Energy storage device and circuit breaker control method for energy storage device

Abstract

The present invention provides an energy storage device and a circuit breaker control method for the energy storage device. The energy storage device comprises a main circuit formed by a plurality of battery modules connected in series in sequence. The energy storage device can be connected with an external device to form a circuit. Each battery module comprises a battery unit, a control unit and a switch group. The energy storage device is further provided with a detection module, a circuit breaker protection module connected in series with the main circuit of the energy storage device and a circuit breaker detection module. The detection module is configured to detect the working state of the energy storage device, and turn on the circuit breaker protection module when it is detected that the energy storage device fails. The circuit breaker protection module is configured to output a circuit breaker driving power supply after being turned on, and drive the circuit breaker in the main circuit of the energy storage device to disconnect through the circuit breaker driving power supply, so as to disconnect the connection circuit between the energy storage device and the external device. The circuit breaker detection module is configured to perform sampling current detection on the circuit breaker protection module at a regular time, and output a shunt failure signal when the sampling current does not meet a preset condition.

Description

Technical Field

[0001] The present invention relates to the field of energy storage devices, and in particular to an energy storage device and a circuit breaker control method for the energy storage device. Background Art

[0002] With the popularization of new energy vehicles and the proposal of goals such as "carbon neutrality" and "carbon peak", the energy structure of the entire society is shifting towards electric energy. Among them, energy storage systems need to be installed in new energy vehicles, and energy storage systems are also required in photovoltaic power generation and wind power generation. When the energy storage system is composed of multiple battery modules connected in series, in order to improve the stability of the energy storage system, the prior art adopts a solution of controlling each battery separately, and each battery can be connected or disconnected from the main circuit separately without affecting other batteries.

[0003] However, for products adopting this technical solution, in the prior art, when the main power supply of the energy storage device fails, the user may still make an error operation to manually close the circuit of the energy storage device. After closing, the energy storage device has no effective disconnection measures. When the main power supply has failed, charging the battery again will cause the battery to be overcharged, which poses a greater safety risk. Summary of the invention

[0004] The object of the present invention is to provide an energy storage device and a circuit breaker control method for the energy storage device to solve the above problems.

[0005] The present invention provides an energy storage device, which includes a main circuit formed by a plurality of battery modules connected in series in sequence, the energy storage device can be connected to an external device to form a circuit, each of the battery modules includes a battery unit, a control unit and a switch group, the control unit is configured to control the switch group to connect a single battery module in series or bypass the main circuit of the energy storage device, and when a battery module is bypassed, a passage connecting the front and rear battery modules is formed in the battery module, the energy storage device is also provided with a detection module, a circuit breaker protection module connected in series with the main circuit of the energy storage device, and a circuit breaker detection module;

[0006] The detection module is configured to detect the working state of the energy storage device and turn on the circuit breaker protection module when it is detected that the energy storage device fails;

[0007] The circuit breaker protection module is configured to output a circuit breaker driving power supply after being turned on, and drive the circuit breaker in the main circuit of the energy storage device to disconnect the connection circuit between the energy storage device and the external device through the circuit breaker driving power supply;

[0008] The circuit breaker detection module is configured to periodically perform sampling current detection on the circuit breaker protection module, and output a shunt failure signal when the sampling current does not meet a preset condition.

[0009] As a further improvement of the present invention, the detection module includes a normally closed switch module connected in series with the circuit breaker protection module, the normally closed switch module includes a normally closed switch and a normally closed switch control circuit connected to the normally closed switch, and the normally closed switch module is configured to determine that the energy storage device has failed and conduct the normally closed switch after losing a control unit signal or receiving a corresponding control unit signal.

[0010] As a further improvement of the present invention, the circuit breaker protection module also includes a power supply module and a shunt release, the input end of the power supply module is connected to the main circuit of the energy storage device, the output end of the power supply module is connected to the shunt release, and the normally closed switch module is connected between the input end of the power supply module and the negative pole of the main circuit of the energy storage device.

[0011] As a further improvement of the present invention, the circuit breaker protection module includes a power output switch module, the power output switch module includes a power output switch and a power output switch control circuit connected to the power output switch, and the power output switch module is configured to close the power output switch when the power module outputs the circuit breaker driving power, so that the circuit breaker driving power reaches the shunt release, and drives the shunt release to disconnect the circuit breaker.

