Battery system relay adhesion detection circuit, control method and storage medium

Abstract

The present application discloses a battery system relay adhesion detection circuit, control method, and storage medium. The detection circuit includes a positive electrode circuit: a battery positive electrode, a backup relay, a main relay, a fuse, and a charge / discharge port positive electrode are connected in series in sequence; a negative electrode circuit: a battery negative electrode, a first switch, a current-sense resistor, a second switch, and a charge / discharge port negative electrode are connected in series in sequence; and a battery management system (BMS) is also included, which is connected to the battery for collecting battery cell temperature and battery cell voltage, and is also connected to the backup relay, the main relay, the current-sense resistor, and the second switch. It is also connected between the backup relay and the main relay via a first voltage acquisition probe, and between the main relay and the charge / discharge port via a second voltage acquisition probe. The present application can promptly detect the adhesion state of the relay and avoid accidents caused by contact welding or short circuit.

Description

Technical Field

[0001] The present application relates to the technical field of battery system detection, and in particular to a battery system relay adhesion detection circuit, a control method, and a storage medium. Background Art

[0002] The charging and discharging channels of large-capacity battery systems are usually controlled by relays, so relays play an extremely important role in lithium battery circuit systems.

[0003] However, when using batteries, if the relay cannot be disconnected due to adhesion, the battery system protection will fail because the relay circuit cannot be controlled. At the same time, the battery charging and discharging ports will remain charged, which may cause the battery system and load equipment to lose control, short circuit, or even more serious safety accidents.

[0004] Relay sticking is extremely dangerous. During battery system operation, the main relay undergoes frequent and prolonged switching cycles, which can lead to contact sticking due to current surges, overloads, and other factors. In reality, it's impossible to control these factors to prevent relay sticking. Therefore, adding auxiliary protection and detection measures to battery systems is an urgent technical challenge in this field. Summary of the Invention

[0005] In response to the above problems, the purpose of this application is to provide a battery system relay adhesion detection circuit, control method and storage medium, which can promptly detect the adhesion state of the relay and avoid accidents caused by contact welding or short circuit.

[0006] According to one aspect of the present application, a battery system relay adhesion detection circuit is provided, comprising:

[0007] Positive circuit: connect the battery positive pole, backup relay, main relay, fuse, and the positive pole of the charge and discharge port in series in sequence;

[0008] Negative electrode circuit: connect the negative electrode of the battery, the first switch, the current-sense resistor, the second switch, and the negative electrode of the charge and discharge port in series in sequence;

[0009] It also includes a battery management system BMS, a first end of which is connected to the battery for collecting the cell temperature, a second end of which is connected to the battery for collecting the cell voltage, a third end of which is connected to the backup relay, a fourth end of which is connected to the main relay, a fifth end of which is connected to the current sensing resistor, a sixth end of which is connected to the second switch, a seventh end of which is connected between the backup relay and the main relay through a first voltage collection probe, and an eighth end of which is connected between the main relay and the charge and discharge port through a second voltage collection probe.

[0010] The battery management system BMS is set to: control the main relay and the backup relay to close, collect the voltage V1 of the first voltage collection probe and the voltage V2 of the second voltage collection probe in real time, calculate the voltage difference between V1 and V2; collect the resistance value R of the current sensing resistor and the voltage V3 across it in real time, and calculate the current value I passing through the current sensing resistor based on the resistance value R and the voltage V3. R ; Instruct the main relay to disconnect, based on the voltage difference and current value I R Determine whether the main relay is stuck; when the battery management system BMS determines that the main relay is stuck, it controls the backup relay to disconnect the circuit.

[0011] Preferably, in some embodiments of the present application, the detection circuit further includes: an alarm device, which is activated when the battery management system BMS determines that the main relay is stuck.

[0012] Preferably, in some embodiments of the present application, the main relay and the backup relay are controlled by independent control chips respectively.

[0013] Preferably, in some embodiments of the present application, based on the voltage difference and the current value I R The conditions for judging whether the main relay is stuck are: the voltage difference is ≤ 1V and the current value is I R >0A.

[0014] Preferably, in some embodiments of the present application, the battery management system BMS is configured to: determine whether the main relay is stuck, including two-level determination: the current I passing through the current-sense resistor when the sticking occurs is preset. R Warning threshold; when the voltage difference is ≤1V and 0A R ≤ warning threshold, record the number of faults, try n (n is a positive integer) times to automatically re-open and close the main relay to eliminate temporary adhesion; if adhesion still exists after n times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the backup relay will be immediately controlled to disconnect the circuit.

