Battery management system and flow battery equipment

Abstract

The utility model relates to a battery management system and flow battery equipment, an analog front-end chip can be respectively connected with the positive and negative electrodes of a flow battery and the positive and negative electrodes of a standby power supply, and the flow battery voltage output by the flow battery can be greater than or equal to the power supply voltage of the analog front-end chip under the condition that a galvanic pile of the flow battery operates. At the moment, the flow battery supplies power to the analog front-end chip. And when the voltage of the flow battery is smaller than the power supply voltage (for example, the electric pile is not operated), the standby power supply can be switched to supply power to the analog front-end chip. According to the scheme, the standby power supply can be used for supplying power to the analog front-end chip when the galvanic pile does not operate, so that the operation of the analog front-end chip is maintained, and the state monitoring of the flow battery when the galvanic pile does not operate is further realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flow battery, in particular to a battery management system and flow battery equipment. BACKGROUND

[0002] The flow battery is a new type of energy storage battery with positive electrolyte and negative electrolyte circulating separately. With the rapid development of renewable energy, the flow battery has become an important candidate in the energy storage field due to its high capacity, wide application field, high efficiency, safety and other advantages. It is of great significance to monitor the state of the flow battery for the stable and safe operation of the flow battery.

[0003] However, in the related art, the chip for monitoring the state of the flow battery is directly powered by the stack, and it is difficult to realize the state monitoring of the flow battery when the stack is not working. UTILITY MODEL CONTENT

[0004] Therefore, it is necessary to provide a battery management system and flow battery equipment to realize the state monitoring of the flow battery when the stack is not working.

[0005] A battery management system applied to a flow battery, comprising: a backup power supply, an analog front-end chip and a controller, a positive electrode of the analog front-end chip is connected to a positive electrode of the backup power supply and a positive electrode of the flow battery, and a negative electrode of the analog front-end chip is connected to a negative electrode of the backup power supply and a negative electrode of the flow battery; the analog front-end chip and the backup power supply are respectively connected to the controller, and the controller is used to switch to supply power to the analog front-end chip by the backup power supply when the voltage of the flow battery is less than the supply voltage of the analog front-end chip.

[0006] In one of the embodiments, the battery management system further comprises a first switching device and a second switching device; the positive electrode of the analog front-end chip is connected to the positive electrode of the flow battery through the first switching device, and / or the negative electrode of the analog front-end chip is connected to the negative electrode of the flow battery through the first switching device; the positive electrode of the analog front-end chip is connected to the positive electrode of the backup power supply through the second switching device, and / or the negative electrode of the analog front-end chip is connected to the negative electrode of the backup power supply through the second switching device.

[0007] In one of the embodiments, the flow battery comprises a plurality of battery units, and the battery management system further comprises a plurality of balancing circuits, one of the battery units is connected to a voltage collection end of the analog front-end chip through one of the balancing circuits.

[0008] In one of the embodiments, the equalization circuit comprises a constant current discharge circuit and a third switch device, a control end of the third switch device is connected to an enable end of the analog front end chip, a first end of the third switch device is connected to a first end of the constant current discharge circuit, a second end of the constant current discharge circuit is connected to a first end of the battery unit and a first voltage acquisition end of the analog front end chip, and a second end of the third switch device is connected to a second end of the battery unit and a second voltage acquisition end of the analog front end chip.

[0009] In one of the embodiments, the equalization circuit further comprises a first resistor, a second resistor and a third resistor, the first voltage acquisition end of the analog front end chip is connected to the second end of the constant current discharge circuit and the first end of the battery unit through the first resistor, the enable end of the analog front end chip is connected to the control end of the third switch device through the second resistor, and the second voltage acquisition end of the analog front end chip is connected to the second end of the third switch device and the second end of the battery unit through the third resistor.

[0010] In one of the embodiments, the flow battery comprises a plurality of battery units, and the battery management system further comprises a plurality of filter protection circuits, one of the battery units is connected to the voltage acquisition end of the analog front end chip through one of the filter protection circuits.

