High-voltage switch detection method, control module, circuit, system and vehicle

Abstract

The embodiment of the invention provides a detection method of a high-voltage switch, a control module, a circuit, a system and a vehicle, under the condition that the vehicle is in different stages, corresponding operation parameters are provided, the operation parameters can comprise the voltage and / or current of a relay, when the high-voltage switch is abnormal, the operation parameters of a high-voltage loop can be influenced, and the reliability of the high-voltage switch is improved. Therefore, whether the high-voltage switch is abnormal can be determined according to the operating parameters of different stages, and the accuracy of abnormality detection of the high-voltage switch is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and particularly to a detection method, a control module, a circuit, a system and a vehicle for a high-voltage switch. Background Art

[0002] The high-voltage circuit refers to a system composed of multiple high-voltage components such as a power battery, a high-voltage distribution box, and high-voltage electrical equipment (such as a motor and an air-conditioning compressor), which is responsible for transmitting the high-voltage electrical energy stored in the power battery to the high-voltage electrical equipment to meet the power requirements of the vehicle and the operating requirements of various high-voltage electrical equipment.

[0003] Among them, the high-voltage distribution box includes a high-voltage switch, and the high-voltage switch is used to control the on-off of the high-voltage circuit to ensure the safe, stable and efficient operation of the high-voltage circuit. The abnormality of the high-voltage switch will affect the safety, stability and reliability of the high-voltage circuit. Therefore, the detection of the high-voltage switch is particularly important.

[0004] The existing detection method mainly involves recycling the high-voltage distribution box and manually analyzing the abnormality of the high-voltage switch. This method is time-consuming and laborious, and lacks preliminary abnormality positioning when an abnormality occurs, and it is difficult to reproduce the abnormality, which affects the accuracy of abnormality detection. Summary of the Invention

[0005] Embodiments of the present application provide a detection method, a control module, a circuit, a system and a vehicle for a high-voltage switch to improve the accuracy of abnormality detection of the high-voltage switch.

[0006] In a first aspect, embodiments of the present application provide a detection method for a high-voltage switch. The high-voltage switch includes a positive switch and a negative switch. The positive switch includes a main positive relay, a pre-charge relay and a pre-charge resistor, and the negative switch includes a main negative relay. The method includes:

[0007] When the vehicle is in the high-voltage power-on stage, determine whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit;

[0008] When the vehicle is in the high-voltage operation stage, determine whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, and the current of the high-voltage circuit;

[0009] When the vehicle is in the high-voltage power-off stage, determine whether at least one relay in the high-voltage switch is abnormal according to the current of the high-voltage circuit.

[0010] In a possible implementation manner, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive-pole switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage loop includes:

[0011] Determining whether the main positive relay and the pre-charge relay are stuck according to the current of the high-voltage loop.

[0012] In a possible implementation manner, determining whether the main positive relay and the pre-charge relay are stuck according to the current of the high-voltage loop includes:

[0013] After the main negative relay is closed and before the pre-charge relay is closed:

[0014] When the current of the high-voltage loop is greater than or equal to a first preset current and less than the maximum set current, determining that the pre-charge relay is stuck;

[0015] When the current of the high-voltage loop is greater than the maximum set current, determining that the main positive relay is stuck;

[0016] When the current of the high-voltage loop is less than the first preset current, determining that the main positive relay and the pre-charge relay are not stuck.

[0017] In a possible implementation manner, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive-pole switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage loop includes:

[0018] Determining whether the pre-charge relay and the main negative relay are abnormally attracted according to the current of the high-voltage loop and the voltage of the positive-pole switch.

[0019] In a possible implementation manner, determining whether the pre-charge relay and the main negative relay are abnormally attracted according to the current of the high-voltage loop and the voltage of the positive-pole switch includes:

[0020] When receiving the power-on signal of the pre-charge relay:

[0021] Within a first preset time, when the current of the high-voltage loop is greater than or equal to a first preset current and less than the maximum set current, determining that the pre-charge relay and the main negative relay are normally attracted;

[0022] When the current of the high-voltage circuit is less than the first preset current within the first preset time, determine that the pre-charge relay or the main negative relay fails to engage properly according to the voltage of the positive pole switch.

[0023] In a possible implementation manner, the determining that the pre-charge relay or the main negative relay fails to engage properly according to the voltage of the positive pole switch includes:

[0024] When the voltage of the positive pole switch is greater than or equal to the first preset voltage, determine that the pre-charge relay fails to engage properly;

[0025] When the voltage of the positive pole switch is less than the first preset voltage, determine that the main negative relay fails to engage properly.

[0026] In a possible implementation manner, the determining that the pre-charge relay fails to engage properly when the voltage of the positive pole switch is greater than or equal to the first preset voltage includes:

[0027] When the voltage of the positive pole switch is greater than or equal to the first preset voltage, determine that the pre-charge relay has a delayed engagement, fails to engage properly, or has a non-conductive engagement according to the current of the high-voltage circuit after the first preset time.

[0028] In a possible implementation manner, the determining that the pre-charge relay has a delayed engagement, fails to engage properly, or has a non-conductive engagement according to the current of the high-voltage circuit after the first preset time includes:

[0029] When the current of the high-voltage circuit is greater than or equal to the first preset current after the first preset time, determine that the pre-charge relay has a delayed engagement;

[0030] When the current of the high-voltage circuit is less than the first preset current after the first preset time, determine that the pre-charge relay fails to engage properly or has a non-conductive engagement.

