Energy storage device protection circuit and control method thereof

Abstract

The application provides an energy storage device protection circuit and a control method thereof. The energy storage device protection circuit obtains a starting signal and a discharge state of an energy storage device management module, and controls a transistor switch module and a relay drive module based on the starting signal and the discharge state. By setting a hybrid switch architecture of the transistor switch module and the relay drive module in the energy storage device protection circuit, and jointly determining the action of the relay drive module by combining the starting signal and the discharge state of the energy storage device management module, the cost and system complexity can be significantly reduced. By fusing the collaborative control of the transistor switch module and the relay drive module, the risk of inconsistent current sharing and overheating burnout caused by multiple MOS transistors in parallel can be avoided. Therefore, by accurately controlling the energy storage device protection circuit, the large current carrying capacity can be ensured, the protection board power consumption, cost and volume can be reduced, and the overall reliability and economy of the system can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a protection circuit for an energy storage device and its control method. Background Technology

[0002] With the iteration of lithium battery technology, lithium-ion rechargeable batteries are gradually replacing traditional lead-acid batteries and becoming the mainstream solution for 12V starting power supplies in heavy-duty vehicles. The instantaneous starting current of a heavy-duty vehicle engine can reach thousands of amperes, and this high current lasts for several seconds. Under normal driving and idling conditions, only a small current is needed to power low-voltage accessories such as instruments, lighting, and fans; the current difference between these two conditions is significant. To avoid the risks of lithium battery failure due to overcharging, over-discharging, overcurrent, and overheating, the industry generally configures protection boards to monitor cell status and control circuit continuity. The current-carrying capacity of the core switching devices on the protection board directly determines the maximum output current of the battery pack, making it a core component of heavy-duty vehicle starting lithium batteries. Market demand for starting battery protection circuits that balance high current carrying capacity, low standby power consumption, low cost, and high reliability continues to increase.

[0003] Currently, the most common protection boards in the industry mainly use MOSFETs (Metal-Oxide-Semiconductor) to control charging and discharging. The maximum load capacity of the protection board is entirely determined by the current carrying capacity of the MOSFETs. To accommodate the high starting current of heavy vehicles (thousands of amperes), the industry's conventional solution is to connect multiple MOSFETs of the same model in parallel to amplify the current. However, due to the differences between individual MOSFETs, the turn-on timing and current sharing of each MOSFET are inconsistent. Under high current conditions, some MOSFETs may overload and burn out. At the same time, connecting too many MOSFETs in parallel not only increases the size and cost of the protection board but also reduces the reliability of the system. Summary of the Invention

[0004] This application provides a protection circuit and control method for energy storage devices to solve the technical problems of existing protection circuits that are difficult to balance high current carrying capacity and low standby power consumption, and that the parallel connection of multiple MOSFETs has inconsistent current sharing and low reliability.

[0005] In a first aspect of the embodiments of this application, an energy storage device protection circuit is provided, the energy storage device protection circuit including: an energy storage device management module, a transistor switch module, and a relay drive module; The discharge control terminal of the energy storage device management module is connected to the first terminal of the transistor switch module and the first terminal of the relay drive module, respectively. The charging control terminal of the energy storage device management module is connected to the second terminal of the transistor switch module; The third terminal of the transistor switch module is connected to the second terminal of the relay drive module; The fourth terminal of the transistor switch module is connected to the third terminal of the relay drive module.

[0006] In one optional implementation, the transistor switch module includes a first transistor switch and a second transistor switch; The first terminal of the first transistor switch is connected to the discharge control terminal of the energy storage device management module, the second terminal of the first transistor switch is connected to the second terminal of the relay drive module, and the third terminal of the first transistor switch is connected to the second terminal of the second transistor switch. The first terminal of the second transistor switch is connected to the charging control terminal of the energy storage device management module, and the third terminal of the second transistor switch is connected to the third terminal of the relay drive module.

[0007] In one optional implementation, the relay drive module includes a relay; The first terminal of the normally open contact switch of the relay is connected to the second terminal of the first transistor switch, and the second terminal of the normally open contact switch of the relay is connected to the third terminal of the second transistor switch.

[0008] In an optional implementation, the relay drive module further includes a freewheeling diode; The anode of the freewheeling diode is connected to the first terminal of the electromagnetic coil of the relay; The cathode of the freewheeling diode is connected to the second terminal of the electromagnetic coil of the relay.

[0009] In an optional implementation, the relay drive module further includes a drive transistor, an enable transistor, a start signal input interface, a first bias resistor, a second bias resistor, a first clamping diode, and a second clamping diode. The drain of the driving transistor is connected to the second terminal of the electromagnetic coil of the relay, the gate of the driving transistor is connected to the cathode of the second clamping diode and the drain of the enabling transistor, and the source of the driving transistor is grounded. The anode of the second clamping diode is connected to the discharge control terminal of the energy storage device management module; The gate of the enabling transistor is connected to the cathode of the first clamping diode and the second end of the first bias resistor, respectively, and the source of the enabling transistor is grounded. The first end of the first bias resistor is connected to the first end of the electromagnetic coil of the relay; The cathode of the first clamping diode is connected to the second end of the second bias resistor, the first end of the second bias resistor is connected to the first end of the electromagnetic coil of the relay, and the anode of the first clamping diode is connected to the start signal input interface.

[0010] In a second aspect of this embodiment, a control method for an energy storage device protection circuit is also provided, applied to the energy storage device protection circuit described in any one of the first aspects above, the method comprising: Obtain the startup signal and the discharge status of the energy storage device management module; Based on the start signal and the discharge state, the transistor switch module and the relay drive module are controlled.

[0011] In an optional implementation, controlling the transistor switching module and the relay driving module based on the start signal and the discharge state includes: When the discharge state is in the condition that discharge is allowed and the start signal is at the first level, the transistor switch module is controlled to be turned on, and the relay drive module is controlled to be in the non-drive state. When the discharge state is in the condition that discharge is allowed and the start signal is at the second level, the transistor switch module is controlled to be turned on, and the relay drive module is controlled to be in the drive state. When the discharge state is under discharge protection, the transistor switch module is controlled to turn off, and the relay drive module is controlled to be in a non-drive state.

[0012] In an optional implementation, controlling the transistor switch module to be turned on and controlling the relay drive module to be in a non-drive state includes: Based on the high level output from the discharge control terminal of the energy storage device management module, the first transistor switch and the second transistor switch are controlled to close. The potential of the gate of the enable transistor in the relay drive module is pulled high to turn on the enable transistor. The potential of the gate of the driving transistor in the relay driving module is pulled low to turn off the driving transistor, the electromagnetic coil of the relay in the relay driving module is not energized, and the normally open contact switch of the relay is opened.

