Photovoltaic overvoltage detection protection circuit and energy storage system

Abstract

The utility model relates to the technical field of energy storage power supplies, in particular to a photovoltaic overvoltage detection protection circuit and an energy storage system, and the circuit comprises a detection module and a switch module. The detection module is used for being connected with a photovoltaic input source and further connected with the control end of the switch module, and the switch module is used for being connected with the photovoltaic input source and a load. Wherein the detection module is used for detecting the input voltage of the photovoltaic input source and outputting a first control signal to the switch module when the input voltage is smaller than a preset threshold value, so that the switch module is switched on, and then the photovoltaic input source supplies power to the load through the switch module; and when the input voltage is greater than or equal to the preset threshold value, a second control signal is output to the switch module, so that the switch module disconnects the photovoltaic input source from the load. On the basis, the input voltage of the photovoltaic input source is detected in real time through the detection module, so that when the input voltage is larger than the preset threshold value, connection between the photovoltaic input source and the load is disconnected, and then devices in the circuit are protected.

Description

[Technical field]

[0001] The utility model relates to the technical field of energy storage power supplies, and in particular to a photovoltaic overvoltage detection protection circuit and an energy storage system. [Background technology]

[0002] As one of the most popular new energy products, energy storage power supply has rich functions, among which photovoltaic input source (PV) charging is indispensable.

[0003] Photovoltaic input source charging circuit diagram Figure 1 As shown, the diode D1 and the resistor R1 are the pre-charging circuit. When the PV input voltage is connected, the PV input voltage first pre-charges the pre-charging capacitor C1 through the diode D1 and the resistor R1. At the same time, the single-chip microcomputer detects whether the PV input voltage value is within the working range. If it is within the range, the single-chip microcomputer sends a drive signal PV_EN after a certain period of time to close the relay RLY1, and the PV input voltage inputs energy through the relay, and the PV circuit starts to work; if not, the single-chip microcomputer does not send a drive signal PV_EN, the relay RLY1 is disconnected, and the PV circuit does not work.

[0004] but, Figure 1 Regardless of whether the PV charging circuit is working or not, the PV input voltage will charge the pre-charge capacitor C1 through the pre-charge circuit. However, considering the cost, the withstand voltage of each component in the existing PV charging circuit is generally not very large. Therefore, when the photovoltaic input voltage is greater than the withstand voltage of each component, it will cause damage to each component, thereby damaging the PV charging function of the energy storage power supply. [Utility Model Content]

[0005] The embodiment of the utility model provides a photovoltaic overvoltage detection protection circuit and an energy storage system, aiming to solve the technical problem in the prior art that when the input voltage of the photovoltaic input source is too large, the components in the circuit will be damaged.

[0006] In order to solve the above technical problems, a technical solution adopted by the embodiment of the utility model is: to provide a photovoltaic overvoltage detection protection circuit, the photovoltaic overvoltage detection protection circuit includes a detection module and a switch module;

[0007] The detection module is used to connect to the photovoltaic input source, the detection module is also connected to the control end of the switch module, and the switch module is also used to connect the photovoltaic input source and the load;

[0008] The detection module is used to detect the input voltage of the photovoltaic input source, and when the input voltage is less than a preset threshold, output a first control signal to the switch module to turn on the switch module, thereby enabling the photovoltaic input source to supply power to the load through the switch module; and

[0009] When the input voltage is greater than or equal to the preset threshold, a second control signal is output to the switch module so that the switch module disconnects the photovoltaic input source from the load.

[0010] Optionally, the detection module includes a detection unit and a control unit;

[0011] The detection unit is used to be connected to the photovoltaic input source, the detection unit is also connected to the control unit, and the control unit is also connected to the photovoltaic input source and the switch module respectively;

[0012] The control unit is used for outputting a first control signal to the switch module when the detection unit detects that the input voltage is less than a preset threshold; and

[0013] When the detection unit detects that the input voltage is greater than or equal to the preset threshold, a second control signal is output to the switch module.

[0014] Optionally, the detection unit includes a resistor R5 and a voltage regulator tube ZD1;

[0015] The resistor R5 is connected to the photovoltaic input source, and is also connected in series with the voltage regulator tube ZD1 . The anode of the voltage regulator tube ZD1 is connected to the control terminal of the control unit.

