Relay sticking detection method, device, battery management system, and battery apparatus

Abstract

The application relates to a relay sticking detection method and device, a battery management system and a battery equipment. When a first relay and a second relay are triggered to be turned off, and the switching actions of a first insulation detection circuit and a second insulation detection circuit are controlled, if it is detected that a sampling voltage suddenly changes following the switching actions, it is considered that the second relay is actually turned off. If it is detected that the sampling voltage does not suddenly change following the switching actions, the detection result of whether the second relay sticks is determined by further combining the sampling voltage and a preset voltage range. According to the above scheme, the sampling voltage suddenly changes and jumps out of the preset voltage range when the second relay does not stick, by controlling the switching actions of the first insulation detection circuit and the second insulation detection circuit. The phenomenon that the second relay sticks is falsely reported due to the fact that the equivalent capacitance of a load connected to a load end of the relay is not completely discharged, and the discharge voltage is obtained by the second sampling circuit voltage division.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a relay adhesion detection method, apparatus, battery management system, and battery device. Background Technology

[0002] With the rapid development of new energy technologies, secondary batteries, represented by lithium batteries, are gradually being applied to various fields such as energy storage systems, electric vehicles, and aerospace, bringing great convenience to people's daily production and life. The Battery Management System (BMS) is a core component for monitoring, protecting, and managing batteries. Relays, as key actuators in the BMS, directly affect the safe operation of the load due to their reliable switching.

[0003] However, in related technologies, when performing continuity testing on relays in battery management systems, the phenomenon of misjudging sticking can easily occur. Summary of the Invention

[0004] Therefore, it is necessary to provide a relay sticking detection method, device, battery management system, and battery equipment to alleviate the phenomenon of misjudging sticking during relay continuity detection and improve the accuracy of relay sticking identification.

[0005] In a first aspect, this application provides a method for detecting relay sticking, the method comprising: when a first relay and a second relay are triggered and turned off, controlling the switching action of a first insulation detection circuit and a second insulation detection circuit, and maintaining the conduction of a second sampling circuit; wherein, the battery terminal of the first relay is connected to the first insulation detection circuit and a battery, the battery terminal of the second relay is connected to the second insulation detection circuit and the battery, the first insulation detection circuit and the second insulation detection circuit are grounded, the load terminal of the first relay is connected to the first pole of a reference source through the first sampling circuit, the load terminal of the second relay is connected to the first pole of the reference source through the second sampling circuit, the battery terminal of the first relay is also connected to the first pole of the reference source through a third sampling circuit, and the battery terminal of the second relay is also connected to the second pole of the reference source; if the voltage change rate of the sampling voltage of the second sampling circuit exceeds a preset change threshold following the switching action, it is determined that the second relay has not stuck; if the voltage change rate of the sampling voltage does not exceed the preset change threshold following the switching action, the sticking detection result of the second relay is determined based on the sampling voltage and a preset voltage range.

[0006] The aforementioned relay sticking detection method, when the second relay, located between the reference source and the second sampling circuit, is actually turned off, controls the switching actions of the first and second insulation detection circuits while maintaining the second sampling circuit's conduction. This causes the rate of change of the sampling voltage in the second sampling circuit to exceed a preset threshold, i.e., a sudden change occurs, thus jumping out of the preset voltage range. Therefore, when the first and second relays are triggered to turn off and the above control method is executed, if a sudden change in the sampling voltage following the switching action is detected, it is considered that the second relay has actually turned off, i.e., there is no sticking. If a sudden change in the sampling voltage following the switching action is detected, the detection result of whether the second relay has stuck is further determined by combining the sampling voltage and the preset voltage range. The above scheme, by controlling the switching actions of the first and second insulation detection circuits and maintaining the second sampling circuit's conduction, causes a sudden change in the sampling voltage of the second relay when sticking has not occurred, jumping out of the preset voltage range. This effectively alleviates the problem of false alarms caused by the second sampling circuit obtaining the discharge voltage due to the incomplete discharge of the equivalent capacitance of the load connected to the load terminal of the relay, thus improving the accuracy of relay sticking identification.

[0007] In some embodiments, controlling the switching of the first insulation detection circuit and the second insulation detection circuit to operate and maintaining the second sampling circuit on when the first relay and the second relay are triggered to turn off includes: acquiring preliminary results of relay adhesion detection when the first relay and the second relay are triggered to turn off; and controlling the switching of the first insulation detection circuit and the second insulation detection circuit to operate and maintaining the second sampling circuit on when the preliminary results include second relay adhesion.

[0008] The above scheme, when the first and second relays are triggered and turned off, firstly performs a preliminary adhesion diagnosis on the first and second relays. If the preliminary result includes adhesion of the second relay, the first insulation detection circuit and the second insulation detection circuit will be switched on and the second sampling circuit will be kept on to verify the preliminary diagnosis result of adhesion of the second relay. This will alleviate the phenomenon of misdiagnosis during the preliminary adhesion diagnosis and improve the accuracy of adhesion diagnosis and detection of the second relay.

[0009] In some embodiments, controlling the switching action of the first insulation detection circuit and the second insulation detection circuit includes: disconnecting the connection between the first insulation detection circuit and the battery terminal of the first relay, and disconnecting the connection between the second insulation detection circuit and the battery terminal of the second relay.

[0010] The above solution, by cutting off the first insulation detection circuit and the second insulation detection circuit, causes the sampling voltage of the second sampling circuit to suddenly increase when the second relay is normally turned off, thereby jumping out of the preset voltage range and reducing the possibility of false alarms and sticking of the second relay. It has the advantages of simple control method and high detection efficiency.

[0011] In some embodiments, the first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch. The second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch.

[0012] The control of the switching action of the first insulation detection circuit and the second insulation detection circuit includes: controlling the first main switch and the second main switch to be turned on, and controlling the first bridge arm circuit to be turned on, while maintaining the second bridge arm off; or, controlling the first main switch and the second main switch to be turned on, and controlling the second bridge arm circuit to be turned on, while maintaining the first bridge arm off.

[0013] In the above scheme, both the first and second insulation detection circuits include a main detection circuit and a bridge arm circuit connected in parallel to maintain the first and second main detection circuits on and control the first bridge arm circuit to turn off, so that the sampling voltage of the second sampling circuit suddenly becomes negative and jumps out of the preset voltage range; or control the second bridge arm circuit to turn off, so that the sampling voltage of the second sampling circuit suddenly becomes positive and jumps out of the preset voltage range, thereby reducing the false alarm and sticking of the second relay and having the advantage of high recognition of sampling voltage change.

[0014] In some embodiments, the first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch. The second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch.

[0015] The control of the switching action of the first insulation detection circuit and the second insulation detection circuit includes: maintaining the first main switch, the second main switch and the second sampling circuit on when the first sampling circuit is off, and controlling the switching action of the first bridge arm circuit and the second bridge arm circuit.

[0016] The above scheme can also, while keeping the first main switch, the second main switch, and the second sampling circuit on while turning off the first sampling circuit, control the switching action of the first bridge arm circuit and the second bridge arm circuit to cause the sampling voltage of the second sampling circuit to suddenly jump out of the preset voltage range, thereby reducing the false alarm and sticking of the second relay and having high accuracy in detecting sudden sampling voltage changes.

[0017] In some embodiments, controlling the switching action of the first bridge arm circuit and the second bridge arm circuit includes: controlling the first bridge arm circuit to be turned on and maintaining the second bridge arm circuit to be turned off; or, controlling the second bridge arm circuit to be turned on and maintaining the first bridge arm circuit to be turned off.

[0018] The above scheme can specifically achieve the sampling voltage change control of the second sampling circuit by controlling the first bridge arm circuit to conduct or the second bridge arm circuit to conduct. It has the advantages of simple change control method and high control efficiency.

[0019] In some embodiments, controlling the switching action of the first bridge arm circuit and the second bridge arm circuit includes: controlling the first bridge arm circuit to be on for a set duration, turning off the first bridge arm circuit and controlling the second bridge arm circuit to be on; or, controlling the second bridge arm circuit to be on for a set duration, turning off the second bridge arm circuit and controlling the first bridge arm circuit to be on.

[0020] The above scheme can also change the conduction mode of the first bridge arm circuit and the second bridge arm circuit to make the sampling voltage of the second sampling circuit change abruptly, so that the sampling voltage can change abruptly from two directions, thereby improving the recognition of the sampling voltage change.

[0021] In some embodiments, controlling the switching actions of the first bridge arm circuit and the second bridge arm circuit includes: controlling the first bridge arm circuit to operate on and off periodically while maintaining the second bridge arm circuit off; or, controlling the second bridge arm circuit to operate on and off periodically while maintaining the first bridge arm circuit off.

[0022] The above scheme, by periodically controlling the on / off state of the first or second bridge arm circuit, causes periodic abrupt changes in the sampling voltage, which can also improve the recognition accuracy of the abrupt changes in the sampling voltage.

[0023] In some embodiments, the first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch. The second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch.

[0024] The control of the switching action of the first insulation detection circuit and the second insulation detection circuit includes: controlling the first main switch and the first bridge arm circuit to be turned on, and turning off the second main switch and the second bridge arm circuit; or, controlling the second main switch and the second bridge arm circuit to be turned on, and turning off the first main switch and the first bridge arm circuit.

[0025] In the above scheme, the first insulation detection circuit and the second insulation detection circuit can be controlled independently. By controlling all switches in one of the insulation detection circuits to be turned on, the sampling voltage of the second sampling circuit can be made to suddenly change to positive or negative voltage, which has high switch control reliability.

[0026] In some embodiments, determining the adhesion detection result of the second relay based on the sampling voltage and the preset voltage range includes: determining that the second relay has adhered if the preset adhesion condition is met based on the sampling voltage and the preset voltage range; and determining that the second relay has not adhered if the preset adhesion condition is not met based on the sampling voltage and the preset voltage range.