[0013] In an optional implementation, controlling the transistor switch module to turn on and controlling the relay drive module to be in a driving state includes: Based on the high level output from the discharge control terminal of the energy storage device management module, the first transistor switch and the second transistor switch are controlled to close. The potential of the gate of the enable transistor in the relay driving module is pulled low to turn off the enable transistor. The potential of the gate of the drive transistor in the relay driving module is high, the drive transistor is turned on, the electromagnetic coil of the relay in the relay driving module is energized, and the normally open contact of the relay is closed.

[0014] In an optional implementation, controlling the transistor switch module to turn off and controlling the relay drive module to be in a non-driven state includes: Based on the discharge protection level output by the discharge control terminal of the energy storage device management module, the first transistor switch and the second transistor switch are controlled to turn off, and the potential of the gate of the driving transistor in the relay driving module is pulled low so that the driving transistor is turned off, the electromagnetic coil of the relay in the relay driving module is not energized, and the normally open contact of the relay remains open.

[0015] The technical solution provided in this application obtains the start signal and the discharge state of the energy storage device management module; based on the start signal and discharge state, it controls the transistor switching module and the relay driving module. This technical solution, by setting a hybrid switching architecture of transistor switching module and relay driving module in the energy storage device protection circuit, and jointly determining the action of the relay driving module with the discharge state of the energy storage device management module when the start signal is obtained, eliminates the need for a complex multi-MOSFET parallel current amplification scheme. It utilizes only the existing transistor switching module and relay driving module of the protection circuit itself to achieve dynamic expansion of high current carrying capacity, significantly reducing the size, cost, and system complexity of the protection board. By integrating the collaborative control of the transistor switching module and the relay driving module, it achieves higher current carrying reliability and better power consumption performance compared to simply relying on a MOSFET parallel current amplification scheme. It also avoids the risks of inconsistent current sharing and overheating burnout caused by multiple MOSFETs in parallel. Therefore, by precisely controlling the energy storage device protection circuit, it can reduce the power consumption, cost, and size of the protection board while ensuring high current carrying capacity, thereby improving the overall reliability and economy of the system. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0019] Figure 1 A schematic diagram of the structure of a protection circuit for an energy storage device provided in an embodiment of this application; Figure 2 A schematic diagram of another energy storage device protection circuit provided in this application embodiment; Figure 3 A schematic diagram illustrating the implementation flow of a control method for an energy storage device protection circuit provided in this application embodiment; Figure 4 A schematic diagram illustrating the implementation flow of another control method for an energy storage device protection circuit provided in this application embodiment; Figure 5 A schematic diagram of a circuit structure in a normal operating mode is provided for an embodiment of this application; Figure 6 This is a schematic diagram of a circuit structure in a startup working mode provided in an embodiment of this application. Detailed Implementation

[0020] 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.

[0021] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0022] Due to unavoidable individual differences in parameters such as threshold voltage, on-resistance, and transconductance during the manufacturing process of MOSFETs, it is difficult to achieve perfect synchronization during the turn-on and turn-off processes of multiple MOSFETs connected in parallel. Specifically, the MOSFET with the lower threshold voltage will turn on first, bearing the entire load current at the moment of turn-on; however, during the current rise, the uneven distribution of current flowing through the MOSFETs due to the different on-resistances of each MOSFET leads to uneven distribution of current. Under high-current conditions, individual MOSFETs carrying a larger current may exceed their safe operating area, resulting in localized overheating or even burnout, which in turn triggers a cascading failure of the entire protection board.

[0023] Secondly, as the number of parallel MOSFETs increases, the physical size and board area of ​​the protection board also increase accordingly. This not only increases material costs and assembly difficulty, but also places higher demands on the limited space layout inside the battery pack. More importantly, the increase in the number of parallel devices means an increase in potential failure points in the system. That is, the failure of any single MOSFET may cause the entire protection board to lose its protection function, thereby reducing the overall reliability of the system.

[0024] To address the aforementioned issues, this application proposes a protection circuit and control method for energy storage devices. The circuit acquires a startup signal and the discharge state of the energy storage device management module; based on the startup signal and discharge state, it controls a transistor switching module and a relay driving module. This technical solution, by setting a hybrid switching architecture of transistor switching modules and relay driving modules in the energy storage device protection circuit, and by combining the startup signal with the discharge state of the energy storage device management module to jointly determine the action of the relay driving module, eliminates the need for a complex multi-MOSFET parallel current amplification scheme. It utilizes only the existing transistor switching module and relay driving module within the protection circuit itself to dynamically expand the high current carrying capacity, significantly reducing the size, cost, and system complexity of the protection board. By integrating the collaborative control of the transistor switching module and relay driving module, it achieves higher current carrying reliability and better power consumption performance compared to simply relying on a MOSFET parallel current amplification scheme. It also avoids the risks of inconsistent current sharing and overheating burnout caused by multiple MOSFETs in parallel. Therefore, by precisely controlling the energy storage device protection circuit, it is possible to reduce the power consumption, cost, and size of the protection board while ensuring high current carrying capacity, thereby improving the overall reliability and economy of the system.

[0025] like Figure 1 The diagram shown is a structural schematic of an energy storage device protection circuit provided in an embodiment of this application. The energy storage device protection circuit 10 includes: an energy storage device management module 11, a transistor switch module 12, and a relay drive module 13.

[0026] The discharge control terminal of the energy storage device management module 11 is connected to the first terminal of the transistor switch module 12 and the first terminal of the relay drive module 13, respectively. The charging control terminal of the energy storage device management module 11 is connected to the second terminal of the transistor switch module 12; The third terminal of the transistor switch module 12 is connected to the second terminal of the relay drive module 13; the fourth terminal of the transistor switch module 12 is connected to the third terminal of the relay drive module 13.

[0027] The energy storage device management module 11 can be a battery management chip or a microcontroller with integrated battery management functions. It is used to collect and monitor parameters such as voltage, current, and temperature of the energy storage device (e.g., a lithium battery pack) in real time, and output discharge control signals and charging control signals based on the monitoring results to control the conduction and cutoff of the main charging and discharging circuit of the energy storage device protection circuit 10. The discharge control terminal of the energy storage device management module 11 can be connected to the first terminal of the transistor switch module 12 and the first terminal of the relay drive module 13 via printed circuit board traces to achieve signal communication. The charging control terminal of the energy storage device management module 11 can be connected to the second terminal of the transistor switch module 12 via printed circuit board traces. This application embodiment does not limit the specific model and packaging form of the energy storage device management module 11.

