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

Abstract

The invention discloses a battery system relay adhesion detection circuit, a control method and a storage medium, and the detection circuit comprises a positive electrode circuit which is sequentially connected with a battery positive electrode, a standby relay, a main relay, a fuse and a charge-discharge port positive electrode in series; the negative electrode circuit is sequentially connected with a battery negative electrode, a first switch, a current detection resistor, a second switch and a charge-discharge port negative electrode in series; and the battery management system BMS is connected to the battery, is used for acquiring the temperature and voltage of the battery cell, is also connected to the standby relay, the main relay, the current detection resistor and the second switch, is also connected between the standby relay and the main relay through a first voltage acquisition probe, and is connected between the main relay and the charging and discharging port through a second voltage acquisition probe. According to the invention, the adhesion state of the relay can be found in time, and accidents caused by contact fusion welding or short circuit are avoided.

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 we use the battery, if the relay cannot be disconnected due to adhesion, the protection of the battery system will fail because the relay circuit cannot be controlled. At the same time, the battery charging and discharging ports will always be charged, which may cause the battery system and load equipment to lose control, short circuit or more serious safety accidents.

[0004] Relay adhesion is extremely dangerous. During the use of the battery system, because the main relay needs to be switched on and off for a long time and frequently, it is very likely that the relay contacts will stick due to current shock, overload, etc. In reality, we cannot control these factors to prevent the relay from sticking. Therefore, adding auxiliary protection and detection measures for relay adhesion in the battery system is a technical problem that needs to be solved urgently 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 positive electrode of the battery, the backup relay, the main relay, the fuse, and the positive electrode of the charging and discharging port in series in sequence;

[0008] Negative electrode circuit: connect the negative electrode of the battery, the first switch, the current sensing 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 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 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 standby relay to close, collect the voltage V1 of the first voltage acquisition probe and the voltage V2 of the second voltage acquisition probe in real time, and calculate the voltage difference between V1 and V2; collect the resistance value R of the current detection resistor and the voltage V3 across it in real time, and calculate the current value I passing through the current detection resistor based on the resistance value R and the voltage V3 R ; instruct the main relay to disconnect, and based on the voltage difference and the current value I R determine whether the main relay is stuck; when the battery management system BMS determines that the main relay is stuck, control the standby 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 standby relay are respectively controlled by independent control chips.

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

[0014] Preferably, in some embodiments of the present application, the battery management system BMS is set to: determine whether the main relay is stuck, including two - level determination: preset the warning threshold of the current I passing through the current detection resistor when sticking occurs; when the voltage difference ≤ 1V and 0A < I R ≤ the warning threshold, record the number of faults, and try to automatically turn on and off the main relay n (n is a positive integer) times to eliminate temporary sticking; if it is still stuck after n times or when the voltage difference ≤ 1V and I R > 5A, immediately control the standby relay to disconnect the circuit. R >5A, immediately control the standby relay 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 sticking detection circuit, including the detection circuit of any one of the above - mentioned embodiments. The control method includes: 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 detection resistor and the voltage V3 across it in real time, and calculating the current value I passing through the current detection resistor based on the resistance value R and the voltage V3 R ; instruct the main relay to disconnect, and based on the voltage difference and the current value I RDetermine whether the main relay is stuck; when the battery management system (BMS) determines that the main relay is stuck, control the standby relay to disconnect the circuit.

[0016] Preferably, in some embodiments of the present application, it 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 condition for determining whether the main relay is stuck is: the voltage difference ≤ 1V and the current value I R > 0A.

[0018] Preferably, in some embodiments of the present application, it further includes: determining whether the main relay is stuck, including two-level determination: the warning threshold of the current I passing through the current detection resistor when the preset adhesion occurs; when the voltage difference ≤ 1V and 0A < I R ≤ warning threshold, record the number of faults, and try to automatically turn on and off the main relay n (n is a positive integer) times to eliminate temporary adhesion; if it is still stuck after n times or when the voltage difference ≤ 1V and I R > 5A, immediately control the standby relay to disconnect the circuit. R >5A, immediately control the standby relay to disconnect the circuit.

[0019] According to another aspect of the present application, the present application also 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 the present application, the above technical features of the present application and the technical features specifically described 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 repeated one by one here.

