Protection circuit and energy storage system

Abstract

The utility model relates to a protection circuit and an energy storage system, the protection circuit comprises a sampling circuit, a first protection circuit and a second protection circuit, the protection circuit obtains a voltage sampling signal through the sampling circuit when an adapter charges the energy storage system, and when the input current of the adapter is over-current, the first protection circuit is connected with the second protection circuit. And the first protection circuit generates a first driving signal according to the received voltage sampling signal to a driving circuit for charging the energy storage system, so that the driving circuit is disconnected, a charging loop of the energy storage system is further disconnected, and overcurrent protection is realized for the energy storage system. When the adapter is reversely connected or short-circuited, the second protection circuit generates a second driving signal according to the received voltage sampling signal and transmits the second driving signal to the driving circuit, so that the driving circuit is disconnected, a charging loop of the energy storage system is further disconnected, reverse connection prevention or short-circuit protection is achieved for the energy storage system, and the safety of the energy storage system is further improved.

Description

Technical Field

[0001] The utility model relates to the field of energy storage safety protection, in particular to a protection circuit and an energy storage system. Background Art

[0002] The power adapter is a power supply conversion device for small portable electronic devices and electronic appliances, which can charge the energy storage system. When the traditional energy storage system is plugged into the adapter for charging, there may be situations where the adapter is reversely connected, the impact current is relatively large when it is just connected, the adapter is short-circuited, or a large current is connected for charging, which can easily damage the machine. Utility Model Content

[0003] The embodiments of the utility model aim to provide a protection circuit and an energy storage system, which can provide overcurrent protection and reverse connection or short circuit protection to the energy storage system, thereby improving safety.

[0004] In order to solve the above technical problems, the present utility model provides the following technical solutions:

[0005] In a first aspect, an embodiment of the utility model provides a protection circuit applied to an energy storage system, the energy storage system comprising a drive circuit and an energy storage device, an adapter charges the energy storage device through the drive circuit, and the protection circuit comprises: a sampling circuit, a first protection circuit and a second protection circuit;

[0006] The sampling circuit is connected to the charging circuit of the energy storage device, the input end of the first protection circuit and the input end of the second protection circuit respectively, and the sampling circuit is used to sample the voltage signal of the charging circuit to obtain a voltage sampling signal;

[0007] The output end of the first protection circuit and the output end of the second protection circuit are commonly connected to the drive circuit. When the input current of the adapter is overcurrent, the first protection circuit is used to generate a first drive signal to the drive circuit according to the received voltage sampling signal, so as to disconnect the drive circuit;

[0008] When the adapter is reversely connected or short-circuited, the second protection circuit is used to generate a second drive signal to the drive circuit according to the received voltage sampling signal, so as to disconnect the drive circuit.

[0009] In some embodiments, the first protection circuit includes a first comparator, a resistor R5, and a resistor R6;

[0010] The inverting input terminal of the first comparator is connected to the sampling circuit, the non-inverting input terminal of the first comparator is connected to one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is connected to the first power supply, the other end of the resistor R6 is grounded, and the output terminal of the first comparator is connected to the driving circuit.

[0011] In some embodiments, the second protection circuit includes a first comparison module and a second comparison module;

[0012] The input end of the first comparison module is connected to the sampling circuit, the output end of the first comparison module is connected to the input end of the second comparison module, and the output end of the second comparison module is connected to the driving circuit;

[0013] The first comparison module is used to generate a corresponding first comparison signal according to the voltage sampling signal and a second reference voltage, and the second comparison module is used to generate a corresponding second drive signal according to the first comparison signal and a third reference voltage.

[0014] In some embodiments, the first comparison module includes a second comparator, a resistor R12, a resistor R18, a capacitor C6, a diode D1, and a resistor R9;

[0015] The inverting input terminal of the second comparator is connected to the sampling circuit, the non-inverting input terminal of the second comparator is respectively connected to one end of the resistor R12, one end of the resistor R18, one end of the capacitor C6 and the cathode of the diode D1, the other end of the resistor R12 is connected to the first power supply, the other end of the resistor R18 and the other end of the capacitor C6 are grounded together, the anode of the diode D1 is connected to the output terminal of the second comparator, one end of the resistor R9 and the input terminal of the second comparison module, and the other end of the resistor R9 is connected to the first power supply.