[0012] As a further improvement of the present invention, the circuit breaker protection module also includes a timing circuit connected in series with the power output switch control circuit, and the timing circuit is configured to output a closing signal at a fixed time after power is supplied by the circuit breaker driving power supply, and the power output switch module is configured to drive the power output switch to close after receiving the closing signal.

[0013] As a further improvement of the present invention, the circuit breaking detection module includes a shunt driving power supply, a shunt sampling resistor connected in series with the shunt releaser, a comparator arranged on the shunt sampling resistor side, and a shunt detection control unit. The comparator and the shunt detection control unit are configured to output a shunt failure signal to the shunt detection control unit when detecting that the voltage on the shunt sampling resistor side exceeds a preset voltage.

[0014] As a further improvement of the present invention, each of the battery modules also includes a current detection module, which is connected in series with the battery and the switch group. The current detection module is configured to control the switch group to bypass the battery module out of the main circuit of the energy storage device when it detects that the battery module is in an overcurrent state.

[0015] As a further improvement of the present invention, the current detection module includes a shunt resistor connected in series with the battery and the switch group, and a current detection amplifier and a high-speed comparator located on the shunt resistor side. The control unit is configured to drive the switch group to bypass the battery module out of the main circuit of the energy storage device when it detects that the voltage across the shunt resistor exceeds a preset threshold.

[0016] The present invention also provides a method for controlling circuit breaker of an energy storage device, which comprises the steps of:

[0017] The circuit breaker protection module is sampled and tested regularly. When the sampled current does not meet the preset conditions, a circuit breaker protection module failure signal is output; when the sampled current meets the preset conditions, the main power supply of the energy storage device is tested;

[0018] When the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply;

[0019] The circuit breaker driving power supply supplies power to the shunt release, and the shunt release works to disconnect the circuit breaker in the main circuit of the energy storage device.

[0020] As a further improvement of the present invention, when the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply, which specifically includes:

[0021] When the circuit breaker is closed and it is detected that the main power supply voltage of the energy storage device does not meet the preset range, the normally closed switch is turned on and the circuit breaker driving power is output through the power module.

[0022] As a further improvement of the present invention, when the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply, which specifically includes:

[0023] When the circuit breaker disconnection instruction needs to be executed and the circuit breaker disconnection fails, the normally closed switch is turned on and the circuit breaker driving power is output through the power module.

[0024] As a further improvement of the present invention, when the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply, which specifically includes:

[0025] When the control unit is reset and there is no signal at the input / output port, the normally closed switch is turned on and the drive power is disconnected through the power module output.

[0026] As a further improvement of the present invention, when the sampled current does not meet the preset condition, outputting a circuit breaker protection module failure signal specifically includes:

[0027] When it is detected for the first time that the sampling current does not meet the preset conditions, the sampling current is detected again after a preset review time. After repeating the detection for a preset number of times, if the sampling current still does not meet the preset conditions, a circuit breaker protection module failure signal is output.

[0028] As a further improvement of the present invention, after the output of the circuit breaker protection module failure signal, the method further includes:

[0029] The control unit uploads the failure information and stops charging and discharging the battery.

[0030] The beneficial effect of the present invention is that the energy storage device provided by the present invention can disconnect the connection circuit between the energy storage device and the external equipment in time when the main power supply of the energy storage device fails by setting a circuit breaker protection module and a detection module.

[0031] In addition, the detection device can stably and efficiently perform the circuit breaking operation after the main power supply of the energy storage device fails by using a normally closed switch in conjunction with the power module in the circuit breaking protection module.

[0032] Furthermore, the energy storage device is also provided with a circuit breaker detection module, which can regularly detect the circuit breaker protection module to prevent its failure.

[0033] In addition, by respectively providing a current detection module in each battery module and cooperating with a circuit breaker protection module, the safety of the energy storage device can be improved in multiple dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a circuit block diagram of an energy storage device in one embodiment of the present invention.

[0035] Figure 2 It is a circuit block diagram of a detection module and a circuit breaker protection module in one embodiment of the present invention.

