Overcurrent protection circuit and photovoltaic power generation system

Abstract

The utility model discloses an overcurrent protection circuit and a photovoltaic power generation system, the overcurrent protection circuit is applied to the photovoltaic power generation system, the photovoltaic power generation system comprises a photovoltaic power optimizer and an MOS driving circuit, the overcurrent protection circuit comprises a current sampling circuit, the current sampling circuit is electrically connected with the output end of the photovoltaic power optimizer, and the MOS driving circuit is electrically connected with the output end of the current sampling circuit; the current sampling circuit is used for receiving output current of the photovoltaic power optimizer and acquiring sampling voltage according to the output current; the current comparison circuit is electrically connected with the current sampling circuit, and the current comparison circuit is used for receiving the sampling voltage and outputting a turn-off signal when the sampling voltage is greater than a preset voltage threshold value; and the control circuit is electrically connected with the current comparison circuit and the MOS driving circuit, when the control circuit receives the turn-off signal, the control circuit is used for generating a control signal, and the MOS driving circuit receives the control signal to control the photovoltaic power optimizer to be in a turn-off state. Through the arrangement, the reliability of the overcurrent protection circuit is improved.

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic power generation, and particularly to an overcurrent protection circuit and a photovoltaic power generation system. Background Art

[0002] For related products such as photovoltaic optimizers in a photovoltaic power generation system, during actual use, due to various reasons such as improper installation of the photovoltaic optimizer, non-standard use, and product aging, there may be a problem that the output end of the photovoltaic optimizer is short-circuited, resulting in an excessive current output at the output end of the photovoltaic optimizer and causing damage to related equipment. In the prior art, to solve the overcurrent problem, generally, the MCU in the overcurrent protection circuit reads the actual value of the output current at the output end of the photovoltaic optimizer. When the actual value of the output current exceeds the set threshold, the MCU determines that overcurrent occurs, and then the MCU cuts off the power circuit of the photovoltaic optimizer by turning off the MOS drive, thereby achieving overcurrent protection.

[0003] However, the solution of the prior art relies only on the MCU to achieve overcurrent protection, resulting in the response speed of short-circuit protection being closely related to the performance of the MCU. When the performance of the MCU is poor or the program of the MCU runs away, the overcurrent protection circuit cannot stably trigger the overcurrent protection function. Summary of the Utility Model

[0004] To solve the deficiencies of the prior art, the purpose of this application is to provide an overcurrent protection circuit and a photovoltaic power generation system with relatively high reliability.

[0005] To achieve the above purpose, this application adopts the following technical solutions:

[0006] In a first aspect, this application provides an overcurrent protection circuit, which is applied to a photovoltaic power generation system. The photovoltaic power generation system includes a photovoltaic power optimizer and a MOS drive circuit for controlling the photovoltaic power optimizer to be in a working state or an off state. The overcurrent protection circuit includes:

[0007] A current sampling circuit, which is electrically connected to the output end of the photovoltaic power optimizer. The current sampling circuit is used to receive the output current of the photovoltaic power optimizer and obtain a sampling voltage according to the output current;

[0008] A current comparison circuit, which is electrically connected to the current sampling circuit. The current comparison circuit is used to receive the sampling voltage and output a turn-off signal when the sampling voltage is greater than a preset voltage threshold;

[0009] A control circuit, which is electrically connected to the current comparison circuit and the MOS drive circuit respectively. When the control circuit receives the turn-off signal, the control circuit is used to generate a control signal, and the MOS drive circuit receives the control signal to control the photovoltaic power optimizer to be in an off state.

[0010] Further, the current sampling circuit includes a sampling resistor, a first operational amplifier, and a first feedback resistor. Two ends of the sampling resistor are respectively connected to the output end of the photovoltaic power optimizer and the reference ground; the non-inverting input terminal and the inverting input terminal of the first operational amplifier are respectively connected to two ends of the sampling resistor, and the output end of the first operational amplifier is connected to the current comparison circuit; two ends of the first feedback resistor are respectively connected to the inverting input terminal and the output end of the first operational amplifier. The first operational amplifier is configured to obtain the sampling voltage across the sampling resistor and amplify the sampling voltage and then transmit it to the current comparison circuit.