[0016] In some embodiments, the second comparison module includes a third comparator, a resistor R16, a resistor R17, and a capacitor C7;

[0017] The inverting input terminal of the third comparator is connected to the output terminal of the first comparison module, the non-inverting input terminal of the third comparator is respectively connected to one end of the resistor R16, one end of the resistor R17 and one end of the capacitor C7, the other end of the resistor R16 is connected to the first power supply, the other end of the resistor R17 and the other end of the capacitor C7 are grounded together, and the output terminal of the third comparator is connected to the driving circuit.

[0018] In some embodiments, the second protection circuit further includes a short circuit reset module and a control module;

[0019] The short-circuit reset module is respectively connected to the control module, the output end of the first comparison module and the input end of the second comparison module, and the control module is also connected to the output end of the first comparison module and the input end of the second comparison module;

[0020] The control module is used to determine whether the adapter is short-circuited or reversely connected according to the received first comparison signal;

[0021] When the adapter is short-circuited or reversely connected, the control module is further used to send a short-circuit reset signal to the short-circuit reset module, so that the short-circuit reset module generates a low-level signal according to the short-circuit reset signal to lower the input terminal potential of the second comparison module.

[0022] In some embodiments, the short circuit reset module includes a resistor R20, a resistor R24 ​​and a transistor Q4;

[0023] One end of the resistor R20 is connected to the control module, the other end of the resistor R20 is respectively connected to one end of the resistor R24 ​​and the base of the transistor Q4, the other end of the resistor R24 ​​and the emitter of the transistor Q4 are grounded, and the collector of the transistor Q4 is respectively connected to the output end of the first comparison module and the input end of the second comparison module.

[0024] In some embodiments, the protection circuit also includes a third protection circuit, which is respectively connected to the sampling circuit and the driving circuit. When the input voltage of the adapter is overvoltage, the third protection circuit is used to generate a third driving signal to the driving circuit based on the received voltage sampling signal to disconnect the driving circuit.

[0025] In some embodiments, the third protection circuit includes a fourth comparator, a resistor R31 and a resistor R32;

[0026] The inverting input terminal of the fourth comparator is connected to the sampling circuit, the non-inverting input terminal of the fourth comparator is respectively connected to one end of the resistor R31 and one end of the resistor R32, the other end of the resistor R31 is connected to the first power supply, the other end of the resistor R32 is grounded, and the output terminal of the fourth comparator is connected to the driving circuit.

[0027] In a second aspect, an embodiment of the utility model provides an energy storage system, wherein the energy storage system includes the protection circuit as described above.

[0028] In various embodiments of the utility model, the protection circuit includes a sampling circuit, a first protection circuit and a second protection circuit, wherein the protection circuit obtains a voltage sampling signal when the adapter charges the energy storage system through the sampling circuit, and when the input current of the adapter is overcurrent, the first protection circuit generates a first drive signal to the drive circuit for charging the energy storage system according to the received voltage sampling signal, so that the drive circuit is disconnected, and then the charging circuit of the energy storage system is disconnected, and overcurrent protection is implemented for the energy storage system. When the adapter is reversely connected or short-circuited, the second protection circuit generates a second drive signal to the drive circuit according to the received voltage sampling signal, so that the drive circuit is disconnected, and then the charging circuit of the energy storage system is disconnected, and reverse connection or short circuit protection is implemented for the energy storage system, thereby improving the safety of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0030] Figure 1 It is a structural schematic diagram of an energy storage system provided by an embodiment of the utility model;

[0031] Figure 2 It is a structural schematic diagram of a protection circuit provided by an embodiment of the utility model;

[0032] Figure 3 It is a structural schematic diagram of a protection circuit provided by an embodiment of the utility model;

[0033] Figure 4 It is a circuit structure diagram of a first protection circuit provided by an embodiment of the utility model;

[0034] Figure 5 This is a schematic diagram of the circuit structure of a second protection circuit provided by an embodiment of the utility model;

[0035] Figure 6 It is a circuit structure schematic diagram of a third protection circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0036] 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.