[0036] Figure 3 It is a circuit block diagram of a circuit breaker detection module in one embodiment of the present invention.

[0037] Figure 4 It is a circuit block diagram of a current detection module in one embodiment of the present invention.

[0038] Figure 5 It is a schematic diagram of the steps of a method for controlling a circuit breaker of an energy storage device in one embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the specific implementation methods of the present invention and the corresponding drawings. Obviously, the described implementation methods are only part of the implementation methods of the present invention, not all implementation methods. Based on the implementation methods of the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] like Figure 1 As shown, this embodiment provides an energy storage device, which includes a main circuit 2 formed by a plurality of battery modules 1 connected in series in sequence. The energy storage device can be connected to an external device to form a circuit. Each battery module 1 includes a battery unit 11, a control unit 12 and a switch group 13. The control unit 12 is configured to control the switch group 13 to connect a single battery module 1 in series into or bypass the main circuit 2 of the energy storage device, and when a battery module 1 is bypassed, a passage connecting the front and rear battery modules 1 is formed therein.

[0042] In each battery module 1, the battery cell 11 may be a single battery, or may include a plurality of single batteries connected in series and / or in parallel, which are connected to form a battery pack to form a battery cell 11 in a basic battery module 1, and the battery cell 11 forms a positive electrode and a negative electrode.

[0043] A control unit 12 is provided in each battery module 1, that is, each battery module 1 can independently control the battery cells 11 therein. The energy storage device can be regarded as a distributed control system. When a problem occurs in a battery module 1, only the battery module 1 needs to be bypassed, and the main circuit 2 of the energy storage device is still accessible and can work normally.

[0044] In this embodiment, the distributed structure of the battery module 1 is arranged so that the control unit 12 in each battery module 1 can be used as a main control unit 12 to send signals to other control units 12 for communication control. In other embodiments of the present invention, a main control unit can also be separately set in the main circuit 2 of the energy storage module to control the control units 12 in other battery modules 1.

[0045] The switch group 13 can be two switches or a single-pole double-throw switch, etc. In this embodiment, the switch group 13 includes a first switch 13a and a second switch 13b. The battery cell 11 is connected in series with the first switch 13a, and the battery cell 11 and the first switch 13a are connected in series and then connected in parallel with the second switch 13b. The control unit 12 determines whether to connect or disconnect the battery cell 11 from the main circuit 2 of the energy storage device according to the situation of the battery cell 11. When the battery cell 11 needs to be connected in series, the first switch 13a is closed and the second switch 13b is disconnected. When the battery cell 11 needs to be bypassed, the first switch 13a is disconnected and the second switch 13b is closed. The control unit 12 can judge the state of the battery cell 11 according to the voltage and / or charge state of the battery cell 11, and the specific control strategy can be set according to the application scenario.

[0046] Furthermore, the energy storage device is also provided with a detection module 3, a circuit breaker protection module 4 connected in series with the main circuit 2 of the energy storage device, and a circuit breaker detection module 6.

[0047] The detection module 3 is configured to detect the working state of the energy storage device, and to turn on the circuit breaker protection module 4 when it is detected that the energy storage device fails. The circuit breaker protection module 4 is configured to output a circuit breaker driving power supply after being turned on, and drive the circuit breaker 7 in the main circuit 2 of the energy storage device to disconnect the connection circuit between the energy storage device and the external device through the circuit breaker driving power supply, so as to disconnect the connection circuit between the energy storage device and the external device. The detection module 3 and the circuit breaker protection module 4 are used in conjunction to disconnect the connection circuit between the energy storage device and the external device when the main power supply of the energy storage device actually fails or is judged to fail, thereby avoiding the situation where the circuit breaker 7 is forcibly closed due to the failure of the main power supply, and protecting the battery from overcharging.

[0048] The circuit breaker detection module 6 is configured to periodically perform sampling current detection on the circuit breaker protection module 4, and output a shunt failure signal when the sampling current does not meet the preset conditions. By additionally providing a detection module for the circuit breaker protection module 4, it can be ensured that the circuit breaker protection module 4 will not fail during the use of the energy storage device, further improving the safety of the energy storage device.