[0011] Further, the current sampling circuit further includes a first delay circuit. The current sampling circuit is connected to the current sampling circuit through the first delay circuit. The first delay circuit is configured to obtain the sampling voltage and delay the sampling voltage and then transmit it to the current sampling circuit.

[0012] Further, the first delay circuit includes a first delay resistor and a first delay capacitor. Two ends of the first delay resistor are respectively connected to the output end of the first operational amplifier and the current sampling circuit, and two ends of the first delay capacitor are respectively connected to the current sampling circuit and the reference ground.

[0013] Further, the current comparison circuit includes a second operational amplifier, a voltage dividing circuit, and a hysteresis resistor. The non-inverting input terminal of the second operational amplifier is connected to the current sampling circuit, the inverting input terminal of the second operational amplifier is connected to the voltage dividing circuit, the output end of the second operational amplifier is connected to the control circuit, and two ends of the hysteresis resistor are respectively connected to the output end and the non-inverting input terminal of the second operational amplifier; the voltage dividing circuit is configured to provide a preset voltage threshold. The second operational amplifier is configured to obtain the sampling voltage and the preset voltage threshold, and output a turn-off signal to the control circuit when the sampling voltage is greater than the preset voltage threshold.

[0014] Further, the voltage dividing circuit includes a first voltage dividing resistor and a second voltage dividing resistor. Two ends of the first voltage dividing resistor are respectively connected to the power supply and one end of the second voltage dividing resistor, the other end of the second voltage dividing resistor is grounded, and the common terminal of the first voltage dividing resistor and the second voltage dividing resistor is connected to the inverting input terminal of the second operational amplifier.

[0015] Further, the control circuit includes a second delay circuit and a trigger. The second delay circuit is respectively connected to the current comparison circuit and the clock signal terminal of the trigger, and the input terminal of the trigger is connected to the MOS driving circuit; the second delay circuit is configured to receive the turn-off signal output by the current comparison circuit, delay the turn-off signal and then transmit it to the trigger. The trigger is configured to receive the turn-off signal to generate a control signal, and the MOS driving circuit receives the control signal to control the photovoltaic power optimizer to be in the turn-off state.

[0016] Further, the second delay circuit includes a second delay resistor and a second delay capacitor. Two ends of the second delay resistor are respectively connected to a power supply and one end of the second delay capacitor. The other end of the second delay capacitor is grounded. A common end of the second delay resistor and the second delay capacitor is respectively connected to a current comparison circuit and a clock signal terminal of a trigger.

[0017] Further, the overcurrent protection circuit further includes a micro control unit. An input end of the micro control unit is connected to an output end of the trigger. An output end of the micro control unit is connected to a reset end of the trigger. When the trigger receives a turn-off signal, an overcurrent signal is generated. The micro control unit is configured to receive the overcurrent signal and generate a reset signal. When the trigger receives the reset signal, the MOS drive circuit is controlled to control the photovoltaic power optimizer to be in an operating state.

[0018] In a second aspect, the present application further provides a photovoltaic power generation system, and the photovoltaic power generation system includes the overcurrent protection circuit of any one of the first aspect.

[0019] The above overcurrent protection circuit improves the reliability of the overcurrent protection circuit by setting a current sampling circuit, a current comparison circuit and a control circuit, and controlling the photovoltaic power optimizer to be in a turn-off state through the MOS drive circuit when the sampled voltage is greater than a preset voltage threshold. Description of the Drawings

[0020] Figure 1 is a circuit structure diagram of the overcurrent protection circuit and the photovoltaic power generation system in the embodiment of the present application;

[0021] Figure 2 is a circuit diagram of the current sampling circuit in the embodiment of the present application;

[0022] Figure 3 is a circuit diagram of the current comparison circuit in the embodiment of the present application;

[0023] Figure 4 is a circuit diagram of the control circuit in the embodiment of the present application;

[0024] Figure 5 is a circuit diagram of the micro control unit in the embodiment of the present application;

[0025] Figure 6 is a timing diagram of the overcurrent protection circuit in the embodiment of the present application. Detailed Embodiments