[0037] Energy storage systems include the input and output of energy and materials, energy conversion and storage equipment, which often involve multiple energies, multiple equipment, multiple materials, and multiple processes. They are complex energy systems that change over time. Figure 1 As shown, the energy storage system 1 includes a drive circuit 11 and an energy storage device, wherein the drive circuit 11 includes a switch tube Q3, a switch tube Q5, a voltage regulator tube ZD1, a resistor R7, a resistor R13, a transistor Q6, a resistor R15 and a resistor R19, the gate of the switch tube Q3, the gate of the switch tube Q5, the anode of the voltage regulator tube ZD1 and one end of the resistor R7 are commonly connected to one end of the resistor R13, the source of the switch tube Q3, the source of the switch tube Q5, the cathode of the voltage regulator tube ZD1 and the other end of the resistor R7 are commonly connected, the drain of the switch tube Q5 is connected to the positive electrode of the energy storage device, the other end of the resistor R13 is connected to the collector of the transistor Q6, the base of the transistor Q6 is respectively connected to one end of the resistor R15 and one end of the resistor R19, the emitter of the transistor Q6 and the other end of the resistor R19 are grounded, that is, the negative electrode of the energy storage device, and the other end of the resistor R15 is used to access the drive signal.

[0038] The power adapter is a power supply conversion device for small portable electronic devices and electronic appliances, which can charge the energy storage system 1. When the adapter charges the energy storage device, the adapter is connected through the input interface CN1.

[0039] In this embodiment, the energy storage device is a rechargeable battery BAT, and the switch tube Q3 and the switch tube Q5 are both PMOS tubes.

[0040] When the adapter charges the energy storage device, the driving signal controls the transistor Q6 to turn on, which in turn turns on the switch tubes Q3 and Q5, and the charging current flows through F1, Q3, Q5 to BAT+, then to GND_BAT, and finally to GND_ACC. Among them, the switch tubes Q3 and Q5 can prevent the current of the battery BAT from flowing back into the adapter.

[0041] When a traditional energy storage system is plugged into an adapter for charging, the adapter may be connected reversely. If the positive and negative terminals of the adapter are plugged in reverse, they are easily damaged. In addition, there are many unstable factors in the external adapter. For example, the impact current is relatively large when it is first connected, which can easily damage the MOS of the machine. The external adapter may also short-circuit or be charged with a large current. If the energy storage system is not protected, it is easy to damage the machine.

[0042] Therefore, the utility model provides a protection circuit, which can protect the energy storage system from reverse connection, short circuit and overcurrent.

[0043] See also Figure 2 , Figure 2 Schematic diagram of a protection circuit provided by an embodiment of the utility model. Figure 2 As shown, the protection circuit 2 includes a sampling circuit 21, a first protection circuit 22 and a second protection circuit 23, wherein the sampling circuit 21 is connected to the charging circuit of the energy storage device, the input end of the first protection circuit 22 and the input end of the second protection circuit 23 respectively, and the output end of the first protection circuit 22 and the output end of the second protection circuit 23 are commonly connected to the drive circuit 11.

[0044] The protection circuit 2 obtains the voltage sampling signal I.ACC.AO when the adapter charges the energy storage system 1 through the sampling circuit 21. The voltage sampling signal I.ACC.AO can represent the magnitude of the input voltage and input current provided by the adapter when charging.

[0045] When the input current of the adapter is overcurrent, the first protection circuit 22 generates a first drive signal to the drive circuit 11 according to the received voltage sampling signal I.ACC.AO, so that the drive circuit 11 is disconnected, and then the charging circuit of the energy storage system 1 is disconnected, thereby realizing overcurrent protection for the energy storage system 1.