[0027] The above scheme is configured with preset adhesion conditions for adhesion detection. By combining the sampling voltage and the preset voltage range to analyze whether the preset adhesion conditions are met, the adhesion diagnosis of the second relay is realized. It has the advantages of high diagnostic efficiency and accurate diagnostic results.

[0028] In some embodiments, the method further includes: determining that the preset adhesion condition is met when the sampling voltage is within the preset voltage range for a first duration of a first preset duration.

[0029] The above scheme uses the sampling voltage remaining within a preset voltage range for a first preset duration as a preset adhesion condition to analyze whether the relay has stuck, which has high adhesion judgment efficiency.

[0030] In some embodiments, the method further includes: acquiring a first voltage to ground of the first insulation detection circuit and a second voltage to ground of the second insulation detection circuit; determining a voltage ratio between the first voltage to ground and the second voltage to ground; and determining that the preset adhesion condition is met when the sampling voltage is within the preset voltage range for a first duration of a first preset duration, and the voltage ratio is less than the preset ratio for a second duration within a preset interval of the first duration of a first duration of a first preset duration of a first preset duration of a second ...

[0031] The above scheme also combines the first ground voltage of the first insulation detection circuit set between the battery terminal of the first relay and the battery, and the second ground voltage of the second insulation detection circuit set between the battery terminal of the second relay and the battery, to comprehensively analyze whether the preset adhesion conditions are met, and has extremely high accuracy in adhesion judgment.

[0032] This application also provides a relay adhesion detection device, the device comprising: a switch control component, used to control the switching action of a first insulation detection circuit and a second insulation detection circuit, and to maintain the conduction of a second sampling circuit when a first relay and a second relay are triggered and turned off; wherein, the battery terminal of the first relay is connected to the first insulation detection circuit and a battery, the battery terminal of the second relay is connected to the second insulation detection circuit and the battery, the first insulation detection circuit and the second insulation detection circuit are grounded, the load terminal of the first relay is connected to the first pole of a reference source through the first sampling circuit, the load terminal of the second relay is connected to the first pole of the reference source through the second sampling circuit, the battery terminal of the first relay is also connected to the first pole of the reference source through a third sampling circuit, and the battery terminal of the second relay is also connected to the second pole of the reference source; a follow-up verification component, used to determine that the second relay has not adhered when the voltage change rate of the sampling voltage of the second sampling circuit exceeds a preset change threshold following the switching action; and an adhesion detection component, used to determine the adhesion detection result of the second relay based on the sampling voltage and a preset voltage range when the voltage change rate of the sampling voltage does not exceed a preset change threshold following the switching action.

[0033] This application also provides a battery management system, including a reference source, a first relay, a second relay, a first sampling circuit, a second sampling circuit, a third sampling circuit, a first insulation detection circuit, a second insulation detection circuit, and a controller; the two ends of the first sampling circuit are respectively connected to the load terminal of the first relay and the first pole of the reference source, the two ends of the second sampling circuit are respectively connected to the load terminal of the second relay and the first pole of the reference source, the battery terminal of the first relay is also connected to the first pole of the reference source through the third sampling circuit, the battery terminal of the second relay is also connected to the second pole of the reference source, the first insulation detection circuit is connected to the battery and the battery terminal of the first relay, the second insulation detection circuit is connected to the battery and the battery terminal of the second relay, the load terminals of the first relay and the second relay are also connected to an electrical load, and the first insulation detection circuit and the second insulation detection circuit are grounded;

[0034] The first relay, the second relay, the first sampling circuit, the second sampling circuit, the first insulation detection circuit, and the second insulation detection circuit are respectively connected to the controller, and the controller is used to execute the steps of the above-described relay adhesion detection method.

[0035] This application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described relay adhesion detection method.

[0036] This application also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described relay adhesion detection method.

[0037] This application also provides a battery device, including a battery and the aforementioned battery management system. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 This is a schematic diagram of the BJB structure of the battery management system in some embodiments of this application;

[0040] Figure 2 This is a schematic flowchart of the relay adhesion detection method in some embodiments of this application;

[0041] Figure 3This is a schematic diagram of the equivalent circuit of the BJB topology in some embodiments of this application;

[0042] Figure 4 This is a schematic flowchart of a relay adhesion detection method in some other embodiments of this application;

[0043] Figure 5 This is a schematic diagram of the sampled voltage waveform in some embodiments of this application;

[0044] Figure 6 This is a schematic diagram of the BJB topology equivalent circuit in some other embodiments of this application;

[0045] Figure 7 This is a schematic diagram of the BJB topology equivalent circuit in some embodiments of this application;

[0046] Figure 8 This is a schematic diagram of the sampling voltage waveform in some other embodiments of this application;

[0047] Figure 9 This is a schematic diagram of the relay adhesion detection device in some embodiments of this application. Detailed Implementation

[0048] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0049] 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0050] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0051] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0052] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0053] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0054] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0055] Currently, judging from market trends, battery applications are becoming increasingly widespread. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. As the application areas of batteries continue to expand, the market demand is also constantly increasing.

[0056] In scenarios such as electric vehicles, the battery voltage platform is relatively high (e.g., 400V, 800V). Voltage leakage can lead to electric shock and other accidents, seriously endangering user safety. In the battery management system, relays are key actuators, and their reliable switching directly affects the high-voltage safety of the entire vehicle. Relay sticking refers to the phenomenon where contacts cannot separate properly due to arc erosion, mechanical jamming, or other reasons. Relay sticking is a major factor contributing to voltage leakage.

[0057] Therefore, in scenarios such as power-on (high voltage up) and power-off (high voltage down) of battery management systems, it is often necessary to detect relay sticking in order to maintain the relay in a non-sticky operating state. However, current relay sticking diagnosis solutions are prone to false alarms of sticking.

[0058] exist Figure 1In the high-voltage sampling architecture of the BJB (Battery Junction Box) of the battery management system shown, the relay that causes false alarms is often the second relay K2, which is the relay set between the reference source S and the second sampling circuit 12.

[0059] Taking electric vehicles as an example, in-depth research revealed that after the vehicle is subjected to high voltage, the equivalent capacitance of the load (i.e., Cx in the diagram) is not fully discharged (usually leaving a residual voltage of 30 volts). When the battery management system is activated and high voltage is applied again, the first sampling circuit 11 and the second sampling circuit 12 are simultaneously closed for adhesion diagnosis. This causes the first sampling circuit 11 and the second sampling circuit 12 to each obtain a portion of the residual voltage (if their resistances are the same, they each divide the residual voltage by half), and this voltage will gradually decrease. Since the second sampling circuit 12 is connected in parallel across the reference source S, even if the second relay K2 is turned off, the sampling voltage of the second sampling circuit 12 will still be within the preset voltage range (usually located near the voltage of the reference source S). Finally, after diagnostic analysis, the system outputs a diagnosis result that the second relay K2 is stuck, causing the second relay K2 to falsely report that it is stuck.

[0060] To alleviate the above phenomenon and reduce the occurrence of false alarms about sticking in the second relay K2, the sampling voltage of the second sampling circuit 12 can be adjusted so that when the second relay K2 is not sticking, the sampling voltage changes abruptly, avoiding the preset voltage range of sticking detection, thus reducing the possibility of false alarms about sticking and enabling sticking diagnosis.

[0061] Based on the above considerations, this application provides a relay sticking detection method. When the second relay, located between the reference source and the second sampling circuit, is actually turned off, by controlling the switching actions of the first and second insulation detection circuits while maintaining the second sampling circuit's conduction, the rate of change of the sampling voltage in the second sampling circuit exceeds a preset threshold, i.e., the sampling voltage undergoes a sudden change, thus jumping out of the preset voltage range. Therefore, when the first and second relays are triggered to turn off, and the above control method is executed, if a sudden change in the sampling voltage following the switching action is detected, it is considered that the second relay has actually turned off, i.e., there is no sticking. If a sudden change in the sampling voltage following the switching action is detected, the detection result of whether the second relay has stuck is further determined by combining the sampling voltage and the preset voltage range.

[0062] The above scheme, by controlling the switching actions of the first and second insulation detection circuits and maintaining the conduction of the second sampling circuit, causes a sudden change in the sampling voltage when the second relay is not stuck, causing it to jump out of the preset voltage range. This effectively mitigates the phenomenon where the equivalent capacitance of the load connected to the relay's load end is not fully discharged, resulting in the second sampling circuit receiving a voltage drop and falsely reporting that the second relay is stuck, thus improving the accuracy of relay sticking detection.

[0063] The relay adhesion detection method of the embodiment of this application is applied to... Figure 1 The BJB high-voltage sampling architecture of the battery management system is shown. The BJB high-voltage sampling architecture includes a reference source S, a first relay K1, a second relay K2, a first sampling circuit 11, a second sampling circuit 12, a third sampling circuit 13, a first insulation detection circuit 14, a second insulation detection circuit 15, and a controller (not shown). The first sampling circuit 11 is located between the load terminal of the first relay K1 and the first pole of the reference source S, that is, the two ends of the first sampling circuit 11 are respectively connected to the load terminal of the first relay K1 and the first pole of the reference source S; the second sampling circuit 12 is located between the load terminal of the second relay K2 and the first pole of the reference source S, that is, the two ends of the second sampling circuit 12 are respectively connected to the load terminal of the second relay K2 and the first pole of the reference source S.

