Protection circuit and energy storage system

Abstract

The application provides a protection circuit and an energy storage system, comprising an output switching circuit, a switching circuit, a sampling circuit, a comparison circuit and a reference signal generating circuit. The switching circuit is connected with an input power supply and a load to form a power supply loop, the sampling circuit is arranged in the power supply loop, the output switching circuit is connected with the switching circuit, the comparison circuit is connected with the sampling circuit, the reference signal generating circuit, the switching circuit and the output switching circuit, the reference signal generating circuit outputs a reference signal corresponding to temperature to the comparison circuit, the comparison circuit outputs an overcurrent signal when the reference signal and a sampling signal output by the sampling circuit meet a preset condition, the output switching circuit switches between a first control signal and a second control signal based on the overcurrent signal or a pulse enable signal output by a controller, and the switching circuit turns on the power supply loop when the first control signal is received and turns off the power supply loop when the second control signal or the overcurrent signal is received.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a protection circuit and an energy storage system. Background Technology

[0002] With the continued development of the portable energy storage inverter industry, users' requirements for the user experience of energy storage products are constantly increasing. Energy storage products continue to evolve towards miniaturization. However, while miniaturization brings advantages in portability, it also introduces increasingly serious heat dissipation problems: the limited space inside the device cavity makes it difficult to effectively dissipate the heat generated during device operation, resulting in the cavity temperature remaining at a high level for a long time, which places extremely high demands on the heat dissipation performance of the device.

[0003] In DC output applications, some loads (such as motors and compressors) require significantly more current during startup than during normal operation. To meet the starting requirements of these large loads, existing protection circuits typically completely remove the current-limiting point to ensure the starting current can pass smoothly. However, this complete removal of the current-limiting point means the power supply not only experiences a large current surge during startup but also continues to carry a load current far exceeding its rated value after the load enters normal operation, causing the power supply to operate under overload conditions for extended periods. Continuous overload operation generates a large amount of heat in the circuit components. In miniaturized products where heat dissipation is already limited, this can easily lead to abnormal temperature rises in the components, potentially causing the power supply to overheat and fail, severely impacting product reliability and lifespan. Summary of the Invention

[0004] This application provides a protection circuit and an energy storage system that can adaptively adjust the current limiting threshold according to temperature, which helps to reduce overheating damage and improve the safety of the energy storage system.

[0005] In a first aspect, embodiments of this application provide a protection circuit, comprising: an output switching circuit, a switching circuit, a sampling circuit, a comparison circuit, and a reference signal generation circuit. The switching circuit is connected to an input power supply and a load respectively to form a power supply loop. The sampling circuit is disposed in the power supply loop. The output switching circuit is connected to the switching circuit. The comparison circuit is connected to the sampling circuit, the reference signal generation circuit, the switching circuit, and the output switching circuit respectively. The sampling circuit is configured to output a sampling signal to the comparison circuit based on the current of the power supply loop. The reference signal generation circuit is configured to output a reference signal corresponding to temperature to the comparison circuit. The comparison circuit is configured to output an overcurrent signal when the reference signal and the sampling signal meet a preset condition. The output switching circuit is configured to switch between a first control signal and a second control signal based on the overcurrent signal or a pulse enable signal output by a controller. The switching circuit is configured to turn on the power supply loop upon receiving the first control signal and to turn off the power supply loop upon receiving the second control signal or the overcurrent signal.

[0006] In one or more embodiments, the output switching circuit includes a pulse generation module and a trigger module; the pulse generation module is connected to the comparison circuit and the trigger module respectively, and the trigger module is connected to the switching circuit; the pulse generation module is configured to generate a pulse signal based on the pulse enable signal or the overcurrent signal; the trigger module is configured to switch the output between the first control signal and the second control signal upon receiving the pulse signal.

[0007] In one or more embodiments, the pulse generation module includes a diode DS1, a resistor R18, a resistor R30, and a capacitor C4; the anode of the diode DS1 is used to receive the pulse enable signal, the cathode of the diode DS1 is connected to the first end of the resistor R18, the second end of the resistor R18 is connected to the first end of the resistor R30, the comparator circuit, and the first end of the capacitor C4, the second end of the capacitor C4 is connected to the trigger module, and the second end of the resistor R30 is grounded.

[0008] In one or more embodiments, the switching circuit includes a first switching module and a second switching module; the first switching module is connected to the output switching circuit and the second switching module respectively, and the first switching module is further configured to connect to the input power supply and the load to form the power supply loop; the second switching module is further configured to be connected to the comparator circuit; the second switching module is configured to turn on upon receiving the overcurrent signal; the first switching module is configured to turn on the power supply loop upon receiving the first control signal, turn off the power supply loop upon receiving the second control signal, and turn off the power supply loop when the second switching module is turned on.

[0009] In one or more embodiments, the first switching module includes a switching unit and a self-locking unit; the self-locking unit is connected to the output switching circuit, the second switching module, and the switching unit respectively; the switching unit is further configured to connect to the input power supply and the load to form the power supply circuit; the self-locking unit is configured to continuously output a conduction signal to the switching unit upon receiving the first control signal, and to output a shutdown signal to the switching unit when the second switching module is turned on or upon receiving the second control signal; the switching unit is configured to turn on the power supply circuit upon receiving the conduction signal, and to turn off the power supply circuit upon receiving the shutdown signal.

[0010] In one or more embodiments, the self-locking unit includes a capacitor C1, a resistor R2, a resistor R3, a switch Q2, a resistor R4, and a resistor R5. The switching unit includes a resistor R8, a diode ZD1, a resistor R7, and a switch Q3. The first terminal of the capacitor C1 is connected to the first terminals of both the resistor R2 and the resistor R1. The second terminal of the resistor R2 is connected to the first terminal of both the resistor R3 and the switch Q2. The second terminals of the capacitor C1, the resistor R3, and the switch Q2 are grounded. The third terminal of the switch Q2 is connected to the resistor R8. The first end of 5 is connected to the first end of the resistor R8. The second end of the resistor R8 is connected to the anode of the diode ZD1, the first end of the resistor R7, and the first end of the switch Q3. The second end of the switch Q3 is connected to the input power supply, the first end of the switch Q1, the first end of the resistor R4, the cathode of the diode ZD1, and the second end of the resistor R7. The third end of the switch Q3 is used to connect to the load. The second end of the switch Q1 is connected to the second end of the resistor R4 and the second end of the resistor R5. The third end of the switch Q1 is connected to the second end of the resistor R1.