[0046] When the adapter is reverse connected or short-circuited, the second protection circuit 23 generates a second drive signal to the drive circuit 11 according to the received voltage sampling signal I.ACC.AO, so that the drive circuit 11 is disconnected, and then the charging circuit of the energy storage system 1 is disconnected, thereby protecting the energy storage system 1 from reverse connection or short circuit, thereby improving the safety of the energy storage system 1.

[0047] The drive circuit 11 is disconnected, which means that the drive circuit 11 is in a non-conducting state, for example Figure 1 The driving circuit 11 shown, if in the disconnected state, means that the switch tube Q6 is turned off, and the switch tubes Q3 and Q5 are both turned off. Therefore, when the driving circuit 11 is disconnected, the charging circuit of the energy storage device is disconnected, and the adapter can no longer charge the energy storage device, so as to realize the reverse connection, short circuit and overcurrent protection of the energy storage device.

[0048] See also Figure 3 , Figure 3 Schematic diagram of a protection circuit provided by an embodiment of the utility model. Figure 3 As shown, the protection circuit 2 further includes a third protection circuit 24, wherein the third protection circuit 24 is respectively connected to the sampling circuit 21 and the driving circuit 11. When the input voltage of the adapter is overvoltage, the third protection circuit 24 generates a third driving signal to the driving circuit 11 according to the received voltage sampling signal I.ACC.AO, so as to disconnect the driving circuit 11, thereby realizing overvoltage protection for the energy storage system 1.

[0049] In some embodiments, Figure 3As shown, the second protection circuit 23 includes a first comparison module 231 and a second comparison module 232, wherein the input end of the first comparison module 231 is connected to the sampling circuit 21, the output end of the first comparison module 231 is connected to the input end of the second comparison module 232, and the output end of the second comparison module 232 is connected to the driving circuit 11.

[0050] After receiving the voltage sampling signal I.ACC.AO, the first comparison module 231 generates a corresponding first comparison signal according to the voltage sampling signal I.ACC.AO and the second reference voltage, and the second comparison module 232 generates a corresponding second drive signal according to the first comparison signal and the third reference voltage.

[0051] If the adapter works normally, the voltage of the voltage sampling signal I.ACC.AO is greater than the second reference voltage, and the first comparison module 231 generates a corresponding first comparison signal. The first comparison signal is a low-level signal, and its voltage is less than the third reference voltage. The second comparison module 232 generates a corresponding second drive signal, which is a high-level signal, thereby making the drive circuit 11 in a pass state, and the adapter charges the energy storage device normally.

[0052] If the adapter is reversely connected or short-circuited, the voltage of the voltage sampling signal I.ACC.AO is less than the second reference voltage, and the first comparison module 231 generates a corresponding first comparison signal. If the first comparison signal is a high-level signal, its voltage is greater than the third reference voltage, and the second comparison module 232 generates a corresponding second drive signal, and the second drive signal is a low-level signal. The low-level signal acts on the drive circuit 11, causing the drive circuit 11 to disconnect, thereby disconnecting the charging circuit of the energy storage device, and realizing anti-reverse connection or short-circuit protection for the energy storage device.

[0053] In some embodiments, Figure 3 As shown, the second protection circuit 23 also includes a short-circuit reset module 233 and a control module 234, wherein the short-circuit reset module 233 is respectively connected to the control module 234, the output end of the first comparison module 231 and the input end of the second comparison module 232, and the control module 234 is also connected to the output end of the first comparison module 231 and the input end of the second comparison module 232.

[0054] The control module 234 determines whether the adapter is short-circuited or reversely connected according to the received first comparison signal. If the adapter is short-circuited or reversely connected, the first comparison signal is a high-level signal, and the control module 234 determines that the first comparison signal is a high-level signal, and then determines that the adapter is short-circuited or reversely connected. On the contrary, if the first comparison signal received by the control module 234 is a low-level signal, it is determined that the adapter is not short-circuited or reversely connected.