[0031] In a possible implementation manner, the determining that the main negative relay fails to engage properly when the voltage of the positive pole switch is less than the first preset voltage includes:

[0032] When the voltage of the positive pole switch is less than the first preset voltage, determine that the main negative relay has a delayed engagement, fails to engage properly, or has a non-conductive engagement according to the current of the high-voltage circuit after the first preset time.

[0033] In a possible implementation manner, the determining that the main negative relay has a delayed engagement, fails to engage properly, or has a non-conductive engagement according to the current of the high-voltage circuit after the first preset time includes:

[0034] After the first preset time, when the current in the high-voltage circuit is greater than or equal to the first preset current, determine the suction delay of the main negative relay;

[0035] After the first preset time, when the current in the high-voltage circuit is less than the first preset current, determine that the main negative relay fails to be correctly suctioned or the suction is not conductive.

[0036] In a possible implementation manner, the determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive electrode switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current in the high-voltage circuit includes:

[0037] Determine whether the resistance value of the pre-charge relay is abnormal according to the voltage of the pre-charge resistor and the voltage of the pre-charge relay;

[0038] And / or, determine whether the resistance value of the main negative relay is abnormal according to the voltage of the pre-charge resistor and the voltage of the main negative relay.

[0039] In a possible implementation manner, the determining whether the resistance value of the pre-charge relay is abnormal according to the voltage of the pre-charge resistor and the voltage of the pre-charge relay includes: after the pre-charge relay is closed and before the pre-charge is completed, when the ratio of the voltage of the pre-charge relay to the voltage of the pre-charge resistor is greater than a first preset ratio, determine that the resistance value of the pre-charge relay is abnormal;

[0040] When the ratio of the voltage of the pre-charge relay to the voltage of the pre-charge resistor is less than or equal to the first preset ratio, determine that the resistance value of the pre-charge relay is normal.

[0041] In a possible implementation manner, the determining whether the resistance value of the main negative relay is abnormal according to the voltage of the pre-charge resistor and the voltage of the main negative relay includes:

[0042] After the pre-charge relay is closed and before the pre-charge is completed, when the ratio of the voltage of the main negative relay to the voltage of the pre-charge resistor is greater than a first preset ratio, determine that the resistance value of the main negative relay is abnormal;

[0043] When the ratio of the voltage of the main negative relay to the voltage of the pre-charge resistor is less than or equal to the first preset ratio, determine that the resistance value of the main negative relay is normal.

[0044] In a possible implementation, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive-pole switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current in the high-voltage circuit includes:

[0045] Determining whether the main positive relay is abnormally engaged according to the current in the high-voltage circuit.

[0046] In a possible implementation, determining whether the main positive relay is abnormally engaged according to the current in the high-voltage circuit includes:

[0047] When the voltage across the capacitor reaches a preset value, the main positive relay is closed, and the pre-charge relay is open, if the current in the high-voltage circuit is less than or equal to a fourth preset current within a third preset time, it is determined that the main positive relay is not correctly engaged or is engaged but not conducting;

[0048] If the current in the high-voltage circuit is greater than the fourth preset current within the third preset time, it is determined that the main positive relay is normally engaged.

[0049] In a possible implementation, the method further includes:

[0050] When it is first determined that the first target relay is stuck, sending a first abnormal signal to the control module so that the control module controls the first target relay to perform a first preset number of engagements and disconnections; the first target relay is the main positive relay or the pre-charge relay;

[0051] When it is determined that the first target relay is stuck during the second preset number of times, sending a first warning message.

[0052] In a possible implementation, the method includes:

[0053] When it is first determined that the resistance value of the second target relay is abnormal, detecting again whether the resistance value of the second target relay is abnormal; the second target relay includes the pre-charge relay and / or the main negative relay;

[0054] When it is determined that the resistance value of the second target relay is abnormal during the third preset number of times, sending a second warning message.

[0055] In a possible implementation, the method further includes:

[0056] When it is first determined that the second target relay has a delayed engagement, detecting again whether the second target relay has a delayed engagement; the second target relay includes the pre-charge relay and / or the main negative relay;

[0057] When it is determined that the second target relay has a suction delay in the third preset number of times, a third warning message is issued.

[0058] In a possible implementation manner, the method further includes:

[0059] When it is first determined that the third target relay fails to correctly suck or the suction is not conductive, a second abnormal signal is sent to the control module, so that the control module controls the third target relay to perform suction and disconnection for a first preset number of times; the third target relay is at least one of the main positive relay, the main negative relay, and the precharge relay;

[0060] When it is determined that the third target relay fails to correctly suck or the suction is not conductive in the third preset number of times, a third warning message is issued.

[0061] In a possible implementation manner, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive electrode switch, the voltage of the main negative relay, and the current in the high-voltage circuit includes:

[0062] Determine whether the resistance value of the main positive relay is abnormal according to the voltage of the positive electrode switch and the current in the high-voltage circuit.

[0063] In a possible implementation manner, determining whether the resistance value of the main positive relay is abnormal according to the voltage of the positive electrode switch and the current in the high-voltage circuit includes:

[0064] When the high-voltage circuit meets the first preset condition, determine the contact resistance of the main positive relay according to the voltage of the positive electrode switch and the current in the high-voltage circuit.