[0064] The battery terminal of the first relay K1 is also connected to the first pole of the reference source S through the third sampling circuit 13. The battery terminal of the second relay K2 is also connected to the second pole of the reference source S. The first terminal of the first insulation detection circuit 14 is connected to the first pole of the battery and the battery terminal of the first relay K1. The first terminal of the second insulation detection circuit 15 is connected to the second pole of the battery and the battery terminal of the second relay K2. The load terminals of the first relay K1 and the second relay K2 are also connected to the electrical load. The second terminals of the first insulation detection circuit 14 and the second terminals of the second insulation detection circuit 15 are grounded. The first relay K1, the second relay K2, the first sampling circuit 11 (through the ADC1 port in the figure), the second sampling circuit 12 (through the ADC2 port in the figure), the third sampling circuit 13 (through the ADC3 port in the figure), the first insulation detection circuit 14 (through the ADC4 port in the figure), and the second insulation detection circuit 15 (through the ADC5 port in the figure) are respectively connected to the controller.

[0065] Furthermore, for ease of understanding, in the BJB high-voltage sampling architecture, the remaining components or circuits between the first insulation detection circuit 14 and the first terminal of the battery can be equivalently represented as resistor Rp1 and capacitor Cp1; the remaining components or circuits between the second insulation detection circuit 15 and the second terminal of the battery can be equivalently represented as resistor Rn1 and capacitor Cn1. The load connected to this BJB architecture can be equivalently represented as load capacitance Cx and equivalent impedance Rx. The remaining components or circuits between the load terminal of the first relay K1 and the load can be equivalently represented as resistor Rp2 and capacitor Cp2; the remaining components or circuits between the load terminal of the second relay K2 and the load can be equivalently represented as resistor Rn2 and capacitor Cn2, ultimately yielding... Figure 1 The equivalent architecture diagram is shown below. In the diagram, Battery+ represents the first terminal of the battery, Battery- represents the second terminal of the battery, and Link+ and Link- are ports used to connect the load; U2 represents the sampling voltage of the first sampling circuit 11, U7 represents the sampling voltage of the second sampling circuit 12, Up1 represents the first voltage to ground, and Un1 represents the second voltage to ground.

[0066] It is understood that the battery management system of this application can be applied to electric vehicles such as electric cars, electric motorcycles, and electric bicycles, as well as to energy storage power systems, aerospace and other fields. There are no specific limitations. In order to facilitate the understanding of the technical solution of this application, the following explanation will take the application of the battery management system to electric vehicles as an example.

[0067] It should be noted that the types of the first relay K1 and the second relay K2 are not unique. In one embodiment, the first relay K1 can be a main positive relay, and the second relay K2 can be a main negative relay. Correspondingly, the first terminal of the battery is positive, and the second terminal is negative, thus enabling adhesion detection of the main negative relay. In another embodiment, the first relay K1 can be a main negative relay, and the second relay K2 can be a main positive relay. Correspondingly, the first terminal of the battery is negative, and the second terminal is positive, thus enabling adhesion detection of the main positive relay. For ease of understanding of the technical solution of this application, the following embodiments can all be considered as the first relay K1 being a main positive relay and the second relay K2 being a main negative relay.

[0068] Please see Figure 2 In one aspect, this application provides a method for detecting relay adhesion, including steps 202, 204 and 206.

[0069] Step 202: When the first relay and the second relay are triggered and turned off, control the switching action of the first insulation detection circuit and the second insulation detection circuit, and maintain the conduction of the second sampling circuit.

[0070] Specifically, the BJB structure of the battery management system is as follows: Figure 1 As shown, the details will not be repeated below. In some embodiments, the battery terminal of the first relay K1 is connected to the first terminal of the first insulation detection circuit 14 and the first pole of the battery, the battery terminal of the second relay K2 is connected to the first terminal of the second insulation detection circuit 15 and the second pole of the battery, the second terminal of the first insulation detection circuit 14 and the second terminal of the second insulation detection circuit 15 are grounded, the load terminal of the first relay K1 is connected to the first pole of the reference source S through the first sampling circuit 11, the load terminal of the second relay K2 is connected to the first pole of the reference source S through the second sampling circuit 12, the battery terminal of the first relay K1 is also connected to the first pole of the reference source S through the third sampling circuit 13, and the battery terminal of the second relay K2 is also connected to the second pole of the reference source S.

[0071] The battery end refers to the end of the relay that is electricalally closer to the battery, while the load end refers to the end of the relay that is electricalally closer to the load. The first and second relays triggering shutdown means that the first and second relays receive a shutdown command from the controller and, under the action of the shutdown command, control the contacts to disconnect. Relay sticking refers to the phenomenon where contacts cannot separate normally due to reasons such as arc erosion or mechanical jamming. Therefore, sticking diagnosis usually needs to be performed when the relays are triggered to shut down.

[0072] The first insulation detection circuit 14 is located between the first terminal of the battery and ground, and is used to detect the insulation performance of the first terminal of the battery to ground; the second insulation detection circuit 15 is located between the second terminal of the battery and ground, and is used to detect the insulation performance of the second terminal of the battery to ground.

[0073] The first sampling circuit 11 is located between the load terminal of the first relay K1 and the first terminal of the reference source S, and is used to sample the voltage between the load terminal of the first relay K1 and the reference source S. The second sampling circuit 12 is located between the load terminal of the second relay K2 and the first terminal of the reference source S, and is used to sample the voltage between the load terminal of the second relay K2 and the reference source S. The third sampling circuit 13 is located between the battery terminal of the first relay K1 and the first terminal of the reference source S, and is used to sample the voltage between the battery terminal of the first relay K1 and the reference source S.

[0074] The reference source S, also known as the reference voltage source, is a component used to provide a stable and accurate voltage output. It is used to calibrate and compare other voltage signals to maintain the stable operation of the BJB architecture. It is understood that the voltage value of the reference source S is not unique; it can be selected based on actual needs. In a more detailed embodiment, the reference source S is a voltage source providing 5V.

[0075] It should be noted that the structures of the first sampling circuit 11, the second sampling circuit 12, and the third sampling circuit 13 are not unique. In one embodiment, a voltage divider circuit can be used to build the above sampling circuits. Specifically, in practical scenarios, the first sampling circuit 11 and the second sampling circuit 12 need to be controlled for switching on and off depending on the actual needs. Therefore, the structures of the first sampling circuit 11 and the second sampling circuit 12 are similar, both including two resistors connected in series and a switching device. That is, the first sampling circuit 11 includes a first resistor R1, a first switching device S1, and a second resistor R2 connected in series, and the second sampling circuit 12 includes a third resistor R3, a second switching device S2, and a fourth resistor R4 connected in series. The third sampling circuit 13 needs to maintain a conducting state, so the third sampling circuit 13 does not need to be configured with a switching device. It may include a fifth resistor R5 and a sixth resistor R6 connected in series.

[0076] It is understood that the types of the first and second switching devices mentioned above are not unique; they can be the same or different. In one embodiment, transistors, field-effect transistors, or insulated-gate bipolar transistors can be used as switching devices, and no specific limitation is made.

[0077] For further reference Figure 1 The second sampling circuit 12 is connected in parallel across the reference source S. If the second relay K2 is stuck or not turned off, the second sampling circuit 12 will be connected in parallel across the reference source S, and the sampling voltage will be basically the same as the voltage of the reference source S. If the second relay K2 has been actually turned off, but there is residual voltage in the equivalent capacitance of the load, the first sampling circuit 11 and the second sampling circuit 12 will divide the voltage to obtain a certain amount of residual voltage, which will gradually decrease as the equivalent capacitance discharges, making the sampling voltage close to the voltage of the reference source S. However, the sticking detection of the second relay K2 is based on setting a preset voltage range for the voltage of the reference source S. When there is residual voltage in the equivalent capacitance of the load, it is easy to falsely report that the second relay K2 is stuck.

[0078] The solution in this embodiment is to control the switching action of the first insulation detection circuit 14 and the second insulation detection circuit 15 so that when the second relay K2 is turned off, the sampling voltage changes abruptly. Even if the voltage of the equivalent capacitance of the load is divided by the sampling circuit, the sampling voltage will not remain within the preset voltage range, thereby reducing the occurrence of false adhesion.

[0079] In practical scenarios, controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15 can specifically involve controlling the first insulation detection circuit 14 to be on or off, and controlling the second insulation detection circuit 15 to be on or off; alternatively, it can involve controlling the bridge arm circuit in the first insulation detection circuit 14 to be on or off, and controlling the bridge arm circuit in the second insulation detection circuit 15 to be on or off. There are no specific limitations; as long as controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15 causes a sudden change in the sampling voltage of the second sampling circuit 12 when the second relay K2 is actually off, any action is acceptable.

[0080] Step 204: If the rate of change of the sampling voltage of the second sampling circuit exceeds a preset change threshold following the switch action, it is determined that the second relay has not stuck.

[0081] Specifically, the voltage change rate is the change in the sampled voltage when the first sampling circuit 11 is switched on (denoted as the real-time sampled voltage) relative to the sampled voltage when the first sampling circuit 11 is not switched on (denoted as the initial sampled voltage). It exceeds a preset change threshold, meaning it is greater than or equal to the preset change threshold. The preset change threshold is a pre-set threshold that the voltage change rate can reach when the second relay K2 is actually turned off. The size of the preset change threshold is not unique and is not limited here; it can be configured according to the actual scenario. For example, in one embodiment, the preset change threshold can be configured to 60%, and in another embodiment, it can be configured to be greater than 60% or less than 60%, without specific limitations.

[0082] In a more detailed embodiment, the absolute value of the difference between the real-time sampled voltage and the initial sampled voltage can be divided by the initial sampled voltage to obtain the voltage change rate.

[0083] It is understood that, in one embodiment, after the first sampling circuit 11 is switched on, the sampling voltage of the second sampling circuit 12 is collected in real time. Each time a sampling voltage is collected, it can be calculated with the sampling voltage when the first sampling circuit 11 is not switched on to obtain the voltage change rate.