[0055] The control module 234 can be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a single chip microcomputer, an ARM (Acorn RISC Machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components. In addition, the control module 234 can also be any conventional processor, controller, microcontroller or state machine. The control module 234 can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP, and / or any other such configuration.

[0056] When the adapter is short-circuited or reversely connected, if the short-circuit or reverse connection has been released, the control module 234 also sends a short-circuit reset signal to the short-circuit reset module 233 so that the adapter can charge the energy storage device normally.

[0057] Specifically, the control module 234 sends a short-circuit reset signal to the short-circuit reset module 233, so that the short-circuit reset module 233 generates a low-level signal according to the short-circuit reset signal, pulls down the input terminal potential of the second comparison module 232, and then makes the second comparison module 232 generate a high-level second drive signal, so that the drive circuit 11 is in a pass state, and the adapter charges the energy storage device normally.

[0058] See also Figures 4 to 6 , Figure 4 : is a schematic diagram of a circuit structure of a first protection circuit 22 provided in an embodiment of the utility model. Figure 5 : is a circuit structure diagram of a second protection circuit 23 provided in an embodiment of the utility model, Figure 6 It is a circuit structure diagram of a third protection circuit 24 provided in an embodiment of the utility model.

[0059] like Figure 4 As shown, the first protection circuit 22 includes a first comparator U1A, a resistor R5 and a resistor R6, wherein the inverting input terminal of the first comparator U1A is connected to the sampling circuit 21, the non-inverting input terminal of the first comparator U1A is connected to one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is connected to the first power supply, the other end of the resistor R6 is grounded, and the output terminal of the first comparator U1A is connected to the driving circuit 11. Specifically, the output terminal of the first comparator U1A is connected to the base of the switch tube Q6 via the resistor R15.

[0060] like Figure 5As shown, the first comparison module 231 includes a second comparator U2C, a resistor R12, a resistor R18, a capacitor C6, a diode D1 and a resistor R9. The inverting input terminal of the second comparator U2C is connected to the sampling circuit 21, the non-inverting input terminal of the second comparator U2C is respectively connected to one end of the resistor R12, one end of the resistor R18, one end of the capacitor C6 and the cathode of the diode D1, the other end of the resistor R12 is connected to the first power supply, the other end of the resistor R18 and the other end of the capacitor C6 are grounded together, the anode of the diode D1 is connected to the output terminal of the second comparator U2C, one end of the resistor R9 and the input terminal of the second comparison module 232, and the other end of the resistor R9 is connected to the first power supply.

[0061] The second comparison module 232 includes a third comparator U2D, a resistor R16, a resistor R17 and a capacitor C7. The inverting input terminal of the third comparator U2D is connected to the output terminal of the first comparison module 231, specifically, the inverting input terminal of the third comparator U2D is connected to the output terminal of the second comparator U2C, the non-inverting input terminal of the third comparator U2D is respectively connected to one end of the resistor R16, one end of the resistor R17 and one end of the capacitor C7, the other end of the resistor R16 is connected to the first power supply, the other end of the resistor R17 and the other end of the capacitor C7 are grounded together, and the output terminal of the third comparator U2D is connected to the driving circuit 11, specifically, the output terminal of the first comparator U1A is connected to the base of the switch tube Q6 via the resistor R15.

[0062] The short circuit reset module 233 includes a resistor R20, a resistor R24 ​​and a transistor Q4. One end of the resistor R20 is connected to the control module 234, the other end of the resistor R20 is respectively connected to one end of the resistor R24 ​​and the base of the transistor Q4, the other end of the resistor R24 ​​is grounded to the emitter of the transistor Q4, the collector of the transistor Q4 is respectively connected to the output end of the first comparison module 231 and the input end of the second comparison module 232, specifically, the collector of the transistor Q4 is respectively connected to the output end of the second comparator U2C and the inverting input end of the third comparator U2D.

[0063] The output terminal of the second comparator U2C and the inverting input terminal of the third comparator U2D are also connected to the control module 234 via the resistor R10, so that the control module 234 receives the first comparison signal.