[0065] When the contact resistance of the main positive relay is greater than the first resistance threshold, determine that the resistance value of the main positive relay is abnormal;

[0066] When the contact resistance of the main positive relay is less than or equal to the first resistance threshold, determine that the resistance value of the main positive relay is normal.

[0067] In a possible implementation manner, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive electrode switch, the voltage of the main negative relay, and the current in the high-voltage circuit includes:

[0068] Determine whether the resistance value of the main negative relay is abnormal according to the voltage of the main negative relay and the current in the high-voltage circuit.

[0069] In a possible implementation, determining whether the resistance value of the main negative relay is abnormal according to the voltage of the main negative relay and the current of the high-voltage circuit includes:

[0070] When the high-voltage switch meets the first preset condition, determine the contact resistance of the main negative relay according to the voltage of the main negative relay and the current of the high-voltage circuit;

[0071] When the contact resistance of the main negative relay is greater than the first resistance threshold, determine that the resistance value of the main negative relay is abnormal;

[0072] When the contact resistance of the main negative relay is less than or equal to the first resistance threshold, determine that the resistance value of the main negative relay is normal.

[0073] In a possible implementation, the first preset condition includes at least one of the following:

[0074] The main positive relay and the main negative relay are closed, and the current of the high-voltage circuit is greater than the second preset current;

[0075] An abnormality occurs in the high-voltage circuit.

[0076] In a possible implementation, the first resistance threshold is less than 50 mΩ.

[0077] In a possible implementation, the second preset current is greater than 20 A.

[0078] In a possible implementation, the method further includes:

[0079] When it is first determined that the resistance value of the fourth target relay is abnormal, detect again whether the resistance value of the fourth target relay is abnormal; the fourth target relay includes the main positive relay and / or the main negative relay;

[0080] When it is determined that the resistance value of the fourth target relay is abnormal within the fourth preset number of times, issue a fourth warning message;

[0081] When it is not determined that the resistance value of the fourth target relay is abnormal within the fourth preset number of times, clear the detection times of the abnormal resistance value.

[0082] In a possible implementation, determining whether at least one relay in the high-voltage switch is abnormal according to the current of the high-voltage circuit includes:

[0083] When the current of the high-voltage circuit is greater than the third preset current, determine that one of the main positive relay and the pre-charge relay, and the main negative relay are stuck;

[0084] When the current in the high-voltage circuit is less than or equal to the third preset current, determine that one of the main positive relay and the precharge relay, and the main negative relay do not stick simultaneously.

[0085] In a possible implementation manner, the method further includes:

[0086] Determine the high-voltage power-off time according to the time when the current in the high-voltage circuit is continuously equal to the third preset current for the first time, and the time when the power-off control signal is first given among the main positive relay and the main negative relay;

[0087] Determine whether the relay that first receives the power-off control signal is delayed in disconnection according to the high-voltage power-off time.

[0088] In a possible implementation manner, the determining whether the relay that first receives the power-off control signal is delayed in disconnection according to the high-voltage power-off time includes:

[0089] When the high-voltage power-off time is greater than or equal to the second preset time, determine that the relay that first receives the power-off control signal is delayed in disconnection;

[0090] When the high-voltage power-off time is less than the second preset time, determine that the relay that first receives the power-off control signal is normally disconnected.

[0091] In a possible implementation manner, the second preset time is greater than the release time of the relay.

[0092] In a possible implementation manner, the method further includes:

[0093] When the discharge circuit meets the second preset condition, determine whether the main positive relay and the precharge relay are stuck according to the current in the discharge circuit.

[0094] In a possible implementation manner, the determining whether the main positive relay and the precharge relay are stuck according to the current in the discharge circuit includes:

[0095] When the current in the discharge circuit is greater than the third preset current, determine that the main positive relay or the precharge relay is stuck;

[0096] When the current in the discharge circuit is less than or equal to the third preset current, determine that the main positive relay and the precharge relay are not stuck.

[0097] In a possible implementation manner, the discharge circuit includes a discharge module, and the discharge module is connected between the main positive relay and the main negative relay;

[0098] The second preset condition includes: the discharge module is equivalently grounded, or the main negative relay is closed.

[0099] In a possible implementation manner, it is determined that the main positive relay or the pre-charge relay is stuck;

[0100] Based on the voltage of the positive electrode switch, it is determined that the main positive relay or the pre-charge relay is stuck.

[0101] In a possible implementation manner, the determining that the main positive relay or the pre-charge relay is stuck according to the voltage of the positive electrode switch includes:

[0102] When the voltage of the positive electrode switch is less than the second preset voltage, it is determined that the main positive relay is stuck;

[0103] When the voltage of the positive electrode switch is greater than or equal to the second preset voltage, it is determined that the pre-charge relay is stuck.

[0104] In a possible implementation manner, the second preset voltage is set based on the difference between the power battery voltage and the voltage across the capacitor, the high-voltage discharge speed, and the state detection time.

[0105] In a possible implementation manner, the determining that the main positive relay or the pre-charge relay is stuck includes:

[0106] When the current in the discharge circuit is greater than or equal to the fourth preset current, it is determined that the main positive relay is stuck;

[0107] When the current in the discharge circuit is less than the fourth preset current, it is determined that the pre-charge relay is stuck.

[0108] In a possible implementation manner, the method further includes:

[0109] When it is first determined that the fifth target relay has a disconnection delay, it is detected again whether the fifth target relay has a disconnection delay; the target relay includes the relay that gives the power-off control signal first among the main positive relay and the main negative relay;

[0110] When it is determined that the fifth target relay has a disconnection delay within the fifth preset number of times, a fifth warning message is issued.