[0084] If the second relay K2 does not stick, then with both the first sampling circuit 11 and the second sampling circuit 12 conducting, the current flow direction of the equivalent architecture can be found in [reference needed]. Figure 3 At this time, the current flow through the second sampling circuit 12 is as shown in I1 in the figure. Even if the voltage is divided to the equivalent capacitance of the load, the sampling voltage of the second sampling circuit 12 will not be too high because the residual voltage is usually not too high (generally around 30 volts).

[0085] When the first insulation detection circuit 14 and the second insulation detection circuit 15 are switched on, the first voltage to ground Up1 of the first insulation detection circuit 14 or the second voltage to ground Un1 of the second insulation detection circuit 15 will be changed, thereby affecting the voltage division of the second sampling circuit 12 and causing a sudden change in the sampling voltage of the second sampling circuit 12 (that is, the rate of change of the sampling voltage exceeds the preset change threshold).

[0086] If the second relay K2 becomes stuck, then there will be a line from the second sampling circuit 12 to the second relay K2 to the second pole of the reference source S. At this time, even if the first insulation detection circuit 14 and the second insulation detection circuit 15 are switched on, there will be no sudden change in the sampling voltage.

[0087] Therefore, if the controller detects a sudden change in the sampling voltage following the switch action, it can be assumed that the second relay K2 has not stuck at this time.

[0088] Step 206: If the rate of change of the sampled voltage does not exceed the preset change threshold following the switch action, determine the adhesion detection result of the second relay based on the sampled voltage and the preset voltage range.

[0089] Specifically, the preset voltage range refers to the pre-set voltage threshold range that can be reached between the load terminal of the second relay K2 and the first pole of the reference source S when the second relay K2 is stuck. When the sampling voltage changes abruptly following the switch action, the controller will directly determine that the second relay K2 is not stuck. However, when the sampling voltage does not change abruptly following the switch action, the controller needs to combine the sampling voltage under the current state with the preset voltage range to output the final sticking detection result.

[0090] The above-described relay sticking detection method, when the second relay K2, located between the reference source S and the second sampling circuit 12, is actually turned off, controls the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, while maintaining the second sampling circuit 12 in operation. This causes a sudden change in the sampling voltage of the second sampling circuit 12, thus causing it to jump out of the preset voltage range. Therefore, when the first and second relays are triggered to turn off, and the above control method is executed, if a sudden change in the sampling voltage following the switching action is detected, it is considered that the second relay K2 has actually turned off, i.e., there is no sticking. If a sudden change in the sampling voltage following the switching action is detected, the detection result of whether the second relay K2 has stuck is further determined by combining the sampling voltage and the preset voltage range. The above scheme, by controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, and maintaining the second sampling circuit 12 in operation, causes a sudden change in the sampling voltage of the second relay K2 when it has not stuck, causing it to jump out of the preset voltage range. This effectively alleviates the problem of false alarms caused by the second sampling circuit 12 obtaining a discharge voltage due to the incomplete discharge of the equivalent capacitance of the load connected to the load terminal of the relay, thus improving the accuracy of relay sticking identification.

[0091] Please see Figure 4 In some embodiments, step 202 includes steps 402 and 404.

[0092] Step 402: When the first and second relays are triggered and turned off, obtain the preliminary results of the relay adhesion detection.

[0093] Step 404: If the preliminary results include the second relay sticking, control the switching action of the first insulation detection circuit and the second insulation detection circuit, and maintain the second sampling circuit on.

[0094] Specifically, in this embodiment, when the first relay and the second relay are triggered and turned off, the first relay K1 and the second relay K2 can be preliminarily diagnosed. Since in actual scenarios, the misjudgment of adhesion often occurs in the second relay K2, the preliminary detection result of adhesion of the first relay K1 can be directly used as the adhesion detection result of the first relay K1.

[0095] As for the second relay K2, since it is located between the second sampling circuit 12 and the reference source S, in the event of adhesion, the second sampling circuit 12 is connected in parallel between the first and second terminals of the reference source S, and its sampling voltage will be the same as or substantially the same as the voltage of the reference source S. Referring to reference 5, where the horizontal axis represents time and the vertical axis represents voltage, if, during the initial diagnostic process, there is residual voltage in the equivalent capacitance of the load, and the voltage obtained by the voltage division of the second sampling circuit 12 is the same as or substantially the same as the voltage of the reference source S, even if the second relay K2 is not actually adhered, this voltage state will be considered to be caused by the adhesion of the second relay K2, i.e., a false alarm of adhesion will occur.

[0096] Therefore, after performing a preliminary adhesion diagnosis on the first relay K1 and the second relay K2 and obtaining a preliminary result that the second relay K2 is stuck, it cannot be directly concluded that the second relay K2 is stuck. Instead, in conjunction with the scheme of the embodiment of this application, the first sampling circuit 11 is controlled to switch and the second sampling circuit 12 is kept on, and then a second adhesion diagnosis is performed using the sampling voltage of the second sampling circuit 12 and a preset voltage range. The result of the second adhesion diagnosis is used as the adhesion diagnosis result of the second relay K2.

[0097] In the above scheme, when the first relay and the second relay are triggered and turned off, a preliminary adhesion diagnosis is first performed on the first relay K1 and the second relay K2. If the preliminary result includes adhesion of the second relay K2, the switching action of the first insulation detection circuit 14 and the second insulation detection circuit 15 will be executed, and the action of the second sampling circuit 12 will be maintained to verify the preliminary diagnosis result of adhesion of the second relay K2, thereby alleviating the phenomenon of misdiagnosis during the preliminary adhesion diagnosis and improving the accuracy of adhesion diagnosis and detection of the second relay K2.

[0098] It should be noted that the above-mentioned method for preliminary adhesion diagnosis of relays is not the only one. In one embodiment, both the first sampling circuit 11 and the second sampling circuit 12 can be turned on. By acquiring the sampling voltage of the first sampling circuit 11 and the sampling circuit of the second sampling circuit 12, and combining them with the pre-set adhesion diagnosis logic, a preliminary result can be obtained.

[0099] Specifically, in one embodiment, for the first relay K1, whether it is stuck can be determined by detecting the magnitude of the sampled voltage. If the first relay K1 is stuck, a path will be formed between the first sampling circuit 11 and the third sampling circuit 13 through the first relay K1, which is equivalent to the first sampling circuit 11 and the third sampling circuit 13 being connected in parallel. Under this BJB architecture, the sum of the sampling voltage of the third sampling circuit 13 and the voltage of the reference source S is equal to the battery voltage, so the sampled voltage of the first sampling circuit 11 will be relatively large. When the first relay K1 is not stuck, even if there is a voltage divider due to the equivalent capacitance of the load, only a small voltage will be sampled at the first sampling circuit 11 (if there is no voltage divider, this voltage will be zero). Based on this, the sticking detection of the first relay K1 can be realized.

[0100] For the second relay K2, a preset voltage range can be set according to the voltage of the reference source S. Taking a 5V reference source S as an example, a preset voltage range of 3V-7V can be set (other embodiments can also be set to other values, such as 4V-6V, etc.). If the sampling voltage of the second sampling circuit 12 is not detected to be within the preset voltage range, it is considered that the second relay K2 has not stuck; if it is within the preset voltage range, it may be that the second relay K2 is stuck, or it may be that there is voltage division of the equivalent capacitance of the load by the second sampling circuit 12.

[0101] In some embodiments, controlling the switching action of the first insulation detection circuit 14 and the second insulation detection circuit 15 includes: disconnecting the connection between the first insulation detection circuit 14 and the battery terminal of the first relay K1, and disconnecting the connection between the second insulation detection circuit 15 and the battery terminal of the second relay K2.

[0102] Specifically, this embodiment uses the example of the first insulation detection circuit 14 and the second insulation detection circuit 15 having the same voltage dividing capability for explanation. Before disconnecting the first insulation detection circuit 14 and the second insulation detection circuit 15, the first voltage to ground Up1 and the second voltage to ground Un1 are each half of the battery voltage. After disconnecting the first insulation detection circuit 14 and the second insulation detection circuit 15, the equivalent circuit diagram can be found in the reference diagram. Figure 6 Considering the overall topology, the equivalent impedance at both ends of the branch corresponding to the second ground voltage Un1 will decrease, resulting in a smaller voltage division of the second ground voltage Un1. This will cause the sampling voltage of the second sampling circuit 12 to suddenly increase, exceeding the preset voltage range, thereby reducing the possibility of false alarms and sticking.

[0103] The above scheme, by cutting off the first insulation detection circuit 14 and the second insulation detection circuit 15, causes the sampling voltage of the second sampling circuit 12 to suddenly increase when the second relay K2 is normally turned off, thereby jumping out of the preset voltage range and reducing the possibility of false alarms and sticking of the second relay K2. It has the advantages of simple control method and high detection efficiency.

[0104] In some embodiments, reference may be made to Figure 1 The first insulation detection circuit 14 includes a first main switch S01, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch S01. The second insulation detection circuit 15 includes a second main switch S02, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch S02.

[0105] Controlling the switching action of the first insulation detection circuit 14 and the second insulation detection circuit 15 includes: controlling the first main switch S01 and the second main switch S02 to be turned on, and controlling the first bridge arm circuit to be turned on, while maintaining the second bridge arm off; or, controlling the first main switch S01 and the second main switch S02 to be turned on, and controlling the second bridge arm circuit to be turned on, while maintaining the first bridge arm off.

[0106] Specifically, the first insulation detection circuit 14 and the second insulation detection circuit 15 have identical structures and the same voltage dividing capability. That is, the resistance values ​​in their bridge arm circuits are identical, and the resistance values ​​of the two resistors connected in series in the first main detection circuit are also identical. Thus, when their connection methods are identical, their voltage dividing capabilities are also identical. In this embodiment, the first main switch S01 and the second main switch S02 are first turned on, so that both the first and second main detection circuits are connected and running. At this time, their voltage division is consistent. When the first bridge arm circuit is connected and running, the voltage division between the two circuits becomes uneven. At this time, the second voltage to ground Un1 will be raised, ultimately causing the sampling voltage to suddenly become negative, jumping out of the preset voltage range. Conversely, when the second bridge arm circuit is connected and running, the voltage division between the two circuits becomes uneven. At this time, the second voltage to ground Un1 will be lowered, ultimately causing the sampling voltage to suddenly become positive (i.e., the sampling voltage increases), jumping out of the preset voltage range.