[0064] like Figure 6As shown, the third protection circuit 24 includes a fourth comparator U2B, a resistor R31 and a resistor R32. The inverting input terminal of the fourth comparator U2B is connected to the sampling circuit 21, the non-inverting input terminal of the fourth comparator U2B is connected to one end of the resistor R31 and one end of the resistor R32 respectively, the other end of the resistor R31 is connected to the first power supply, the other end of the resistor R32 is grounded, and the output terminal of the fourth comparator U2B is connected to the driving circuit 11. Specifically, the output terminal of the fourth comparator U2B is connected to the base of the switch tube Q6 via the resistor R15.

[0065] like Figure 1 and Figure 4 As shown, the sampling circuit 21 includes a sampling resistor R21, a capacitor C5, a resistor R22, a resistor R23, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C3 and a differential amplifier U1B, wherein R21 is connected in series in the charging circuit of the energy storage device. In this embodiment, the resistor R21 is connected to the power ground GND_ACC and the negative electrode GND_BAT of the battery respectively. At the same time, the current signal I_ACC+ derived from one end of the resistor R21 reaches the non-inverting input end of the differential amplifier via the resistor R22 and the resistor R2, and the current signal I_ACC- derived from the other end of the resistor R21 reaches the inverting input end of the differential amplifier via the resistor R23 and the resistor R3. After the differential amplification of the differential amplifier, a voltage sampling signal I.ACC.AO is obtained at the output end of the differential amplifier, and its magnitude represents the input current magnitude and input voltage magnitude of the adapter.

[0066] The voltage sampling signal I.ACC.AO is transmitted to the inverting input terminal of the first comparator U1A, the inverting input terminal of the second comparator U2C and the inverting input terminal of the fourth comparator U2B. The first comparator U1A compares the voltage sampling signal I.ACC.AO with the first reference voltage to obtain the corresponding first drive signal Com_ACC_EN1. The second comparator U2C generates a corresponding first comparison signal by comparing the voltage sampling signal I.ACC.AO with the second reference voltage. The third comparator U2D compares the first comparison signal with the third reference voltage to generate a corresponding second drive signal Com_ACC_EN2. The fourth comparator U2B compares the voltage sampling signal I.ACC.AO with the fourth reference voltage to obtain the corresponding third drive signal Com_ACC_EN3. The first drive signal Com_ACC_EN1, the second drive signal Com_ACC_EN2 and the third drive signal Com_ACC_EN3 are all transmitted to the base of the transistor Q6.

[0067] In some embodiments, the voltage of the first power supply is greater than the fourth reference voltage, the fourth reference voltage is greater than the first reference voltage or the third reference voltage, the first reference voltage may be equal to the third reference voltage, and the first reference voltage or the third reference voltage is greater than the second reference voltage. For ease of understanding, specific detailed embodiments are listed for further explanation. For example, the first power supply voltage is 3.3V, the first reference voltage is 1.65V, the second reference voltage is 0.25V, the third reference voltage is 1.65V, and the fourth reference voltage is 2.2V. The first reference voltage, the second reference voltage, the third reference voltage, and the fourth reference voltage can all be obtained by dividing the voltage of the first power supply. It should be noted that the above parameters can be set according to requirements and are not used to limit the present utility model.

[0068] Combination Figures 4 to 6 , the working principle of the protection circuit 2 can be described as follows:

[0069] When the adapter is charging normally, that is, the charging current does not exceed the set current threshold, such as 16A, the voltage of the voltage sampling signal I.ACC.AO is less than 1.65V, and the first comparator U1A outputs the corresponding first drive signal Com_ACC_EN1, which is a high-level signal. The high-level first drive signal Com_ACC_EN1 acts on the base of the transistor Q6, so that the transistor Q6 is turned on, and then the switch tube Q3 and the switch tube Q5 are turned on, and the adapter starts to charge normally.