[0011] In one of the embodiments, the filter protection circuit comprises a fourth resistor, a fifth resistor, a first capacitor, a second capacitor and a bidirectional Zener diode, a first end of the fourth resistor is connected to a first end of the first capacitor and a first end of the battery unit, a second end of the fourth resistor is connected to a first end of the second capacitor and a first end of the bidirectional Zener diode, the first end of the bidirectional Zener diode is further connected to a first voltage acquisition end of the analog front end chip, a second end of the first capacitor is connected to a first end of the fifth resistor and a second end of the battery unit, a second end of the fifth resistor is connected to a second end of the second capacitor and a second end of the bidirectional Zener diode, and the second end of the bidirectional Zener diode is further connected to a second voltage acquisition end of the analog front end chip.

[0012] In one of the embodiments, the filter protection circuit further comprises a first fuse and a second fuse, the first end of the battery unit is connected to the first end of the first capacitor and the first end of the fourth resistor through the first fuse, and the second end of the battery unit is connected to the second end of the first capacitor and the first end of the fifth resistor through the second fuse.

[0013] In one of the embodiments, the analog front end chip is a positive and negative voltage monitoring type analog front end chip.

[0014] A flow battery device comprises a flow battery and the above-mentioned battery management system.

[0015] The above-mentioned battery management system and flow battery device, the analog front-end chip can be connected with the positive and negative poles of the flow battery and the positive and negative poles of the backup power source respectively. In the case that the flow battery stack is operating, the flow battery voltage output by the flow battery will be greater than or equal to the supply voltage of the analog front-end chip, at which time the flow battery supplies power to the analog front-end chip. When the flow battery voltage is less than the supply voltage (for example, the stack is not operating), the backup power source can be switched to supply power to the analog front-end chip. Through this scheme, the backup power source can supply power to the analog front-end chip when the stack is not operating, thereby maintaining the operation of the analog front-end chip and realizing flow battery state monitoring when the stack is not operating. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0017] Figure 1 The figure is a structure schematic diagram of the battery management system in an embodiment of the present application.

[0018] Figure 2 The figure is a structure schematic diagram of the battery management system in another embodiment of the present application.

[0019] Figure 3 The figure is a structure schematic diagram of the battery management system in another embodiment of the present application.

[0020] Figure 4 The figure is a structure schematic diagram of the battery management system in another embodiment of the present application.

[0021] Explanation of reference signs:

[0022] 101-backup power source, 102-analog front-end chip, K1-first switch device, K2-second switch device, 105-balancing circuit, K3-third switch device, 301-constant current discharge circuit, R1-first resistor, R2-second resistor, R3-third resistor, 106-filter protection circuit, R4-fourth resistor, R5-fifth resistor, C1-first capacitor, C2-second capacitor, DZ-bidirectional Zener diode, FB1-first fuse, FB2-second fuse. DETAILED DESCRIPTION

[0023] For the purpose of clarity, the present application will be described in greater detail below with reference to the accompanying drawings. The embodiments of the present application are shown in the drawings. However, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0025] It should be understood that the terms "first", "second" and so on used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the application, the first resistor can be referred to as the second resistor, and similarly, the second resistor can be referred to as the first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0026] It should be understood that "connection" in the following embodiments means that the circuits, modules, units and the like connected to each other have the transmission of electrical signals or data.

[0027] It should be understood that "at least one" means one or more, and "multiple" means two or more. "At least part of the element" means part or all of the element.

[0028] As used herein, the singular forms "a", "an" and "the" can include plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprise / comprising" or "have / having" specify the presence of the stated features, integers, steps, operations, components, parts or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in the specification includes any and all combinations of the related listed items.

[0029] The battery management system provided by the embodiments of the present application is applied to a flow battery, wherein the flow battery can be a container type flow battery formed by a plurality of battery units in series and / or parallel. The battery unit includes a stack, a circulating pump, a positive electrode liquid storage tank for storing positive electrode electrolyte, and a negative electrode liquid storage tank for storing negative electrode electrolyte. The battery management system is connected with the stack and the circulating pump of the flow battery, and can control the operation of the circulating pump and collect parameters such as voltage and current during the operation of the battery unit.