[0015] According to another aspect of the present application, the present application also provides a control method for a battery system relay adhesion detection circuit, including a detection circuit of any one of the above embodiments, the control method comprising: controlling the main relay and the standby relay to close, collecting the voltage V1 of the first voltage acquisition probe and the voltage V2 of the second voltage acquisition probe in real time, and calculating the voltage difference between V1 and V2; collecting the resistance value R of the current sensing resistor and the voltage V3 at both ends thereof in real time, and calculating the current value I passing through the current sensing resistor based on the resistance value R and the voltage V3. R ; Instruct the main relay to disconnect, based on the voltage difference and current value I R ​Determine whether the main relay is stuck; when the battery management system BMS determines that the main relay is stuck, it controls the backup relay to disconnect the circuit.

[0016] Preferably, in some embodiments of the present application, the method further includes: when the battery management system BMS determines that the main relay is stuck, the alarm device is activated.

[0017] Preferably, in some embodiments of the present application, based on the voltage difference and the current value I R The conditions for judging whether the main relay is stuck are: the voltage difference is ≤ 1V and the current value is I R >0A.

[0018] Preferably, in some embodiments of the present application, it further includes: judging whether the main relay is stuck, including two-level judgment: the current I passing through the current-sense resistor when the sticking occurs is preset. R Warning threshold; when the voltage difference is ≤1V and 0A R ≤ warning threshold, record the number of faults, try n (n is a positive integer) times to automatically re-open and close the main relay to eliminate temporary adhesion; if adhesion still exists after n times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the backup relay will be immediately controlled to disconnect the circuit.

[0019] According to another aspect of the present application, the present application further provides a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, the control method of any one of the above embodiments can be implemented.

[0020] It should be understood that within the scope of this application, the above-mentioned technical features of this application and the technical features described in detail below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be listed here one by one.

[0021] Compared with the existing technology, this application has the following technical effects:

[0022] This application can promptly detect the sticking state of the relay, avoiding accidents caused by contact welding or short circuit. When the relay is detected to be sticky, the spare relay cuts off the circuit and the LED light alarm is used to quickly locate and handle the fault, thereby increasing the reliability of the relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other features and advantages of the present application will become more apparent by describing in detail example embodiments thereof with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram of a battery system relay adhesion detection circuit according to an embodiment of the present application is shown. ​

[0025] Reference numerals: 1 battery; 2 backup relay; 3 main relay; 4 fuse; 5 charge and discharge port; 6 first switch; 7 current-sense resistor; 8 second switch; 9 battery management system BMS; 10 first voltage acquisition probe; 11 second voltage acquisition probe; 12 first terminal; 13 second terminal. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, beneficial effects, and significant improvements of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, all the embodiments described are only some of the embodiments of this application, not all of them; based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] The present application will be further described below in conjunction with specific implementations. It should be understood that these embodiments are only used to illustrate the present application and are not intended to limit the scope of the present application.

[0028] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment herein. The appearance of such phrases in various places in the specification does not necessarily refer to the same embodiment, nor does it limit mutually exclusive independent or alternative embodiments. Those skilled in the art will appreciate that an embodiment herein may be combined with other embodiments as long as no structural conflicts arise.

[0029] In the description herein, unless otherwise specified or limited, the technical terms "installed," "connected," and "connected" should be understood broadly, and may refer to a movable connection, a fixed connection or integration, or connection via a connector. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this application based on the specific circumstances.

[0030] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to having a specific orientation, being installed or operated in a specific orientation, and should not be understood as limiting the embodiments in this document.

[0031] In the description herein, terms such as "first" and "second" are used only to distinguish different objects and should not be understood to indicate relative importance or to limit the quantity, specific order, or primary and secondary relationship of the described technical features. In the description herein, "plurality" means at least two.

[0032] Embodiments of the present application will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present application, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts.