[0107] In the above scheme, both the first insulation detection circuit 14 and the second insulation detection circuit 15 include a main detection circuit and a bridge arm circuit connected in parallel to maintain the first main detection circuit and the second main detection circuit on, and control the first bridge arm circuit to turn off so that the sampling voltage of the second sampling circuit 12 suddenly becomes negative and jumps out of the preset voltage range; or control the second bridge arm circuit to turn off so that the sampling voltage of the second sampling circuit 12 suddenly becomes positive and jumps out of the preset voltage range, thereby reducing the false alarm sticking of the second relay K2, and has the advantage of high recognition of sampling voltage change.

[0108] In some embodiments, the first insulation detection circuit 14 includes a first main switch S01, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch S01. The second insulation detection circuit 15 includes a second main switch S02, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch S02.

[0109] Controlling the switching action of the first insulation detection circuit 14 and the second insulation detection circuit 15 includes: maintaining the first main switch S01, the second main switch S02 and the second sampling circuit 12 on when the first sampling circuit 11 is off, and controlling the switching action of the first bridge arm circuit and the second bridge arm circuit.

[0110] Specifically, the structures of the first insulation detection circuit 14 and the second insulation detection circuit 15 are as follows: Figure 1 As shown, based on a similar principle, in this embodiment, turning off the first sampling circuit 11 will cause the current flowing in the second sampling circuit to reverse, that is, as... Figure 7 The I2 direction shown is the same as... Figure 3 The direction of I1 shown is opposite, and correspondingly, the sampling voltage is negative at this time.

[0111] Afterwards, the first main switch S01, the second main switch S02, and the second sampling circuit 12 are kept on. By controlling the switching action of the first bridge arm circuit and the second bridge arm circuit, the voltage division of the second ground voltage Un1 will be changed, thereby causing the sampling voltage of the second sampling circuit 12 to change abruptly (such as changing to positive voltage), and finally jump out of the preset voltage range, reducing the possibility of false adhesion.

[0112] The above scheme can also, while keeping the first main switch S01, the second main switch S02 and the second sampling circuit 12 on while turning off the first sampling circuit 11, control the switching action of the first bridge arm circuit and the second bridge arm circuit to make the sampling voltage of the second sampling circuit 12 jump out of the preset voltage range, thereby reducing the false alarm sticking of the second relay K2 and having high accuracy in detecting sampling voltage jumps.

[0113] In some embodiments, controlling the switching action of the first bridge arm circuit and the second bridge arm circuit includes: controlling the first bridge arm circuit to be turned on and maintaining the second bridge arm circuit to be turned off; or, controlling the second bridge arm circuit to be turned on and maintaining the first bridge arm circuit to be turned off.

[0114] Specifically, when the first sampling circuit 11 is off, and the first main switch S01, the second main switch S02, and the second sampling circuit 12 are kept on, and the first bridge arm circuit is controlled to be on, the voltage flowing through the second sampling circuit 12 is negative, and the second voltage to ground Un1 is raised, ultimately causing the sampling voltage to change further from a negative voltage (e.g., becoming a larger negative voltage). Conversely, when the second bridge arm circuit is on, the second voltage to ground Un1 is pulled low, causing the sampling voltage to jump from negative to positive.

[0115] The controller, through the aforementioned control method, causes sudden changes in the sampling voltage of varying degrees and types, thereby identifying whether the second relay K2 is stuck. Conversely, if the second relay K2 is stuck, no sudden change will occur. In this case, the sticking status of the second relay K2 can be identified by combining the actual sampled voltage and the preset voltage range.

[0116] The above scheme can specifically achieve the sampling voltage change control of the second sampling circuit 12 by controlling the first bridge arm circuit to be turned on or the second bridge arm circuit to be turned on. It has the advantages of simple change control method and high control efficiency.

[0117] In some embodiments, controlling the switching action of the first bridge arm circuit and the second bridge arm circuit includes: controlling the first bridge arm circuit to be on for a set duration, turning off the first bridge arm circuit and controlling the second bridge arm circuit to be on; or controlling the second bridge arm circuit to be on for a set duration, turning off the second bridge arm circuit and controlling the first bridge arm circuit to be on.

[0118] Specifically, unlike the above embodiment where the first sampling circuit 11 is turned off while the first main switch S01, the second main switch S02, and the second sampling circuit 12 are kept on, and one of the bridge arm circuits is directly turned off, the solution in this embodiment can also control the first bridge arm circuit and the second bridge arm circuit to be turned on once in sequence while the first sampling circuit 11 is turned off and the first main switch S01, the second main switch S02, and the second sampling circuit 12 are kept on, so that the sampling voltage undergoes sudden changes in two directions in sequence.

[0119] For example, if the first bridge arm circuit is turned on for a set duration, the sampling voltage will first be negative and then suddenly become even more negative. After that, the first bridge arm circuit is turned off and the second bridge arm circuit is turned on, the sampling voltage will suddenly change towards positive. That is, two sudden changes will occur in sequence.

[0120] It is understandable that the set duration is not unique and should be configured according to actual needs. The only requirement is that the sampling voltage change within the set duration can be recognized by the controller, and there is no specific limitation.

[0121] The above scheme can also change the conduction mode of the first bridge arm circuit and the second bridge arm circuit to make the sampling voltage of the second sampling circuit 12 change abruptly, so that the sampling voltage can change abruptly from two directions, thereby improving the recognition of the sampling voltage change.

[0122] In some embodiments, controlling the switching action of the first bridge arm circuit and the second bridge arm circuit includes: controlling the first bridge arm circuit to operate on and off periodically to maintain the second bridge arm circuit off; or, controlling the second bridge arm circuit to operate on and off periodically to maintain the first bridge arm circuit off.

[0123] Specifically, unlike the scheme in the above embodiment where the first sampling circuit 11 is turned off and the first main switch S01, the second main switch S02, and the second sampling circuit 12 are kept on, the scheme in this embodiment can control one of the bridge arm circuits to be turned off periodically, so that the sudden change in the sampling voltage occurs periodically.

[0124] For example, in one embodiment, when the first bridge arm circuit is controlled to periodically switch on and off, the sampled voltage will periodically abruptly change to a larger negative voltage within the negative voltage range.

[0125] It is understood that the above-mentioned periodic on / off control method is not the only one. In one embodiment, periodic on / off control can be achieved by inputting a pulse width modulation signal to the control terminal of the switching device of the bridge arm circuit.

[0126] The above scheme, by periodically controlling the on / off state of the first or second bridge arm circuit, causes periodic abrupt changes in the sampling voltage, which can also improve the recognition accuracy of the abrupt changes in the sampling voltage.

[0127] In some embodiments, the first insulation detection circuit 14 includes a first main switch S01, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch S01. The second insulation detection circuit 15 includes a second main switch S02, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch S02.

[0128] Controlling the switching action of the first insulation detection circuit 14 and the second insulation detection circuit 15 includes: controlling the first main switch S01 and the first bridge arm circuit to be turned on, and turning off the second main switch S02 and the second bridge arm circuit; or, controlling the second main switch S02 and the second bridge arm circuit to be turned on, and turning off the first main switch S01 and the first bridge arm circuit.

[0129] Specifically, unlike the control scheme in the above embodiment where both the first main switch S01 and the second main switch S02 operate simultaneously (e.g., simultaneously turn off or simultaneously turn on), in this embodiment, the first main switch S01 and the second main switch S02 can be independently controlled to turn on and off under different control signals.

[0130] Therefore, a sudden change in the sampling voltage can be caused by controlling any one of the insulation detection circuits to be fully connected and running (that is, both the main detection circuit and the bridge arm circuit are connected and conducting).

[0131] Specifically, when the first main switch S01 and the first bridge arm circuit are turned on, and the second main switch S02 and the second bridge arm circuit are turned off, the second voltage to ground Un1 will be raised due to the uneven voltage division of the first insulation detection circuit 14 and the second insulation detection circuit 15, causing the sampling voltage to suddenly become negative.

[0132] When the first main switch S01 and the first bridge arm circuit are turned off, and the second main switch S02 and the second bridge arm circuit are turned on, the uneven voltage division of the first insulation detection circuit 14 and the second insulation detection circuit 15 will cause the second voltage to ground Un1 to be pulled down, ultimately causing the sampling voltage to suddenly become a larger positive voltage, jumping out of the preset voltage range.

[0133] In the above scheme, the first insulation detection circuit 14 and the second insulation detection circuit 15 can be controlled independently. By controlling all switches in one of the insulation detection circuits to be turned on, the sampling voltage of the second sampling circuit 12 can be made to suddenly change to positive or negative voltage, which has high switch control reliability.

[0134] In some embodiments, determining the adhesion detection result of the second relay K2 based on the sampling voltage and a preset voltage range includes: determining that the second relay K2 has adhered if the preset adhesion condition is met based on the sampling voltage and the preset voltage range; and determining that the second relay K2 has not adhered if the preset adhesion condition is not met based on the sampling voltage and the preset voltage range.

[0135] Specifically, the preset adhesion condition refers to a pre-set condition that the sampling voltage of the second sampling circuit 12 must meet between itself and a preset voltage range when the second relay K2 becomes stuck. The controller stores the preset adhesion condition. After controlling the switching action of the first insulation detection circuit 14 and the second insulation detection circuit 15 to obtain the sampling voltage of the second sampling circuit 12, it compares and analyzes the voltage with the preset voltage range to determine whether the preset adhesion condition is met. The result of this determination determines whether the second relay K2 has become stuck.