[0030] Referring to Figure 1 The application provides a battery management system applied to a flow battery, comprising: a backup power supply 101, an analog front-end chip 102 and a controller (not shown in the figure), a positive electrode of the analog front-end chip 102 being connected to a positive electrode of the backup power supply 101 and a positive electrode of the flow battery, and a negative electrode of the analog front-end chip 102 being connected to a negative electrode of the backup power supply 101 and a negative electrode of the flow battery; the analog front-end chip 102 and the backup power supply 101 being respectively connected to the controller, and the controller being used for switching to supply power to the analog front-end chip 102 by the backup power supply 101 in the case that a voltage of the flow battery is less than a supply voltage of the analog front-end chip 102.

[0031] Specifically, the analog front-end chip 102 (AFE) refers to a chip located at the front end of a circuit, which can convert analog signals from various sensors (such as temperature sensors, pressure sensors, etc.) or other analog signal sources into digital signals for subsequent processing by a controller, so as to realize sensing signal acquisition and monitoring. The backup power supply 101 refers to a power supply connected to maintain the operation of the analog front-end chip 102 when the normal power supply circuit (i.e., the flow battery power supply) of the analog front-end chip 102 is disconnected. The type of the backup power supply 101 is not unique, and in an embodiment, it can be a lithium battery. In this way, even if the power is used up, the minimum discharge voltage can still be maintained to supply power to the analog front-end chip 102. The controller is a device used to process AFE and other sensing data, perform algorithm operation and decision-making, and realize the operation scheduling and monitoring of the flow battery.

[0032] The specific types of the positive electrode and the negative electrode of the flow battery are not unique, and in an embodiment, the positive electrode and the negative electrode of the flow battery can be the positive electrode and the negative electrode of a single battery cell stack. In another embodiment, the positive electrode and the negative electrode of the flow battery can be a total positive electrode and a total negative electrode formed by a plurality of battery cells, and the specific types are not limited.

[0033] The positive electrode and the negative electrode of the analog front-end chip 102 are respectively connected to the positive electrode and the negative electrode of the flow battery. Therefore, during the normal operation of the flow battery, the flow battery can provide power greater than or equal to the supply voltage to supply power to the analog front-end chip 102. Correspondingly, in this state, the backup power supply 101 is turned off, or the supply circuit between the backup power supply 101 and the analog front-end chip 102 is disconnected, and the controller can compare the voltage of the flow battery with the supply voltage in real time.

[0034] When it is detected that the voltage of the flow battery is less than the supply voltage, at this time, the battery cell stack in the flow battery is usually not in operation, and at this time, the backup power supply 101 is switched to supply power to the analog front-end chip 102, that is, the backup power supply 101 is turned on, or the supply circuit between the backup power supply 101 and the analog front-end chip 102 is turned on.

[0035] The battery management system analog front-end chip 102 can be connected with the positive and negative poles of the flow battery and the positive and negative poles of the backup power supply 101 respectively. When the flow battery stack is in operation, the flow battery output voltage will be greater than or equal to the supply voltage of the analog front-end chip 102, and the flow battery supplies power to the analog front-end chip 102 at this time. When the flow battery voltage is less than the supply voltage (for example, the stack is not in operation), the backup power supply 101 can be switched to supply power to the analog front-end chip 102. Through this scheme, the backup power supply 101 can supply power to the analog front-end chip 102 when the stack is not in operation, thereby maintaining the operation of the analog front-end chip 102 and realizing flow battery state monitoring when the stack is not in operation.

[0036] Please refer to Figure 2 In one embodiment, the battery management system further comprises a first switching device K1 and a second switching device K2; the positive pole of the analog front-end chip 102 is connected to the positive pole of the flow battery through the first switching device K1, and / or the negative pole of the analog front-end chip 102 is connected to the negative pole of the flow battery through the first switching device K1; the positive pole of the analog front-end chip 102 is connected to the positive pole of the backup power supply 101 through the second switching device K2, and / or the negative pole of the analog front-end chip 102 is connected to the negative pole of the backup power supply 101 through the second switching device K2.

[0037] Specifically, in the embodiment, switching devices are arranged on the power supply circuit between the flow battery and the analog front-end chip 102 and the power supply circuit between the backup power supply 101 and the analog front-end chip 102. Specifically, the switching devices can be arranged at the positive pole and / or the negative pole, which is not limited herein. In this way, the switching of the power supply circuit is realized by controlling the on-off of the switching devices, which has high reliability of power supply switching.