[0049] In this embodiment, the circuit breaker 7 is an air switch. In other embodiments of the present invention, the circuit breaker 7 may also be a vacuum circuit breaker or a gas circuit breaker.

[0050] like Figure 2As shown, in this embodiment, the detection module 3 includes a normally closed switch module 3a connected in series with the circuit breaker protection module 4, and the normally closed switch module 3a includes a normally closed switch 31 and a normally closed switch control circuit 32 connected to the normally closed switch 31. The contact of the normally closed switch 31 in the disconnected state is a normally open contact, and the contact in the closed state is a normally closed contact. The normally closed switch control circuit 32 controls the normally closed switch 31, and the normally closed switch module 3a is configured to determine that the energy storage device fails after losing the control unit 12 signal or receiving the corresponding control unit 12 signal, and conduct the normally closed switch 31.

[0051] Specifically, in this embodiment, the failure of the main power supply of the energy storage device mainly includes the following three situations:

[0052] 1. When the circuit breaker 7 in the main circuit 2 of the energy storage device is in a closed state and it is detected that the main power supply voltage of the energy storage device does not meet the preset range, the control unit 12 of the energy storage device cannot operate.

[0053] 2. When the instruction to disconnect the circuit breaker 7 needs to be executed and the circuit breaker 7 fails to disconnect, it is determined that the driving voltage of the main power circuit breaker 7 of the energy storage device fails, and the control signal of the control unit 12 needs to be set low.

[0054] 3. During the operation of the board, when the control unit 12 is reset, there is no signal at the input / output port.

[0055] When one of the above three situations occurs, that is, when the control unit 12 has no signal in the energy storage device circuit or the control signal of the control unit 12 is set to low, the detection module 3 set with the normally closed switch 31 will be turned on, thereby turning on the circuit breaker protection module 4 to enable the circuit breaker drive power supply to control the circuit breaker 7, thereby avoiding the failure to open the circuit breaker 7 due to the failure of the control unit 12. In other embodiments of the present invention, when there is a situation where there is no signal from other control units 12, it can also be determined that the circuit breaker protection module 4 needs to be started. By using the normally closed switch 31 to constitute the detection module 3 and control the circuit breaker protection module 4, the circuit breaker 7 can still be stably and effectively disconnected after the energy storage device control unit 12 fails, thereby protecting the energy storage device.

[0056] Furthermore, the circuit breaker protection module 4 includes a power supply module 41 and a shunt release 42, the input end of the power supply module 41 is connected to the main circuit 2 of the energy storage device, the output end of the power supply module 41 is connected to the shunt release 42, and a normally closed switch module 3a is connected between the input end of the power supply module 41 and the negative pole of the main circuit 2 of the energy storage device.

[0057] Specifically, in this embodiment, the power module 41 is a DC-DC isolated power module. After the normally closed switch 31 is turned on, the voltage between the main circuit 2 of the energy storage device is reduced to the voltage required to drive the circuit breaker protection module 4 through the transformer of the power module 41, and then used as a circuit breaker driving power supply.

[0058] Furthermore, the circuit breaker protection module 4 also includes a power output switch module 43, which includes a power output switch 431 and a power output switch control circuit 432 connected to the power output switch 431. The power output switch module 43 is configured to close the power output switch 431 when the power module 41 outputs the circuit breaker drive power, so that the circuit breaker drive power reaches the shunt release 42, so that the coil of the shunt release 42 generates current and energy, and then the shunt release 42 is disconnected from the circuit breaker 7.

[0059] Furthermore, the circuit breaker protection module 4 also includes a timing circuit 44 connected in series with the power output switch control circuit 432. The timing circuit 44 is configured to output a closing signal at a fixed time after the circuit breaker driving power supply is supplied. The power output switch module 43 is configured to drive the power output switch 431 to close after receiving the closing signal. After a delay of a period of time, the timing circuit 44 outputs a closing signal to the power output switch control circuit 432 to ensure that the energy storage capacitor of the shunt drive can be fully charged. The specific timing time can be specifically adjusted according to the actual product specifications.