[0011] In one or more embodiments, the second switching module includes a resistor R27 and a switching transistor Q6; the first terminal of the switching transistor Q6 is connected to the first terminal of the resistor R27 and the comparator circuit, the second terminal of the switching transistor Q6 is connected to the output switching circuit and the first switching module, and the third terminal of the switching transistor Q6 is grounded to the second terminal of the resistor R27.

[0012] In one or more embodiments, the reference signal generation circuit includes resistor R24, resistor R26, thermistor RT1, and diode ZD2; the first end of resistor R24 ​​is used to receive a reference signal, the second end of resistor R24 ​​is connected to the comparator circuit, the first end of resistor R26, and the cathode of diode ZD2, the second end of resistor R26 is connected to the first end of thermistor RT1, and the second end of thermistor RT1 and the anode of diode ZD2 are grounded.

[0013] In one or more embodiments, the sampling circuit includes a sampling module and a differential amplifier module; the sampling module is disposed in the power supply circuit, and the differential amplifier module is connected to the sampling module and the comparison circuit respectively; the sampling module is configured to sample the current of the power supply circuit and obtain a corresponding voltage signal; the differential amplifier module is configured to differentially amplify the voltage signal to obtain the sampling signal and output the sampling signal to the comparison circuit.

[0014] Secondly, embodiments of this application provide an energy storage system, which includes a protection circuit as described in any embodiment of the first aspect.

[0015] The beneficial effects of this application are as follows: This application provides a protection circuit and electrical equipment. The protection circuit dynamically adjusts the current limiting threshold based on real-time temperature through a reference signal generation circuit. It allows a large starting current to pass through in the initial stage of load startup and adaptively adjusts the current limiting threshold as the temperature rises, thereby reducing the phenomenon of overheating damage caused by continuous overload operation of the power supply and improving the safety and reliability of the energy storage system under complex operating conditions. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0017] Figure 1 An exemplary block diagram of a protection circuit provided in an embodiment of this application is shown; Figure 2 An exemplary block diagram of a protection circuit provided in another embodiment of this application is shown; Figure 3An exemplary circuit diagram of a protection circuit provided in an embodiment of this application is shown; Figure 4 An exemplary block diagram of a protection circuit provided in another embodiment of this application is shown. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0020] It should be noted that, unless there is a conflict, the various features in the embodiments of this application can be combined with each other, all of which are within the protection scope of this application. Furthermore, the terms "first" and "second" used herein do not limit the data or execution order, but only distinguish between identical or similar items with essentially the same function and effect.

[0021] In a first aspect, embodiments of this application provide a protection circuit, see [reference]. Figure 1 The protection circuit 100 includes: an output switching circuit 10, a switching circuit 20, a sampling circuit 30, a comparison circuit 40, and a reference signal generation circuit 50.

[0022] A switching circuit 20 is connected to the input power supply 200 and the load 300 respectively to form a power supply loop. A sampling circuit 30 is located in the power supply loop. An output switching circuit 10 is connected to the switching circuit 20. A comparison circuit 40 is connected to the sampling circuit 30, the reference signal generation circuit 50, the switching circuit 20, and the output switching circuit 10 respectively. The sampling circuit 30 is configured to output a sampling signal to the comparison circuit 40 based on the current of the power supply loop. The reference signal generation circuit 50 is configured to output a reference signal corresponding to temperature to the comparison circuit 40. The comparison circuit 40 is configured to output an overcurrent signal when the reference signal and the sampling signal meet preset conditions. The output switching circuit 10 is configured to switch the output between a first control signal and a second control signal based on the overcurrent signal or a pulse enable signal output by the controller. The switching circuit 20 is configured to turn on the power supply loop upon receiving the first control signal and turn off the power supply loop upon receiving the second control signal or the overcurrent signal.

[0023] Input power supply 200 refers to a power supply device that provides DC power to the entire power supply circuit, such as an energy storage battery pack or other DC power supply device, which continuously provides the required power for the normal operation and startup process of load 300.

[0024] Load 300 refers to electrical equipment driven by input power 200, including but not limited to motors, compressors, and other loads that require a large starting current at startup.

[0025] The output switching circuit 10 is a functional circuit that can switch the output between two control signals according to the external input signal. The circuit responds to the pulse enable signal issued by the controller or the overcurrent signal output by the comparator circuit 40, and alternately switches between the first control signal and the second control signal, thereby controlling the on and off states of the power supply circuit.

[0026] A controller is the core processing unit responsible for the overall system operation management and logic control. It includes microcontroller units (MCUs), general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), microcontrollers, advanced reduced instruction set computers (ARMs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of these components.

[0027] The pulse enable signal is a pulse signal sent by the controller to the output switching circuit 10 when the on / off state of the power supply circuit needs to be changed. Unlike traditional level control signals, the output switching circuit 10 uses the rising edge of a pulse as a valid trigger condition. Each time a valid pulse arrives, the output switching circuit 10 performs an output switching action. Specifically, when the power supply circuit is off, the controller sends a pulse enable signal, triggering the output switching circuit 10 to switch from the second control signal output to the first control signal output. The switching circuit 20 then turns on the power supply circuit, and the input power supply 200 begins supplying power to the load 300. When the power supply circuit is on, the controller sends a pulse enable signal, the output switching circuit 10 switches from the first control signal output to the second control signal output, the switching circuit 20 then turns off the power supply circuit, and the input power supply 200 stops supplying power to the load 300. By using a pulse enable signal to trigger the output switching circuit 10 to perform the switching action, the controller does not need to continuously output a control level to complete the switching control of the power supply circuit's on / off state, reducing the resource consumption of the controller.

[0028] Switching circuit 20 is a functional circuit located between input power supply 200 and load 300, used to control the on / off state of the power supply circuit. When a first control signal is received, switching circuit 20 turns on the power supply circuit, allowing input power supply 200 to supply power to load 300 normally; when a second control signal or an overcurrent signal output by comparator circuit 40 is received, switching circuit 20 turns off the power supply circuit, cutting off the current path between input power supply 200 and load 300, causing input power supply 200 to stop supplying power to load 300.

[0029] The sampling circuit 30 refers to a circuit that monitors the current state in the power supply circuit in real time. In this application, the sampling circuit 30 is located between the switching circuit 20 and the load 300. In practical applications, the sampling circuit 30 can also be located between the input power supply 200 and the switching circuit 20. The sampling circuit 30 samples the current flowing through the power supply circuit and converts the collected current information into a corresponding sampling signal, which is then output to the comparison circuit 40 to provide real-time current data for subsequent overcurrent judgment.