[0038] It should be pointed out that the types of the first switching device K1 and the second switching device K2 are not unique. In one embodiment, they can be relays, which are not limited in particular.

[0039] In one embodiment, the flow battery comprises a plurality of battery units, and the battery management system further comprises a plurality of balancing circuits, please refer to Figure 3 One battery unit is connected to the voltage acquisition end of the analog front-end chip 102 through one balancing circuit 105.

[0040] Specifically, the battery unit, that is, the battery structure that can independently charge and discharge electric energy in the flow battery, can be a single battery cell or a battery box or battery cabinet composed of a plurality of battery cells, which is not limited in particular.

[0041] In actual scenarios, flow batteries used as energy storage systems generally need to be very large, often using large-scale structures in the form of containers, and have the characteristics of high power and large current. The maximum balancing capability of the AFE chip is 300mA (milliampere), which is far from the requirement of 10A (ampere) or more for the balancing current of the flow battery. Therefore, the embodiment is configured with an additional balancing circuit 105, so that each battery unit is connected to the voltage collection end of the analog front-end chip 102 through the balancing circuit 105. In this way, when the voltage of any battery unit is too large, it can be discharged to maintain the voltage consistency of each battery unit.

[0042] It should be pointed out that the type of balancing circuit 105 is not unique. In an embodiment, an external MOS balancing circuit 105 can be used to provide 10A of balancing current for a single battery unit.

[0043] Please continue to refer to Figure 3 In one embodiment, the balancing circuit 105 includes a constant-current discharge circuit 301 and a third switching device K3. The control end of the third switching device K3 is connected to the enable end of the analog front-end chip 102. The first end of the third switching device K3 is connected to the first end of the constant-current discharge circuit 301. The second end of the constant-current discharge circuit 301 is connected to the first end of the battery unit and the first voltage collection end of the analog front-end chip 102. The second end of the third switching device K3 is connected to the second end of the battery unit and the second voltage collection end of the analog front-end chip 102.

[0044] Specifically, the constant-current discharge circuit 301 is a discharge circuit that maintains a constant current during discharge. Its specific type is not unique and can be a constant-current circuit based on a transistor, an operational amplifier, or a constant-current circuit based on a voltage regulator chip, without limitation. The type of third switching device K3 is not unique and will vary depending on the type of constant-current discharge circuit 301. In one embodiment, the third switching device K3 can be a field effect transistor.

[0045] Please continue to refer to Figure 3 In one embodiment, the balancing circuit 105 further includes a first resistor R1, a second resistor R2, and a third resistor R3. The first voltage collection end of the analog front-end chip 102 is connected to the second end of the constant-current discharge circuit 301 and the first end of the battery unit through the first resistor R1. The enable end of the analog front-end chip 102 is connected to the control end of the third switching device K3 through the second resistor R2. The second voltage collection end of the analog front-end chip 102 is connected to the second end of the third switching device K3 and the second end of the battery unit through the third resistor R3.

[0046] Specifically, the scheme of the embodiment, at the connection of the equalization circuit 105 and each port of the analog front-end chip 102, a resistor is further arranged, which can effectively improve the operation reliability of the equalization circuit 105. It can be understood that the first resistor R1, the second resistor R2 and the third resistor R3 can be a single resistor or a resistor assembly formed by a plurality of resistors in series and / or parallel, and the specific form is not limited.

[0047] In one of the embodiments, the flow battery includes a plurality of battery units, and the battery management system further includes a plurality of filter protection circuits, please refer to Figure 4 , one battery unit is connected to the voltage collection end of the analog front-end chip 102 through one filter protection circuit 106.

[0048] Specifically, considering that in actual scenarios, the energy storage system built by using the flow battery is generally arranged in an outdoor open area, and is generally continuously operated for 24 hours, and has a long service life of 15-20 years, regular maintenance is essential. The scheme of the embodiment further arranges a filter protection circuit 106 between the battery unit and the analog front-end chip 102, so as to support the connector hot plug of the battery unit and the interface overvoltage protection function, and ensure the service life of the battery management system.