[0026] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the specific embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0027] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0028] Unless otherwise defined, the technical terms or scientific terms involved in the present application should have the ordinary meanings understood by those with ordinary skills in the technical field to which the present application belongs. The words such as "a", "an", "one kind", "the" and the like involved in the present application do not indicate a limitation in quantity and may represent a singular or plural number. The terms "include", "comprise", "have" and any variations thereof involved in the present application are intended to cover non-exclusive inclusion. The words such as "connect", "be connected", "couple" and the like involved in the present application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "plurality" involved in the present application means greater than or equal to two. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may represent: A exists alone, A and B exist simultaneously, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0029] As Figure 1 shown, the present application provides an overcurrent protection circuit 100 and a photovoltaic power generation system 200, and the overcurrent protection circuit 100 is applied to the photovoltaic power generation system 200. The photovoltaic power generation system 200 includes a photovoltaic power optimizer 21 and a MOS drive circuit 13. The MOS drive circuit 13 is electrically connected to the photovoltaic power optimizer 21, and the MOS drive circuit 13 is used to control the photovoltaic power optimizer 21 to be in a working state or an off state. The working state means that the photovoltaic power optimizer 21 normally outputs voltage and current, and the off state means that the photovoltaic power optimizer 21 stops outputting voltage and current. The MOS drive circuit 13 can control the photovoltaic power optimizer 21 to switch between the working state and the off state.

[0030] Specifically, the overcurrent protection circuit 100 includes: a current sampling circuit 11, a current comparison circuit 12, and a control circuit 13. The current sampling circuit 11 is electrically connected to the output terminal PV of the photovoltaic power optimizer 21. When the photovoltaic power optimizer 21 is in the working state, the current sampling circuit 11 is used to receive the output current of the photovoltaic power optimizer 21, and the current sampling circuit 11 also obtains a sampling voltage according to the output current. The current comparison circuit 12 is electrically connected to the current sampling circuit 11. The current comparison circuit 12 is used to receive the sampling voltage output by the current sampling circuit 11. The current comparison circuit 12 is also used to obtain a preset voltage threshold, and outputs a turn-off signal when the sampling voltage is greater than the preset voltage threshold. The control circuit 13 is respectively electrically connected to the current comparison circuit 12 and the control terminal of the MOS driving circuit 13. When the control circuit 13 receives the turn-off signal output by the current comparison circuit 12, the control circuit 13 generates a control signal, and the control circuit 13 transmits the control signal to the MOS driving circuit 13. The MOS driving circuit 13 receives the control signal and switches from the conducting state to the cut-off state to control the photovoltaic power optimizer 21 to be in the off state.

[0031] In the embodiment of the present application, the control circuit 13 includes a D flip-flop U3 circuit, and the D flip-flop U3 circuit controls the MOS driving circuit 13 to be cut off to control the photovoltaic power optimizer 21 to be in the off state. Since in the prior art, the MCU is used to obtain the sampling voltage and control the photovoltaic power optimizer 21 to switch from the working state to the off state according to the magnitude of the sampling voltage, the overcurrent protection circuit 100 overly relies on the performance of the MCU. In the embodiment of the present application, the D flip-flop U3 circuit is used to control the photovoltaic power optimizer 21 to switch from the working state to the off state, so that the overcurrent protection circuit 100 can stably trigger overcurrent protection, thereby improving the reliability of the overcurrent protection circuit 100.

[0032] As Figure 2 shown, as an implementation manner, the current sampling circuit 11 includes a sampling resistor R1, a first operational amplifier U1, and a first feedback resistor R2. Two ends of the sampling resistor R1 are respectively connected to the output terminal PV of the photovoltaic power optimizer 21 and the reference ground. The output current of the photovoltaic power optimizer 21 flowing through the sampling resistor R1 can generate a sampling voltage across the sampling resistor R1. The non-inverting input terminal and the inverting input terminal of the first operational amplifier U1 are respectively connected to two ends of the sampling resistor R1, and the output terminal of the first operational amplifier U1 is connected to the current comparison circuit 12. Two ends of the first feedback resistor R2 are respectively connected to the inverting input terminal and the output terminal of the first operational amplifier U1. The first operational amplifier U1 is used to obtain the sampling voltage across the sampling resistor R1 and amplify the sampling voltage and then transmit it to the current comparison circuit 12.