[0016] Optionally, the control unit includes a switch tube Q6, a resistor R7 and a resistor R10;

[0017] The control end of the switch tube Q6 is connected to the anode of the voltage regulator tube ZD1, and the control end of the switch tube Q6 is also grounded through the resistor R10. The first end of the switch tube Q6 is connected to the photovoltaic input source through the resistor R7, and the first end of the switch tube Q6 is also connected to the switch module.

[0018] Optionally, the switch module includes a resistor R4, a resistor R6, a switch tube Q4, a switch tube Q5 and a voltage regulator tube ZD2;

[0019] The control end of the switch tube Q5 is connected to the detection module, the first end of the switch tube Q5 is respectively connected to the resistor R4 and the control end of the switch tube Q4 through the resistor R6, the first end of the switch tube Q4 is respectively connected to the first end of the resistor R4 and the photovoltaic input source, the second end of the switch tube Q4 is used to be connected to the load, and the voltage regulator tube ZD2 is connected in parallel with the resistor R4.

[0020] Optionally, the photovoltaic overvoltage detection protection circuit further includes an anti-reverse connection module, wherein the anti-reverse connection module is a diode D5;

[0021] The anode of the diode D5 is connected to the photovoltaic input source, and the cathode of the diode D5 is connected to the detection module.

[0022] Optionally, the photovoltaic overvoltage detection protection circuit further includes a delay module;

[0023] The delay module is connected to the control unit and the switch module respectively;

[0024] The delay module is used to receive the input voltage at the moment when the detection unit detects that the input voltage is greater than or equal to the preset threshold value, so as to prevent the switch module from being turned on based on the input voltage.

[0025] Optionally, the delay module includes a resistor R8 and a capacitor C3;

[0026] The first end of the resistor R8 is connected to the control unit, the second end of the resistor R8 is connected to the switch module and the first end of the capacitor C3 respectively, and the second end of the capacitor C3 is grounded.

[0027] Optionally, the photovoltaic overvoltage detection protection circuit further includes a discharge module, wherein the discharge module is a resistor R9;

[0028] The resistor R9 is connected in parallel with the capacitor C3.

[0029] In order to solve the above technical problems, another technical solution adopted by the embodiment of the utility model is: to provide an energy storage system, the energy storage system comprising:

[0030] Photovoltaic input source;

[0031] load; and

[0032] The photovoltaic overvoltage detection protection circuit as described above, wherein the photovoltaic input source is connected to the input end of the photovoltaic overvoltage detection protection circuit, and the output end of the photovoltaic overvoltage detection protection circuit is connected to the load.

[0033] Different from the related art, the utility model provides a photovoltaic overvoltage detection protection circuit and energy storage system, wherein the photovoltaic overvoltage detection protection circuit includes a detection module and a switch module; the detection module is used to connect to the photovoltaic input source, the detection module is also connected to the control end of the switch module, and the switch module is also used to connect the photovoltaic input source and the load. The detection module is used to detect the input voltage of the photovoltaic input source, and when the input voltage is less than a preset threshold, output a first control signal to the switch module to turn on the switch module, thereby allowing the photovoltaic input source to supply power to the load through the switch module; and when the input voltage is greater than or equal to the preset threshold, output a second control signal to the switch module to disconnect the photovoltaic input source from the load. Based on this, the input voltage of the photovoltaic input source is detected in real time by the detection module, so that when the input voltage is greater than the preset threshold, the photovoltaic input source is disconnected from the load, thereby protecting the components in the circuit.

Brief Description of the Drawings

[0034] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and the figures in the drawings do not constitute proportional limitations unless otherwise stated.

[0035] Figure 1 It is a circuit diagram of a photovoltaic input source charging circuit provided by an embodiment of the utility model;

[0036] Figure 2 It is a structural block diagram of an energy storage system provided by an embodiment of the utility model;

[0037] Figure 3 This is a structural block diagram of a photovoltaic overvoltage detection protection circuit provided by an embodiment of the utility model;

[0038] Figure 4 It is a circuit diagram of a photovoltaic overvoltage detection protection circuit provided by an embodiment of the utility model;

[0039] Figure 5 It is a circuit diagram of an energy storage system provided by an embodiment of the utility model. [Specific implementation method]

[0040] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0041] The technical features involved in the various embodiments of the present application described below do not conflict with each other and can be combined with each other.

[0042] When an element is referred to as being “connected to” another element, it can be directly connected to the other element, or one or more intervening elements may be present therebetween.