[0049] Please refer to Figure 4 , in one of the embodiments, the filter protection circuit 106 includes a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2 and a bidirectional Zener diode DZ, the first end of the fourth resistor R4 is connected to the first end of the first capacitor C1 and the first end of the battery unit, the second end of the fourth resistor R4 is connected to the first end of the second capacitor C2 and the first end of the bidirectional Zener diode DZ, the first end of the bidirectional Zener diode DZ is also connected to the first voltage collection end of the analog front-end chip 102, the second end of the first capacitor C1 is connected to the first end of the fifth resistor R5 and the second end of the battery unit, the second end of the fifth resistor R5 is connected to the second end of the second capacitor C2 and the second end of the bidirectional Zener diode DZ, and the second end of the bidirectional Zener diode DZ is also connected to the second voltage collection end of the analog front-end chip 102.

[0050] Specifically, the bidirectional Zener diode DZ has a bidirectional conduction characteristic, and based on the pyroelectric effect and the breakdown voltage, when an overvoltage occurs in the circuit, the bidirectional Zener diode DZ will automatically conduct, guiding the excess voltage to the ground, so as to protect other electronic elements from being damaged. The electronic element has the functions of shock, static voltage, voltage limiting, suppression or discharge protection. The scheme of the embodiment uses the fourth resistor R4, the fifth resistor R5, the first capacitor C1, the second capacitor C2 and the bidirectional Zener diode DZ to build the filter protection circuit 106, so as to support the sampling connector hot plug and protect the AFE chip from being damaged by overvoltage.

[0051] Please continue to refer to Figure 4 In one embodiment, the filter protection circuit 106 further comprises a first fuse FB1 and a second fuse FB2, the first end of the battery unit is connected to the first end of the first capacitor C1 and the first end of the fourth resistor R4 through the first fuse FB1, and the second end of the battery unit is connected to the second end of the first capacitor C1 and the first end of the fifth resistor R5 through the second fuse FB2.

[0052] Specifically, the fuse, i.e. the fuse, is an electrical appliance that breaks the circuit when the current exceeds the specified value, and the fuse melts with the heat generated by itself. The scheme of the present embodiment, the filter protection circuit 106 is further provided with a fuse, so that the overcurrent protection of the battery management system is realized, and the operation safety and operation reliability of the battery management system are further improved.

[0053] In one embodiment, the analog front-end chip 102 is an analog front-end chip 102 with positive and negative voltage monitoring.

[0054] Specifically, the analog front-end chip 102 with positive and negative voltage monitoring, i.e. the analog front-end chip 102 capable of collecting positive and negative voltages. The scheme of the present embodiment considers that it is very necessary to collect negative voltage of the flow battery in some scenarios, so the analog front-end chip 102 with positive and negative voltage monitoring is selected to build the battery management system, which can improve the voltage collection range.

[0055] In one embodiment, the application also adopts a multi-battery pack monitor chip to monitor and manage the state of a plurality of series or parallel battery packs, greatly improving the voltage collection efficiency of the flow battery.

[0056] The application also provides a flow battery device comprising a flow battery and the above-mentioned battery management system.

[0057] Specifically, the structure and implementation of the battery management system are as shown in the above embodiments and the drawings, which will not be described here. The flow battery device, the analog front-end chip 102 of the battery management system can be connected to the positive and negative poles of the flow battery and the positive and negative poles of the backup power supply 101 respectively. In the case of operation of the flow battery stack, the flow battery voltage output by the flow battery will be greater than or equal to the supply voltage of the analog front-end chip 102, and at this time the flow battery supplies power to the analog front-end chip 102. When the flow battery voltage is less than the supply voltage (for example, the stack is not operating), the backup power supply 101 can be switched to supply power to the analog front-end chip 102. Through this scheme, the backup power supply 101 can supply power to the analog front-end chip 102 when the stack is not operating, thereby maintaining the operation of the analog front-end chip 102, and realizing the flow battery state monitoring when the stack is not operating.

[0058] In the description of the specification, the description of the terms "some embodiments", "other embodiments", etc. means that the particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the above terms in various places in the specification are not necessarily all referring to the same embodiment or example.

[0059] Any of the technical features of the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described in the above description. However, any combination of the technical features is considered to be within the scope of the present application.