[0030] The comparator circuit 40 is a circuit that compares the sampled signal with the reference signal in real time and determines whether an overcurrent has occurred. The preset condition is that the current value corresponding to the sampled signal is greater than or equal to the current limiting threshold corresponding to the reference signal. That is, when the actual current in the power supply circuit exceeds the maximum allowable current limiting point at the current temperature, the comparator circuit 40 determines that an overcurrent has occurred and outputs an overcurrent signal to the switching circuit 20 and the output switching circuit 10, triggering the protection action.

[0031] Temperature refers to the operating temperature of key components. The reference signal generation circuit 50 is capable of outputting a reference signal corresponding to the current operating temperature to the comparator circuit 40 based on the real-time operating temperature, such as the current operating temperature of the switching circuit 20. This allows for dynamic adjustment of the current limiting threshold based on the temperature. The current limiting threshold is the maximum current value allowed to pass through the power supply circuit at the current temperature, and this threshold adaptively adjusts with temperature changes. Specifically, at lower temperatures, the current limiting threshold corresponding to the reference signal is higher, allowing the power supply circuit to pass a larger starting current to meet the load-bearing starting requirements of the large load 300. As the temperature rises, the current limiting threshold corresponding to the reference signal gradually decreases, and the current limiting point adaptively decreases to prevent the power supply from overheating and being damaged due to continuous overload.

[0032] In the protection circuit 100, during normal operation, the controller sends a pulse enable signal to the output switching circuit 10, triggering the output switching circuit 10 to output a first control signal. Upon receiving the first control signal, the switching circuit 20 turns on the power supply circuit, and the input power supply 200 supplies power to the load 300 normally. Simultaneously, the sampling circuit 30 continuously monitors the current in the power supply circuit and outputs the sampled signal to the comparison circuit 40 in real time. The reference signal generation circuit 50 generates a corresponding reference signal based on the current temperature and outputs the reference signal to the comparison circuit 40. The comparison circuit 40 compares the two signals in real time. When the voltage of the sampled signal is less than or equal to the voltage of the reference signal, i.e., the current in the current power supply circuit does not exceed the current limiting threshold, the comparison circuit 40 does not output an overcurrent signal, and the power supply circuit maintains normal operation. When the voltage of the sampled signal is greater than the voltage of the reference signal, that is, when the current in the current power supply circuit exceeds the current current limiting threshold, i.e., an overcurrent occurs, the comparator circuit 40 will output an overcurrent signal. After the overcurrent signal is output, it will directly act on the switching circuit 20, triggering the switching circuit 20 to turn off the power supply circuit and cut off the current path between the input power supply 200 and the load 300; on the other hand, it will be output to the output switching circuit 10, causing it to switch the output of the second control signal, which will also control the switching circuit 20 to turn off.

[0033] Understandably, after the switching circuit 20 receives an overcurrent signal and shuts off the power supply circuit, the current in the power supply circuit disappears, the sampling signal drops, the overcurrent judgment condition of the comparison circuit 40 is no longer met, and the comparison circuit 40 no longer outputs an overcurrent signal. At this time, the output switching circuit 10 continuously outputs a second control signal to keep the switching circuit 20 in the off state, preventing the power supply circuit from automatically resuming conduction after the overcurrent signal disappears, thus ensuring the stability and reliability of the protection action. Finally, after the power supply circuit is shut off, the system will wait for the controller to send another pulse enable signal to trigger the output switching circuit 10 to switch back to the first control signal output, restoring the conduction of the power supply circuit, thereby achieving a controllable restart of the power supply circuit.

[0034] In this embodiment, by setting a reference signal generation circuit 50 dynamically correlated with temperature, the protection circuit 100 can adaptively adjust the current limiting threshold according to the actual temperature, thereby achieving a better current protection strategy in different operating stages. At the initial startup stage of the load 300, the operating temperature is still relatively low, and the current limiting threshold corresponding to the reference signal is relatively large. This allows the power supply circuit to provide sufficient inrush current at startup, ensuring reliable startup of loads 300 with large startup currents (such as motors, large-capacity capacitive loads 300, etc.), and preventing startup failure or abnormal startup process due to an excessively small current limiting threshold. Once the load 300 enters normal operating mode, as the circuit continues to operate, the temperature gradually increases, and the current limiting threshold corresponding to the reference signal becomes lower than the current limiting threshold corresponding to the initial operating stage. This reduces the phenomenon of overheating damage to the switching circuit 20 due to long-term overload operation, improving the thermal protection effect of the circuit. Compared to traditional fixed current limiting threshold schemes, the adaptive current limiting mechanism in this embodiment takes into account both the 300-load start-up capability and overheat protection capability. Moreover, it can dynamically adjust the protection strategy according to the actual operating temperature without manual intervention. While ensuring the normal operation of the 300-load, it reduces the overheating damage caused by continuous overload operation of the power supply, and improves the safety and reliability of the energy storage system under complex operating conditions.

[0035] In some of these embodiments, see Figure 2 The output switching circuit 10 includes a pulse generation module 11 and a trigger module 12. The pulse generation module 11 is connected to the comparator circuit 40 and the trigger module 12, respectively, and the trigger module 12 is connected to the switching circuit 20. The pulse generation module 11 is configured to generate a pulse signal based on a pulse enable signal or an overcurrent signal. The trigger module 12 is configured to switch the output between a first control signal and a second control signal upon receiving the pulse signal.

[0036] The pulse generation module 11 generates a pulse signal with a fixed pulse width and amplitude at its output terminal when an input signal is detected, and transmits the pulse signal to the trigger module 12 to drive the trigger module 12 to perform the corresponding state switching action.

[0037] Trigger module 12 refers to a logic control module with state memory and latching functions. After receiving the pulse signal output by pulse generation module 11, trigger module 12 performs an output switching operation based on the current output state: if the current output is the first control signal, it switches to the second control signal output upon receiving the pulse signal; if the current output is the second control signal, it switches to the first control signal output upon receiving the pulse signal. After completing the state switching, trigger module 12 can autonomously latch the current output state, maintaining the current output state unchanged without continuous pulse signal input until the next valid pulse signal is input, at which point the switching operation is performed again. Specifically, trigger module 12 uses the rising or falling edge of the pulse signal as the valid trigger condition. Upon receiving a valid pulse signal, trigger module 12 performs an output state switching operation, thereby controlling the on or off state of switch circuit 20.