[0021] Compared with the prior art, the present application has the following technical effects:

[0022] The present application can timely detect the adhesion state of the relay, avoid accidents caused by contact welding or short circuit, and when the relay adhesion is detected, cooperate with the standby relay to cut off the circuit and the LED lamp to alarm, realizing the rapid positioning and processing of faults and increasing the reliability of the relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] By referring to the drawings and describing its exemplary embodiments in detail, the above and other features and advantages of the present application will become more obvious.

[0024] Figure 1 The 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 Spare Relay; 3 Main Relay; 4 Fuse; 5 Charge and Discharge Port; 6 First Switch; 7 Current Detection Resistor; 8 Second Switch; 9 Battery Management System BMS; 10 First Voltage Acquisition Probe; 11 Second Voltage Acquisition Probe; 12 First End; 13 Second End. Detailed Embodiments

[0026] To make the objectives, technical solutions, beneficial effects and remarkable progress of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, all the described embodiments are only part of the embodiments of the present application, rather than all the embodiments; based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

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

[0028] The mention of "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of this article. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments in this article can be combined with other embodiments without structural conflicts.

[0029] In the description of this article, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection" should be understood in a broad sense. It can be a movable connection, a fixed connection or integrated, or it can be connected through a certain connector. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0030] In the description of this article, terms indicating orientation or positional relationships such as "upper", "lower", "left", "right", "horizontal", "longitudinal", "height", "length", "width" are used to accurately describe the embodiments and simplify the description, rather than limiting the parts or structures involved to have a specific orientation, be installed or operated in a specific orientation, and cannot be understood as a limitation to the embodiments in this article.

[0031] In the description of this article, terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order or primary and secondary relationships of the described technical features. In the description of this article, the meaning of "multiple" is at least two.

[0032] Embodiments of the present application will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the present application will now be described in detail, examples of which are shown in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to represent the same or similar parts.

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

[0034] Positive circuit: The positive electrode of battery 1, standby relay 2, main relay 3, fuse 4, and the positive electrode of the charge and discharge port 5 are connected in series in sequence;

[0035] Negative circuit: The negative electrode of battery 1, first switch 6, current detection resistor 7, second switch 8, and the negative electrode of the charge and discharge port 5 are connected in series in sequence;

[0036] It further includes a battery management system BMS9, whose first terminal 12 is connected to battery 1 for collecting the temperature of the battery cells, whose second terminal 13 is connected to battery 1 for collecting the voltage of the battery cells, whose third terminal is connected to standby relay 2, whose fourth terminal is connected to main relay 3, whose fifth terminal is connected to current detection resistor 7, whose sixth terminal is connected to second switch 8, whose seventh terminal is connected between standby relay 2 and main relay 3 through the first voltage acquisition probe 10, and whose eighth terminal is connected between main relay 3 and charge and discharge port 5 through the 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, main relay 3, standby relay 2, current detection resistor 7, and voltage acquisition probe will form a complete relay adhesion detection and control circuit. When both the main relay 3 and the standby relay 2 are in the closed state, the charge and discharge port 5 of the lithium battery system starts to charge and discharge.

[0038] As can be understood by those skilled in the art, the first terminal 12 of the battery management system BMS9 is connected to battery 1 for collecting the temperature of the battery cells, and its purpose is to monitor the working temperature of the battery to 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 standby relay 2, main relay 3, first switch 6, and second switch 8). The second terminal 13 of the battery management system BMS9 is connected to battery 1 for collecting the voltage of the battery cells, and its purpose is to determine whether the battery state is overvoltage or undervoltage, to avoid damaging the battery or the load due to abnormal voltage during the charge and discharge process of the battery, combined with the relay adhesion detection logic: if a voltage difference (V1 - V2 ≤ 1V) and current (I R > 0A) are still detected after the main relay is disconnected, the adhesion fault can be confirmed.

[0039] Further, as can be understood by those skilled in the art, the first switch 6 can be set as a manual switch. When the battery temperature / voltage is abnormal or the main relay fails, it can cooperate with the standby relay 2 and the main relay 3 in the positive circuit to realize the on / off of the charge and discharge circuit, and the circuit can be manually disconnected when necessary. The second switch 8 can be set as a manual switch and / or controlled to be turned on and off by the battery management system BMS9. Multiple switches can improve the reliability of disconnecting the battery negative electrode, avoid single-point failure (such as switch adhesion), and at the same time play a role in isolating the current detection resistor 7. When the first switch 6 and the second switch 8 are disconnected, the current detection resistor 7 can be protected from external short-circuit impact.