[0028] The transistor switching module 12 described above can be a metal-oxide-semiconductor field-effect transistor switching circuit, used to control the conduction or cutoff of the energy storage device charging and discharging circuit according to the discharge control signal and charging control signal output by the energy storage device management module 11.

[0029] The aforementioned relay drive module 13 may include a relay and its drive control circuit, used to control the on / off state of the relay during the startup process of the device containing the energy storage device (such as the startup of a heavy vehicle), based on the combined logic of the discharge control signal output by the energy storage device management module 11 and the externally input startup control signal. The first terminal of the relay drive module 13 can be connected to the discharge control terminal of the energy storage device management module 11 via a printed circuit board trace to receive the discharge control signal.

[0030] In addition, the transistor switch module 12 also includes a first transistor switch 12-1 and a second transistor switch 12-2, and the relay drive module 13 includes a relay 13-1, a freewheeling diode 13-2, a drive transistor 13-3, an enable transistor 13-4, a start signal input interface 13-5, a first bias resistor 13-6, a second bias resistor 13-7, a first clamping diode 13-8, and a second clamping diode 13-9.

[0031] The energy storage device protection circuit provided in this application includes: an energy storage device management module, a transistor switch module, and a relay drive module. The discharge control terminal of the energy storage device management module is connected to the first terminal of the transistor switch module and the first terminal of the relay drive module, respectively; the charging control terminal of the energy storage device management module is connected to the second terminal of the transistor switch module; the third terminal of the transistor switch module is connected to the second terminal of the relay drive module; and the fourth terminal of the transistor switch module is connected to the third terminal of the relay drive module.

[0032] By simultaneously connecting the discharge control terminal of the energy storage device management module to both the transistor switch module and the relay drive module, the discharge control signal output by the energy storage device management module can control not only the on / off state of the transistor switch module but also the enable state of the relay drive module, thus achieving multi-level coordinated control of the energy storage device's discharge circuit. Simultaneously, by connecting the third and fourth terminals of the transistor switch module to the second and third terminals of the relay drive module, respectively, the normally open contacts of the relays inside the relay drive module can form a parallel connection with the transistor switch module. During normal operation of the energy storage device, the transistor switch module alone carries the operating current, utilizing its low power consumption and fast switching speed to achieve low-power normal operation. During the startup process of the energy storage device, the relay drive module controls the conduction of its internal relays, closing the normally open contacts of the relays and forming a parallel current shunt channel with the transistor switch module. Utilizing the extremely low contact resistance and strong overload resistance of the relay contacts, it withstands the large current surge during startup, effectively protecting the transistor switch module from overcurrent damage.

[0033] Specifically, such as Figure 2 The diagram shown is a structural schematic of another energy storage device protection circuit provided in an embodiment of this application. Figure 2 exist Figure 1 Based on this, the components and their connection relationships of the transistor switch module 12 and the relay drive module 13 are described in detail. The energy storage device protection circuit 10 includes: energy storage device management module 11, transistor switch module 12, and relay drive module 13. The transistor switch module 12 includes a first transistor switch 12-1 and a second transistor switch 12-2.

[0034] The first terminal of the first transistor switch 12-1 is connected to the discharge control terminal of the energy storage device management module 11, the second terminal of the first transistor switch 12-1 is connected to the second terminal of the relay drive module 13, and the third terminal of the first transistor switch 12-1 is connected to the second terminal of the second transistor switch 12-2.

[0035] The first terminal of the second transistor switch 12-2 is connected to the charging control terminal of the energy storage device management module 11, and the third terminal of the second transistor switch 12-2 is connected to the third terminal of the relay drive module 13.

[0036] Meanwhile, the second terminal of the first transistor switch 12-1 can also be grounded, and the third terminal of the second transistor switch 12-2 is connected to the negative terminal of the energy storage element.

[0037] The aforementioned first transistor switch 12-1 can be an N-channel metal-oxide-semiconductor field-effect transistor (MOSFET) or a P-channel MOSFET, used to control the conduction or cutoff of the energy storage device's discharge circuit according to the discharge control signal output from the discharge control terminal of the energy storage device management module 11. The first terminal of the first transistor switch 12-1 is its control terminal (i.e., gate), used to receive the discharge control signal output from the discharge control terminal of the energy storage device management module 11; the second terminal of the first transistor switch 12-1 is its first power terminal (i.e., drain or source), connected to the second terminal of the relay drive module 13, and also used for grounding; the third terminal of the first transistor switch 12-1 is its second power terminal (i.e., source or drain), connected to the second terminal of the second transistor switch 12-2. When the discharge control signal is at an effective level (e.g., high level), the first transistor switch 12-1 is turned on, allowing the energy storage device to discharge; when the discharge control signal is at an invalid level (e.g., low level), the first transistor switch 12-1 is turned off, cutting off the discharge circuit of the energy storage device.

[0038] The aforementioned second transistor switch 12-2 can be an N-channel metal-oxide-semiconductor field-effect transistor (MOSFET) or a P-channel MOSFET, used to control the conduction or cutoff of the energy storage device's charging circuit according to the charging control signal output from the charging control terminal of the energy storage device management module 11. The first terminal of the second transistor switch 12-2 is its control terminal (i.e., gate), used to receive the charging control signal output from the charging control terminal of the energy storage device management module 11; the second terminal of the second transistor switch 12-2 is its first power terminal (i.e., source or drain), connected to the third terminal of the first transistor switch 12-1; the third terminal of the second transistor switch 12-2 is its second power terminal (i.e., drain or source), connected to the third terminal of the relay drive module 13, and also used to connect to the negative terminal of the energy storage element. When the charging control signal is at an effective level (e.g., high level), the second transistor switch 12-2 is turned on, allowing external power to charge the energy storage device; when the charging control signal is at an invalid level (e.g., low level), the second transistor switch 12-2 is turned off, cutting off the charging circuit of the energy storage device.

[0039] In addition, the relay drive module 13 includes a relay 13-1, a freewheeling diode 13-2, a drive transistor 13-3, an enable transistor 13-4, a start signal input interface 13-5, a first bias resistor 13-6, a second bias resistor 13-7, a first clamping diode 13-8, and a second clamping diode 13-9.

[0040] The first terminal of the normally open contact switch of relay 13-1 is connected to the second terminal of the first transistor switch 12-1, and the second terminal of the normally open contact switch of relay 13-1 is connected to the third terminal of the second transistor switch 12-2.

[0041] The anode of the freewheeling diode 13-2 is connected to the first terminal of the electromagnetic coil of the relay 13-1.

[0042] The cathode of the freewheeling diode 13-2 is connected to the second terminal of the electromagnetic coil of the relay 13-1.