[0038] In the output switching circuit 10, when the power supply circuit needs to be turned on, the controller sends a pulse enable signal to the pulse generation module 11. Upon receiving the pulse enable signal, the pulse generation module 11 generates a pulse signal at its output terminal and outputs it to the trigger module 12. After receiving the pulse signal, the trigger module 12 switches its output state from the second control signal to the first control signal. Driven by the first control signal, the switching circuit 20 turns on the power supply circuit, and the input power supply 200 begins to supply power to the load 300 normally. Under normal operation, when the power supply circuit needs to be turned off, the controller sends a pulse enable signal to the pulse generation module 11 again. Upon receiving the pulse enable signal, the pulse generation module 11 generates a pulse signal at its output terminal and outputs it to the trigger module 12. Upon receiving the pulse signal, the trigger module 12 switches its output state from the first control signal to the second control signal. Driven by the second control signal, the switching circuit 20 turns off the power supply circuit, and the input power supply 200 stops supplying power to the load 300. In the event of an overcurrent, the comparator circuit 40 outputs an overcurrent signal and sends it to the pulse generation module 11. Similarly, the pulse generation module 11 receives the pulse enable signal, generates a pulse signal at its output terminal, and outputs it to the trigger module 12. After receiving the pulse signal, the trigger module 12 switches its output state from the first control signal to the second control signal to protect the load 300 and the power supply from overcurrent damage. At this time, after the power supply circuit is turned off, the trigger module 12 automatically latches the second control signal output. In this way, even if the overcurrent signal disappears, the power supply circuit remains in the off state until the controller sends the pulse enable signal again to restore power supply.

[0039] In this embodiment, the pulse generation module 11 can generate a pulse signal upon detecting a pulse enable signal or an overcurrent signal, driving the trigger module 12 to complete the output signal switching. Furthermore, the trigger module 12 has an autonomous output state latching function, allowing it to stably maintain the current output state without continuous input signals after the state switch is completed. This effectively avoids erroneous output state switching caused by control signal jitter or brief interruptions, ensuring the stability and reliability of the power supply circuit's on / off control. In addition, the overcurrent signal can directly trigger the pulse generation module 11 to generate a pulse signal, driving the trigger module 12 to independently complete the shutdown action without going through the controller's intermediate processing stage. This effectively shortens the overcurrent protection response path and reduces the resource consumption of the controller. Simultaneously, the trigger module 12 autonomously latches its output in the shutdown state, ensuring that the power supply circuit will not unexpectedly resume conduction due to changes in the controller's output level after the overcurrent fault is cleared, thereby ensuring the reliable execution of the overcurrent protection action.

[0040] In some of these embodiments, see Figure 3 The pulse generation module 11 includes a diode DS1, a resistor R18, a resistor R30, and a capacitor C4. The anode of the diode DS1 is used to receive the pulse enable signal. The cathode of the diode DS1 is connected to the first end of the resistor R18. The second end of the resistor R18 is connected to the first end of the resistor R30, the comparator circuit 40, and the first end of the capacitor C4. The second end of the capacitor C4 is connected to the trigger module 12. The second end of the resistor R30 is grounded.

[0041] The unidirectional conduction characteristic of diode DS1 ensures that current can only be transmitted unidirectionally from the controller side to the pulse generation module 11, preventing the internal signal of the pulse generation module 11 from flowing back to the controller side, thus achieving signal isolation between the controller and the pulse generation module 11. At the same time, diode DS1 also isolates the pulse enable signal path from the overcurrent signal path, ensuring that the two trigger signals do not interfere with each other and drive the pulse generation module 11 independently.

[0042] Resistor R18 is used to limit the current flowing through this branch to prevent damage to downstream devices due to excessive current. Resistor R30 is used to clamp the potential of the first terminal of capacitor C4 to a low level when there is no valid signal input, ensuring that the first terminal of capacitor C4 is in a defined initial potential state, avoiding level uncertainty caused by floating, and preventing false triggering of the trigger module 12; at the same time, resistor R30 and capacitor C4 together form a discharge circuit, providing a discharge path for capacitor C4 after the trigger signal disappears, so that capacitor C4 can act on the next trigger signal, ensuring the normal response capability of the pulse generation module 11 to continuous trigger signals.

[0043] In the pulse generation module 11, when the first terminal of capacitor C4 receives a pulse enable signal or an overcurrent signal output by comparator circuit 40 through diode DS1 and resistor R18, since the voltage across capacitor C4 cannot change abruptly, the second terminal of capacitor C4 generates a positive pulse signal and outputs it to trigger module 12.

[0044] In this embodiment, the pulse generation module 11 consists of four passive components: diode DS1, resistor R18, resistor R30, and capacitor C4. The circuit structure is simple and can generate pulse signals without complex integrated logic devices, thus reducing the implementation cost and design complexity of the circuit.

[0045] In some of these embodiments, see Figure 3 The trigger module 12 includes a D flip-flop U4 and a resistor R6. The D flip-flop U4 is connected to the pulse generation module 11 and the first end of the resistor R6, respectively. The second end of the resistor R6 is connected to the switching circuit 20.

[0046] Specifically, the clock input of D flip-flop U4 is connected to pulse generation module 11 (such as the second terminal of capacitor C4), the positive output of D flip-flop U4 is connected to switching circuit 20, and the negative output of D flip-flop U4 is connected to its input. In D flip-flop U4, the negative output is connected to its data input, thus forming a T flip-flop logic structure. This causes the positive output level of D flip-flop U4 to flip once for each valid clock pulse received. Specifically, if the current positive output outputs a first control signal (such as a high-level signal), it flips to a second control signal (such as a low-level signal) after receiving a pulse signal; conversely, if the current positive output outputs a second control signal (such as a low-level signal), it flips to the first control signal (such as a high-level signal) after receiving a pulse signal.

[0047] After completing its state transition, the D flip-flop U4 automatically latches the current output level, maintaining a stable state without requiring a continuous input signal until the next valid pulse arrives and it flips again. Resistor R6 is used to limit the current between the output terminal and the switching circuit 20 to prevent damage to the device due to excessive current.

[0048] In some of these embodiments, see Figure 4The switching circuit 20 includes a first switching module 21 and a second switching module 22. The first switching module 21 is connected to the output switching circuit 10 and the second switching module 22 respectively. The first switching module 21 is also used to connect to the input power supply 200 and the load 300 to form a power supply loop. The second switching module 22 is also connected to the comparator circuit 40. The second switching module 22 is configured to turn on when it receives an overcurrent signal. The first switching module 21 is configured to turn on the power supply loop when it receives a first control signal, turn off the power supply loop when it receives a second control signal, and turn off the power supply loop when the second switching module 22 is turned on.

[0049] The first switch module 21 refers to the main switch module connected in series between the input power supply 200 and the load 300, which directly controls the on / off state of the power supply circuit. In this application, the first switch module 21 is located between the input power supply 200 and the sampling circuit 30. In normal operating mode, when the first switch module 21 receives a first control signal, the first switch module 21 is turned on, and the input power supply 200 supplies power to the load 300 normally through the first switch module 21, thus the power supply circuit is on; when the first switch module 21 receives a second control signal, the first switch module 21 is turned off, the power supply circuit is disconnected, and the input power supply 200 stops supplying power to the load 300. In the event of an overcurrent, the second switch module 22 is turned on, driving the first switch module 21 to disconnect the power supply circuit.