[0043] The terms "first", "second", etc. in the specification and claims of the present utility model are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more.

[0044] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0045] See also Figure 2 , Figure 2 is a structural block diagram of an energy storage system provided by an embodiment of the utility model, such as Figure 2 As shown, the energy storage system 1 includes a photovoltaic input source 100, a load 200 and a photovoltaic overvoltage detection protection circuit 300, wherein the photovoltaic overvoltage detection protection circuit 300 is connected to the photovoltaic input source 100 and the load 200 respectively. The photovoltaic overvoltage detection protection circuit 300 is used to detect the input voltage output by the photovoltaic input source 100, so as to output the input voltage to power the load 200 when the input voltage is less than a preset threshold; or to disconnect the photovoltaic input source 100 from the load 200 when the input voltage is greater than or equal to the preset threshold, so as to avoid the large voltage output by the photovoltaic input source 100 from damaging the load 200. In some embodiments, the preset threshold is set based on the withstand voltage value of the load 200, and the preset threshold is set by the withstand voltage value of the load 200 to avoid damaging the load 200 when the input voltage of the photovoltaic input source 100 is greater than the withstand voltage value of the load 200.

[0046] In some embodiments, when the load 200 is Figure 1When the photovoltaic charging circuit in the photovoltaic input source 100 is connected, the photovoltaic input source 100 will be connected to the diode D1 and the relay RLY1 through the photovoltaic overvoltage detection protection circuit 300. When the input voltage output by the photovoltaic input source 100 is less than the preset threshold value, the input voltage will be output to the diode D1 and / or the relay RLY1 through the photovoltaic overvoltage detection protection circuit 300, thereby charging the energy storage power supply (BAT+). When the input voltage output by the photovoltaic input source 100 is greater than or equal to the preset threshold value, the photovoltaic overvoltage detection protection circuit 300 will disconnect the output of the photovoltaic input source 100. At this time, no matter whether the relay RLY1 is opened or closed, the input voltage of the photovoltaic input source 100 will not be output to the photovoltaic charging circuit, thereby protecting the devices in the photovoltaic charging circuit.

[0047] See also Figure 3 , Figure 3 is a structural block diagram of a photovoltaic overvoltage detection protection circuit provided by an embodiment of the utility model, such as Figure 3 As shown, the photovoltaic overvoltage detection protection circuit 300 includes a detection module 31 and a switch module 32; the detection module 31 is used to connect to the photovoltaic input source 100, and the detection module 31 is also connected to the control end of the switch module 32, and the switch module 32 is also used to connect the photovoltaic input source 100 and the load 200.

[0048] The detection module 31 is used to detect the input voltage of the photovoltaic input source 100, and when the input voltage is less than a preset threshold, output a first control signal to the switch module 32 to turn on the switch module 32, thereby enabling the photovoltaic input source 100 to supply power to the load 200 through the switch module 32; and

[0049] When the input voltage is greater than or equal to the preset threshold, a second control signal is output to the switch module 32 so that the switch module 32 disconnects the photovoltaic input source 100 from the load 200 .

[0050] Further, such as Figure 3 As shown, the detection module 31 includes a detection unit 311 and a control unit 312; the detection unit 311 is used to connect to the photovoltaic input source 100, the detection unit 311 is also connected to the control unit 312, and the control unit 312 is also connected to the photovoltaic input source 100 and the switch module 32 respectively.

[0051] The control unit 312 is used to output a first control signal to the switch module 32 when the detection unit 311 detects that the input voltage is less than a preset threshold; and to output a second control signal to the switch module 32 when the detection unit 311 detects that the input voltage is greater than or equal to the preset threshold.

[0052] For details, please refer to Figure 4 , Figure 4 is a circuit diagram of a photovoltaic overvoltage detection protection circuit provided by an embodiment of the utility model, such as Figure 4 As shown, the detection unit 311 includes a resistor R5 and a voltage regulator ZD1; the control unit 312 includes a switch tube Q6, a resistor R7 and a resistor R10.

[0053] The resistor R5 is connected to the photovoltaic input source 100, the resistor R5 is connected in series with the voltage regulator tube ZD1, and the anode of the voltage regulator tube ZD1 is also connected to the control end of the control unit 312;

[0054] The control end of the switch tube Q6 is connected to the anode of the voltage regulator tube ZD1, and the control end of the switch tube Q6 is also grounded through the resistor R10. The first end of the switch tube Q6 is connected to the photovoltaic input source 100 through the resistor R7, and the first end of the switch tube Q6 is also connected to the switch module 32.