[0136] The above scheme is configured with preset adhesion conditions for adhesion detection. By combining the sampling voltage and the preset voltage range to analyze whether the preset adhesion conditions are met, the adhesion diagnosis of the second relay K2 is realized. It has the advantages of high diagnostic efficiency and accurate diagnostic results.

[0137] In some embodiments, the method further includes: determining that a preset adhesion condition is met when the sampling voltage is within a preset voltage range for a first duration of a first preset duration.

[0138] Specifically, in this embodiment, the preset voltage range is determined by the voltage of the reference source S. The range is not unique; it simply needs to include the voltage of the reference source S, with an upper limit greater than the voltage of the reference source S and a lower limit less than the voltage of the reference source S. For example, in one embodiment, the preset voltage range can be set to 3V-7V as in the previous embodiment; in other embodiments, it can be 4V-6V, 3.5V-6.5V, etc., without specific limitations.

[0139] The first duration is the duration for which the sampled voltage remains within a preset voltage range. The value of the first preset duration is not unique and can be configured according to the specific scenario and requirements. For example, in one embodiment, the first preset duration can be set to 1000ms (milliseconds). In another embodiment, it can be configured to other values, such as any value within the range of 500ms-1500ms; no specific limitation is imposed.

[0140] The controller acquires the sampled voltage from the second sampling circuit 12 and compares it with a preset voltage range. If the sampled voltage is within the preset voltage range, timing begins. If the sampled voltage remains within the preset voltage range after the timing reaches a first preset duration, the preset adhesion condition is considered to be met.

[0141] The above scheme uses the condition that the sampling voltage remains within a preset voltage range for a first preset duration as a preset adhesion condition to analyze whether the relay has stuck, which has a high efficiency in adhesion judgment.

[0142] Furthermore, in another embodiment, the preset adhesion condition can be considered met if the sampled voltage is detected to be within a preset voltage range; no specific limitation is made.

[0143] In some embodiments, the method further includes: acquiring a first voltage to ground of the first insulation detection circuit 14 and a second voltage to ground of the second insulation detection circuit 15; determining a voltage ratio between the first voltage to ground and the second voltage to ground; and determining that a preset adhesion condition is met when the sampling voltage is within a preset voltage range for a first duration of a first preset duration, and the voltage ratio is less than a preset ratio for a second duration within a preset interval of the first duration of a first duration of a first preset duration of a second ...

[0144] Specifically, the first voltage to ground is the voltage between the first insulation detection circuit 14 and ground; the first voltage to ground is the voltage between the second insulation detection circuit 15 and ground. The second duration refers to the duration during which the voltage ratio remains less than a preset ratio.

[0145] In practical scenarios, you can refer to the following: Figure 1 If a unilateral insulation fault occurs in the BJB, it will cause a significant difference in the voltage distribution between the first pair-to-ground voltage Up1 and the second pair-to-ground voltage Un1, resulting in a large proportional difference in the voltage ratio Up1 / Un1. Specifically, if an insulation fault occurs between the second insulation detection circuit 15 and the second terminal of the battery, the resistance value of resistor Rn1 will be less than the set value (e.g., 5 kΩ), causing the second pair-to-ground voltage Un1 to tend towards 0. In this case, the sampling voltage of the second sampling circuit 12 is also likely to approach the preset voltage range, thus triggering a false alarm and sticking.

[0146] Therefore, in this embodiment, under the condition that the sampling voltage is within the preset voltage range for a first duration of the first preset duration, it is still necessary to further analyze the voltage ratio of the first voltage to ground and the second voltage to ground, and consider the impact of unilateral insulation fault on adhesion diagnosis.

[0147] Finally, the preset adhesion condition is considered met only if, within a certain range of the first duration of the sampled voltage within the preset voltage range, there exists a voltage ratio less than the preset ratio, and the duration of this state reaches the second preset duration.

[0148] It is understood that the setting of the preset interval is not unique; it can be set in conjunction with the first preset duration, selecting any segment of the first preset duration as the preset interval. For example, in one embodiment, the first preset duration is set to 1000ms, and correspondingly, the interval between 350ms and 500ms of the first preset duration can be used as the preset interval.

[0149] At the start of the preset interval, the voltage ratio is compared with a preset ratio. If the voltage ratio is less than the preset ratio, timing is started. Finally, if the timing reaches the second preset duration within the preset interval, and the sampling voltage is within the first preset voltage range for the first duration, the preset adhesion condition is considered to be met.

[0150] It should be noted that the preset ratio and the second preset duration are not unique. The second preset duration must be set to be less than the length of the set interval, and the preset ratio is determined in conjunction with the set insulation fault boundary resistance value. For example, in a more detailed embodiment, the set interval is 350ms-500ms, and the length of the set interval is 150ms. In this case, the second preset duration can be set to 100ms.

[0151] For further reference Figure 1 In a more detailed embodiment, the first main detection circuit includes resistors R7 and R8 connected in series, the first bridge arm circuit includes a third switching device S3 connected in series and resistor R9, the second main detection circuit includes resistors R10 and R11 connected in series, and the second bridge arm circuit includes a fourth switching device S4 connected in series and resistor R12. Accordingly, Up / Un = (R7 + R8) / ((R10 + R11) / / Rn1). In a more detailed embodiment, the insulation fault boundary resistance is set to 5 kΩ, and the above formula yields a preset ratio of 379.

[0152] The above scheme also combines the first ground voltage of the first insulation detection circuit 14 set between the battery terminal of the first relay K1 and the battery, and the second ground voltage of the second insulation detection circuit 15 set between the battery terminal of the second relay K2 and the battery to comprehensively analyze whether the preset adhesion conditions are met, which has extremely high accuracy in adhesion judgment.

[0153] To facilitate understanding of the technical solution of this application, the following detailed embodiments will be used to explain and illustrate this application.

[0154] The BJB architecture of the battery management system is as follows Figure 1As shown, when the vehicle is under high voltage, the first relay K1 and the second relay K2 are turned off, allowing the equivalent impedance of the load to discharge the voltage stored in the equivalent capacitance of the load. When the BMS wakes up and applies high voltage again, the first sampling circuit 11 and the second sampling circuit 12 are both closed, maintaining the first insulation detection circuit 14 and the second insulation detection circuit 15 in operation, performing preliminary adhesion diagnosis on the first relay K1 and the second relay K2, and obtaining preliminary results.

[0155] If the second relay K2 is not actually stuck, but because the second sampling circuit 12 obtains the residual voltage of the load capacitor through voltage division, the sampling voltage waveform of the second sampling circuit 12 is as follows: Figure 5 As shown, at this time, a false alarm of sticking may occur because the sampling voltage is within the preset voltage range. Therefore, if the preliminary results include the second relay K2 sticking, the controller keeps the first main switch S01 of the first insulation detection circuit 14 on and the second main switch S02 of the second insulation detection circuit 15 on, and controls the first bridge arm circuit of the first insulation detection circuit 14 to be on, while keeping the second bridge arm circuit of the second insulation detection circuit 15 off.

[0156] If the second relay K2 is not actually stuck, the above actions will cause the equivalent insulation resistance of the battery's first terminal to ground to decrease because the resistance of the first bridge arm circuit is incorporated into the first insulation detection circuit 14. This will lead to a redistribution of voltage between the first insulation detection circuit 14 and the second insulation detection circuit 15. According to the equivalent circuit diagram, the branch corresponding to the second voltage to ground (i.e., the branch where Rn1 and Cn1 are connected in parallel) will form a parallel relationship with the series structure of Rp2, Rsp (the total equivalent resistance of the first sampling circuit 11), and the reference source S, resulting in an increase in the sampling voltage U2 of the first sampling circuit 11. Furthermore, due to the large equivalent capacitance of the load, the voltage cannot change abruptly, ultimately resulting in a negative voltage change at the second sampling circuit 12, causing the sampling voltage to jump out of the preset voltage range. For details, please refer to [reference needed]. Figure 8 The horizontal axis represents time, and the vertical axis represents voltage.

[0157] Therefore, if the sampling voltage changes abruptly from positive to negative following the above action, the output will indicate that the second relay K2 has not stuck (meaning the initial result is inaccurate at this point). If the sampling voltage does not change abruptly following the above action, further analysis will be performed by combining the sampling voltage with the preset voltage range.

[0158] If the analyzed sampling voltage is within the preset voltage range of 3V-7V, and the first duration reaches 350ms, the controller collects the first voltage to ground and the second voltage to ground, calculates the voltage ratio, and compares it with a preset ratio (e.g., 379). If the voltage ratio is less than the preset ratio, timing begins. Finally, if the first duration is within the preset range of 350ms-500ms, the second duration where the voltage ratio is less than the preset ratio reaches the second preset duration (e.g., 100ms), and the first duration reaches the first preset duration (e.g., 1000ms), then the second relay K2 is considered to have stuck. Otherwise, the second relay K2 is considered not to have stuck.

[0159] It is understood that in the embodiments of this application, the structures of the first insulation detection circuit 14 and the second insulation detection circuit 15 are identical, and the resistance values ​​of the two circuits at the same position are also identical, so that when the connection methods of the first insulation detection circuit 14 and the second insulation detection circuit 15 are identical, the same voltage division effect can be achieved.

[0160] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0161] Based on the same inventive concept, this application also provides a relay adhesion detection device for implementing the relay adhesion detection method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the relay adhesion detection device provided below can be found in the limitations of the relay adhesion detection method described above, and will not be repeated here.

[0162] Please see Figure 9 This application also provides a relay adhesion detection device, which includes a switch control component 702, a follow-up verification component 704, and an adhesion detection component 706.