[0050] The second switching module 22 is an auxiliary switching device used for overcurrent protection. When the power supply circuit is working normally, the comparator circuit 40 does not generate an overcurrent signal, and the second switching module 22 is in the off state, without interfering with the on / off state of the first switching module 21. In the event of an overcurrent, the comparator circuit 40 outputs an overcurrent signal to the second switching module 22, and the second switching module 22 is turned on. Its on state drives the first switching module 21 to turn off the power supply circuit, reducing the damage caused by the overcurrent to the input power supply 200 and the load 300.

[0051] In this embodiment, when an overcurrent occurs, the second switching module 22 is driven by the overcurrent signal output by the comparator circuit 40, and directly drives the first switching module 21 to turn off the power supply circuit. Since the overcurrent protection path of the second switching module 22 is independent of the control path of the output switching circuit 10, even if the output switching circuit 10 fails to respond in time for some reason, the second switching module 22 can still independently control the first switching module 21 to complete the protection shutdown action, thereby improving the safety and reliability of the circuit operation.

[0052] In some of these embodiments, see Figure 3The first switching module 21 includes a switching unit 211 and a self-locking unit 212. The self-locking unit 212 is connected to the output switching circuit 10, the second switching module 22, and the switching unit 211. The switching unit 211 is also used to connect to the input power supply 200 and the load 300 to form a power supply circuit. The self-locking unit 212 is configured to continuously output a conduction signal to the switching unit 211 when receiving a first control signal, and to output a shutdown signal to the switching unit 211 when the second switching module 22 is turned on or when a second control signal is received. The switching unit 211 is configured to turn on the power supply circuit when receiving the conduction signal and to turn off the power supply circuit when receiving the shutdown signal.

[0053] Switching unit 211 refers to the main switching device connected in series between input power supply 200 and load 300, directly controlling the on / off state of the power supply circuit. In this application, switching unit 211 is located between input power supply 200 and sampling circuit 30. Self-locking unit 212 refers to a device capable of outputting a corresponding signal and locking the output signal based on the received control signal and the on / off state of second switching module 22, until the control signal or the on / off state of second switching module 22 changes.

[0054] In the first switching module 21, when the self-locking unit 212 receives the first control signal output by the output switching circuit 10, the self-locking unit 212 outputs a conduction signal. After the first control signal disappears, if the self-locking unit 212 does not receive the second control signal and the second switching module 22 remains in the off state, the self-locking unit 212 continues to output a conduction signal to the switching unit 211. The switching unit 211 remains in the conduction state, and the input power supply 200 supplies power to the load 300 normally through the switching unit 211, keeping the power supply circuit conducting. When the self-locking unit 212 receives the second control signal output by the output switching circuit 10, or when the second switching module 22 is turned on, the self-locking unit 212 stops outputting the conduction signal and instead outputs a turn-off signal to the switching unit 211. The switching unit 211 then turns off, the power supply circuit is disconnected, and the input power supply 200 stops supplying power to the load 300.

[0055] In this embodiment, under overcurrent conditions, the output signal is locked by setting a self-locking unit 212 in the first switch module 21 to ensure that the power supply circuit will not be accidentally restored to conduction before the overcurrent fault is cleared, thus providing reliable protection for the input power supply 200 and the load 300 and improving the safety and reliability of the circuit.

[0056] In some of these embodiments, see Figure 3The self-locking unit 212 includes a capacitor C1, a resistor R2, a resistor R3, a switch Q2, a resistor R1, a switch Q1, a resistor R4, and a resistor R5. The switching unit 211 includes a resistor R8, a diode ZD1, a resistor R7, and a switch Q3. The first terminal of capacitor C1 is connected to the first terminals of resistors R2 and R1 respectively. The second terminal of resistor R2 is connected to the first terminal of resistor R3 and the first terminal of switch Q2 respectively. The second terminals of capacitor C1, resistor R3, and switch Q2 are grounded. The third terminal of switch Q2 is connected to the first terminals of resistors R5 and R8 respectively. The second terminal of resistor R8 is connected to the anode of diode ZD1, the first terminal of resistor R7, and the first terminal of switch Q3 respectively. The second terminal of switch Q3 is connected to the input power supply 200, the first terminal of switch Q1, the first terminal of resistor R4, the cathode of diode ZD1, and the second terminal of resistor R7 respectively. The third terminal of switch Q3 is used to connect to the load 300. The second terminal of switch Q1 is connected to the second terminals of resistors R4 and R5 respectively. The third terminal of switch Q1 is connected to the second terminal of resistor R1.

[0057] In this circuit, capacitor C1 and resistor R2 form an RC filter circuit to filter the signal input to the first terminal of switch Q2. Resistor R2 also limits the current amplitude input to the first terminal of switch Q2, protecting it. Resistor R3 provides a grounding path for the first terminal of switch Q2 when the input signal is unstable, ensuring reliable grounding and reducing the possibility of interference signals triggering mis-turn-on of switch Q2. Diode ZD1 is a Zener diode that clamps the voltage between the first and second terminals of switch Q3 within a safe range, preventing overvoltage damage to switch Q3. When the signal at the first terminal of resistor R8 is unstable, resistor R7 provides a pull-up path for the first terminal of switch Q3, reliably pulling it high and suppressing interference signals from triggering mis-turn-on of switch Q3.

[0058] Each switching transistor can be any controllable switch, such as an Insulated Gate Bipolar Transistor (IGBT), an Integrated Gate Commutated Thyristor (IGCT), a Gate Turn-Off Thyristor (GTO), a Silicon Controlled Rectifier (SCR), a Junction Gate Field Effect Transistor (JFET), or a MOS-controlled Thyristor (MCT). Specifically, switching transistor Q2 is an NPN transistor. The first terminal of switching transistor Q2 is the base of the NPN transistor, the second terminal of switching transistor Q2 is the emitter of the NPN transistor, and the third terminal of switching transistor Q2 is the collector of the NPN transistor. Switch Q1 is a PNP transistor. The first terminal of switch Q1 is the emitter of the PNP transistor, the second terminal of switch Q1 is the base of the PNP transistor, and the third terminal of switch Q1 is the collector of the PNP transistor. Switch Q3 is a PMOS transistor. The first terminal of switch Q3 is the gate of the PMOS transistor, the second terminal of switch Q3 is the source of the PMOS transistor, and the third terminal of switch Q3 is the drain of the PMOS transistor.