[0033] Figure 1 FIG. 1 is a schematic diagram of a battery system relay adhesion detection circuit according to an embodiment of the present application. Figure 1 As shown, a battery system relay adhesion detection circuit of the present application includes:

[0034] Positive circuit: connect the positive pole of battery 1, backup relay 2, main relay 3, fuse 4, and positive pole of charge and discharge port 5 in series in sequence;

[0035] Negative electrode circuit: connect the negative electrode of battery 1, first switch 6, current-sense resistor 7, second switch 8, and negative electrode of charging and discharging port 5 in series in sequence;

[0036] It also includes a battery management system BMS9, a first end 12 of which is connected to the battery 1 for collecting the cell temperature, a second end 13 of which is connected to the battery 1 for collecting the cell voltage, a third end of which is connected to the backup relay 2, a fourth end of which is connected to the main relay 3, a fifth end of which is connected to the current sensing resistor 7, a sixth end of which is connected to the second switch 8, a seventh end of which is connected between the backup relay 2 and the main relay 3 through a first voltage acquisition probe 10, and an eighth end of which is connected between the main relay 3 and the charge and discharge port 5 through a second voltage acquisition probe 11.

[0037] Specifically, in some embodiments of the present application, taking the detection of a lithium battery system as an example, when the lithium battery system is turned on, the battery management system BMS9, the main relay 3, the backup relay 2, the current-sense resistor 7, and the voltage acquisition probe form a complete relay adhesion detection and control circuit. When the main relay 3 and the backup relay 2 are both in the closed state, the charge and discharge port 5 of the lithium battery system begins charging and discharging.

[0038] As can be understood by those skilled in the art, the first terminal 12 of the battery management system BMS9 is connected to the battery 1 for collecting the cell temperature, the purpose of which is to monitor the operating temperature of the battery and prevent thermal runaway (such as short circuit, fire) caused by overheating. When the temperature is abnormal, the BMS can trigger protection measures (such as disconnecting any one of the backup relay 2, the main relay 3, the first switch 6, and the second switch 8). The second terminal 13 of the battery management system BMS9 is connected to the battery 1 for collecting the cell voltage, the purpose of which is to determine whether the battery status is overvoltage or undervoltage, and to avoid damage to the battery or load due to abnormal voltage during battery charging and discharging, combined with the relay adhesion detection logic: if the voltage difference (V1-V2≤1V) is still detected after the main relay is disconnected and the current (I R >0A), the adhesion fault can be confirmed.

[0039] Furthermore, as those skilled in the art will appreciate, the first switch 6 can be configured as a manual switch. When the battery temperature or voltage is abnormal or the main relay fails, it can cooperate with the backup relay 2 and main relay 3 of the positive circuit to open and close the charge and discharge circuits, and the circuit can be manually disconnected when necessary. The second switch 8 can be configured as a manual switch and / or its opening and closing can be controlled by the battery management system (BMS) 9. Multiple switches can improve the reliability of disconnecting the battery's negative terminal, avoid single-point failures (such as switch sticking), and simultaneously isolate the current-sense resistor 7. When the first and second switches 6 and 8 are disconnected, they protect the current-sense resistor 7 from external short-circuit shocks.

[0040] Furthermore, as those skilled in the art will appreciate, by providing the fuse 4 in the circuit, hardware-level protection can be provided when the battery management system BMS9 and the backup relay 2 and the main relay 3 all fail.

[0041] This application further improves the safety of the battery system through multi-parameter collaborative monitoring, ensuring that the circuit is cut off in time when the battery temperature / voltage is abnormal or the main relay fails.

[0042] Preferably, in some embodiments of the present application, the battery management system BMS9 is configured to: control the main relay 3 and the backup relay 2 to be closed, collect the voltage V1 of the first voltage acquisition probe 10 and the voltage V2 of the second voltage acquisition probe 11 in real time, and calculate the voltage difference between V1 and V2; collect the resistance R of the current sensing resistor 7 and the voltage V3 across it in real time, and calculate the current value>I passing through the current sensing resistor 7 based on the resistance R and the voltage V3. R ; Instruct the main relay 3 to disconnect, based on the voltage difference and current value I R Determine whether the main relay 3 is stuck; when the battery management system BMS9 determines that the main relay 3 is stuck, it controls the backup relay 2 to disconnect the circuit.

[0043] Specifically, in some embodiments of the present application, when the main relay 3 and the backup relay 2 are closed, the battery management system BMS9 can collect voltages V1 and V2 through the first voltage acquisition probe 10 and the second voltage acquisition probe 11, and obtain the voltage difference by the difference between the two.

[0044] The current value through the current-sense resistor 7 is calculated by the resistance R of the current-sense resistor 7 and the voltage V3 across it. Using simple Ohm's law (I R =V3 / R), the current value I flowing through the current sensing resistor 7 can be calculated R .

[0045] During the operation of the lithium battery, the battery management system BMS9 continuously collects the voltage difference and the current value flowing through the current-sense resistor 7, and makes a comprehensive judgment based on the instructions issued to the main relay 3.