[0043] The drain of the driving transistor 13-3 is connected to the second terminal of the electromagnetic coil of the relay 13-1. The gate of the driving transistor 13-3 is connected to the cathode of the second clamping diode 13-9 and the drain of the enable transistor 13-4, respectively. The source of the driving transistor 13-3 is grounded. The anode of the second clamping diode 13-9 is connected to the discharge control terminal of the energy storage device management module 11.

[0044] The gate of the enable transistor 13-4 is connected to the cathode of the first clamping diode 13-8 and the second end of the first bias resistor 13-6, respectively, and the source of the enable transistor 13-4 is grounded.

[0045] The first terminal of the first bias resistor 13-6 is connected to the first terminal of the electromagnetic coil of the relay 13-1; The cathode of the first clamping diode 13-8 is connected to the second terminal of the second bias resistor 13-7, the first terminal of the second bias resistor 13-7 is connected to the first terminal of the electromagnetic coil of the relay 13-1, and the anode of the first clamping diode 13-8 is connected to the start signal input interface 13-5.

[0046] The aforementioned relay 13-1 can be an electromagnetic relay or a contactor, comprising an electromagnetic coil and a normally open contact switch. The first end of the electromagnetic coil of relay 13-1 is connected to a first power supply terminal (e.g., V_BAT), and the second end of the electromagnetic coil is connected to the drain of the driving transistor 13-3. The first end of the normally open contact switch of relay 13-1 (i.e., the second end of the relay driving module 13) is connected to the second end of the first transistor switch 12-1, and the second end of the normally open contact switch of relay 13-1 (i.e., the third end of the relay driving module 13) is connected to the third end of the second transistor switch 12-2. When the driving transistor 13-3 is turned on, the electromagnetic coil of relay 13-1 is energized, and its normally open contact switch closes, forming a parallel current-sharing channel with the transistor switch module 12; when the driving transistor 13-3 is turned off, the electromagnetic coil of relay 13-1 is de-energized, and its normally open contact switch opens.

[0047] The freewheeling diode 13-2 mentioned above can be a switching diode (such as 1N4148, BAS16, etc.) or a Schottky diode (such as BAT54 series, etc.). Its anode is connected to the first terminal of the electromagnetic coil of relay 13-1, and its cathode is connected to the second terminal of the electromagnetic coil of relay 13-1. That is, the freewheeling diode 13-2 is connected in reverse parallel across the electromagnetic coil of relay 13-1. When the driving transistor 13-3 switches from on to off, the reverse induced electromotive force generated by the electromagnetic coil of relay 13-1 forms a freewheeling circuit through the freewheeling diode 13-2, preventing the induced electromotive force from damaging the driving transistor 13-3.

[0048] The aforementioned driving transistor 13-3 can be an N-channel metal-oxide field-effect transistor (N-MOSFET) or an NPN bipolar junction transistor (BJT). Its drain (collector) is connected to the second terminal of the electromagnetic coil of relay 13-1, its gate (base) is connected to the cathode of the second clamping diode 13-9 and the drain of the enable transistor 13-4, and its source (emitter) is grounded. The driving transistor 13-3 controls the on / off state of the electromagnetic coil of relay 13-1 based on the level of its gate (base). When the gate of driving transistor 13-3 is high, driving transistor 13-3 is turned on, and the electromagnetic coil of relay 13-1 is energized; when the gate of driving transistor 13-3 is low, driving transistor 13-3 is turned off, and the electromagnetic coil of relay 13-1 is de-energized.

[0049] The aforementioned enabling transistor 13-4 can be an N-channel metal-oxide field-effect transistor (N-MOSFET) or an NPN bipolar junction transistor (BJT). Its drain (collector) is connected to the gate of the driving transistor 13-3, and its gate (base) is connected to the cathode of the first clamping diode 13-8 and the second terminal of the first bias resistor 13-6, respectively. Its source (emitter) is grounded. The enabling transistor 13-4 is used to control the conduction or cutoff of the driving transistor 13-3 according to the level of its gate (base). When the enabling transistor 13-4 is turned on, its drain pulls the gate of the driving transistor 13-3 low to ground level, causing the driving transistor 13-3 to be turned off. When the enabling transistor 13-4 is turned off, the gate of the driving transistor 13-3 is pulled up to the first power supply terminal through the second bias resistor 13-7, causing the driving transistor 13-3 to be turned on.

[0050] The aforementioned start signal input interface 13-5 is used to receive external start control signals (such as a START signal). Start signal input interface 13-5 is connected to the anode of the first clamping diode 13-8. The external start control signal is high when the device containing the energy storage device is not started, and low during the start-up process. When the external start control signal is low, the first clamping diode 13-8 is turned on, pulling the gate of the enable transistor 13-4 low, thus turning off the enable transistor 13-4 and allowing the drive transistor 13-3 to turn on, closing the normally open contact switch of the relay 13-1.

[0051] The aforementioned first bias resistor 13-6 can be a surface-mount resistor or a leaded resistor. Its first terminal is connected to the first terminal of the electromagnetic coil of the relay 13-1, and its second terminal is connected to the gate of the enable transistor 13-4. The first bias resistor 13-6 is used to pull up the gate of the enable transistor 13-4 to the first power supply terminal, so that the enable transistor 13-4 remains in the conducting state when there is no external start control signal. The resistance value of the first bias resistor 13-6 can be in the range of 10kΩ to 100kΩ.

[0052] The aforementioned second bias resistor 13-7 can be a surface-mount resistor or a leaded resistor. Its first terminal is connected to the first terminal of the electromagnetic coil of relay 13-1, and its second terminal is connected to the gate of driving transistor 13-3. The second bias resistor 13-7 is used to pull up the gate of driving transistor 13-3 to the first power supply terminal, so that driving transistor 13-3 remains in the conducting state when enabling transistor 13-4 is turned off. The resistance value of the second bias resistor 13-7 can be in the range of 10kΩ to 100kΩ.

[0053] The aforementioned first clamping diode 13-8 can be a switching diode (such as 1N4148, BAS16, etc.) or a Schottky diode (such as the BAT54 series, etc.). Its anode is connected to the start signal input interface 13-5, and its cathode is connected to the gate of the enable transistor 13-4. The first clamping diode 13-8 is used to couple the external start control signal to the gate of the enable transistor 13-4. When the external start control signal is low, the first clamping diode 13-8 is turned on, pulling the gate of the enable transistor 13-4 low; when the external start control signal is high, the first clamping diode 13-8 is turned off, and the gate of the enable transistor 13-4 is pulled up to the first power supply terminal through the first bias resistor 13-6.