[0055] Specifically, after the photovoltaic input source 100 outputs the input voltage, the input voltage will be applied to the voltage regulator tube ZD1. When the input voltage is less than the voltage regulation value of the voltage regulator tube ZD1, the voltage regulator tube ZD1 is not broken down. At this time, the switch tube Q6 is in a cut-off state, so that the input voltage of the photovoltaic input source 100 is input to the control end of the switch module 32 through the resistor R7, so that the switch module 32 is turned on, and then the photovoltaic input source 100 supplies power to the load 200 through the switch module 32. If the input voltage is greater than the voltage regulation value of the voltage regulator tube ZD1, the voltage regulator tube ZD1 is broken down by the input voltage. At this time, the switch tube Q6 is turned on based on the input voltage, so that the switch module receives a low level, and then the switch module 32 disconnects the photovoltaic input source 100 from the load 200.

[0056] Further, such as Figure 4As shown, the switch module 32 includes a resistor R4, a resistor R6, a switch tube Q4, a switch tube Q5 and a voltage regulator tube ZD2; the control end of the switch tube Q5 is connected to the detection module 31, the first end of the switch tube Q5 is respectively connected to the resistor R4 and the control end of the switch tube Q4 through the resistor R6, the first end of the switch tube Q4 is respectively connected to the first end of the resistor R4 and the photovoltaic input source 100, the second end of the switch tube Q4 is used to connect to the load 200, and the voltage regulator tube ZD2 is connected in parallel with the resistor R4.

[0057] Specifically, when the input voltage is less than the voltage regulation value of the voltage regulator tube ZD1, the switch tube Q6 is turned off, and the control end of the switch tube Q5 receives the input voltage based on the resistor R7, so that it is in a conducting state. When the switch tube Q5 is turned on, the photovoltaic input source 100, the resistor R4, the resistor R6 and the switch tube Q5 form a loop, so that the switch tube Q4 is turned on, and then the photovoltaic input source 100 supplies power to the load 200 through the switch tube Q4. When the input voltage is greater than the voltage regulation value of the voltage regulator tube ZD1, the voltage regulator tube ZD1 is broken down, the switch tube Q6 is in a conducting state, and the control end of the switch tube Q5 is in a cut-off state based on the low level received by the switch tube Q6. At this time, the G pole and the S pole of the switch tube Q4 are cut off due to the absence of a voltage drop, thereby disconnecting the photovoltaic input source 100 from the load 200.

[0058] The voltage regulator ZD2 is a clamping diode, which is mainly used to protect the switch tube Q4 from being damaged when the input voltage of the photovoltaic input source 100 is too large. Specifically, when the input voltage is too large, that is, when the voltage across the resistor R4 is greater than the voltage regulation value of the voltage regulator diode ZD2, the voltage regulator ZD2 is broken down. At this time, the voltage across the resistor R4 is the voltage regulation value of the voltage regulator ZD2, thereby protecting the switch tube Q4.

[0059] In some embodiments, Figure 3 As shown, the photovoltaic overvoltage detection protection circuit 300 further includes an anti-reverse connection module 33, and the anti-reverse connection module 33 is respectively connected to the photovoltaic input source 100 and the detection module 31. The anti-reverse connection module 33 is used to prevent the input voltage of the photovoltaic input source 100 from being input into the photovoltaic overvoltage detection protection circuit 300 when the photovoltaic input source 100 is reversely connected to the photovoltaic overvoltage detection protection circuit 300, thereby avoiding damage to the components in the photovoltaic overvoltage detection protection circuit 300.

[0060] Specifically, Figure 4As shown, the anti-reverse connection module 33 is a diode D5 ; the anode of the diode D5 is connected to the photovoltaic input source 100 , and the cathode of the diode D5 is connected to the detection module 31 .

[0061] In yet another embodiment, Figure 3 As shown, the photovoltaic overvoltage detection protection circuit 300 also includes a delay module 34 and a discharge module 35, wherein the delay module 34 is connected to the control unit 312 and the switch module 32 respectively, and the discharge module 35 is connected to the delay module 34. The delay module 34 is used to receive the input voltage at the moment when the input voltage breaks down the voltage regulator tube ZD1, thereby preventing the input voltage from flowing into the switch tube Q5 through the resistor R7, thereby protecting the load 200.