[0046] Preferably, in some embodiments of the present application, the detection circuit further includes an alarm device, which is activated when the battery management system BMS9 determines that the main relay 3 is stuck. In some specific embodiments, an LED light is selected as the alarm device. When the battery management system BMS9 determines that the main relay 3 is stuck, it first issues an alarm through the LED light and then controls the backup relay 2 to disconnect the circuit, thereby providing protection.

[0047] Preferably, in some embodiments of the present application, the main relay 3 and the backup relay 2 are controlled by independent control chips respectively, and the control chip is arranged in the battery management system BMS9. As those skilled in the art can understand, separate and independent control greatly increases the effectiveness and reliability of the control mechanism.

[0048] Preferably, in some embodiments of the present application, based on the voltage difference and the current value I R The conditions for judging whether the main relay 3 is stuck are: the voltage difference is ≤ 1V and the current value is I R >0A.

[0049] Specifically, in some embodiments of the present application, when the lithium battery system triggers system protection due to lithium battery overtemperature, overvoltage or undervoltage, the battery management system BMS9 first limits the lithium battery system current value to 0 and issues an alarm through the LED light. Secondly, the lithium battery system issues a disconnection command to the main relay 3. After receiving the disconnection command, the main relay 3 disconnects, and the current I R It should be 0A; when the main relay 3 is stuck, the main relay 3 cannot respond to the disconnection command of the battery management system BMS9, and the lithium battery system will always be in the on state. When the battery management system BMS9 issues the main relay 3 disconnection command, it can collect the voltage difference ≤ 1V and the current I R When it is greater than 0A, it can be determined that the main relay 3 has been stuck. In order to prevent the lithium battery system from getting out of control of charging and discharging, the battery management system BMS9 will issue an alarm through the alarm device and issue a disconnection command for the backup relay 2 to ensure that the lithium battery system effectively disconnects the charging and discharging channels and ensures that the lithium battery system is used within a safe range.

[0050] Preferably, in some embodiments of the present application, the battery management system BMS is configured as follows:

[0051] Determine whether the main relay is stuck, including two levels of judgment:

[0052] The current I flowing through the current sense resistor when sticking occurs is set R The warning threshold;

[0053] When the voltage difference is ≤1V and 0A R When the value is less than or equal to the warning threshold, the fault count is recorded and the main relay is automatically switched on and off for n (n is a positive integer) attempts to eliminate temporary sticking.

[0054] If adhesion still occurs after n times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the backup relay will be immediately controlled to disconnect the circuit.

[0055] Specifically, in some possible embodiments, there may be a short pulse current or slight adhesion (not completely welded), and directly cutting off the circuit may affect the availability of the battery system. In this case, a two-level judgment can be made on the possible adhesion of the main relay 3:

[0056] The current I passing through the current-sense resistor 7 when adhesion occurs is preset R The warning threshold, for example, the threshold is 5A;

[0057] When the voltage difference is ≤1V and 0A R When the current is less than or equal to 5A, the battery management system BMS9 records the number of faults and tries n times (which can be preset by a person skilled in the art as needed, and is preset to 3 times here) to automatically re-open and close the main relay 3 to eliminate temporary adhesion;

[0058] If adhesion still occurs after 3 times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the battery management system BMS9 immediately controls the backup relay 2 to disconnect the circuit, thereby playing a protective role.

[0059] Specifically, in some embodiments of the present application, in order to determine whether the main relay 3 is stuck, it is also necessary to embed state machine logic in the battery management system BMS9, and at the same time add a fault counter and a hierarchical processing program. The battery management system BMS9 can support high-frequency switching of the driving chip of the main relay 3, such as MOSFET auxiliary control.

[0060] According to another aspect of the present application, the present application further provides a control method for a battery system relay adhesion detection circuit, including the detection circuit of any one of the above embodiments, the control method comprising:

[0061] Control the main relay 3 and the backup relay 2 to close;

[0062] Collect the voltage V1 of the first voltage acquisition probe 10 and the voltage V2 of the second voltage acquisition probe 11 in real time, and calculate the voltage difference between V1 and V2;

[0063] ​​The resistance R of the current-sensing resistor 7 and the voltage V3 across it are collected in real time, and the current value I passing through the current-sensing resistor 7 is calculated based on the resistance R and the voltage V3. R ;

[0064] Instruct the main relay 3 to open, based on the voltage difference and current value I R Determine whether main relay 3 is stuck;

[0065] When the battery management system BMS9 determines that the main relay 3 is stuck, it controls the backup relay 2 to disconnect the circuit.