[0054] The aforementioned second clamping diode 13-9 can be a switching diode (such as 1N4148, BAS16, etc.) or a Schottky diode (such as BAT54 series, etc.). Its anode is connected to the discharge control terminal of the energy storage device management module 11, and its cathode is connected to the gate of the driving transistor 13-3. The second clamping diode 13-9 is used to couple the discharge control signal of the energy storage device management module 11 to the gate of the driving transistor 13-3. When the discharge control signal is low (i.e., the energy storage device management module 11 is in discharge protection state), the second clamping diode 13-9 is turned on, pulling the gate of the driving transistor 13-3 low, keeping the driving transistor 13-3 off, and the relay 13-1 remains open and is not controlled by the external start control signal, thus realizing the control of the relay driving module 13 by the energy storage device management module 11.

[0055] also, Figure 2 The positive terminal of the energy storage element is connected to the positive input terminal of the energy storage device protection circuit 10 to provide positive power to the energy storage device protection circuit 10; the negative terminal of the energy storage element is connected to the third terminal of the first transistor switch 12-1 and / or the third terminal of the second transistor switch 12-2 to serve as the negative reference ground of the energy storage device protection circuit 10. The energy storage element can be a lithium battery pack, a lithium-ion capacitor pack, or a supercapacitor pack.

[0056] Figure 2 Capacitors 1 to n (shown as capacitors 1 to n in the diagram) are used to achieve voltage smoothing filtering and energy storage in the energy storage device. The equivalent capacitance values ​​of capacitors 1 to n (n is a positive integer, such as 2, 3, etc.) can be selected according to actual application requirements. For example, they can be connected in parallel between the positive and negative terminals of the energy storage device to absorb voltage ripple and provide instantaneous current.

[0057] The original vehicle fuse box provides the signal source for the start control signal and may have a start signal output interface for outputting start control signals (such as the START signal). This start signal output interface is connected to the start signal input interface 13-5 of the relay drive module 13. The original vehicle fuse box outputs a high-level signal when the vehicle is not started and a low-level signal during vehicle start-up.

[0058] The starter relay is used to respond to the operation of the ignition switch or start button, controlling the energization and de-energization of the starter motor. The starter relay has a control terminal, which is high when the starter relay is not activated and low when the starter relay is activated (i.e., during vehicle startup). This control terminal signal can be used as a start control signal, outputting through the original vehicle fuse box's start signal output interface to the start signal input interface 13-5 of the relay driver module 13.

[0059] based on Figure 2 The circuit structure shown in this application illustrates the working principle of the energy storage device protection circuit 10 provided in this embodiment: When the device containing the energy storage device (such as a vehicle) is not started, the external start control signal received by the start signal input interface 13-5 is at a high level. At this time, the first clamping diode 13-8 is cut off, and the gate of the enable transistor 13-4 is pulled up to the first power supply terminal (e.g., V_BAT) through the first bias resistor 13-6, turning on the enable transistor 13-4. After the enable transistor 13-4 turns on, it pulls the gate of the drive transistor 13-3 low, turning off the drive transistor 13-3, de-energizing the electromagnetic coil of the relay 13-1, and keeping its normally open contact switch open. At this time, the energy storage device supplies power to the load through the transistor switch module 12 (the first transistor switch 12-1 and the second transistor switch 12-2). Since the MOSFET is a voltage-driven device, the drive current is almost zero, so the power consumption is extremely low, making it suitable for long-term standby.

[0060] When the device containing the energy storage device needs to start, the external start control signal received by the start signal input interface 13-5 becomes low. At this time, the first clamping diode 13-8 turns on, pulling the gate of the enable transistor 13-4 low, thus turning off the enable transistor 13-4. After the enable transistor 13-4 turns off, the gate of the drive transistor 13-3 is pulled up to the first power supply terminal through the second bias resistor 13-7, turning on the drive transistor 13-3. The electromagnetic coil of the relay 13-1 is energized, and its normally open contact switch closes. At this time, the normally open contact switch of the relay 13-1 and the transistor switch module 12 form a parallel shunt channel, jointly providing a large starting current for the load and effectively sharing the current burden of the transistor switch module 12.

[0061] After the startup process is completed, the external startup control signal received by the startup signal input interface 13-5 returns to a high level, enabling transistor 13-4 is turned on again, driving transistor 13-3 is turned off, and the normally open contact switch of relay 13-1 is opened, restoring the normal working mode powered only by transistor switch module 12.

[0062] When the energy storage device management module 11 detects an abnormal state such as over-discharge, over-current, or over-temperature in the energy storage device, its discharge control terminal outputs a low-level discharge control signal. At this time, the second clamping diode 13-9 is turned on, pulling the gate of the driving transistor 13-3 low, keeping the driving transistor 13-3 off, and the relay 13-1 remains open and unaffected by external start control signals. Simultaneously, the energy storage device management module 11 controls the first transistor switch 12-1 to turn off through its discharge control terminal, completely cutting off the discharge circuit of the energy storage device and achieving the protection function.

[0063] like Figure 3 The diagram shown is a schematic flowchart of an implementation process for a control method for an energy storage device protection circuit provided in this application embodiment, applied to the above-mentioned... Figure 1 , Figure 2 The energy storage device protection circuit shown may specifically include the following steps: S301, obtain the start signal and the discharge status of the energy storage device management module.

[0064] The aforementioned start signal refers to the start control signal of the device (e.g., vehicle) where the energy storage device is located. This start signal can be taken from the control terminal of the original vehicle's start relay or the start signal output interface of the original vehicle's fuse box. When the device where the energy storage device is located is not started, the start signal is at a high level; when the device where the energy storage device is located is in the start-up process, the start signal is at a low level.

[0065] The above discharge state refers to the energy storage device management module (such as...) Figure 1 or Figure 2 The operating state of the energy storage device management module 11) can include a discharge-allowed state and a discharge protection state. When the energy storage device management module detects that the voltage, current, temperature and other parameters of the energy storage device are all within the normal operating range, the energy storage device management module outputs a valid level (e.g., high level) discharge control signal through its discharge control terminal, which is the discharge-allowed state. When the energy storage device management module detects that the energy storage device has experienced abnormal conditions such as over-discharge, over-current, or over-temperature, the energy storage device management module outputs an invalid level (e.g., low level) discharge control signal through its discharge control terminal, which is the discharge protection state.

[0066] In this embodiment, the start-up signal and the discharge state of the energy storage device management module can be obtained. This step is used to monitor in real time the start-up command of the device where the energy storage device is located and the judgment result of the energy storage device management module on the working state of the energy storage device, so as to provide a basis for subsequent control of the transistor switching module (such as...). Figure 1 or Figure 2 The transistor switch module 12 shown) and the relay drive module (such as Figure 1 or Figure 2 The relay drive module 13 shown provides a basis for decision-making in the control of the system.