[0060] By setting the above detection module 3 and the circuit breaker protection module 4, it is possible to effectively disconnect the connection circuit between the energy storage device and the external device in time after the main power supply of the energy storage device fails, so as to prevent the external charging and discharging device from continuing to charge the battery and causing the battery to be overcharged. In addition, after the control unit 12 fails, this embodiment can still stably output the circuit breaker driving power supply to drive the shunt release 42 to disconnect the circuit breaker 7 by using the normally closed switch 31, thereby further improving the safety and reliability of the energy storage device.

[0061] like Figure 3 As shown, in this embodiment, the circuit breaking detection module 6 includes a shunt driving power supply 61, a shunt sampling resistor 62 connected in series with the shunt release 41, a shunt comparator 63 arranged on the side of the shunt sampling resistor 62, and a shunt detection control unit 64. The shunt comparator 63 and the shunt detection control unit 64 are configured to output a shunt failure signal to the shunt detection control unit 64 when detecting that the voltage on the side of the shunt sampling resistor 62 exceeds a preset voltage.

[0062] Since the shunt release 41 can actually be equivalent to the superposition of inductance and resistance, after the driving power reaches the coil of the shunt release 41, the current on the coil shows a linear upward trend. When the energy accumulated on the coil of the shunt release 41 reaches a certain level, the shunt release 41 will trip. Therefore, the sampling current can be controlled to play a detection role without causing the shunt release 41 to work. Exemplarily, in this embodiment, the sampling current is controlled to be less than 0.5A.

[0063] Furthermore, in the present embodiment, the discrete drive signal is set to a PWM square wave. Exemplarily, the PWM square wave period is 380us, the duty cycle is 19%, and the default detection is to continuously send 5 cycles of square waves (a total of 2ms). During the operation of the energy storage device, a detection is performed every 30 minutes, and the detection logic signal is set to trigger an interrupt at a falling edge. Once the MCU detects the falling edge, it immediately stops sending the PWM wave and determines that the loop is valid. During the detection process, when the shunt detection control unit 64 does not receive the falling edge of the detection signal, it will send it again after 500ms. If the falling edge signal is still not received after 4 consecutive detections, it is determined that the detection loop has failed. In other embodiments of the present invention, the above parameters can be adaptively modified and adjusted according to product specifications and application scenarios.

[0064] When the failure of the shunt release 41 is detected, the shunt detection control unit 64 uploads the failure information, stops charging and discharging the battery, and waits for professionals to inspect and repair the energy storage device.

[0065] like Figure 4 As shown, further, in this embodiment, each battery module 1 also includes a current detection module 5, which is connected in series with the battery and the switch group 13. The current detection module 5 is configured to control the switch group 13 to bypass the battery module 1 out of the main circuit 2 of the energy storage device when it is detected that the battery module 1 is in an overcurrent state. In this embodiment, the first switch 13a is opened and the second switch 13b is closed.

[0066] Specifically, the current detection module 5 includes a shunt resistor 51 connected in series with the battery and the switch group 13, and a current detection amplifier 52 and a high-speed comparator 53 located on the side of the shunt resistor 51. The control unit 12 is configured to drive the switch group 13 to bypass the battery module 1 out of the main circuit 2 of the energy storage device when it is detected that the voltage across the shunt resistor 51 exceeds the preset threshold. The current detection amplifier 52 and the high-speed comparator 53 can measure the voltage across the shunt resistor 51 with high precision and compare it with the preset voltage threshold. When the voltage across the shunt resistor 51 does not exceed the voltage threshold, the output signal is set high and does not affect the closing and closing of the switch group 13; when the voltage across the shunt resistor 51 exceeds the voltage threshold, the output signal is set low, and the switch group 13 control circuit does not output a drive signal.

[0067] Furthermore, in this embodiment, the switch group 13 uses MOSFET devices, combined with the current detection module 5, the response speed of current detection is greatly improved, and the current climbing can be quickly identified to effectively distinguish between short-circuit large current and normal large current, thereby improving the reliability of overcurrent protection action execution and reducing design costs.

[0068] The current detection module 5 can effectively provide overcurrent protection for a single battery module 1. When an external short circuit occurs, the battery unit 11 is bypassed and enters a charge-discharge-prohibited state to protect the battery unit 11. The circuit breaker protection module 4 and the current detection module 5 are provided to protect the energy storage device as a whole and the single battery module 1, respectively, thereby improving the safety of the energy storage device in multiple dimensions.