[0059] In this circuit, when switch Q2 receives the first control signal output by output switching circuit 10 and the second switch module 22 is turned off, switch Q2 is turned on. Resistors R4 and R5, together with switch Q2, divide the input power supply 200 to form a voltage divider network. The output voltage divider signal is output to the first terminal of switch Q1 to provide a conduction bias for switch Q1, thus turning on switch Q1. After switch Q1 is turned on, the input power supply 200 continuously provides a high level to the first terminal of switch Q2 through switch Q1 and resistor R1, maintaining the potential of the first terminal of switch Q2 above the conduction threshold, thus keeping switch Q2 in the conducting state. The continuous conduction of switch Q2, in turn, maintains the conduction bias of switch Q1 through the voltage divider network, thus keeping switch Q1 in the conducting state as well. Thus, a feedback loop is formed between switching transistors Q1 and Q2 to maintain mutual conduction, constituting a self-locking logic. At this time, the first terminal of switching transistor Q3 is grounded through resistor R8 and switching transistor Q2, switching transistor Q3 is turned on, the power supply loop is open, and the input power supply 200 supplies power to the load 300 normally through switching transistor Q3. When switching transistor Q2 receives the second control signal output by the output switching circuit 10 or the second switching module 22 is turned on, switching transistors Q1 and Q2 are turned off, the first terminal of switching transistor Q3 is pulled high through resistor R7, switching transistor Q3 is turned off, the power supply loop is disconnected, and the input power supply 200 stops supplying power to the load 300.

[0060] In this embodiment, by setting the above-mentioned device, the power supply state can be switched and locked after receiving the control signal, without the need for continuous external control signal maintenance, thus reducing the power consumption and complexity of the circuit.

[0061] In some of these embodiments, see Figure 3The second switching module 22 includes a resistor R27 and a switching transistor Q6. The first terminal of the switching transistor Q6 is connected to the first terminal of the resistor R27 and the comparator circuit 40, the second terminal of the switching transistor Q6 is connected to the output switching circuit 10 and the first switching module 21, and the third terminal of the switching transistor Q6 is grounded to the second terminal of the resistor R27.

[0062] Switch Q6 can be any controllable switch, such as an Insulated Gate Bipolar Transistor (IGBT), an Integrated Gate Commutated Thyristor (IGCT), a Gate Turn-Off Thyristor (GTO), a Silicon Controlled Rectifier (SCR), a Junction Gate Field-Effect Transistor (JFET), or a MOS-controlled Thyristor (MCT). Specifically, switch Q6 can be an NPN transistor, with its first terminal being the base, second terminal the collector, and third terminal the emitter. Specifically, the second terminal of switch Q6 is connected to the first terminal of resistor R2. When the comparator circuit 40 outputs an overcurrent signal, switch Q6 turns on, pulling the first terminal of switch Q2 low, turning off switch Q2, which in turn turns off switch Q3, disconnecting the power supply circuit.

[0063] In this embodiment, the second switch module 22 consists of only two components: a resistor R27 and a switch transistor Q6. The number of components is small and the circuit topology is simple, which helps to reduce the material cost and assembly complexity of the overall circuit.

[0064] In some of these embodiments, see Figure 3 The reference signal generation circuit 50 includes resistors R24 and R26, a thermistor RT1, and a diode ZD2. The first terminal of resistor R24 ​​is used to receive the reference signal Vref. The second terminal of resistor R24 ​​is connected to the comparator circuit 40, the first terminal of resistor R26, and the cathode of diode ZD2. The second terminal of resistor R26 is connected to the first terminal of the thermistor RT1. The second terminal of the thermistor RT1 and the anode of diode ZD2 are grounded.

[0065] Specifically, resistors R24 and R26, along with the thermistor RT1, form a voltage divider network. The reference signal Vref is a DC voltage signal with a fixed amplitude. The reference signal Vref is divided by the series connection of resistors R24, R26, and thermistor RT1, forming a reference signal at the common node between the second terminal of resistor R24 ​​and the first terminal of resistor R26. This reference signal is output to comparator circuit 40 as the comparison threshold for determining overcurrent conditions. Diode ZD2 is connected in parallel across the series branch of resistor R26 and thermistor RT1, clamping the reference voltage at the common node to prevent abnormal fluctuations from exceeding a preset range. This protects the input of the subsequent comparator circuit 40 from excessive voltage surges, improving the stability and reliability of the circuit.

[0066] In the reference signal generation circuit 50, the resistance of the thermistor RT1 adaptively adjusts with changes in operating temperature, thus enabling the output reference voltage to possess temperature-adaptive characteristics. Specifically, the thermistor RT1 can be a negative temperature coefficient (NTC) thermistor. When the temperature rises, the resistance of the thermistor RT1 decreases, the voltage of the reference signal decreases accordingly, and the overcurrent protection threshold decreases accordingly; when the temperature decreases, the resistance of the thermistor RT1 increases, the voltage of the reference signal increases accordingly, and the overcurrent protection threshold increases accordingly. By influencing the resistance of the thermistor RT1 with temperature, the voltage of the reference signal is dynamically adjusted according to changes in ambient temperature, compensating for the insufficient protection accuracy of fixed threshold protection schemes under different temperature conditions. By reasonably selecting the parameters of resistors R24 and R26 and the thermistor RT1, the reference voltage range under different temperature conditions can be flexibly set, thereby meeting the differentiated requirements of overcurrent protection thresholds in different application scenarios, exhibiting good engineering applicability and design flexibility.

[0067] In some of these embodiments, see Figure 3 The sampling circuit 30 includes a sampling module 31 and a differential amplifier module 32. The sampling module 31 is located in the power supply circuit, and the differential amplifier module 32 is connected to both the sampling module 31 and the comparator circuit 40. The sampling module 31 is configured to sample the current in the power supply circuit and obtain the corresponding voltage signal. The differential amplifier module 32 is configured to differentially amplify the voltage signal to obtain the sampling signal and output the sampling signal to the comparator circuit 40.

[0068] The sampling module 31 is connected in series in the power supply circuit. When current flows through the power supply circuit, a voltage drop proportional to the magnitude of the current is generated across the sampling module 31, thereby converting the current signal into a voltage signal that can be processed by subsequent circuits. Specifically, the sampling module 31 is a high-side sampling module 31. (See [reference needed]) Figure 3 The sampling module 31 includes resistors R15, R16, R17 and capacitor C3. The first end of resistor R15 is connected to the switching circuit 20 and the first end of resistor R16. The second end of resistor R15 is connected to the load 300 and the first end of resistor R17. The second end of resistor R16 is connected to the first input terminal of differential amplifier module 32 and the first end of capacitor C3. The second end of resistor R17 is connected to the second input terminal of differential amplifier module 32 and the second end of capacitor C3.