[0067] S302 controls the transistor switching module and the relay drive module based on the start signal and discharge state.

[0068] In the embodiments of this application, the transistor switching module and the relay driving module can be controlled based on the start signal and the discharge state.

[0069] The specific details of how the transistor switching module and relay drive module are controlled based on the start-up signal and discharge state will be explained below. Figure 4 The process shown will be explained in detail here.

[0070] Based on the above description of the technical solution provided in the embodiments of this application, the start-up signal and the discharge state of the energy storage device management module are obtained; and the transistor switching module and the relay driving module are controlled based on the start-up signal and the discharge state. This technical solution, by setting a hybrid switching architecture of transistor switching module and relay driving module in the energy storage device protection circuit, and jointly determining the action of relay driving module with the discharge state of energy storage device management module when the start-up signal is obtained, does not rely on a complex multi-MOSFET parallel current expansion scheme. It can achieve dynamic expansion of high current carrying capacity using only the existing transistor switching module and relay driving module of the protection circuit itself, which significantly reduces the size, cost and system complexity of the protection board. By integrating the collaborative control of transistor switching module and relay driving module, it has higher current carrying reliability and better power consumption performance compared with the simple MOSFET parallel current expansion scheme. At the same time, it avoids the risks of inconsistent current sharing and overheating burnout caused by multi-MOSFET parallel connection. Thus, by accurately controlling the energy storage device protection circuit, it can reduce the power consumption, cost and size of protection board while ensuring high current carrying capacity, and improve the overall reliability and economy of the system.

[0071] like Figure 4 The diagram shown is a schematic representation of the implementation flow of another control method for an energy storage device protection circuit provided in this application. Figure 4 exist Figure 3Based on this, the paper describes in detail how to control the transistor switching module and the relay drive module based on the start-up signal and discharge state, which may include the following: S401, when the discharge state is allowed to discharge and the start signal is at the first level, controls the transistor switch module to turn on and controls the relay drive module to be in a non-drive state.

[0072] In this embodiment, when the discharge state is "discharge permitted" and the start signal is at the first level, it indicates that the device containing the energy storage device is not currently performing a start-up operation, and the energy storage device management module allows the energy storage device to discharge normally. At this time, the energy storage device protection circuit is in normal operating mode, which can control the transistor switch module to conduct and control the relay drive module to be in a non-drive state.

[0073] Specifically, to control the transistor switch module to be on and the relay drive module to be in a non-driven state, this can include controlling the first transistor switch and the second transistor switch to close based on the high level output from the discharge control terminal of the energy storage device management module. The potential of the gate of the enable transistor in the relay drive module is pulled high to turn it on. The potential of the gate of the drive transistor in the relay drive module is pulled low to turn it off, de-energizing the electromagnetic coil of the relay in the relay drive module and opening the normally open contact switch of the relay.

[0074] In normal operating mode, the energy storage device can be supplied with the load by the transistor switching module alone. By utilizing the low power consumption and fast switching speed of the transistor switching module, low power consumption normal power supply can be achieved. At the same time, the relay drive module is in a non-drive state. The normally open contacts of the relay remain open, the relay does not participate in current conduction, its electromagnetic coil is not energized, and no power consumption is generated.

[0075] Correspondingly, when the discharge state is "discharge allowed" and the start signal is at the first level, the circuit diagram for controlling the transistor switch module to turn on and the relay drive module to be in a non-drive state can be as follows: Figure 5 As shown. Figure 5 The diagram shown is a schematic representation of a circuit structure in a normal operating mode according to an embodiment of this application. Figure 5 In the circuit configuration shown, the discharge control terminal of the energy storage device management module 11 outputs a high-level (i.e., effective) discharge control signal, which is transmitted to the first terminal of the transistor switch module 12 and the first terminal of the relay drive module 13. Simultaneously, the charging control terminal of the energy storage device management module 11 outputs a high-level charging control signal to the second terminal of the transistor switch module 12.

[0076] In transistor switch module 12, both the first transistor switch 12-1 and the second transistor switch 12-2 are closed (i.e., on). Specifically, the control terminal (gate) of the first transistor switch 12-1 receives a high level output from the discharge control terminal and is turned on, allowing current to flow through the discharge circuit of the energy storage device; the control terminal (gate) of the second transistor switch 12-2 receives a high level output from the charging control terminal and is turned on, allowing current to flow through the charging circuit of the energy storage device. Thus, a complete power supply circuit is formed between the energy storage device (whose positive terminal is connected to the positive input terminal of the energy storage device protection circuit 10) and the load, wherein the total discharge current I_dis = I1, and the current path corresponding to I1 is: positive terminal of the energy storage device, load, first transistor switch 12-1, second transistor switch 12-2, negative terminal of the energy storage device (connected to the negative terminal of the energy storage device via the third terminal of the second transistor switch 12-2), and the energy storage device supplies power to the load normally through transistor switch module 12.

[0077] In the relay drive module 13, the external start control signal received by the start signal input interface 13-5 is at the first level (i.e., high level), indicating that the device containing the energy storage device is not currently performing a start operation. At this time, the first clamping diode 13-8 is in the off state because its anode (connected to the start signal input interface 13-5) is at a high level and its cathode (connected to the gate of the enable transistor 13-4) is at a low level. The gate of the enable transistor 13-4 is pulled up to the first power supply terminal (e.g., V_BAT) through the first bias resistor 13-6, and the gate potential is pulled up to a high level, enabling the enable transistor 13-4 is turned on. After the enable transistor 13-4 is turned on, its drain pulls the gate of the drive transistor 13-3 connected to it down to ground level, and the drive transistor 13-3 is turned off. After the drive transistor 13-3 is turned off, the electromagnetic coil of the relay 13-1 is not energized and does not generate electromagnetic attraction, and the normally open contact of the relay 13-1 remains open. Meanwhile, the freewheeling diode 13-2 has no forward bias voltage across it and is not working.

[0078] In this state, since the normally open contact of relay 13-1 remains open, the relay does not participate in current conduction, and the energy storage device supplies power to the load only through transistor switching module 12. Because the transistors (e.g., MOSFETs) in transistor switching module 12 are voltage-driven devices with almost zero gate drive current, their power consumption is extremely low, making them suitable for long-term standby or normal operation. Simultaneously, the electromagnetic coil of relay 13-1 is not energized, generating no coil power consumption, thus avoiding the problem of high power consumption caused by continuous energization of the electromagnetic coil in traditional relay-type protection circuits during long-term standby.