[0033] As Figure 2As shown in the figure, further, the current sampling circuit 11 further includes a first delay circuit 111. The current sampling circuit 11 is connected to the current sampling circuit 11 through the first delay circuit 111. The first delay circuit 111 is used to obtain the sampling voltage and transmit the sampling voltage to the current sampling circuit 11 after a delay.

[0034] Specifically, the first delay circuit 111 includes a first delay resistor R3 and a first delay capacitor C1. Two ends of the first delay resistor R3 are respectively connected to the output end of the first operational amplifier U1 and the current sampling circuit 11. Two ends of the first delay capacitor C1 are respectively connected to the current sampling circuit 11 and the reference ground. After the first operational amplifier U1 outputs the sampling voltage, the sampling voltage first charges the first delay capacitor C1, and after a period of time, the sampling voltage will be transmitted to the current comparison circuit 12. By changing the resistance value of the first delay resistor R3 and the capacitance value of the first delay capacitor C1, the delay time of the first delay circuit 111 can be changed.

[0035] It should be noted that when the photovoltaic power optimizer 21 is powered on, the photovoltaic power optimizer 21 will generate a power-on current. If the magnitude of the power-on current exceeds a preset current threshold, it will cause the overcurrent protection circuit 100 to malfunction. Since the duration of the power-on current is short, by setting the first delay circuit 111, it is possible to prevent the power-on current from being transmitted to the current comparison circuit 12 and causing the overcurrent protection circuit 100 to malfunction, thereby improving the reliability of the overcurrent protection circuit 100.

[0036] As Figure 3 shown in the figure, as an implementation manner, the current comparison circuit 12 includes a second operational amplifier U2, a voltage dividing circuit 121, and a hysteresis resistor R4. The non-inverting input terminal of the second operational amplifier U2 is connected to the current sampling circuit 11. The inverting input terminal of the second operational amplifier U2 is connected to the voltage dividing circuit 121. The output terminal of the second operational amplifier U2 is connected to the control circuit 13. Two ends of the hysteresis resistor R4 are respectively connected to the output terminal of the second operational amplifier U2 and the non-inverting input terminal of the second operational amplifier U2. The voltage dividing circuit 121 is used to provide a preset voltage threshold. The second operational amplifier U2 obtains the sampling voltage through the non-inverting input terminal. The second operational amplifier U2 also obtains the preset voltage threshold through the inverting input terminal. The second operational amplifier U2 compares the magnitudes of the voltage values of the sampling voltage and the preset voltage threshold. When the sampling voltage is greater than the preset voltage threshold, the second operational amplifier U2 generates a turn-off signal and transmits the turn-off signal to the control circuit 13.

[0037] Specifically, the voltage dividing circuit 121 includes a first voltage dividing resistor R5 and a second voltage dividing resistor R6. Two ends of the first voltage dividing resistor R5 are respectively connected to a power supply VCC and one end of the second voltage dividing resistor R6. The other end of the second voltage dividing resistor R6 is grounded. A common end of the first voltage dividing resistor R5 and the second voltage dividing resistor R6 is connected to an inverting input end of a second operational amplifier U2.

[0038] In an embodiment of the present application, the power supply VCC is a regulated DC power supply with an output voltage of 5V. The power supply voltage output by the power supply VCC is divided by the first voltage dividing resistor R5 and the second voltage dividing resistor R6. At this time, the voltage on the second voltage dividing resistor R6 is the preset voltage threshold. By connecting the inverting input end of the second operational amplifier U2 to the common end of the first voltage dividing resistor R5 and the second voltage dividing resistor R6, the second operational amplifier U2 can obtain the preset voltage threshold. It can be understood that by changing the resistance values of the first voltage dividing resistor R5 and the second voltage dividing resistor R6, the magnitude of the preset voltage threshold can be changed.

[0039] As Figure 4 shown, as an implementation manner, the control circuit 13 includes a second delay circuit 131 and a flip-flop U3. The second delay circuit 131 is respectively connected to the current comparison circuit 12 and a clock signal terminal CP of the flip-flop U3. An input terminal D of the flip-flop U3 is connected to the MOS driving circuit 13. The second delay circuit 131 is configured to receive a turn-off signal output by the current comparison circuit 12, delay the turn-off signal, and then transmit it to the flip-flop U3. The flip-flop U3 is configured to receive the turn-off signal to generate a control signal. The MOS driving circuit 13 receives the control signal to control the photovoltaic power optimizer 21 to be in a turn-off state.