[0111] In a possible implementation manner, the method further includes:

[0112] When it is first determined that the sixth target relay is stuck, a third abnormal signal is sent to the control module so that the control module controls the sixth target relay to disconnect; the sixth target relay includes the main positive relay and / or the pre-charge relay;

[0113] When it is determined that the sixth target relay is stuck for the sixth preset number of times, a sixth warning message is issued.

[0114] In a possible implementation, the method further includes:

[0115] When it is determined that the high-voltage switch is abnormal, the operating parameters of the high-voltage circuit are stored, and the operating parameters include at least one of the voltage of the positive electrode switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit.

[0116] In a possible implementation, the method further includes:

[0117] When the vehicle is in the high-voltage power-on stage, at least one of the voltage of the positive electrode switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit is acquired;

[0118] When the vehicle is in the high-voltage operation stage, at least one of the voltage of the positive electrode switch, the voltage of the main negative relay, and the current of the high-voltage circuit is acquired;

[0119] When the vehicle is in the high-voltage power-off stage, the current of the high-voltage switch is acquired.

[0120] In a second aspect, the present application provides a control module, including: a memory, a processor;

[0121] The memory stores computer execution instructions;

[0122] The processor executes the computer execution instructions stored in the memory, so that the processor executes the method described in the first aspect.

[0123] In a third aspect, the present application provides a detection circuit for a high-voltage switch, including:

[0124] A high-voltage switch, a voltage detection module, a current detection module, and the control module described in the second aspect;

[0125] The high-voltage switch includes a positive switch and a negative switch. The first end of the positive switch is connected to the positive electrode of the battery, the second end of the positive switch is connected to the first end of the high-voltage electrical device, the first end of the negative switch is connected to the negative electrode of the battery, and the second end of the positive switch is connected to the second end of the high-voltage electrical device;

[0126] The positive switch includes a main positive relay, a pre-charge relay, and a pre-charge resistor, and the negative switch includes a main negative relay;

[0127] The first end of the main positive relay is connected to the first end of the pre-charge relay as the first end of the positive switch, the second end of the main positive relay is connected to the second end of the pre-charge resistor as the second end of the positive switch, the second end of the pre-charge relay is connected to the second end of the pre-charge resistor, the first end of the main negative relay is used as the first end of the negative switch, and the second end of the main negative relay is used as the second end of the negative switch.

[0128] The voltage detection module is connected to the first end of the main positive relay, the second end of the main positive relay, the second end of the main negative relay, the first end of the main negative relay, the second end of the pre-charge relay, and the control module;

[0129] The current detection module is connected to the second end of the main positive relay, the first end of the high-voltage electrical device, and the control module;

[0130] The voltage detection module is configured to detect at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charge relay, and the voltage of the pre-charge resistor, and send it to the control module;

[0131] The current detection module is configured to detect the current in the high-voltage circuit and send it to the control module;

[0132] The control module is configured to determine whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current in the high-voltage circuit.

[0133] In a possible implementation, the voltage detection module includes a first interface, a second interface, a third interface, a fourth interface, and a fifth interface;

[0134] The first interface is connected to the first end of the main positive relay, and the second interface is connected to the second end of the main positive relay;

[0135] The third interface is connected to the second end of the main negative relay, and the fourth interface is connected to the first end of the main negative relay and grounded;

[0136] The fifth interface is connected to the second end of the pre-charge relay.

[0137] In a possible implementation, it further includes a first switch and a second switch;

[0138] The first end of the first switch is connected to the first interface, and the second end of the first switch is connected to the first end of the main positive relay;

[0139] The first end of the second switch is connected to the fourth interface, and the second end of the second switch is connected to the first end of the main negative relay;

[0140] The first switch is used to control whether the first interface and the first end of the main positive relay are connected;

[0141] The second switch is used to control whether the fourth interface and the first end of the main negative relay are connected.

[0142] In a possible implementation, it further includes a discharge module;

[0143] The first end of the discharge module is connected to the second end of the main positive relay, and the second end of the discharge module is connected to the second end of the main negative relay;

[0144] The discharge module is used to discharge the residual voltage of the high-voltage circuit when the vehicle is in the high-voltage power-off stage.

[0145] In a possible implementation, the discharge module includes a discharge component and a fourth switch;

[0146] The first end of the fourth switch serves as the first end of the discharge module, the second end of the fourth switch is connected to the first end of the discharge component, and the second end of the discharge component serves as the second end of the discharge module.

[0147] Fourthly, the present application provides a high-voltage system, including the detection circuit of the high-voltage switch described in the third aspect, a power battery, and a high-voltage electrical device;

[0148] The detection circuit is connected to the power battery and the high-voltage electrical device.

[0149] Fifthly, the present application provides a vehicle, including the high-voltage system described in the fourth aspect.

[0150] Sixthly, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the first aspect and / or various possible implementation manners of the first aspect as described above.

[0151] In a seventh aspect, an embodiment of the present application provides a computer program product, including a computer program which, when executed by a processor, implements the above first aspect and / or various possible implementation manners of the first aspect.