[0079] Furthermore, the anode of the second clamping diode 13-9 is connected to the discharge control terminal (currently high level) of the energy storage device management module 11, and its cathode is connected to the gate of the driving transistor 13-3 (currently pulled low to ground level by the enabling transistor 13-4). The second clamping diode 13-9 is in the off state and does not participate in circuit control. The first bias resistor 13-6 and the second bias resistor 13-7 respectively act as pull-up resistors to ensure that the gates of each transistor maintain a defined voltage level when there is no external signal interference.

[0080] S402, when the discharge state is allowed to discharge and the start signal is at the second level, controls the transistor switch module to turn on and controls the relay drive module to be in the drive state.

[0081] In this embodiment, when the discharge state is "discharge allowed" and the start signal is at the second level, it indicates that the device containing the energy storage device is currently undergoing a startup operation, and the energy storage device management module allows the energy storage device to discharge normally. At this time, the energy storage device protection circuit is in startup mode, controlling the transistor switch module to remain on and controlling the relay drive module to be in drive mode.

[0082] Specifically, controlling the transistor switch module to turn on and the relay drive module to be in a driving state can include controlling the first transistor switch and the second transistor switch to close based on the high level output from the discharge control terminal of the energy storage device management module. The potential of the gate of the enable transistor in the relay drive module is pulled low to turn it off, and the potential of the gate of the drive transistor in the relay drive module is high, turning the drive transistor on. This energizes the electromagnetic coil of the relay in the relay drive module, closing the normally open contact of the relay.

[0083] In startup mode, the energy storage device can be supplied with the load by a combination of a transistor switching module and a normally open relay contact connected in parallel. Because the normally open relay contact has extremely low contact resistance, it can withstand surge currents several times its rated value for a short period. This provides effective shunt protection for the transistor switching module during startup, preventing overload damage caused by the large startup current flowing entirely through the transistor switching module.

[0084] Correspondingly, when the discharge state is "discharge allowed" and the start signal is at the second level, the circuit diagram for controlling the transistor switch module to turn on and controlling the relay drive module to be in the drive state is as follows: Figure 6 As shown. Figure 6 The diagram shown is a schematic representation of a circuit structure in a startup operating mode according to an embodiment of this application. Figure 6In the circuit configuration shown, the discharge control terminal of the energy storage device management module 11 outputs a high-level (i.e., effective) discharge control signal, which is transmitted to the first terminal of the transistor switch module 12 and the first terminal of the relay drive module 13. Simultaneously, the charging control terminal of the energy storage device management module 11 outputs a high-level charging control signal to the second terminal of the transistor switch module 12.

[0085] In transistor switch module 12, both the first transistor switch 12-1 and the second transistor switch 12-2 are closed (i.e., on). Specifically, the control terminal (gate) of the first transistor switch 12-1 receives a high-level output from the discharge control terminal and is turned on, allowing current to flow through the discharge circuit of the energy storage device; the control terminal (gate) of the second transistor switch 12-2 receives a high-level output from the charging control terminal and is turned on, allowing current to flow through the charging circuit of the energy storage device. Transistor switch module 12 remains on, providing a current path for the load.

[0086] In the relay drive module 13, the external start control signal received by the start signal input interface 13-5 is at the second level (i.e., low level). This low-level signal indicates that the device containing the energy storage device is currently in the start-up operation. At this time, the anode of the first clamping diode 13-8 (connected to the start signal input interface 13-5) is at a low level, and its cathode (connected to the gate of the enable transistor 13-4) is pulled up to a high level by the first bias resistor 13-6. The anode voltage is lower than the cathode voltage, and the first clamping diode 13-8 is forward-biased, pulling the gate potential of the enable transistor 13-4 down to a low level, thus turning off the enable transistor 13-4. After the enable transistor 13-4 is turned off, its drain no longer pulls the gate of the drive transistor 13-3 down. The gate of the drive transistor 13-3 is pulled up to the first power supply terminal (e.g., V_BAT) through the second bias resistor 13-7, and the gate potential is at a high level, turning on the drive transistor 13-3. After the driving transistor 13-3 is turned on, the electromagnetic coil of the relay 13-1 is energized, generating an electromagnetic attraction force that pulls the normally open contact of the relay 13-1 into the closed state.

[0087] At this time, the normally open contact of relay 13-1 and transistor switch module 12 form a parallel connection, jointly supplying power to the load. The loop current I_dis = I1 + I2, where the current path includes two parallel paths: Path 1 I1 is the positive terminal of the energy storage device, the load, the first transistor switch 12-1, the second transistor switch 12-2, and the negative terminal of the energy storage device (i.e., the transistor switch module path); Path 2 I2 is the positive terminal of the energy storage device, the load, the normally open contact of relay 13-1, and the negative terminal of the energy storage device (i.e., the relay contact path). The two paths are connected in parallel to jointly carry the large current when the device containing the energy storage device starts up.

[0088] Because the normally open contact of relay 13-1 has extremely low contact resistance (typically in the milliohm range) when closed, it can withstand surge currents several times its rated value for a short period. Most of the starting current flows through the relay contact path, with only a small portion flowing through the transistor switch module 12. Therefore, the normally open contact of relay 13-1 provides effective shunt protection for the transistor switch module 12 during startup, preventing overload damage caused by the entire large starting current flowing through the transistor switch module 12.

[0089] In this state, the freewheeling diode 13-2 is connected in reverse parallel across the electromagnetic coil of the relay 13-1, with its cathode connected to the first terminal of the electromagnetic coil and its anode connected to the second terminal. Since the voltage across the electromagnetic coil is forward when energized, the freewheeling diode 13-2 is in reverse cutoff and does not participate in circuit operation. The anode of the second clamping diode 13-9 is connected to the discharge control terminal (currently high level) of the energy storage device management module 11, and its cathode is connected to the gate of the driving transistor 13-3 (currently pulled up to high level by the second bias resistor 13-7). The cathode potential is higher than the anode potential, so the second clamping diode 13-9 is in cutoff and does not participate in circuit control.

[0090] In addition, the original vehicle fuse box provides the source of the start control signal, and its start signal output interface is connected to the start signal input interface 13-5 of the relay drive module 13. The original vehicle start relay K responds to the operation of the ignition switch or start button. During the start-up process, its control terminal becomes low, and this low-level signal serves as the start control signal (START signal), transmitted to the start signal input interface 13-5 through the start signal output interface of the original vehicle fuse box. The original vehicle start switch (such as the ignition switch or start button) triggers the start-up process. When the user operates the original vehicle start switch, the start relay is energized, and its control terminal potential switches from high to low.