[0163] The switch control component 702 is used to control the switching action of the first insulation detection circuit and the second insulation detection circuit when the first relay and the second relay are triggered and turned off, and to maintain the conduction of the second sampling circuit; the follow-up verification component 704 is used to determine that the second relay has not stuck when the voltage change rate of the sampling voltage of the second sampling circuit exceeds a preset change threshold following the switch action; the sticking detection component 706 is used to determine the sticking detection result of the second relay based on the sampling voltage and the preset voltage range when the voltage change rate of the sampling voltage does not exceed a preset change threshold following the switch action.

[0164] In some embodiments, the switch control component 702 is further configured to acquire preliminary results of relay sticking detection when the first relay and the second relay are triggered to turn off; and if the preliminary results include second relay sticking, control the switching action of the first insulation detection circuit and the second insulation detection circuit, and maintain the second sampling circuit on.

[0165] In some embodiments, the switch control component 702 is further configured to disconnect the connection between the first insulation detection circuit and the battery terminal of the first relay, and to disconnect the connection between the second insulation detection circuit and the battery terminal of the second relay.

[0166] In some embodiments, the switch control component 702 is further configured to control the first main switch and the second main switch to be turned on, and control the first bridge arm circuit to be turned on, while maintaining the second bridge arm off; or, control the first main switch and the second main switch to be turned on, and control the second bridge arm circuit to be turned on, while maintaining the first bridge arm off.

[0167] In some embodiments, the switch control component 702 is further configured to maintain the first main switch, the second main switch, and the second sampling circuit on when the first sampling circuit is off, and control the switching action of the first bridge arm circuit and the second bridge arm circuit.

[0168] In some embodiments, the switch control component 702 is further configured to control the first bridge arm circuit to be turned on and maintain the second bridge arm circuit to be turned off; or, control the second bridge arm circuit to be turned on and maintain the first bridge arm circuit to be turned off.

[0169] In some embodiments, the switch control component 702 is further configured to, when controlling the first bridge arm circuit to conduct for a set duration, turn off the first bridge arm circuit and control the second bridge arm circuit to conduct; or, when controlling the second bridge arm circuit to conduct for a set duration, turn off the second bridge arm circuit and control the first bridge arm circuit to conduct.

[0170] In some embodiments, the switch control component 702 is further configured to control the periodic switching operation of the first bridge arm circuit to maintain the second bridge arm circuit off; or, to control the periodic switching operation of the second bridge arm circuit to maintain the first bridge arm circuit off.

[0171] In some embodiments, the switch control component 702 is further configured to control the first main switch and the first bridge arm circuit to be turned on, and to turn off the second main switch and the second bridge arm circuit; or, to control the second main switch and the second bridge arm circuit to be turned on, and to turn off the first main switch and the first bridge arm circuit.

[0172] In some embodiments, the adhesion detection component 706 is further configured to determine that the second relay has adhered if a preset adhesion condition is met based on the sampling voltage and a preset voltage range; and to determine that the second relay has not adhered if the preset adhesion condition is not met based on the sampling voltage and the preset voltage range.

[0173] Each component in the aforementioned relay adhesion detection device can be implemented entirely or partially through software, hardware, or a combination thereof. These components can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can invoke and execute the corresponding operations of each component.

[0174] The aforementioned relay adhesion detection device, when the second relay K2, located between the reference source S and the second sampling circuit 12, is actually turned off, controls the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, while maintaining the second sampling circuit 12 in operation. This causes a sudden change in the sampling voltage of the second sampling circuit 12, thus causing it to jump out of the preset voltage range. Therefore, when the first relay K1 and the second relay K2 are triggered to turn off, and the above control method is executed, if a sudden change in the sampling voltage following the switching action is detected, it is considered that the second relay K2 has actually turned off, i.e., there is no adhesion. If a sudden change in the sampling voltage following the switching action is detected, the detection result of whether the second relay K2 has adhered is further determined by combining the sampling voltage and the preset voltage range. The above scheme, by controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, and maintaining the second sampling circuit 12 in operation, causes a sudden change in the sampling voltage of the second relay K2 when it has not adhered, causing it to jump out of the preset voltage range. This effectively alleviates the problem of false alarms caused by the second sampling circuit 12 obtaining a discharge voltage due to the incomplete discharge of the equivalent capacitance of the load connected to the load terminal of the relay, thus improving the accuracy of relay sticking identification.

[0175] Please refer to the following: Figure 1This application also provides a battery management system, including a reference source S, a first relay K1, a second relay K2, a first sampling circuit 11, a second sampling circuit 12, a third sampling circuit 13, a first insulation detection circuit 14, a second insulation detection circuit 15, and a controller; the two ends of the first sampling circuit 11 are respectively connected to the load terminal of the first relay K1 and the first terminal of the reference source S; the two ends of the second sampling circuit 12 are respectively connected to the load terminal of the second relay K2 and the first terminal of the reference source S; the battery terminal of the first relay K1 is also connected to the first terminal of the reference source S through the third sampling circuit 13; and the battery terminal of the second relay K2 is also connected to... The second pole of the reference source S is connected to the first pole of the battery and the battery terminal of the first relay K1 via the first insulation detection circuit 14. The second insulation detection circuit 15 is connected to the second pole of the battery and the battery terminal of the second relay K2. The load terminals of the first relay K1 and the second relay K2 are also connected to the electrical load. The first insulation detection circuit 14 and the second insulation detection circuit 15 are grounded. The first relay K1, the second relay K2, the first sampling circuit 11, the second sampling circuit 12, the first insulation detection circuit 14, and the second insulation detection circuit 15 are respectively connected to the controller. The controller is used to execute the steps of the above-mentioned relay adhesion detection method.

[0176] Specifically, the implementation of the relay adhesion detection method is as shown in the above embodiments and accompanying drawings, and will not be repeated here. In some embodiments, the first sampling circuit 11 is disposed between the load terminal of the first relay K1 and the first pole (e.g., positive pole) of the reference source S, the second sampling circuit 12 is disposed between the load terminal of the second relay K2 and the first pole of the reference source S, the battery terminal of the first relay K1 is also connected to the first pole of the reference source S through the third sampling circuit 13, the battery terminal of the second relay K2 is also connected to the second pole (e.g., negative pole) of the reference source S, the first terminal of the first insulation detection circuit 14 is connected to the first pole (e.g., positive pole) of the battery and the battery terminal of the first relay K1, the first terminal of the second insulation detection circuit 15 is connected to the second pole (e.g., negative pole) of the battery and the battery terminal of the second relay K2, the load terminals of the first relay K1 and the second relay K2 are also connected to the electrical load, and the second terminals of the first insulation detection circuit 14 and the second terminals of the second insulation detection circuit 15 are grounded.

[0177] In the aforementioned battery management system, when the second relay K2, located between the reference source S and the second sampling circuit 12, is actually turned off, the sampling voltage of the second sampling circuit 12 will change abruptly by controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, while maintaining the second sampling circuit 12 in operation. This causes the voltage to jump out of the preset voltage range. Therefore, when the first relay K1 and the second relay K2 are triggered to turn off and the above control method is executed, if a sudden change in the sampling voltage following the switching action is detected, it is considered that the second relay K2 has actually turned off, i.e., there is no sticking. If a sudden change in the sampling voltage following the switching action is detected, the detection result of whether the second relay K2 has stuck is further determined by combining the sampling voltage and the preset voltage range. The above scheme, by controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, and maintaining the second sampling circuit 12 in operation, causes a sudden change in the sampling voltage of the second relay K2 when it has not stuck, jumping out of the preset voltage range. This effectively alleviates the problem of false alarms caused by the second sampling circuit 12 obtaining a discharge voltage due to the incomplete discharge of the equivalent capacitance of the load connected to the load terminal of the relay, thus improving the accuracy of relay sticking identification.

[0178] This application also provides a battery device, including a battery and the aforementioned battery management system.

[0179] The structure and implementation of the battery management system are as described in the above embodiments and will not be repeated here. In this battery device, when the second relay K2, located between the reference source S and the second sampling circuit 12, is actually turned off, the sampling voltage of the second sampling circuit 12 is kept on by controlling the operation of the first sampling circuit 11. This causes a sudden change in the sampling voltage of the second sampling circuit 12, thus causing it to jump out of the preset voltage range. Therefore, when the first relay K1 and the second relay K2 are triggered to turn off, and the above control method is executed, if a sudden change in the sampling voltage following the switch action is detected, it is considered that the second relay K2 has actually turned off, i.e., there is no sticking. If a sudden change in the sampling voltage following the switch action is detected, the detection result of whether the second relay K2 has stuck is further determined by combining the sampling voltage and the preset voltage range. The above scheme, by controlling the switch action of the first sampling circuit 11 and keeping the second sampling circuit 12 on, causes a sudden change in the sampling voltage of the second relay K2 when it is not stuck, causing it to jump out of the preset voltage range. This effectively alleviates the problem of false alarms caused by the second sampling circuit 12 obtaining a discharge voltage due to the incomplete discharge of the equivalent capacitance of the load connected to the load terminal of the relay, thus improving the accuracy of relay sticking identification.

[0180] This application also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the following steps of the relay adhesion detection method:

[0181] When the first and second relays are triggered and turned off, the first and second insulation detection circuits are controlled to switch on and off, and the second sampling circuit is kept on. If the rate of change of the sampling voltage of the second sampling circuit exceeds a preset change threshold following the switch action, it is determined that the second relay has not stuck. If the rate of change of the sampling voltage does not exceed the preset change threshold following the switch action, the sticking detection result of the second relay is determined according to the sampling voltage and the preset voltage range.

[0182] This application also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the following relay adhesion detection method:

[0183] When the first and second relays are triggered and turned off, the first and second insulation detection circuits are controlled to switch on and off, and the second sampling circuit is kept on. If the rate of change of the sampling voltage of the second sampling circuit exceeds a preset change threshold following the switch action, it is determined that the second relay has not stuck. If the rate of change of the sampling voltage does not exceed the preset change threshold following the switch action, the sticking detection result of the second relay is determined according to the sampling voltage and the preset voltage range.