[0152] The detection method, control module, circuit, system and vehicle of the high-voltage switch provided by the embodiments of the present application have corresponding operating parameters in different stages of the vehicle. The operating parameters may include the voltage and / or current of the relay. When the high-voltage switch is abnormal, the operating parameters of the high-voltage circuit will be affected. Therefore, it is possible to determine whether the high-voltage switch is abnormal according to the operating parameters in different stages, improving the accuracy of abnormal detection of the high-voltage switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0153] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0154] Figure 1 It is a schematic structural diagram of the high-voltage circuit provided by the present application;

[0155] Figure 2 It is a schematic flowchart of the detection method of the high-voltage switch provided by the present application;

[0156] Figure 3 It is a schematic structural diagram of the control device provided by the present application;

[0157] Figure 4 It is a schematic structural diagram of the detection circuit of the high-voltage switch provided by the present application;

[0158] Figure 5 It is a schematic circuit diagram of the detection circuit of the high-voltage switch provided by the present application.

[0159] Through the above drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0160] Here, exemplary embodiments will be described in detail, and examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0161] As Figure 1As shown in the figure, the high-voltage circuit includes a power battery 30, a high-voltage distribution box 10, and high-voltage electrical equipment 20. The high-voltage distribution box 10 includes a high-voltage switch, and the high-voltage switch is used to control the on-off of the high-voltage circuit. If the high-voltage switch malfunctions, it will affect the safety, stability, and reliability of the high-voltage circuit. Due to the lack of operation monitoring data for high-voltage switches (such as components like positive relays, main negative relays, and pre-charge relays), currently, the high-voltage distribution box 10 is mainly recycled, and then the high-voltage switch is manually analyzed for abnormalities. This method is time-consuming and laborious, and there is a lack of preliminary abnormality positioning when the abnormality occurs. Due to the influence of factors such as the environment, conditions, and operation methods during the analysis of the high-voltage switch abnormality, it is difficult to reproduce the abnormality again, affecting the accuracy of the high-voltage switch abnormality detection.

[0162] Therefore, this application proposes a detection method for high-voltage switches. When a high-voltage switch malfunctions, the operating parameters of the high-voltage circuit (at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit) will be affected. Therefore, it is possible to determine whether the high-voltage switch is abnormal based on the operating parameters of the high-voltage circuit, improving the accuracy of the high-voltage switch abnormality detection.

[0163] The following uses specific embodiments to elaborate in detail on the technical solution of this application and how the technical solution of this application solves the above technical problems. These several specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of this application will be described below in conjunction with the accompanying drawings.

[0164] Figure 2 Flow schematic of the detection method for the high-voltage switch provided by this application Figure 1 As Figure 2 shown, this method includes:

[0165] S101. When the vehicle is in the high-voltage power-on stage, determine whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit.

[0166] Among them, the high-voltage power-on stage refers to the stage where the vehicle switches from the off state to the ready-to-run state.

[0167] The high-voltage switch includes a positive switch and a negative switch. The first end of the positive switch is connected to the positive pole of the power battery, the second end of the positive switch is connected to the first end of the high-voltage electrical equipment, the first end of the negative switch is connected to the negative pole of the power battery, and the second end of the negative switch is connected to the second end of the high-voltage electrical equipment. The positive switch and the negative switch are used to control the on-off of the high-voltage circuit, thereby controlling whether to supply power to the high-voltage electrical equipment.

[0168] The positive pole switch may include a main positive relay, a pre-charge relay, and a pre-charge resistor; the first end of the main positive relay is connected to the first end of the pre-charge relay and serves as the first end of the positive pole switch; the second end of the main positive relay is connected to the second end of the pre-charge resistor and serves as the second end of the positive pole switch, and the second end of the pre-charge relay is connected to the first end of the pre-charge resistor. The negative pole switch may include a main negative relay, the first end of the main negative relay serves as the first end of the negative pole switch, and the second end of the main negative relay serves as the second end of the negative pole switch.

[0169] In some alternative embodiments, the high-voltage circuit includes a power battery, a high-voltage switch, and high-voltage electrical equipment, and the high-voltage switch is connected to the power battery and the high-voltage electrical equipment.

[0170] Exemplarily, the rated voltage of the power battery may be 350V.

[0171] Exemplarily, the high-voltage electrical equipment may include a drive motor, an electric compressor, a DC-DC converter, an on-vehicle charger, etc.

[0172] The high-voltage circuit may further include a capacitor, the first end of the capacitor is connected to the second end of the positive pole switch, and the second end of the capacitor is connected to the second end of the negative pole switch.

[0173] Correspondingly, when the vehicle is in the high-voltage power-on stage, the pre-charge relay and the main negative relay are closed, and the main positive relay is open to charge the capacitor. When the voltage across the capacitor reaches a preset value of the battery voltage, the main positive relay is closed and the pre-charge relay is open, and the vehicle is ready to enter the high-voltage operation stage. The preset value may be any value within, for example, 90% - 95%.

[0174] Exemplarily, the initial contact resistance of the main positive relay, the main negative relay, and the pre-charge relay may be 0.5 mΩ, and the resistance value of the pre-charge resistor may be 100 Ω.

[0175] Exemplarily, the abnormalities of the relay may include adhesion, suction delay, incorrect suction, non-conduction during suction, etc. Among them, suction delay, incorrect suction, and non-conduction during suction may be referred to as suction abnormalities.

[0176] In some alternative embodiments, according to the current of the high-voltage circuit, it is determined whether the main positive relay and the pre-charge relay are adhered. It can be understood that the adhesion of the main positive relay or the pre-charge relay will affect the current of the high-voltage circuit. For example, when the main positive relay is adhered, the current of the high-voltage circuit will be relatively large, and when the pre-charge relay is adhered, the current of the high-voltage circuit will be relatively small. Therefore, according to the current of the high-voltage circuit during the high-voltage power-on stage, it can be more accurately determined whether the main positive relay and the pre-charge relay are adhered.