[0062] Specifically, Figure 4 As shown, the delay module 34 includes a resistor R8 and a capacitor C3;

[0063] The first end of the resistor R8 is connected to the control unit, the second end of the resistor R8 is connected to the switch module and the first end of the capacitor C3 respectively, and the second end of the capacitor C3 is grounded.

[0064] Among them, the capacitor C3 mainly plays a delay role. When the input voltage is greater than or equal to the preset voltage, the input voltage will break down the voltage regulator tube ZD1. At this time, if the delay module 34 does not exist, the switch tube Q5 will be turned on earlier than the switch tube Q6, so that the input voltage supplies power to the load 200 through the switch tube Q4, thereby damaging the load 200. When the delay module 34 is added to the control end of the switch tube Q5, and the input voltage breaks down the voltage regulator tube ZD1 before the switch tube Q6 is turned on, the input voltage will charge the capacitor C3 through the resistor R7 and the resistor R8, thereby ensuring that the switch tube Q6 is turned on earlier than the switch tube Q5. After the switch tube Q6 is turned on, the voltage at the control end of the switch tube Q5 is pulled down by the switch tube Q6, so that it is in a cut-off state, so that the switch tube Q4 is also in a cut-off state, thereby disconnecting the connection between the photovoltaic input source 100 and the load 200, and achieving the purpose of protecting the load 200.

[0065] Further, such as Figure 4As shown, the discharge module 35 is the resistor R9, and the resistor R9 is connected in parallel with the capacitor C3. The resistor R9 is used to discharge the electric energy stored in the capacitor C3. It should be noted that when the photovoltaic input source 100 disconnects the output, the capacitor C3 will discharge the stored electric energy through the resistor R9, so that the switch tube Q5 is quickly turned off, and it can also ensure that when the photovoltaic input source 100 outputs the input voltage again, the delay module 34 can play a delay role.

[0066] The embodiment of the utility model provides a photovoltaic overvoltage detection protection circuit, which includes a detection module and a switch module; the detection module is used to connect to the photovoltaic input source, the detection module is also connected to the control end of the switch module, and the switch module is also used to connect the photovoltaic input source and the load. Wherein, the detection module is used to detect the input voltage of the photovoltaic input source, and when the input voltage is less than a preset threshold, output a first control signal to the switch module to turn on the switch module, so that the photovoltaic input source supplies power to the load through the switch module; and when the input voltage is greater than or equal to the preset threshold, output a second control signal to the switch module to disconnect the photovoltaic input source from the load. Based on this, the input voltage of the photovoltaic input source is detected in real time by the detection module, so that when the input voltage is greater than the preset threshold, the photovoltaic input source is disconnected from the load, thereby protecting the components in the circuit.

[0067] In some embodiments, see Figure 5 , Figure 5 is a circuit diagram of an energy storage system provided by an embodiment of the utility model, such as Figure 5 As shown, when the load 200 is a photovoltaic charging circuit, if the input voltage of the photovoltaic input source 100 is less than the preset voltage (that is, the voltage value of the voltage regulator ZD1), the switch tube Q6 is turned off and the switch tube Q5 is turned on, so that the resistor R4 and the resistor R6 divide the voltage, and then the switch tube Q4 is in the on state. At this time, the photovoltaic input source 100 (PV-IN) will pre-charge the capacitor C4 through the switch tube Q4 and the pre-charging circuit (diode D6, resistor R11), and when the single-chip microcomputer detects that the input voltage is within the preset range, it will send a drive signal PV EN to the switch tube Q11 after a preset time to close the relay RLY2, so that the input voltage charges the energy storage power supply (BAT+) through the relay RLY2.