[0069] like Figure 5 As shown, this embodiment also provides a circuit breaker control method for the energy storage device, which includes the steps of:

[0070] S1: regularly sampling current detection of the circuit breaker protection module 4, when the sampling current does not meet the preset conditions, outputting the failure signal of the circuit breaker protection module 4; when the sampling current meets the preset conditions, detecting the main power supply of the energy storage device.

[0071] S2: When the main power supply of the energy storage device is detected to fail, the power supply module 41 is turned on to output the circuit-breaking driving power supply.

[0072] S3: The circuit breaker driving power supply supplies power to the shunt release 42, and the shunt release 42 works to disconnect the circuit breaker 7 in the main circuit of the energy storage device.

[0073] In step S1, it specifically includes:

[0074] When it is detected for the first time that the sampling current does not meet the preset conditions, the sampling current is detected again after a preset review time. After repeating the detection for a preset number of times, if the sampling current still does not meet the preset conditions, a circuit breaker protection module failure signal is output.

[0075] When the failure of the shunt release 41 is detected, the control unit uploads the failure information, stops charging and discharging the battery, and waits for professionals to inspect and repair the energy storage device.

[0076] In step S2, it specifically includes:

[0077] When the circuit breaker 7 is closed and it is detected that the voltage of the main power supply of the energy storage device does not meet the preset range, the normally closed switch 31 is turned on and the circuit breaker driving power is output through the power module 41. Or

[0078] Alternatively, when the instruction to disconnect the circuit breaker 7 needs to be executed and the circuit breaker 7 fails to disconnect, the normally closed switch 31 is turned on and the circuit breaker driving power is output through the power module 41.

[0079] Alternatively, when the control unit 12 is reset and there is no signal at the input / output port, the normally closed switch 31 is turned on and the circuit-breaking driving power is output through the power module 41 .

[0080] In step S3, it specifically includes:

[0081] The circuit breaker driving power supply supplies power to the timing circuit 44. After a delay of a period of time, the timing circuit 44 outputs a closing signal to the power output switch control circuit 432. The power output switch control circuit 432 drives the power output switch 431 to close, and the shunt release 42 obtains power to disconnect the circuit breaker 7.

[0082] In summary, the energy storage device provided in this embodiment can disconnect the connection circuit between the energy storage device and the external device in time when the main power supply of the energy storage device fails by setting a circuit breaker protection module and a detection module. In addition, the detection device can stably and efficiently perform the circuit breaker operation after the main power supply of the energy storage device fails by using a normally closed switch in conjunction with the power module in the circuit breaker protection module. Furthermore, the energy storage device is also provided with a circuit breaker detection module, which can regularly detect the circuit breaker protection module to prevent it from failing. In addition, by respectively setting a current detection module in each battery module, in conjunction with the circuit breaker protection module, the safety of the energy storage device can be improved in multiple dimensions.

[0083] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0084] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An energy storage device, comprising a main circuit formed by a plurality of battery modules connected in series in sequence, the energy storage device can be connected to an external device to form a circuit, each of the battery modules comprises a battery unit, a control unit and a switch group, the control unit is configured to control the switch group to connect a single battery module in series into or bypass the main circuit of the energy storage device, and when a battery module is bypassed, a passage connecting the front and rear battery modules is formed in the battery module, characterized in that: The energy storage device is also provided with a detection module, a circuit breaker protection module connected in series with the main circuit of the energy storage device, and a circuit breaker detection module; The detection module is configured to detect the working state of the energy storage device and turn on the circuit breaker protection module when it is detected that the energy storage device fails; The circuit breaker protection module is configured to output a circuit breaker driving power supply after being turned on, and drive the circuit breaker in the main circuit of the energy storage device to disconnect the connection circuit between the energy storage device and the external device through the circuit breaker driving power supply; The circuit breaker detection module is configured to periodically perform sampling current detection on the circuit breaker protection module, and output a shunt failure signal when the sampling current does not meet a preset condition; The circuit breaker protection module further includes a power supply module and a shunt release, wherein the input end of the power supply module is connected to the main circuit of the energy storage device, and the output end of the power supply module is connected to the shunt release; the power supply module is configured to output a circuit breaker driving power supply; The circuit breaker protection module includes a power output switch module, which includes a power output switch and a power output switch control circuit connected to the power output switch; the power output switch is closed to allow the circuit breaker drive power to reach the shunt release; The circuit breaker protection module further includes a timing circuit connected in series with the power output switch control circuit, the timing circuit being configured to output a closing signal at a fixed time after power is supplied via the circuit breaker driving power supply, and the power output switch module being configured to drive the power output switch to close after receiving the closing signal; The detection module includes a normally closed switch module connected in series with the circuit breaker protection module, the normally closed switch module includes a normally closed switch and a normally closed switch control circuit connected to the normally closed switch, the normally closed switch module is configured to determine that the energy storage device has failed and conduct the normally closed switch after losing a control unit signal or receiving a corresponding control unit signal; the normally closed switch module is connected between the input end of the power module and the negative pole of the main circuit of the energy storage device.