[0040] Specifically, the second delay circuit 131 includes a second delay resistor R7 and a second delay capacitor C2. Two ends of the second delay resistor R7 are respectively connected to the power supply VCC and one end of the second delay capacitor C2. The other end of the second delay capacitor C2 is grounded. A common end of the second delay resistor R7 and the second delay capacitor C2 is respectively connected to the current comparison circuit 12 and the clock signal terminal CP of the flip-flop U3. The turn-off signal output by the current comparison circuit 12 first fills the second delay capacitor C2. After a period of time, the turn-off signal will be transmitted to the flip-flop U3. By changing the resistance value of the second delay resistor R7 and the capacitance value of the second delay capacitor C2, the delay time of the second delay circuit 131 can be changed. Through the above settings, it is possible to avoid misoperation of the flip-flop U3 caused by fluctuations in the current output by the photovoltaic power optimizer 21, thereby improving the reliability of the overcurrent protection circuit 100.

[0041] As Figure 5As shown, as an implementation, the overcurrent protection circuit 100 further includes a microcontroller unit 14, where the microcontroller unit 14 is an MCU (Microcontroller Unit). The input end GPIO2 of the microcontroller unit 14 is connected to the output end Q of the flip-flop U3, and the output end GPIO1 of the microcontroller unit 14 is connected to the reset end SD of the flip-flop U3. When the flip-flop U3 receives the shutdown signal, it generates an overcurrent signal. The flip-flop U3 transmits the overcurrent signal to the microcontroller unit 14. The microcontroller unit 14 is used to receive the overcurrent signal to start and generate a reset signal. The microcontroller unit 14 transmits the reset signal to the flip-flop U3, and the flip-flop U3 is reset upon receiving the reset signal, so that the MOS drive circuit 13 switches to the conduction state to control the photovoltaic power optimizer 21 to be in the working state.

[0042] As an implementation, the present application further provides a photovoltaic power generation system 200, including the above-mentioned overcurrent protection circuit 100.

[0043] The present application also provides as Figure 6 shown in the timing diagram, Figure 6 where OCP is the shutdown signal output by the current comparison circuit 12, SD_HW is the control signal generated by the control circuit 13, OCP_STATE is the overcurrent signal generated by the flip-flop U3, and RST_OCP is the reset signal generated by the microcontroller unit 14. It can be seen from the figure that when the current comparison circuit 12 determines that the sampled voltage is greater than the preset voltage threshold, the shutdown signal switches from low level to high level, so that the control signal generated by the control circuit 13 switches from high level to low level, and then controls the MOS drive circuit to switch from the conduction state to the cut-off state to control the photovoltaic power optimizer 21 to be in the shutdown state. In addition, when the control circuit 13 receives the shutdown signal, it will also cause the overcurrent signal to switch from low level to high level to drive the microcontroller unit 14 to start. After the microcontroller unit 14 starts for a period of time, the reset signal switches from high level to low level to reset the flip-flop U3, and then the control signal generated by the control circuit 13 switches from low level to high level to control the MOS drive circuit to switch from the cut-off state to the conduction state.

[0044] It should be understood that for those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present application.

Claims

1. An overcurrent protection circuit, applied to a photovoltaic power generation system, the photovoltaic power generation system comprising a photovoltaic power optimizer and a MOS drive circuit for controlling the photovoltaic power optimizer to be in an operating state or an off state, characterized in that: The overcurrent protection circuit comprises: A current sampling circuit, the current sampling circuit is electrically connected to the output end of the photovoltaic power optimizer, the current sampling circuit is used to receive the output current of the photovoltaic power optimizer and obtain a sampling voltage according to the output current; a current comparison circuit, the current comparison circuit being electrically connected to the current sampling circuit, the current comparison circuit being used to receive the sampling voltage and output a shutdown signal when the sampling voltage is greater than a preset voltage threshold; A control circuit, wherein the control circuit is electrically connected to the current comparison circuit and the MOS drive circuit respectively, and when the control circuit receives the shutdown signal, the control circuit is used to generate a control signal, and the MOS drive circuit receives the control signal to control the photovoltaic power optimizer to be in the shutdown state.