[0177] It should be noted that considering that the large current generated by the adhesion of the main positive relay may damage circuit components, the adhesion of the main positive relay can be detected during the high-voltage power-on stage. Further, in order to reduce the impact of the transient large current during the detection of the adhesion of the main positive relay, the adhesion detection can be preferentially performed during the high-voltage power-off process.

[0178] In some specific embodiments, when the current It in the high-voltage circuit 1 is greater than or equal to the first preset current I 1 and less than the maximum set current I 1max (that is, I 1 ≤It 1 <I 1max ), it is determined that the pre-charge relay is adhered; when the current It in the high-voltage circuit 1 is greater than the maximum set current I 1max (that is, I t1 >I 1max ), it is determined that the main positive relay is adhered; when the current It in the high-voltage circuit 1 is less than the first preset current I 1 (that is, I t1 <I 1 ), it is determined that the main positive relay and the pre-charge relay are not adhered, so that it is possible to determine whether the main positive relay and the pre-charge relay are adhered based on the current in the high-voltage circuit.

[0179] Exemplarily, considering that in order to ensure the stability of the high-voltage power-on process, the main negative relay can be closed first, and then the pre-charge relay can be closed. Therefore, the current in the high-voltage circuit can be detected after the main negative relay is closed and before the pre-charge relay is closed. When the current in the high-voltage circuit is greater than or equal to the first preset current and less than the maximum set current, it is determined that the pre-charge relay is adhered; when the current in the high-voltage circuit is greater than the maximum set current, it is determined that the main positive relay is adhered; when the current in the high-voltage circuit is less than the first preset current, it is determined that the main positive relay and the pre-charge relay are not adhered. The first preset current can be determined according to the difference between the power battery voltage and the voltage across the capacitor, the capacitor, the pre-charge resistor, and the high-voltage circuit resistor. For example, it can be 0 to 10 A, such as 0.2 A. The maximum set current can be 10 A, for example. In this example, the current in the high-voltage circuit can be 1.2 A.

[0180] It should be noted that during the high-voltage power-on stage and the high-voltage operation stage, the main negative relay needs to be closed. Therefore, during the high-voltage power-on stage and the high-voltage operation stage, the adhesion of the main negative relay does not need to be detected.

[0181] In some specific embodiments, after determining that the main positive relay is stuck, the main negative relay can be immediately disconnected to prevent excessive pre-charge current from damaging circuit components (such as capacitors).

[0182] In some specific embodiments, when it is first determined that the first target relay is stuck, a first abnormal signal is sent to the control module (for example, the battery management system BMS, the vehicle control unit VCU) so that the control module controls the first target relay to perform a first preset number of energizations and disconnections. When it is determined that the first target relay is stuck within the second preset number of times, a first warning message is issued. Among them, the first target relay includes the main positive relay or the pre-charge relay; an energization and a disconnection are one operation; the first preset number of times can be determined according to the actual situation, and the second preset number of times can be, for example, 3 to 5.

[0183] Exemplarily, during the high-voltage power-on process, when the abnormal state of the relay being stuck is first detected, the system does not give a warning signal; at this time, the signal is fed back to the control module to perform multiple energizations and disconnections of the relay and then detect again. If it is detected that the relay is stuck for 3 to 5 consecutive times, the system gives a warning signal corresponding to the relay being stuck.

[0184] In some alternative embodiments, it is possible to determine whether the pre-charge relay and the main negative relay are abnormally energized according to the current in the high-voltage circuit and the voltage of the positive pole switch. Abnormal energization of the pre-charge relay or the main negative relay will affect the current in the high-voltage circuit, and abnormal energization of the pre-charge relay will also affect the voltage of the positive pole switch. Therefore, it is possible to determine more accurately whether the pre-charge relay and the main negative relay are abnormally energized according to the current in the high-voltage circuit and the voltage of the positive pole switch.

[0185] In some alternative examples, within the first preset time, when the current in the high-voltage circuit is greater than or equal to the first preset current and less than the maximum set current, it is determined that the pre-charge relay and the main negative relay are normally energized; within the first preset time, when the current in the high-voltage circuit is less than the first preset current, it is determined that there is a relay with abnormal energization among the pre-charge relay and the main negative relay, and then according to the voltage of the positive pole switch, it is determined which specific relay among the pre-charge relay and the main negative relay is abnormally energized.

[0186] It should be noted that the first preset time refers to a period of time after the pre-charge relay is closed. The first preset time can be determined according to the closing time of the relay when it leaves the factory and the pre-charge time under normal conditions. For example, if the closing time is 14 ms and the pre-charge time is 200 ms, then the first preset time can be 14 + 200×0.5 = 114 ms. Multiple current values of the high-voltage circuit can be measured within the first preset time. When multiple current values are greater than or equal to the first preset current, it can be determined that the current of the high-voltage circuit is greater than or equal to the first preset current. The specific number of multiple current values can be determined according to the actual situation.

[0187] For example, when receiving the power-on signal of the pre-charge relay, at this time the pre-charge relay is closed, the current of the high-voltage circuit can be detected within the first preset time after the pre-charge relay is closed. If the current of the high-voltage circuit is greater than or equal to the first preset current and less than the maximum set current within the first preset time, it is determined that the pre-charge relay and the main negative relay are normally closed. If the current of the high-voltage circuit is less than the first preset current within the first preset time, it is determined that the pre-charge relay or the main negative relay is abnormally closed.