[0066] Preferably, in some embodiments of the present application, the method further includes: when the battery management system BMS9 determines that the main relay 3 is stuck, the alarm device is activated.

[0067] Preferably, in some embodiments of the present application, based on the voltage difference and the current value I R The conditions for judging whether the main relay 3 is stuck are: the voltage difference ≤ 1 and the current value I R >0A.

[0068] Specifically, in some possible embodiments, there may be a short pulse current or slight adhesion (not completely welded), and directly cutting off the circuit may affect the availability of the battery system. In this case, a two-level judgment can be made on the possible adhesion of the main relay 3:

[0069] The current I passing through the current-sense resistor 7 when adhesion occurs is preset R The warning threshold, for example, the threshold is 5A;

[0070] When the voltage difference is ≤1V and 0A R When the current is less than or equal to 5A, the battery management system BMS9 records the number of faults and tries n times (which can be preset by a person skilled in the art as needed, and is preset to 3 times here) to automatically re-open and close the main relay 3 to eliminate temporary adhesion;

[0071] If adhesion still occurs after 3 times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the battery management system BMS9 immediately controls the backup relay 2 to disconnect the circuit, thereby playing a protective role.

[0072] Preferably, in some embodiments of the present application, the method further comprises:

[0073] Determine whether the main relay is stuck, including two levels of judgment:

[0074] The current I flowing through the current sense resistor when sticking occurs is set R The warning threshold;

[0075] When the voltage difference is ≤1V and 0A R ​​When the value is less than or equal to the warning threshold, the fault count is recorded and the main relay is automatically switched on and off for n (n is a positive integer) attempts to eliminate temporary sticking.

[0076] If adhesion still occurs after n times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the backup relay will be immediately controlled to disconnect the circuit.

[0077] Specifically, in some possible embodiments, there may be a short pulse current or slight adhesion (not completely welded), and directly cutting off the circuit may affect the availability of the battery system. In this case, a two-level judgment can be made on the possible adhesion of the main relay 3:

[0078] The current I passing through the current-sense resistor 7 when adhesion occurs is preset R The warning threshold, for example, the threshold is 5A;

[0079] When the voltage difference is ≤1V and 0A R When the current is less than or equal to 5A, the battery management system BMS9 records the number of faults and tries n times (which can be preset by a person skilled in the art as needed, and is preset to 3 times here) to automatically re-open and close the main relay 3 to eliminate temporary adhesion;

[0080] If adhesion still occurs after 3 times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the battery management system BMS9 immediately controls the backup relay 2 to disconnect the circuit, thereby playing a protective role.

[0081] Specifically, in some embodiments of the present application, when the lithium battery system triggers system protection due to lithium battery overtemperature, overvoltage or undervoltage, the battery management system BMS9 first limits the lithium battery system current value to 0 and issues an alarm through the LED light. Secondly, the lithium battery system will issue a disconnection command to the main relay 3. The main relay 3 disconnects after receiving the disconnection command, and the current passing through the current sensing resistor 7 should be 0A; when the main relay 3 is stuck, the main relay 3 cannot respond to the disconnection command of the battery management system BMS9, and the lithium battery system will always be in a path state. When the battery management system BMS9 can collect a voltage difference of ≤1V and a current much greater than 0A after issuing the main relay 3 disconnection command, it can be determined that the main relay 3 is stuck. In order to prevent the lithium battery system from getting out of control of charging and discharging, the battery management system BMS9 will issue an alarm through the alarm device and issue a disconnection command for the standby relay 2 to ensure that the lithium battery system effectively disconnects the charging and discharging channel and ensures that the lithium battery system is used within a safe range.

[0082] According to another aspect of the present application, the present application further provides a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, the control method of any one of the above embodiments can be implemented.

[0083] ​The present application discloses a battery system relay adhesion detection circuit, control method and storage medium, which have a relatively simple structure. It mainly determines whether the relay is adhered by collecting the control instructions of the battery management system BMS to the relay and the voltage difference and current of the circuit, and then controls the adhesion circuit by adding a spare relay, which reduces the circuit difficulty and cost. When the battery management system BMS detects that the main relay cannot be disconnected due to adhesion, it will alarm through the LED light, and then control the spare relay to cut off the power to the battery circuit, thereby ensuring the safety of the lithium battery system and the load. Through the adhesion detection and control circuit, the adhesion state of the relay can be discovered in time, avoiding safety accidents caused by the inability to disconnect or close normally due to adhesion of the relay. With the help of the spare relay cutting off the circuit and the LED light alarm, the fault can be quickly located and handled, which increases the reliability of the relay.