[0069] The differential amplifier module 32 refers to a differential amplifier circuit composed of an operational amplifier and its peripheral resistor network. It is used to amplify voltage signals, thereby expanding the small differential voltage signal to an amplitude range suitable for processing by the comparator circuit 40, improving the signal-to-noise ratio and the sensitivity and accuracy of overcurrent detection in the sampling circuit 30. For details, please refer to [link to relevant documentation]. Figure 3 The differential amplifier module 32 includes resistors R21 and R22, operational amplifier U1, resistor R19, capacitor C5, resistor R25, and capacitor C7. The first terminal of resistor R21 is connected to the first terminal of resistor R16 and the first terminal of capacitor C3. The first terminal of resistor R22 is connected to the first terminal of resistor R17 and the second terminal of capacitor C3. The inverting input terminal of operational amplifier U1 is connected to the second terminal of resistor R21, the first terminal of resistor R19, and the first terminal of capacitor C5. The non-inverting input terminal of operational amplifier U1 is connected to the first terminal of resistor R25 and the first terminal of capacitor C7. The output terminal of operational amplifier U1 is connected to comparator circuit 40, the second terminal of resistor R19 is connected to the first terminal of capacitor C5, and the first terminals of resistor R25 and capacitor C7 are grounded.

[0070] In this embodiment, the current of the power supply circuit is sampled and amplified by the sampling module 31 and the differential amplification module 32, so that the output sampling signal can be adapted to the detection range of the comparison circuit 40.

[0071] In some of these embodiments, see Figure 3 The comparator circuit 40 includes a comparator U2, resistors R20 and R23, capacitor C6, and diode DS2. The positive input terminal of comparator U2 is connected to the sampling circuit 30, and the negative input terminal of comparator U2 is connected to the reference signal generation circuit 50. The output terminal of comparator U2 is connected to the first terminals of resistors R20 and R23. The second terminal of resistor R20 is connected to the first power supply Vcc. The second terminal of resistor R23 is connected to the first terminal of capacitor C6, the first terminal of resistor R28, and the anode of diode DS2. The second terminal of capacitor C6 is grounded. The second terminal of resistor R28 is connected to the switching circuit 20. The cathode of diode DS1 is connected to the output switching circuit 10.

[0072] Specifically, the positive input terminal of comparator U2 is connected to the output terminal of operational amplifier U1, the negative input terminal of comparator U2 is connected to the second terminal of resistor R24, the first terminal of resistor R26, and the cathode of diode ZD2, the second terminal of resistor R28 is connected to the first terminal of switching transistor Q6, and the cathode of diode DS1 is connected to the first terminal of capacitor C4. During circuit operation, comparator U2 compares the voltage signals at the positive and negative input terminals. When the voltage of the sampled signal is higher than the voltage of the reference signal, it indicates that an overcurrent may occur in the power supply circuit. Comparator U2 outputs a high-level signal (overcurrent signal). This high-level signal is processed by the RC delay network formed by resistor R23 and capacitor C6 and then output in two paths: one path drives switching transistor Q6 to conduct through resistor R28, causing capacitor C1 to discharge, thereby turning off the switching circuit 20; the other path outputs the overcurrent signal to the output switching circuit 10 through diode DS2, causing the output switching circuit 10 to switch to the second control signal output, thereby turning off the circuit. The delay circuit formed by resistor R23 and capacitor C6 helps to avoid false triggering caused by instantaneous interference. The protection action can only be triggered after the overcurrent state has lasted for a certain period of time, thereby helping to improve the reliability and anti-interference capability of the circuit.

[0073] The following is combined Figure 3 The embodiments shown illustrate in detail the specific working process of the protection circuit provided in this application.

[0074] In this protection circuit, during normal operation, when the controller outputs a pulse enable signal, since the voltage across capacitor C4 cannot change abruptly, a positive pulse signal is generated at the second terminal of capacitor C4, triggering D flip-flop U4 to output a high-level first control signal. When the controller outputs a pulse enable signal again, a positive pulse signal is generated at the second terminal of capacitor C4 again, triggering D flip-flop U4 to output a low-level second control signal, and so on. When D flip-flop U4 outputs a high-level first control signal, the first control signal charges capacitor C1 through resistor R6. The voltage across capacitor C1 is divided by resistors R2 and R3. The voltage divider signal turns on switch Q2, grounding the first terminal of switch Q3 through resistor R8. Switch Q3 is turned on, and the power supply circuits for input power supply 200, switching circuit 20, sampling circuit 30, and load 300 are connected, with input power supply 200 supplying power to load 300. Simultaneously, input power supply 200 is divided by switch Q1, resistors R1, R2, and R3, and the voltage divider signal maintains the conduction of switch Q2, achieving self-locking.

[0075] When the input power supply 200 supplies power to the load 300, the sampling circuit 30 samples the current flowing through resistor R15 and outputs the sampled signal to the comparator circuit 40. Furthermore, the reference signal Vref is divided by a series connection of resistors R24 and R26 with the thermistor RT1, forming a reference signal at the common node between the second end of resistor R24 ​​and the first end of resistor R26. This reference signal is output to the comparator circuit 40 as the comparison threshold for determining the overcurrent condition. The thermistor RT1 is placed near the switching transistor Q3 to sample its temperature. As the temperature of the switching transistor Q3 increases, the resistance of the thermistor RT1 decreases, the voltage at the negative input terminal of comparator U2 decreases, and the current limiting threshold decreases.

[0076] Comparator U2 compares the voltage of the sampled signal and the reference signal. When the voltage of the sampled signal is less than the voltage of the reference signal, it indicates that no overcurrent has occurred in the power supply circuit, and comparator U2 outputs a low-level signal, not triggering overcurrent protection. When the voltage of the sampled signal is greater than the voltage of the reference signal, it indicates that an overcurrent has occurred in the power supply circuit, and comparator U2 outputs a high-level signal (overcurrent signal). This high-level signal is delayed by resistor R23 and capacitor C6, and then output to switch Q6, turning on switch Q6 and rapidly discharging capacitor C1 to near 0V. At this point, switch Q2 is turned off, thus turning off switches Q1 and Q3, and shutting off the power supply circuit. Simultaneously, this high-level signal generates a positive pulse signal through capacitor C4 to the D flip-flop, which outputs a low-level second control signal, also turning off switch Q2.