[0188] In some specific embodiments, within the first preset time, the current I of the high-voltage circuit t1 is less than the first preset current I 1 and the voltage U of the positive electrode switch t1 is greater than or equal to the first preset voltage U 1 (that is, I t1 <I 1 , U t1 ≥U1), it is determined that the pre-charge relay is abnormally closed; within the first preset time, the current I of the high-voltage circuit t1 is less than the first preset current I 1 and the voltage U of the positive electrode switch t1 is less than the first preset voltage U 1 (that is, I t1 <I 1 , U t1 <U1), it is determined that the main negative relay is abnormally closed, so that it is possible to determine that the pre-charge relay or the main negative relay is abnormally closed based on the current of the high-voltage circuit and the voltage of the positive electrode switch. The first preset voltage can be 300 V. In this embodiment, the voltage of the positive electrode switch can be 350 V or 0 V, for example.

[0189] In some specific examples, when the current of the high-voltage circuit (such as 0 A) is less than the first preset current (such as 0.2 A) and the voltage of the positive electrode switch is greater than or equal to the first preset voltage within the first preset time, according to the current of the high-voltage circuit after the first preset time, it is determined that the pre-charge relay has a delayed closing, fails to close correctly, or has a non-conductive closing.

[0190] Exemplarily, after the first preset time, when the current in the high-voltage circuit (e.g., 1 A) is greater than or equal to the first preset current, the pre-charge relay pull-in delay is determined; after the first preset time, when the current in the high-voltage circuit (e.g., 0 A) is less than the first preset current, it is determined that the pre-charge relay fails to pull in correctly or is not conducting when pulled in.

[0191] In some specific examples, within the first preset time, when the current in the high-voltage circuit is less than the first preset current and the voltage of the positive switch is less than the first preset voltage, based on the current in the high-voltage circuit after the first preset time, the main negative relay pull-in delay, failure to pull in correctly, or non-conduction when pulled in is determined.

[0192] Exemplarily, after the first preset time, when the current in the high-voltage circuit is greater than or equal to the first preset current, the main negative relay pull-in delay is determined; after the first preset time, when the current in the high-voltage circuit is less than the first preset current, it is determined that the main negative relay fails to pull in correctly or is not conducting when pulled in.

[0193] In a specific embodiment, when the pull-in delay of the second target relay is determined for the first time, the second target relay, including the pre-charge relay and / or the main negative relay, is detected again for pull-in delay; when the pull-in delay of the second target relay is determined within the third preset number of times, a third warning message is issued. Among them, the third preset number of times can be, for example, 2 to 10.

[0194] Exemplarily, during the high-voltage power-on process, when pre-charging (high-voltage power-on) is still successful, when the pull-in delay of the pre-charge relay and / or the main negative relay is detected for the first time, the system does not give a warning signal and does not perform multiple pull-ins; if the relay is detected to have a pull-in delay for the third preset number of consecutive times (which can be an integer between 2 and 10, for example), the system gives a corresponding abnormal state warning signal, thereby reducing excessive maintenance work caused by occasional relay pull-in delays.

[0195] In some alternative embodiments, the resistance value of the pre-charge relay can be determined based on the voltage of the pre-charge resistor and the voltage of the pre-charge relay, and the resistance value of the main negative relay can also be determined based on the voltage of the pre-charge resistor and the voltage U S3 of the main negative relay, so that the resistance values of the pre-charge relay and the main negative relay can be determined more accurately based on the voltages of the relays during the high-voltage power-on stage.

[0196] In a specific embodiment, after the pre-charge relay is closed and before pre-charging is completed, when the ratio of the voltage U S2 of the pre-charge relay to the voltage U R1 of the pre-charge resistor is greater than the first preset ratio P1 (i.e., U S2 / UR1 > P1), it is determined that the resistance value of the pre-charge relay is abnormal; when the ratio of the voltage U of the pre-charge relay to the voltage U of the pre-charge resistor is less than or equal to the first preset ratio (that is, U S2 and the voltage U of the pre-charge resistor R1 is less than or equal to the first preset ratio (i.e., U S2 / U R1 ≤ P1), it is determined that the resistance value of the pre-charge relay is normal.

[0197] For example, when the ratio (e.g., 0.2) of the voltage of the pre-charge relay (e.g., 6V) to the voltage of the pre-charge resistor (e.g., 30V) is greater than the first preset ratio (e.g., 0.1), it is determined that the resistance value of the pre-charge relay has increased abnormally.

[0198] In a specific embodiment, after the pre-charge relay is closed and before the pre-charge is completed, when the ratio of the voltage U of the main negative relay to the voltage U of the pre-charge resistor is greater than the first preset ratio P1 (that is, U S3 and the voltage U of the pre-charge resistor R1 is greater than the first preset ratio P1 (i.e., U S3 / U R1 > P1), it is determined that the resistance value of the main negative relay is abnormal; when the ratio of the voltage U of the main negative relay to the voltage U of the pre-charge resistor is less than or equal to the first preset ratio P1 (that is, U S3 and the voltage U of the pre-charge resistor R1 is less than or equal to the first preset ratio P1 (i.e., U S3 / U R1 ≤ P1), it is determined that the resistance value of the main negative relay is normal.