[0040] Further, as can be understood by those skilled in the art, by setting a fuse 4 in the circuit, hardware-level protection can be provided when both the battery management system BMS9 and the standby relay 2 and the main relay 3 fail.

[0041] Through multi-parameter collaborative monitoring, the safety of the battery system is further improved in this application, which can ensure 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 this application, the battery management system BMS9 is set to: control the main relay 3 and the standby relay 2 to close, 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 value R of the current detection resistor 7 and the voltage V3 across it in real time, and calculate the current value passing through the current detection resistor 7 based on the resistance value R and the voltage V3 >I R ; instruct the main relay 3 to disconnect, based on the voltage difference and the current value I R Judge whether the main relay 3 is stuck; when the battery management system BMS9 determines that the main relay 3 is stuck, control the standby relay 2 to disconnect the circuit.

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

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

[0045] During the operation of the lithium battery system, the battery management system BMS9 continuously collects the voltage difference and the current value flowing through the current detection resistor 7, and makes a comprehensive judgment through 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 lamp is selected as the alarm device. When the battery management system BMS9 determines that the main relay 3 is stuck, it first alarms through the LED lamp, and then disconnects the circuit by controlling the standby relay 2, thereby playing a protective role.

[0047] Preferably, in some embodiments of the present application, the main relay 3 and the standby relay 2 are respectively controlled by independent control chips, and the control chips are arranged in the battery management system BMS9. As can be understood by those skilled in the art, separate 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 condition for judging whether the main relay 3 is stuck is: the voltage difference ≤ 1V and the current value I R > 0A.

[0049] Specifically, in some embodiments of the present application, when the lithium battery system triggers system protection due to overheating, overvoltage or undervoltage of the lithium battery, the battery management system BMS9 first limits the current value of the lithium battery system to 0 and alarms through the LED lamp. Secondly, the lithium battery system issues a disconnection instruction to the main relay 3, and the main relay 3 disconnects after receiving the disconnection instruction. The current I R through the current detection resistor 7 should be 0A; when the main relay 3 is stuck, the main relay 3 cannot respond to the disconnection instruction of the battery management system BMS9, and the lithium battery system will always be in a conducting state. When the battery management system BMS9 can collect a voltage difference ≤ 1V and a current I R greater than 0A after issuing the disconnection instruction to the main relay 3, it can be determined that the main relay 3 is stuck. In order to prevent the lithium battery system from losing control of charge and discharge, the battery management system BMS9 will alarm through the alarm device and issue a disconnection instruction to the standby relay 2 to ensure that the charge and discharge channels of the lithium battery system are effectively disconnected and ensure 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 set as:

[0051] Judging whether the main relay is stuck includes two-level determination:

[0052] The current I passing through the current detection resistor when preset adhesion occurs R of the warning threshold;

[0053] When the voltage difference ≤ 1V and 0A < I R ≤ the warning threshold, record the number of faults, and attempt to automatically turn on and off the main relay n (n is a positive integer) times to eliminate temporary adhesion;

[0054] If it is still adhered after n times or when the voltage difference ≤ 1V and I R > 5A, immediately control the standby relay to disconnect the circuit.

[0055] Specifically, in some possible embodiments, there may be short pulse currents or slight adhesion (incomplete welding). Directly cutting off the circuit may affect the availability of the battery system. At this time, a two-level determination of the possible adhesion of the main relay 3 can be further performed:

[0056] The warning threshold of the current I passing through the current detection resistor 7 when preset adhesion occurs R For example, this threshold is 5A;

[0057] When the voltage difference ≤ 1V and 0A < I R ≤ 5A, the battery management system BMS9 records the number of faults and attempts n times (which can be preset by those skilled in the art according to needs, and is preset to 3 times here) to automatically turn on and off the main relay 3 to eliminate temporary adhesion;

[0058] If it is still adhered after 3 times or when the voltage difference ≤ 1V and I R > 5A, the battery management system BMS9 immediately controls the standby relay 2 to disconnect the circuit, thereby playing a protective role.

[0059] Specifically, in some embodiments of the present application, to determine whether the main relay 3 is adhered, 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 driving chip of the main relay 3 by the battery management system BMS9 can support high-frequency on and off, such as MOSFET auxiliary control.