[0184] In some embodiments, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0185] When the first and second relays are triggered and turned off, the first and second insulation detection circuits are controlled to switch on and off, and the second sampling circuit is kept on. If the rate of change of the sampling voltage of the second sampling circuit exceeds a preset change threshold following the switch action, it is determined that the second relay has not stuck. If the rate of change of the sampling voltage does not exceed the preset change threshold following the switch action, the sticking detection result of the second relay is determined according to the sampling voltage and the preset voltage range.

[0186] In the aforementioned computer equipment, storage medium, and computer program products, when the second relay K2, located between the reference source S and the second sampling circuit 12, is actually turned off, the sampling voltage of the second sampling circuit 12 will change abruptly by controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, while maintaining the second sampling circuit 12 in operation. This causes the voltage to jump out of the preset voltage range. Therefore, when the first relay K1 and the second relay K2 are triggered to turn off, and the above control method is executed, if a sudden change in the sampling voltage following the switching action is detected, it is considered that the second relay K2 has actually turned off, i.e., there is no sticking. If a sudden change in the sampling voltage following the switching action is detected, the detection result of whether the second relay K2 has stuck is further determined by combining the sampling voltage and the preset voltage range. The above scheme, by controlling the switching actions of the first insulation detection circuit 14 and the second insulation detection circuit 15, and maintaining the second sampling circuit 12 in operation, causes a sudden change in the sampling voltage of the second relay K2 when it has not stuck, jumping out of the preset voltage range. This effectively alleviates the problem of false alarms caused by the second sampling circuit 12 obtaining a discharge voltage due to the incomplete discharge of the equivalent capacitance of the load connected to the load terminal of the relay, thus improving the accuracy of relay sticking identification.

[0187] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for detecting relay adhesion, characterized in that, The method includes: When the first and second relays are triggered and turned off, the switching action of the first and second insulation detection circuits is controlled, and the second sampling circuit is kept on. Specifically, the battery terminal of the first relay is connected to the first terminal of the first insulation detection circuit and the first pole of the battery; the battery terminal of the second relay is connected to the first terminal of the second insulation detection circuit and the second pole of the battery; the second terminals of the first and second insulation detection circuits are grounded; the load terminal of the first relay is connected to the first pole of a reference source through the first sampling circuit; the load terminal of the second relay is connected to the first pole of the reference source through the second sampling circuit; the battery terminal of the first relay is also connected to the first pole of the reference source through a third sampling circuit; and the battery terminal of the second relay is also connected to the second pole of the reference source. If the rate of change of the sampling voltage of the second sampling circuit exceeds a preset threshold following the switching action, it is determined that the second relay has not stuck. If the rate of change of the sampled voltage does not exceed a preset threshold following the switching action, the adhesion detection result of the second relay is determined based on the sampled voltage and the preset voltage range.

2. The relay adhesion detection method according to claim 1, characterized in that, When the first and second relays are deactivated, controlling the switching of the first and second insulation detection circuits and maintaining the second sampling circuit on includes: When the first and second relays are triggered and turned off, obtain preliminary results of relay adhesion detection; If the preliminary results include the second relay sticking, the first insulation detection circuit and the second insulation detection circuit are controlled to switch on and off, and the second sampling circuit is kept on.

3. The relay adhesion detection method according to claim 1, characterized in that, The control of the switching action of the first insulation detection circuit and the second insulation detection circuit includes: Disconnect the first insulation detection circuit from the battery terminal of the first relay, and disconnect the second insulation detection circuit from the battery terminal of the second relay.

4. The relay adhesion detection method according to claim 1, characterized in that, The first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch. The second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch. The control of the switching action of the first insulation detection circuit and the second insulation detection circuit includes: Control the first main switch and the second main switch to be turned on, and control the first bridge arm circuit to be turned on, while keeping the second bridge arm off; Alternatively, control the first main switch and the second main switch to be turned on, and control the second bridge arm circuit to be turned on, while keeping the first bridge arm off.

5. The relay adhesion detection method according to claim 1, characterized in that, The first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch. The second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch. The control of the switching action of the first insulation detection circuit and the second insulation detection circuit includes: When the first sampling circuit is turned off, the first main switch, the second main switch, and the second sampling circuit are kept on to control the switching action of the first bridge arm circuit and the second bridge arm circuit.

6. The relay adhesion detection method according to claim 5, characterized in that, The control of the switching actions of the first bridge arm circuit and the second bridge arm circuit includes: Control the first bridge arm circuit to be turned on, and keep the second bridge arm circuit off; Alternatively, control the second bridge arm circuit to be turned on, while keeping the first bridge arm circuit off.

7. The relay adhesion detection method according to claim 5, characterized in that, The control of the switching actions of the first bridge arm circuit and the second bridge arm circuit includes: While controlling the first bridge arm circuit to be on for a set duration, the first bridge arm circuit is turned off, and the second bridge arm circuit is turned on. Alternatively, while controlling the second bridge arm circuit to conduct for a set duration, the second bridge arm circuit can be turned off, and the first bridge arm circuit can be turned on.

8. The relay adhesion detection method according to claim 5, characterized in that, The control of the switching actions of the first bridge arm circuit and the second bridge arm circuit includes: The first bridge arm circuit is controlled to operate on and off periodically, while the second bridge arm circuit remains off. Alternatively, the second bridge arm circuit can be controlled to operate on and off periodically, while the first bridge arm circuit remains off.

9. The relay adhesion detection method according to claim 1, characterized in that, The first insulation detection circuit includes a first main switch, and a first bridge arm circuit and a first main detection circuit connected in parallel. The structure formed by the first bridge arm circuit and the first main detection circuit connected in parallel is connected in series with the first main switch. The second insulation detection circuit includes a second main switch, and a second bridge arm circuit and a second main detection circuit connected in parallel. The structure formed by the second bridge arm circuit and the second main detection circuit connected in parallel is connected in series with the second main switch. The control of the switching action of the first insulation detection circuit and the second insulation detection circuit includes: Control the first main switch and the first bridge arm circuit to be turned on, and turn off the second main switch and the second bridge arm circuit; Alternatively, control the second main switch and the second bridge arm circuit to be turned on, and turn off the first main switch and the first bridge arm circuit.

10. The relay adhesion detection method according to any one of claims 1-9, characterized in that, The step of determining the adhesion detection result of the second relay based on the sampled voltage and the preset voltage range includes: If, based on the sampling voltage and the preset voltage range, the preset adhesion condition is met, it is determined that the second relay has become stuck. If, based on the sampled voltage and the preset voltage range, it is determined that the preset adhesion condition is not met, then it is determined that the second relay has not adhered.

11. The relay adhesion detection method according to claim 10, characterized in that, The method further includes: If the sampling voltage is within the preset voltage range for a first duration that reaches a first preset duration, it is determined that the preset adhesion condition is met.

12. The relay adhesion detection method according to claim 10, characterized in that, The method further includes: Obtain the first voltage to ground of the first insulation detection circuit and the second voltage to ground of the second insulation detection circuit; Determine the voltage ratio between the first voltage to ground and the second voltage to ground; If the sampling voltage is within the preset voltage range for a first duration of a first preset duration, and the voltage ratio is less than the preset ratio for a second duration within a preset interval of the first duration, then the preset adhesion condition is determined to be satisfied.

13. A relay adhesion detection device, characterized in that, The device includes: A switch control component is used to control the switching action of a first insulation detection circuit and a second insulation detection circuit when the first relay and the second relay are triggered and turned off, and to maintain the conduction of a second sampling circuit; wherein, the battery terminal of the first relay is connected to the first terminal of the first insulation detection circuit and the first pole of the battery, the battery terminal of the second relay is connected to the first terminal of the second insulation detection circuit and the second pole of the battery, the second terminals of the first insulation detection circuit and the second insulation detection circuit are grounded, the load terminal of the first relay is connected to the first pole of a reference source through the first sampling circuit, the load terminal of the second relay is connected to the first pole of the reference source through the second sampling circuit, the battery terminal of the first relay is also connected to the first pole of the reference source through a third sampling circuit, and the battery terminal of the second relay is also connected to the second pole of the reference source; A follow-up verification component is used to determine that the second relay has not stuck when the rate of change of the sampled voltage of the second sampling circuit exceeds a preset change threshold following the switching action; An adhesion detection component is used to determine the adhesion detection result of the second relay based on the sampled voltage and a preset voltage range, provided that the voltage change rate of the sampled voltage does not exceed a preset change threshold in accordance with the switching action.

14. A battery management system, characterized in that, It includes a reference source, a first relay, a second relay, a first sampling circuit, a second sampling circuit, a third sampling circuit, a first insulation detection circuit, a second insulation detection circuit, and a controller; The two ends of the first sampling circuit are respectively connected to the load terminal of the first relay and the first pole of the reference source. The two ends of the second sampling circuit are respectively connected to the load terminal of the second relay and the first pole of the reference source. The battery terminal of the first relay is also connected to the first pole of the reference source through the third sampling circuit. The battery terminal of the second relay is also connected to the second pole of the reference source. The first insulation detection circuit is connected to the battery and the battery terminal of the first relay. The second insulation detection circuit is connected to the battery and the battery terminal of the second relay. The load terminals of the first relay and the second relay are also connected to the electrical load. The first insulation detection circuit and the second insulation detection circuit are grounded. The first relay, the second relay, the first sampling circuit, the second sampling circuit, the first insulation detection circuit, and the second insulation detection circuit are respectively connected to the controller, and the controller is used to execute the steps of the relay adhesion detection method according to any one of claims 1 to 12.

15. A battery device, characterized in that, Includes the battery and the battery management system as described in claim 14.

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