[0077] In this embodiment, the thermistor RT1 is placed close to the switching transistor Q3 to collect its operating temperature in real time, and the overcurrent protection threshold is dynamically adjusted according to the operating temperature. During the initial circuit startup, the temperature of the switching transistor Q3 is relatively low, the resistance of the thermistor RT1 is relatively high, and the current limiting point is correspondingly high, which helps to withstand the large inrush current at startup, thus facilitating smooth load startup. Once the load enters normal operating condition, as the temperature of the switching transistor Q3 gradually increases, the resistance of the thermistor RT1 decreases accordingly, and the current limiting point adaptively decreases, thereby providing relatively strict overcurrent protection during normal load operation and helping to reduce the risk of power supply overheating and damage due to prolonged overload.

[0078] Secondly, embodiments of this application provide an energy storage system, which includes a protection circuit as described in any embodiment of the first aspect.

[0079] In this embodiment, the protection circuit has the same structure and function as the protection circuit described in any embodiment of the first aspect, and will not be repeated here.

[0080] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A protection circuit, characterized in that, include: Output switching circuit, switching circuit, sampling circuit, comparison circuit and reference signal generation circuit; The switching circuit is used to connect to the input power supply and the load respectively to form a power supply loop. The sampling circuit is located in the power supply loop. The output switching circuit is connected to the switching circuit. The comparison circuit is connected to the sampling circuit, the reference signal generation circuit, the switching circuit and the output switching circuit respectively. The sampling circuit is configured to output a sampling signal to the comparison circuit based on the current of the power supply circuit; The reference signal generation circuit is configured to output a reference signal corresponding to the temperature to the comparison circuit; The comparison circuit is configured to output an overcurrent signal when the reference signal and the sampled signal meet a preset condition; The output switching circuit is configured to switch the output between the first control signal and the second control signal based on the overcurrent signal or the pulse enable signal output by the controller. The switching circuit is configured to turn on the power supply circuit upon receiving the first control signal, and to turn off the power supply circuit upon receiving the second control signal or the overcurrent signal.

2. The protection circuit according to claim 1, characterized in that, The output switching circuit includes a pulse generation module and a trigger module; The pulse generation module is connected to the comparison circuit and the trigger module respectively, and the trigger module is connected to the switching circuit; The pulse generation module is configured to generate a pulse signal based on the pulse enable signal or the overcurrent signal; The trigger module is configured to switch between the first control signal and the second control signal upon receiving the pulse signal.

3. The protection circuit according to claim 2, characterized in that, The pulse generation module includes a diode DS1, a resistor R18, a resistor R30, and a capacitor C4. The anode of the diode DS1 is used to receive the pulse enable signal. The cathode of the diode DS1 is connected to the first end of the resistor R18. The second end of the resistor R18 is connected to the first end of the resistor R30, the comparator circuit, and the first end of the capacitor C4. The second end of the capacitor C4 is connected to the trigger module. The second end of the resistor R30 is grounded.

4. The protection circuit according to claim 1, characterized in that, The switching circuit includes a first switching module and a second switching module; The first switching module is connected to the output switching circuit and the second switching module respectively. The first switching module is also used to connect to the input power supply and the load to form the power supply circuit. The second switching module is also connected to the comparator circuit. The second switch module is configured to turn on upon receiving the overcurrent signal; The first switch module is configured to turn on the power supply circuit upon receiving the first control signal, turn off the power supply circuit upon receiving the second control signal, and turn off the power supply circuit when the second switch module is turned on.

5. The protection circuit according to claim 4, characterized in that, The first switch module includes a switch unit and a self-locking unit; The self-locking unit is connected to the output switching circuit, the second switching module and the switching unit respectively. The switching unit is also used to connect to the input power supply and the load to form the power supply circuit. The self-locking unit is configured to continuously output an on signal to the switching unit when it receives the first control signal, and to output an off signal to the switching unit when the second switching module is turned on or when it receives the second control signal; The switching unit is configured to turn on the power supply circuit upon receiving the turn-on signal, and to turn off the power supply circuit upon receiving the turn-off signal.

6. The protection circuit according to claim 5, characterized in that, The self-locking unit includes capacitor C1, resistor R2, resistor R3, switching transistor Q2, resistor R1, switching transistor Q1, resistor R4, and resistor R5. The switching unit includes resistor R8, diode ZD1, resistor R7, and switching transistor Q3. The first terminal of capacitor C1 is connected to the first terminals of resistors R2 and R1 respectively. The second terminal of resistor R2 is connected to the first terminal of resistor R3 and the first terminal of switch Q2 respectively. The second terminals of capacitor C1, resistor R3, and switch Q2 are grounded. The third terminal of switch Q2 is connected to the first terminals of resistors R5 and R8 respectively. The second terminal of resistor R8 is connected to the anode of diode ZD1, the first terminal of resistor R7, and the first terminal of switch Q3 respectively. The second terminal of switch Q3 is connected to the input power supply, the first terminal of switch Q1, the first terminal of resistor R4, the cathode of diode ZD1, and the second terminal of resistor R7 respectively. The third terminal of switch Q3 is used to connect to the load. The second terminal of switch Q1 is connected to the second terminals of resistors R4 and R5 respectively. The third terminal of switch Q1 is connected to the second terminal of resistor R1.

7. The protection circuit according to any one of claims 4-6, characterized in that, The second switching module includes a resistor R27 and a switching transistor Q6; The first terminal of the switching transistor Q6 is connected to the first terminal of the resistor R27 and the comparator circuit, the second terminal of the switching transistor Q6 is connected to the output switching circuit and the first switching module, and the third terminal of the switching transistor Q6 is grounded to the second terminal of the resistor R27.

8. The protection circuit according to any one of claims 1-5, characterized in that, The reference signal generation circuit includes resistor R24, resistor R26, thermistor RT1, and diode ZD2; The first end of resistor R24 ​​is used to receive a reference signal. The second end of resistor R24 ​​is connected to the comparator circuit, the first end of resistor R26, and the cathode of diode ZD2. The second end of resistor R26 is connected to the first end of the thermistor RT1. The second end of the thermistor RT1 and the anode of diode ZD2 are grounded.

9. The protection circuit according to any one of claims 1-5, characterized in that, The sampling circuit includes a sampling module and a differential amplifier module; The sampling module is located in the power supply circuit, and the differential amplifier module is connected to both the sampling module and the comparison circuit. The sampling module is configured to sample the current of the power supply circuit and obtain the corresponding voltage signal; The differential amplifier module is configured to differentially amplify the voltage signal to obtain the sampled signal, and output the sampled signal to the comparison circuit.

10. An energy storage system, characterized in that, Includes the protection circuit as described in any one of claims 1-9.

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