[0060] 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 the detection circuit of any one of the above embodiments. The control method includes:

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

[0062] Real-time collect the voltage V1 of the first voltage acquisition probe 10 and the voltage V2 of the second voltage acquisition probe 11, and calculate the voltage difference between V1 and V2;

[0063] Collect the resistance value R of the current-detecting resistor 7 and the voltage V3 across its two ends in real time, and calculate the current value I passing through the current-detecting resistor 7 based on the resistance value R and the voltage V3 R ;

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

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

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

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

[0068] Specifically, in some possible embodiments, there may be short pulse currents or slight adhesions (not completely welded), and directly cutting off the circuit may affect the availability of the battery system. At this time, a two-stage determination of possible adhesion of the main relay 3 can be further performed:

[0069] Preset the warning threshold of the current I passing through the current-detecting resistor 7 when adhesion occurs, for example, the threshold is 5A; R When the voltage difference ≤ 1V and 0A < I

[0070] ≤ 5A, the battery management system BMS9 records the number of faults and attempts to automatically reconnect and disconnect the main relay 3 n times (which can be preset by those skilled in the art as needed, and here it is preset as 3 times) to eliminate temporary adhesion; R If it is still stuck after 3 times or when the voltage difference ≤ 1V and I

[0071] > 5A, the battery management system BMS9 immediately controls the standby relay 2 to disconnect the circuit, so as to play a protective role. R > 5A, the battery management system BMS9 immediately controls the standby relay 2 to disconnect the circuit, so as to play a protective role.

[0072] Preferably, in some embodiments of the present application, it further includes:

[0073] Judging whether the main relay is stuck includes two-stage determination:

[0074] Preset the warning threshold of the current I passing through the current-detecting resistor when adhesion occurs; R ;

[0075] When the voltage difference ≤ 1V and 0A < I RWhen it is less than or equal to the warning threshold, record the number of faults, and attempt to automatically turn the main relay on and off n (n is a positive integer) times to eliminate temporary adhesion;

[0076] If it is still adhered after n attempts or when the voltage difference is less than or equal to 1V and I R > 5A, immediately control the backup relay to disconnect the circuit.

[0077] Specifically, in some possible embodiments, there may be short pulse currents or slight adhesion (not fully welded). Directly cutting off the circuit may affect the availability of the battery system. At this time, a two-level determination can be further performed on the possible adhesion of the main relay 3:

[0078] Preset the warning threshold of the current I R passing through the current detection resistor 7 when adhesion occurs. For example, this threshold is 5A;

[0079] When the voltage difference is less than or equal to 1V and 0A < I R ≤ 5A, the battery management system BMS9 records the number of faults and attempts n times (which can be preset by those skilled in the art according to needs, and is preset to 3 times here) to automatically turn the main relay 3 on and off to eliminate temporary adhesion;

[0080] If it is still adhered after 3 attempts or when the voltage difference is less than or equal to 1V and I R > 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 overheating, overvoltage, undervoltage, etc. of the lithium battery, the battery management system BMS9 first limits the current value of the lithium battery system to 0 and gives an alarm through the LED light. Secondly, the lithium battery system will issue a disconnection command to the main relay 3. After receiving the disconnection command, the main relay 3 disconnects, and the current passing through the current detection resistor 7 should be 0A; when the main relay 3 is adhered, 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 conducting state. When the battery management system BMS9 can collect a voltage difference less than or equal to 1V and a current much greater than 0A after issuing the disconnection command of the main relay 3, it can be determined that the main relay 3 is adhered. In order to prevent the lithium battery system from losing control of charging and discharging, the battery management system BMS9 will give 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.

[0082] According to another aspect of the present application, the present application also 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] A relay adhesion detection circuit, control method, and storage medium for a battery system of the present application have a relatively simple structure. Mainly, the battery management system (BMS) judges whether the relay is adhered by collecting the control instruction of the relay and the voltage difference and current value of the circuit. Then, by adding a standby relay, the adhered circuit is controlled, reducing the circuit complexity and cost. When the BMS detects that the main relay cannot be disconnected due to adhesion, an alarm is given through an LED light, and then the standby relay is controlled to cut off the power supply of the lithium 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 detected in time, avoiding safety accidents caused by the relay being unable to be normally disconnected or closed due to adhesion. With the standby relay cutting off the circuit and the LED light alarming, the rapid positioning and handling of faults are realized, increasing the reliability of the relay.