[0070] When the adapter is overcurrent, that is, the charging current exceeds the set current threshold, such as 16A, the voltage of the voltage sampling signal I.ACC.AO is greater than 1.65V, and the first comparator U1A outputs the corresponding first drive signal Com_ACC_EN1, which is a low-level signal. The low-level first drive signal Com_ACC_EN1 acts on the base of the transistor Q6, so that the transistor Q6 is turned off, and then the switch tube Q3 and the switch tube Q5 are turned off. The adapter cannot charge the energy storage device, thereby realizing overcurrent protection for the energy storage device.

[0071] When the adapter is short-circuited or reversely connected, the voltage of the voltage sampling signal I.ACC.AO is pulled to 0V or a negative voltage, and the voltage of the voltage sampling signal I.ACC.AO is less than 0.25V, and the second comparator U2C outputs the corresponding first comparison signal, which is a high-level signal.

[0072] After the control module 234 receives the high-level first comparison signal, it determines that the adapter is short-circuited or reversely connected. After the inverting input terminal of the third comparator U2D receives the high-level first comparison signal, the voltage of the first comparison signal is greater than 1.65V, and the third comparator U2D outputs the corresponding second drive signal Com_ACC_EN2, which is a low-level signal. The low-level second drive signal Com_ACC_EN2 acts on the base of the transistor Q6, so that the transistor Q6 is turned off, and then the switch tube Q3 and the switch tube Q5 are turned off, and the adapter cannot charge the energy storage device, realizing protection against short circuit or reverse connection.

[0073] At the same time, when the control module 234 determines that the short circuit is released, a short circuit reset signal ACC_RESET is sent to the base of the transistor Q4, which is a high-level signal, so that the transistor Q4 is turned on, and the potential of the inverting input terminal of the third comparator U2D is pulled down, so that the third comparator U2D outputs a high-level signal, and the high-level signal acts on the base of the transistor Q6, so that the transistor Q6 is turned on, and then the switch tube Q3 and the switch tube Q5 are turned on, charging is resumed, and the adapter starts to charge normally.

[0074] Furthermore, when the adapter is over-voltaged, for example, the voltage of the voltage sampling signal I.ACC.AO exceeds a preset voltage threshold, such as 36.6V, the voltage of the voltage sampling signal I.ACC.AO is less than 2.2V, and the fourth comparator U2B outputs a corresponding third drive signal Com_ACC_EN3, which is a low-level signal. The low-level third drive signal Com_ACC_EN3 acts on the base of the transistor Q6, so that the transistor Q6 is turned off, and then the switch tube Q3 and the switch tube Q5 are turned off, and the adapter cannot charge the energy storage device, thereby achieving overvoltage protection for the energy storage device.

[0075] In summary, the protection circuit can implement overcurrent protection for the energy storage device through the first protection circuit, and can implement adapter short circuit or reverse connection protection for the energy storage device through the second protection circuit, thereby improving the safety of the energy storage system.

[0076] 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 protection circuit, characterized in that: Applied to an energy storage system, the energy storage system includes a drive circuit and an energy storage device, the adapter charges the energy storage device through the drive circuit, and the protection circuit includes: a sampling circuit, a first protection circuit and a second protection circuit; The sampling circuit is connected to the charging circuit of the energy storage device, the input end of the first protection circuit and the input end of the second protection circuit respectively, and the sampling circuit is used to sample the voltage signal of the charging circuit to obtain a voltage sampling signal; The output end of the first protection circuit and the output end of the second protection circuit are commonly connected to the drive circuit. When the input current of the adapter is overcurrent, the first protection circuit is used to generate a first drive signal to the drive circuit according to the received voltage sampling signal, so as to disconnect the drive circuit; When the adapter is reversely connected or short-circuited, the second protection circuit is used to generate a second drive signal to the drive circuit according to the received voltage sampling signal, so as to disconnect the drive circuit.

2. The protection circuit according to claim 1, characterized in that: The first protection circuit includes a first comparator, a resistor R5 and a resistor R6; The inverting input terminal of the first comparator is connected to the sampling circuit, the non-inverting input terminal of the first comparator is connected to one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is connected to the first power supply, the other end of the resistor R6 is grounded, and the output terminal of the first comparator is connected to the driving circuit.

