected to both ends of the step-up transformer, which is used to adjust the output voltage of the second voltage conversion unit.

5. The compensation circuit as described in claim 4, characterized in that, The voltage feedback module includes a voltage acquisition unit, a voltage feedback unit, and a voltage regulation unit; The voltage acquisition unit has its input terminal connected to the output terminal of the step-up transformer and its output terminal connected to the input terminal of the voltage feedback unit. The output terminal of the voltage acquisition unit is also connected to the adjustment terminal of the voltage regulation unit, and the output terminal of the voltage regulation unit is connected to the input terminal of the step-up transformer.

6. The compensation circuit as described in claim 1, characterized in that, The second voltage conversion module includes a first power supply conversion circuit and a second power supply conversion circuit; The first power conversion circuit has its input terminal connected to the output terminal of the inverter, and its output terminal connected to the input terminal of the second power conversion circuit and the power supply terminal of the control module, respectively. The output terminal of the second power conversion circuit is connected to the power supply terminal of the switching module; The first power conversion circuit is used to convert the output voltage of the inverter into a first power supply voltage and supply power to the control module. The second power conversion circuit is used to convert the first power supply voltage into a second power supply voltage and supply power to the switching module.

7. The compensation circuit as described in claim 1, characterized in that, The control module is used for: When the plate voltage is less than or equal to a first preset voltage, a first control signal is output, which is used to control the switch module to close; and, When the plate voltage is greater than or equal to the second preset voltage, a second control signal is output, which is used to control the switching module to disconnect.

8. The compensation circuit as described in claim 1, characterized in that, The control module includes a first comparator unit, a second comparator unit, and a pull-up unit, wherein the pull-up unit is used to provide a comparison voltage; The first comparator unit has its positive input terminal connected to the positive plate of the photovoltaic module, its negative input terminal connected to the negative plate of the photovoltaic module, and its output terminal connected to the negative input terminal of the second comparator unit. The second comparator unit has its positive input connected to the pull-up unit and its output connected to the switch module.

9. A PID board, characterized in that, It includes a circuit board and a compensation circuit as described in any one of claims 1 to 8, wherein the compensation circuit is disposed on the circuit board.

10. A photovoltaic system, characterized in that, Including the PID board as described in claim 9 above.

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