[0084] The preferred embodiments of the present application have been described above. It should be understood that the present application is not limited to the above specific implementation manners. The equipment and structures not described in detail should be understood to be implemented in a common manner in the art; any person skilled in the art can make many possible changes and modifications to the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes, without departing from the scope of the technical solution of the present application. This does not affect the essence of the present application. Therefore, any simple modification, equivalent change, and modification made to the above embodiments according to the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of protection of the technical solution of the present application.

Claims

1. Battery system relay adhesion detection circuit, characterized in that, including, Positive circuit: The battery positive electrode, standby relay, main relay, fuse, and charging and discharging port positive electrode are connected in series in sequence; Negative circuit: The battery negative electrode, first switch, current detection resistor, second switch, and charging and discharging port negative electrode are connected in series in sequence; It further includes a battery management system BMS. Its first end is connected to the battery for collecting the cell temperature, its second end is connected to the battery for collecting the cell voltage, its third end is connected to the standby relay, its fourth end is connected to the main relay, its fifth end is connected to the current detection resistor, its sixth end is connected to the second switch, its seventh end is connected between the standby relay and the main relay through a first voltage acquisition probe, and its eighth end is connected between the main relay and the charging and discharging port through a second voltage acquisition probe; The battery management system BMS is set to: Control the main relay and standby relay to close, Real-time collect the voltage V1 of the first voltage acquisition probe and the voltage V2 of the second voltage acquisition probe, and calculate the voltage difference between V1 and V2; Collect the resistance value R of the current-detecting resistor and the voltage V3 across its two ends in real time, and calculate the current value I passing through the current-detecting resistor based on the resistance value R and the voltage V3 R ; The main relay described in the instruction is disconnected, based on the voltage difference and the current value I R Determine whether the main relay is stuck When the battery management system BMS determines that the main relay is stuck, control the standby relay to disconnect the circuit.

2. The detection circuit according to claim 1, wherein 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, wherein The main relay and standby relay are respectively controlled by independent control chips.

4. The detection circuit according to claim 1, characterized in that, Based on the voltage difference and the current value I R The condition for determining whether the main relay is stuck is as follows: The voltage difference ≤ 1V and the current I R > 0A.

5. The detection circuit according to any one of claims 1 or 4, wherein The battery management system BMS is set to: The determination of whether the main relay is stuck includes two-level determination: The current I passing through the current detection resistor when the preset adhesion occurs R The warning threshold value; When the voltage difference ≤ 1V and 0A < I R ≤ the warning threshold, record the number of faults, and attempt to automatically turn the main relay on and off n times to eliminate temporary adhesion, where n is a positive integer; If it still adheres after n times or when the voltage difference ≤ 1V and I R > 5A, immediately control the standby relay to disconnect the circuit.

6. Control method for a battery system relay adhesion detection circuit, characterized in that, Including the detection circuit according to any one of claims 1-5, the control method includes: Control the main relay and standby relay to close, Collect the voltage V1 of the first voltage acquisition probe and the voltage V2 of the second voltage acquisition probe in real time, and calculate the voltage difference between V1 and V2; collect the resistance value R of the current detection resistor and the voltage V3 across its two ends in real time, and calculate the current value I passing through the current detection resistor based on the resistance value R and the voltage V3 R ; Disconnect the main relay as instructed, based on the voltage difference and the current value I R Determine whether the main relay is stuck; after the battery management system (BMS) determines that the main relay is stuck, control the standby relay to disconnect the circuit.

7. The control method according to claim 6, wherein It further includes: When the battery management system BMS determines that the main relay is stuck, the alarm device is activated.

8. The control method according to claim 6, characterized in that, It further includes: Based on the voltage difference and the current value I R The condition for determining whether the main relay is stuck is as follows: The voltage differential ≤ 1V and the current I R > 0A.

9. The control method according to any one of claims 6 or 8, characterized in that, It further includes: The determination of whether the main relay is stuck includes two-level determination: The current I passing through the current detection resistor when preset adhesion occurs R of the warning threshold value; When the voltage difference ≤ 1V and 0A < I R ≤ the warning threshold, record the number of faults, and attempt to automatically switch the main relay on and off n times to eliminate temporary adhesion, where n is a positive integer; If it still adheres after n times or when the voltage difference ≤ 1V and I R > 5A, immediately control the standby relay to disconnect the circuit.

10. A computer-readable storage medium having computer instructions stored thereon, characterized in that, When the computer instruction is executed by the processor, it implements the control method according to any one of claims 6-9.

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