[0084] The above describes the preferred embodiments of the present application. It should be understood that the present application is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present application without departing from the scope of the technical solutions of the present application, or modify them into equivalent embodiments with equivalent changes, which does not affect the substantive content of the present application. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application that do not depart from the content of the technical solutions of the present application are still within the scope of protection of the technical solutions of the present application.

Claims

1. Battery system relay adhesion detection circuit, characterized in that, include, Positive circuit: connect the battery positive pole, backup relay, main relay, fuse, and the positive pole of the charge and discharge port in series in sequence; Negative electrode circuit: connect the negative electrode of the battery, the first switch, the current-sense resistor, the second switch, and the negative electrode of the charge and discharge port in series in sequence; It also includes a battery management system BMS, a first end of which is connected to the battery for collecting the battery cell temperature, a second end of which is connected to the battery for collecting the battery cell voltage, a third end of which is connected to the backup relay, a fourth end of which is connected to the main relay, a fifth end of which is connected to the current detection resistor, a sixth end of which is connected to the second switch, a seventh end of which is connected between the backup relay and the main relay through a first voltage collection probe, and an eighth end of which is connected between the main relay and the charge and discharge port through a second voltage collection probe; The battery management system BMS is embedded with state machine logic and is provided with a fault counter and a classification processing program. The battery management system BMS supports high-frequency switching of the driving chip of the main relay; The battery management system BMS is configured as follows: Control the main relay and the backup relay to close, Collecting the voltage V1 of the first voltage acquisition probe and the voltage V2 of the second voltage acquisition probe in real time, and calculating the voltage difference between V1 and V2; The resistance value R of the current-sensing resistor and the voltage V3 at both ends thereof are collected in real time, and the current value I passing through the current-sensing resistor is calculated based on the resistance value R and the voltage V3. R ; Instruct the main relay to open, based on the voltage difference and the current value I R Determine whether the main relay is stuck, the judgment conditions are: voltage difference ≤ 1V and current value I R >0A; when the battery management system BMS determines that the main relay is stuck, it controls the backup relay to disconnect the circuit; The determination of whether the main relay is stuck includes two levels of determination: Preset the current value I passing through the current sense resistor when adhesion occurs R Warning threshold; when the voltage difference is ≤1V and 0A R ≤ warning threshold, record the number of faults, try n times to automatically re-open and close the main relay to eliminate temporary adhesion, n is a positive integer; if adhesion still exists after n times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the backup relay will be immediately controlled to disconnect the circuit.​ 2. The detection circuit according to claim 1, characterized in that The detection circuit further includes an alarm device, which is activated when the battery management system BMS determines that the main relay is stuck.

3. The detection circuit according to claim 1, characterized in that: The main relay and the backup relay are controlled by independent control chips respectively.

4. A control method for a battery system relay adhesion detection circuit, characterized in that: The detection circuit according to any one of claims 1 to 3, wherein the control method comprises: Control the main relay and the backup relay to close, The voltage V1 of the first voltage acquisition probe and the voltage V2 of the second voltage acquisition probe are collected in real time, and the voltage difference between V1 and V2 is calculated; the resistance R of the current sensing resistor and the voltage V3 at both ends of the current sensing resistor are collected in real time, and the current value I passing through the current sensing resistor is calculated based on the resistance R and the voltage V3. R ; Instruct the main relay to open, based on the voltage difference and the current value I R Determine whether the main relay is stuck, the judgment conditions are: voltage difference ≤ 1V and current value I R >0A; when the battery management system BMS determines that the main relay is stuck, it controls the backup relay to disconnect the circuit; The determination of whether the main relay is stuck includes two levels of determination: Preset the current value I passing through the current sense resistor when adhesion occurs R Warning threshold; when the voltage difference is ≤1V and 0A R ≤ warning threshold, record the number of faults, try n times to automatically re-open and close the main relay to eliminate temporary adhesion, n is a positive integer; if adhesion still exists after n times or when the voltage difference is ≤1V and I R When the current is greater than 5A, the backup relay will be immediately controlled to disconnect the circuit.​ 5. The control method according to claim 4, characterized in that: Also includes: When the battery management system BMS determines that the main relay is stuck, the alarm device is activated.

6. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by a processor, the control method according to any one of claims 4 to 5 is implemented.

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