[0091] S403, when the discharge state is under discharge protection, controls the transistor switch module to turn off and controls the relay drive module to be in a non-drive state.

[0092] In this embodiment, when the discharge state is under discharge protection, the energy storage device management module detects abnormal conditions such as over-discharge, overcurrent, or over-temperature in the energy storage device. The energy storage device management module outputs an invalid level (e.g., low level) discharge control signal through its discharge control terminal. At this time, the energy storage device protection circuit is in discharge protection mode, controlling the transistor switch module to turn off and controlling the relay drive module to be in a non-drive state.

[0093] Specifically, controlling the transistor switch module to turn off and the relay drive module to be in a non-drive state can include controlling the first transistor switch and the second transistor switch to turn off according to the discharge protection level output by the discharge control terminal of the energy storage device management module, and pulling down the potential of the gate of the drive transistor in the relay drive module so that the drive transistor is turned off, the electromagnetic coil of the relay in the relay drive module is not energized, and the normally open contact of the relay remains open.

[0094] In discharge protection mode, the first transistor switch of the energy storage device is turned off according to the low level output from the discharge control terminal, thus cutting off the discharge circuit. Simultaneously, this low level pulls the gate of the driving transistor low through the second clamping diode, keeping the driving transistor off. The relay's electromagnetic coil is not energized, and its normally open contact remains open. At this time, regardless of whether the start signal is the first or second level, the relay cannot conduct. This achieves the highest priority control of the relay drive module by the energy storage device management module, ensuring that the discharge circuit is completely cut off in abnormal states of the energy storage device, effectively protecting the safety of the energy storage device.

[0095] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0096] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0097] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A protection circuit for an energy storage device, characterized in that, The energy storage device protection circuit includes: an energy storage device management module, a transistor switch module, and a relay drive module; The discharge control terminal of the energy storage device management module is connected to the first terminal of the transistor switch module and the first terminal of the relay drive module, respectively. The charging control terminal of the energy storage device management module is connected to the second terminal of the transistor switch module; The third terminal of the transistor switch module is connected to the second terminal of the relay drive module; The fourth terminal of the transistor switch module is connected to the third terminal of the relay drive module.

2. The energy storage device protection circuit according to claim 1, characterized in that, The transistor switch module includes a first transistor switch and a second transistor switch; The first terminal of the first transistor switch is connected to the discharge control terminal of the energy storage device management module, the second terminal of the first transistor switch is connected to the second terminal of the relay drive module, and the third terminal of the first transistor switch is connected to the second terminal of the second transistor switch. The first terminal of the second transistor switch is connected to the charging control terminal of the energy storage device management module, and the third terminal of the second transistor switch is connected to the third terminal of the relay drive module.

3. The energy storage device protection circuit according to claim 2, characterized in that, The relay drive module includes a relay; The first terminal of the normally open contact switch of the relay is connected to the second terminal of the first transistor switch, and the second terminal of the normally open contact switch of the relay is connected to the third terminal of the second transistor switch.

4. The energy storage device protection circuit according to claim 3, characterized in that, The relay drive module also includes a freewheeling diode; The anode of the freewheeling diode is connected to the first terminal of the electromagnetic coil of the relay; The cathode of the freewheeling diode is connected to the second terminal of the electromagnetic coil of the relay.

5. The energy storage device protection circuit according to claim 3, characterized in that, The relay drive module further includes a drive transistor, an enable transistor, a start signal input interface, a first bias resistor, a second bias resistor, a first clamping diode, and a second clamping diode; The drain of the driving transistor is connected to the second terminal of the electromagnetic coil of the relay, the gate of the driving transistor is connected to the cathode of the second clamping diode and the drain of the enabling transistor, and the source of the driving transistor is grounded. The anode of the second clamping diode is connected to the discharge control terminal of the energy storage device management module; The gate of the enabling transistor is connected to the cathode of the first clamping diode and the second end of the first bias resistor, respectively, and the source of the enabling transistor is grounded. The first end of the first bias resistor is connected to the first end of the electromagnetic coil of the relay; The cathode of the first clamping diode is connected to the second end of the second bias resistor, the first end of the second bias resistor is connected to the first end of the electromagnetic coil of the relay, and the anode of the first clamping diode is connected to the start signal input interface.

6. A control method for a protection circuit of an energy storage device, characterized in that, The method, applied to the energy storage device protection circuit as described in any one of claims 1 to 5, comprises: Obtain the startup signal and the discharge status of the energy storage device management module; Based on the start signal and the discharge state, the transistor switch module and the relay drive module are controlled.

7. The method according to claim 6, characterized in that, The control of the transistor switching module and the relay driving module based on the start signal and the discharge state includes: When the discharge state is in the condition that discharge is allowed and the start signal is at the first level, the transistor switch module is controlled to be turned on, and the relay drive module is controlled to be in the non-drive state. When the discharge state is in the condition that discharge is allowed and the start signal is at the second level, the transistor switch module is controlled to be turned on, and the relay drive module is controlled to be in the drive state. When the discharge state is under discharge protection, the transistor switch module is controlled to turn off, and the relay drive module is controlled to be in a non-drive state.

8. The method according to claim 7, characterized in that, The control of the transistor switch module to be turned on and the control of the relay drive module to be in a non-drive state include: Based on the high level output from the discharge control terminal of the energy storage device management module, the first transistor switch and the second transistor switch are controlled to close. The potential of the gate of the enable transistor in the relay drive module is pulled high to turn on the enable transistor. The potential of the gate of the driving transistor in the relay driving module is pulled low to turn off the driving transistor, the electromagnetic coil of the relay in the relay driving module is not energized, and the normally open contact switch of the relay is opened.

9. The method according to claim 7, characterized in that, The control of the transistor switch module to be turned on and the control of the relay drive module to be in a driving state include: Based on the high level output from the discharge control terminal of the energy storage device management module, the first transistor switch and the second transistor switch are controlled to close. The potential of the gate of the enable transistor in the relay driving module is pulled low to turn off the enable transistor. The potential of the gate of the drive transistor in the relay driving module is high, the drive transistor is turned on, the electromagnetic coil of the relay in the relay driving module is energized, and the normally open contact of the relay is closed.

10. The method according to claim 7, characterized in that, The control of turning off the transistor switch module and putting the relay drive module in a non-drive state includes: Based on the discharge protection level output by the discharge control terminal of the energy storage device management module, the first transistor switch and the second transistor switch are controlled to turn off, and the potential of the gate of the driving transistor in the relay driving module is pulled low so that the driving transistor is turned off, the electromagnetic coil of the relay in the relay driving module is not energized, and the normally open contact of the relay remains open.

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