3. The protection circuit according to claim 1, characterized in that: The second protection circuit includes a first comparison module and a second comparison module; The input end of the first comparison module is connected to the sampling circuit, the output end of the first comparison module is connected to the input end of the second comparison module, and the output end of the second comparison module is connected to the driving circuit; The first comparison module is used to generate a corresponding first comparison signal according to the voltage sampling signal and a second reference voltage, and the second comparison module is used to generate a corresponding second drive signal according to the first comparison signal and a third reference voltage.

4. The protection circuit according to claim 3, characterized in that: The first comparison module includes a second comparator, a resistor R12, a resistor R18, a capacitor C6, a diode D1 and a resistor R9; The inverting input terminal of the second comparator is connected to the sampling circuit, the non-inverting input terminal of the second comparator is respectively connected to one end of the resistor R12, one end of the resistor R18, one end of the capacitor C6 and the cathode of the diode D1, the other end of the resistor R12 is connected to the first power supply, the other end of the resistor R18 and the other end of the capacitor C6 are grounded together, the anode of the diode D1 is connected to the output terminal of the second comparator, one end of the resistor R9 and the input terminal of the second comparison module, and the other end of the resistor R9 is connected to the first power supply.

5. The protection circuit according to claim 3, characterized in that: The second comparison module includes a third comparator, a resistor R16, a resistor R17 and a capacitor C7; The inverting input terminal of the third comparator is connected to the output terminal of the first comparison module, the non-inverting input terminal of the third comparator is respectively connected to one end of the resistor R16, one end of the resistor R17 and one end of the capacitor C7, the other end of the resistor R16 is connected to the first power supply, the other end of the resistor R17 and the other end of the capacitor C7 are grounded together, and the output terminal of the third comparator is connected to the driving circuit.

6. The protection circuit according to claim 3, characterized in that: The second protection circuit also includes a short circuit reset module and a control module; The short-circuit reset module is respectively connected to the control module, the output end of the first comparison module and the input end of the second comparison module, and the control module is also connected to the output end of the first comparison module and the input end of the second comparison module; The control module is used to determine whether the adapter is short-circuited or reversely connected according to the received first comparison signal; When the adapter is short-circuited or reversely connected, the control module is further used to send a short-circuit reset signal to the short-circuit reset module, so that the short-circuit reset module generates a low-level signal according to the short-circuit reset signal to lower the input terminal potential of the second comparison module.

7. The protection circuit according to claim 6, characterized in that: The short circuit reset module includes a resistor R20, a resistor R24 ​​and a transistor Q4; One end of the resistor R20 is connected to the control module, the other end of the resistor R20 is respectively connected to one end of the resistor R24 ​​and the base of the transistor Q4, the other end of the resistor R24 ​​and the emitter of the transistor Q4 are grounded, and the collector of the transistor Q4 is respectively connected to the output end of the first comparison module and the input end of the second comparison module.

8. The protection circuit according to any one of claims 1 to 7, characterized in that: The protection circuit also includes a third protection circuit, which is respectively connected to the sampling circuit and the driving circuit. When the input voltage of the adapter is overvoltage, the third protection circuit is used to generate a third driving signal to the driving circuit based on the received voltage sampling signal to disconnect the driving circuit.

9. The protection circuit according to claim 8, characterized in that: The third protection circuit includes a fourth comparator, a resistor R31 and a resistor R32; The inverting input terminal of the fourth comparator is connected to the sampling circuit, the non-inverting input terminal of the fourth comparator is respectively connected to one end of the resistor R31 and one end of the resistor R32, the other end of the resistor R31 is connected to the first power supply, the other end of the resistor R32 is grounded, and the output terminal of the fourth comparator is connected to the driving circuit.

10. An energy storage system, characterized in that: The energy storage system comprises a drive circuit, an energy storage device and a protection circuit as described in any one of claims 1 to 9, wherein the adapter charges the energy storage device through the drive circuit.

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