[0068] When the input voltage is greater than the preset voltage, the switch tube Q4 will be in the cut-off state. At this time, the photovoltaic input source 100 cannot charge the capacitor C4 through the switch tube Q4 and the pre-charging circuit, and the single-chip microcomputer will not send a driving signal to the switch tube Q11, the relay RLY2 is disconnected, and the photovoltaic charging circuit does not work. It should be noted that by controlling the switch tube Q4 to be cut off when the input voltage is greater than the voltage stabilization value of the voltage stabilizing tube ZD1, the input voltage is prevented from entering the photovoltaic charging circuit through the pre-charging circuit, thereby preventing the various components in the photovoltaic charging circuit from being damaged when the input voltage is greater than the withstand voltage value of the various components, thereby protecting the safety of the energy storage power supply and improving the reliability of the energy storage power supply.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of ​​the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A photovoltaic overvoltage detection protection circuit, characterized in that: The photovoltaic overvoltage detection and protection circuit includes a detection module and a switch module; The detection module is used to connect to the photovoltaic input source, the detection module is also connected to the control end of the switch module, and the switch module is also used to connect the photovoltaic input source and the load; The detection module is used to detect the input voltage of the photovoltaic input source, and when the input voltage is less than a preset threshold, output a first control signal to the switch module to turn on the switch module, thereby enabling the photovoltaic input source to supply power to the load through the switch module; and When the input voltage is greater than or equal to the preset threshold, outputting a second control signal to the switch module so that the switch module disconnects the photovoltaic input source from the load; Wherein, the detection module includes a detection unit and a control unit; The detection unit is used to be connected to the photovoltaic input source, the detection unit is also connected to the control unit, and the control unit is also connected to the photovoltaic input source and the switch module respectively; The control unit is used for outputting a first control signal to the switch module when the detection unit detects that the input voltage is less than a preset threshold; and When the detection unit detects that the input voltage is greater than or equal to the preset threshold, outputting a second control signal to the switch module; The detection unit includes a resistor R5 and a voltage regulator tube ZD1; The resistor R5 is connected to the photovoltaic input source, and is also connected in series with the voltage regulator tube ZD1 . The anode of the voltage regulator tube ZD1 is connected to the control terminal of the control unit.

2. The photovoltaic overvoltage detection protection circuit according to claim 1, characterized in that: The control unit includes a switch tube Q6, a resistor R7 and a resistor R10; The control end of the switch tube Q6 is connected to the anode of the voltage regulator tube ZD1, and the control end of the switch tube Q6 is also grounded through the resistor R10. The first end of the switch tube Q6 is connected to the photovoltaic input source through the resistor R7, and the first end of the switch tube Q6 is also connected to the switch module.

3. The photovoltaic overvoltage detection protection circuit according to claim 1, characterized in that: The switch module includes a resistor R4, a resistor R6, a switch tube Q4, a switch tube Q5 and a voltage regulator tube ZD2; The control end of the switch tube Q5 is connected to the detection module, the first end of the switch tube Q5 is respectively connected to the resistor R4 and the control end of the switch tube Q4 through the resistor R6, the first end of the switch tube Q4 is respectively connected to the first end of the resistor R4 and the photovoltaic input source, the second end of the switch tube Q4 is used to be connected to the load, and the voltage regulator tube ZD2 is connected in parallel with the resistor R4.

4. The photovoltaic overvoltage detection protection circuit according to claim 1, characterized in that: The photovoltaic overvoltage detection protection circuit also includes an anti-reverse connection module, wherein the anti-reverse connection module is a diode D5; The anode of the diode D5 is connected to the photovoltaic input source, and the cathode of the diode D5 is connected to the detection module.

5. The photovoltaic overvoltage detection protection circuit according to claim 1, characterized in that: The photovoltaic overvoltage detection protection circuit also includes a delay module; The delay module is connected to the control unit and the switch module respectively; The delay module is used to receive the input voltage at the moment when the detection unit detects that the input voltage is greater than or equal to the preset threshold value, so as to prevent the switch module from being turned on based on the input voltage.

6. The photovoltaic overvoltage detection protection circuit according to claim 5, characterized in that: The delay module includes a resistor R8 and a capacitor C3; The first end of the resistor R8 is connected to the control unit, the second end of the resistor R8 is connected to the switch module and the first end of the capacitor C3 respectively, and the second end of the capacitor C3 is grounded.

7. The photovoltaic overvoltage detection protection circuit according to claim 6, characterized in that: The photovoltaic overvoltage detection protection circuit also includes a discharge module, wherein the discharge module is a resistor R9; The resistor R9 is connected in parallel with the capacitor C3.

8. An energy storage system, characterized in that: The energy storage system comprises: Photovoltaic input source; load; and The photovoltaic overvoltage detection protection circuit according to any one of claims 1 to 7, wherein the photovoltaic input source is connected to the input end of the photovoltaic overvoltage detection protection circuit, and the output end of the photovoltaic overvoltage detection protection circuit is connected to the load.

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