[0060] The above embodiments only express several implementation manners of the application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the application. It should be pointed out that, for those skilled in the art, some modifications and improvements can be made without departing from the concept of the application, and these are all within the protection scope of the application. Therefore, the protection scope of the application should be subject to the appended claims.

Claims

1. A battery management system, characterized in that, Applications in flow batteries include: Backup power supply; A simulated front-end chip, wherein the positive terminal of the simulated front-end chip is connected to the positive terminal of the backup power supply and the positive terminal of the flow battery, and the negative terminal of the simulated front-end chip is connected to the negative terminal of the backup power supply and the negative terminal of the flow battery; The controller is connected to the analog front-end chip and the backup power supply respectively. The controller is used to switch to powering the analog front-end chip with the backup power supply when the voltage of the flow battery is lower than the supply voltage of the analog front-end chip.

2. The battery management system according to claim 1, characterized in that, The battery management system further includes a first switching device and a second switching device; The positive terminal of the analog front-end chip is connected to the positive terminal of the flow battery through the first switching device, and / or the negative terminal of the analog front-end chip is connected to the negative terminal of the flow battery through the first switching device; The positive terminal of the analog front-end chip is connected to the positive terminal of the backup power supply through the second switching device, and / or the negative terminal of the analog front-end chip is connected to the negative terminal of the backup power supply through the second switching device.

3. The battery management system according to claim 1, characterized in that, The flow battery includes multiple battery cells, and the battery management system further includes multiple equalization circuits. Each battery cell is connected to the voltage acquisition terminal of the analog front-end chip through one of the equalization circuits.

4. The battery management system according to claim 3, characterized in that, The equalization circuit includes a constant current discharge circuit and a third switching device. The control terminal of the third switching device is connected to the enable terminal of the analog front-end chip. The first terminal of the third switching device is connected to the first terminal of the constant current discharge circuit. The second terminal of the constant current discharge circuit is connected to the first terminal of the battery cell and the first voltage acquisition terminal of the analog front-end chip. The second terminal of the third switching device is connected to the second terminal of the battery cell and the second voltage acquisition terminal of the analog front-end chip.

5. The battery management system according to claim 4, characterized in that, The equalization circuit further includes a first resistor, a second resistor, and a third resistor. The first voltage acquisition terminal of the analog front-end chip is connected to the second terminal of the constant current discharge circuit and the first terminal of the battery cell through the first resistor. The enable terminal of the analog front-end chip is connected to the control terminal of the third switching device through the second resistor. The second voltage acquisition terminal of the analog front-end chip is connected to the second terminal of the third switching device and the second terminal of the battery cell through the third resistor.

6. The battery management system according to claim 1, characterized in that, The flow battery includes multiple battery cells, and the battery management system also includes multiple filter protection circuits. Each battery cell is connected to the voltage acquisition terminal of the analog front-end chip through one of the filter protection circuits.

7. The battery management system according to claim 6, characterized in that, The filter protection circuit includes a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, and a bidirectional Zener diode. The first end of the fourth resistor is connected to the first end of the first capacitor and the first end of the battery cell. The second end of the fourth resistor is connected to the first end of the second capacitor and the first end of the bidirectional Zener diode. The first end of the bidirectional Zener diode is also connected to the first voltage acquisition terminal of the analog front-end chip. The second end of the first capacitor is connected to the first end of the fifth resistor and the second end of the battery cell. The second end of the fifth resistor is connected to the second end of the second capacitor and the second end of the bidirectional Zener diode. The second end of the bidirectional Zener diode is also connected to the second voltage acquisition terminal of the analog front-end chip.

8. The battery management system according to claim 7, characterized in that, The filter protection circuit also includes a first fuse and a second fuse. The first end of the battery cell is connected to the first end of the first capacitor and the first end of the fourth resistor through the first fuse. The second end of the battery cell is connected to the second end of the first capacitor and the first end of the fifth resistor through the second fuse.

9. The battery management system according to any one of claims 1-8, characterized in that, The analog front-end chip is an analog front-end chip with positive and negative voltage monitoring capabilities.

10. A flow battery device, characterized in that, Includes a flow battery and a battery management system as described in any one of claims 1-9.

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