2. The energy storage device according to claim 1, characterized in that: The power output switch module is configured to close the power output switch when the power module outputs the circuit breaker driving power, so that the circuit breaker driving power reaches the shunt release, and drives the shunt release to disconnect the circuit breaker.

3. The energy storage device according to claim 1, characterized in that: The circuit breaking detection module includes a shunt driving power supply, a shunt sampling resistor connected in series with the shunt releaser, a comparator arranged on the side of the shunt sampling resistor, and a shunt detection control unit. The comparator and the shunt detection control unit are configured to output a shunt failure signal to the shunt detection control unit when detecting that the voltage on the side of the shunt sampling resistor exceeds a preset voltage.

4. The energy storage device according to claim 1, characterized in that: Each of the battery modules also includes a current detection module, which is connected in series with the battery and the switch group. When the current detection module detects that the battery module is in an overcurrent state, it is configured to control the switch group to bypass the battery module out of the main circuit of the energy storage device.

5. The energy storage device according to claim 4, characterized in that: The current detection module includes a shunt resistor connected in series with the battery and the switch group, and a current detection amplifier and a high-speed comparator located on the side of the shunt resistor. The control unit is configured to drive the switch group to bypass the battery module out of the main circuit of the energy storage device when it is detected that the voltage across the shunt resistor exceeds a preset threshold.

6. A method for controlling circuit breaker of an energy storage device according to any one of claims 1 to 5, characterized in that: Includes steps: The circuit breaker protection module is sampled and tested regularly. When the sampled current does not meet the preset conditions, a circuit breaker protection module failure signal is output; when the sampled current meets the preset conditions, the main power supply of the energy storage device is tested; When the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply; The circuit breaker driving power supply supplies power to the shunt release, and the shunt release works to disconnect the circuit breaker in the main circuit of the energy storage device.

7. The energy storage device disconnection control method according to claim 6, characterized in that: When the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply, which specifically includes: When the circuit breaker is closed and it is detected that the main power supply voltage of the energy storage device does not meet the preset range, the normally closed switch is turned on and the circuit breaker driving power is output through the power module.

8. The energy storage device disconnection control method according to claim 6, characterized in that: When the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply, which specifically includes: When the circuit breaker disconnection instruction needs to be executed and the circuit breaker disconnection fails, the normally closed switch is turned on and the circuit breaker driving power is output through the power module.

9. The energy storage device disconnection control method according to claim 6, characterized in that: When the main power supply of the energy storage device fails, the power supply module is turned on to output the circuit-breaking driving power supply, which specifically includes: When the control unit is reset and there is no signal at the input / output port, the normally closed switch is turned on and the drive power is disconnected through the power module output.

10. The energy storage device disconnection control method according to claim 6, characterized in that: When the sampled current does not meet the preset condition, outputting a circuit breaker protection module failure signal specifically includes: When it is detected for the first time that the sampling current does not meet the preset conditions, the sampling current is detected again after a preset review time. After repeating the detection for a preset number of times, if the sampling current still does not meet the preset conditions, a circuit breaker protection module failure signal is output.

11. The energy storage device disconnection control method according to claim 6, characterized in that: After the output circuit breaker protection module failure signal is sent, the method further includes: The control unit uploads the failure information and stops charging and discharging the battery.

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