2. The overcurrent protection circuit according to claim 1, characterized in that: The current sampling circuit includes a sampling resistor, a first operational amplifier and a first feedback resistor, wherein the two ends of the sampling resistor are respectively connected to the output end and the reference ground of the photovoltaic power optimizer; the in-phase input end and the inverting input end of the first operational amplifier are respectively connected to the two ends of the sampling resistor, and the output end of the first operational amplifier is connected to the current comparison circuit; the two ends of the first feedback resistor are respectively connected to the inverting input end of the first operational amplifier and the output end of the first operational amplifier, and the first operational amplifier is used to obtain the sampling voltage at the two ends of the sampling resistor, and transmit the sampling voltage to the current comparison circuit after amplifying it.

3. The overcurrent protection circuit according to claim 2, characterized in that: The current sampling circuit also includes a first delay circuit, through which the current sampling circuit is connected to the current sampling circuit, and the first delay circuit is used to obtain the sampling voltage and transmit the sampling voltage to the current sampling circuit after delay.

4. The overcurrent protection circuit according to claim 3, characterized in that: The first delay circuit includes a first delay resistor and a first delay capacitor, wherein two ends of the first delay resistor are respectively connected to the output end of the first operational amplifier and the current sampling circuit, and two ends of the first delay capacitor are respectively connected to the current sampling circuit and a reference ground.

5. The overcurrent protection circuit according to claim 1, characterized in that: The current comparison circuit includes a second operational amplifier, a voltage divider circuit and a hysteresis resistor, the non-inverting input terminal of the second operational amplifier is connected to the current sampling circuit, the inverting input terminal of the second operational amplifier is connected to the voltage divider circuit, the output terminal of the second operational amplifier is connected to the control circuit, and the two ends of the hysteresis resistor are respectively connected to the output terminal of the second operational amplifier and the non-inverting input terminal of the second operational amplifier; the voltage divider circuit is used to provide the preset voltage threshold, the second operational amplifier is used to obtain the sampling voltage and the preset voltage threshold, and output the shutdown signal to the control circuit when the sampling voltage is greater than the preset voltage threshold.

6. The overcurrent protection circuit according to claim 5, characterized in that: The voltage-dividing circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor, wherein two ends of the first voltage-dividing resistor are respectively connected to a power supply and one end of the second voltage-dividing resistor, the other end of the second voltage-dividing resistor is grounded, and a common end of the first voltage-dividing resistor and the second voltage-dividing resistor is connected to an inverting input end of the second operational amplifier.

7. The overcurrent protection circuit according to claim 1, characterized in that: The control circuit includes a second delay circuit and a trigger, wherein the second delay circuit is respectively connected to the clock signal end of the current comparison circuit and the trigger, and the input end of the trigger is connected to the MOS drive circuit; the second delay circuit is used to receive the shutdown signal output by the current comparison circuit, and transmit the shutdown signal to the trigger after delay, the trigger is used to receive the shutdown signal to generate the control signal, and the MOS drive circuit receives the control signal to control the photovoltaic power optimizer to be in the shutdown state.

8. The overcurrent protection circuit according to claim 7, characterized in that: The second delay circuit includes a second delay resistor and a second delay capacitor, the two ends of the second delay resistor are respectively connected to a power supply and one end of the second delay capacitor, the other end of the second delay capacitor is grounded, and the common end of the second delay resistor and the second delay capacitor is respectively connected to the current comparison circuit and the clock signal end of the trigger.

9. The overcurrent protection circuit according to claim 7, characterized in that: The overcurrent protection circuit also includes a microcontroller unit, an input end of the microcontroller unit is connected to an output end of the trigger, an output end of the microcontroller unit is connected to a reset end of the trigger, the trigger generates an overcurrent signal when receiving the shutdown signal, the microcontroller unit is used to receive the overcurrent signal and generate a reset signal, and the trigger receives the reset signal to control the photovoltaic power optimizer to be in the working state through the MOS drive circuit.

10. A photovoltaic power generation system, characterized in that: The photovoltaic power generation system comprises the overcurrent protection circuit described in any one of claims 1-9.

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