[0199] Exemplarily, the voltage difference between the voltage of the positive electrode switch and the voltage of the pre-charge relay can be calculated to obtain the voltage of the pre-charge resistor, or the voltage of the pre-charge relay can be directly measured.

[0200] Exemplarily, the first preset ratio can be determined according to the pre-charge resistor, capacitor, and the required time for pre-charge completion, and can be, for example, 0.1.

[0201] In a specific embodiment, when it is first determined that the resistance value of the second target relay is abnormal, the resistance value of the second target relay is detected again. The second target relay includes the pre-charge relay and / or the main negative relay; when it is determined that the resistance value of the second target relay is abnormal within the third preset number of times, a second warning message is issued.

[0202] Exemplarily, during the high-voltage power-on process, when the pre-charge (high-voltage power-on) is still successful, when the abnormal increase in the relay resistance value is detected for the first time, the system will not give a warning signal and will not perform multiple closures; if the relay is detected to be abnormal for the third preset number of times continuously (which can be, for example, an integer between 2 and 10), the system gives a corresponding warning signal for the abnormal state, so as to reduce excessive maintenance work caused by occasional abnormal increase in the relay resistance value.

[0203] In some alternative embodiments, when the vehicle is in the high-voltage power-on stage, the pre-charge relay and the main negative relay are closed, and the main positive relay is open to charge the capacitor. When the voltage across the capacitor reaches a preset value of the battery voltage (for example, 90%-95% of the battery voltage), the main positive relay is closed and the pre-charge relay is open, and the vehicle is ready to enter the high-voltage operation stage. When the pre-charge relay is open and the main positive relay is closed, if the main positive relay fails to pull in properly, it will affect the current in the high-voltage circuit. Therefore, it is possible to determine whether the main positive relay fails to pull in properly based on the current in the high-voltage circuit.

[0204] In a specific embodiment, when the voltage across the capacitor reaches the preset value, the main positive relay is closed, and the pre-charge relay is open, if the current in the high-voltage circuit is less than or equal to the fourth preset current within the third preset time, it is determined that the main positive relay fails to pull in properly or fails to pull in completely. If the current in the high-voltage circuit is greater than the fourth preset current within the third preset time, it is determined that the main positive relay pulls in properly. The fourth preset current can be, for example, a value close to 0, such as 0. Among them, the third preset time can be determined according to the actual situation and is not limited here.

[0205] For example, if the current in the high-voltage circuit continuously equals 0, it is determined that the main positive relay fails to pull in properly or fails to conduct. If the current in the high-voltage circuit is greater than 0, it is determined that the main positive relay pulls in properly.

[0206] In a specific embodiment, when it is first determined that the third target relay fails to pull in properly or fails to conduct, the second abnormal information is sent to the control module so that the control module controls the third target relay to perform the first preset number of pulls-in and disconnections. The third target relay is at least one of the main positive relay, the main negative relay, and the pre-charge relay. If it is determined that the third target relay fails to pull in properly or fails to conduct during the third preset number of times, the third warning information is issued.

[0207] Exemplarily, during the high-voltage power-on process, when it is first detected that the relay is in an abnormal state of failing to pull in properly or failing to conduct, at this time, the first pre-charge fails and the power-on cannot be successful. The system does not give a warning signal. Instead, the signal is fed back to the control module for multiple pulls-in of this relay. If this relay is detected to be abnormal for the third preset number of times continuously (for example, an integer between 2 and 10), the system gives a corresponding warning signal for the abnormal state, thereby reducing excessive maintenance work caused by accidental improper pulling-in or non-conduction of the pre-charge relay.

[0208] S102. When the vehicle is in the high-voltage operation stage, determine whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive electrode switch, the voltage of the main negative relay, and the current in the high-voltage circuit.

[0209] Among them, the high-voltage operation stage refers to the stage when the high-voltage electrical equipment of the vehicle has been normally powered on and the vehicle can drive and be used normally. When the vehicle is in the high-voltage operation stage, the main positive relay and the main negative relay are closed, and the pre-charge relay is open.

[0210] In an alternative embodiment, the resistance value of the main positive relay can be determined according to the voltage of the positive electrode switch and the current in the high-voltage circuit, so that it is possible to accurately determine whether the main positive relay is abnormal according to the current in the high-voltage circuit and the voltage of the positive electrode switch in the high-voltage operation stage.

[0211] In some specific embodiments, when the high-voltage circuit meets the first preset condition, the contact resistance R of the main positive relay is determined according to the voltage of the positive electrode switch and the current in the high-voltage circuit S1 ; when the contact resistance R of the main positive relay S1 is greater than the first resistance threshold (that is, R S1 > ), it is determined that the resistance value of the main positive relay is abnormal; when the contact resistance R of the main positive relay S1 is less than or equal to the first resistance threshold (that is, R S1 ≤ ), it is determined that the resistance value of the main positive relay is normal.

[0212] Exemplarily, foreign objects on the contact points, oxidation of the contact points, etc. can cause the resistance value of the relay to be abnormal.

[0213] Exemplarily, the magnitude of the first resistance threshold can be set according to the model of the relay, generally less than 50 mΩ.

[0214] For example, if the voltage of the positive electrode switch is 100 mV and the current in the high-voltage circuit is 200 A, then the contact voltage R of the main positive relay S1 = 100 mV / 200 A = 0.5 mΩ. The first resistance threshold can be, for example, 10 mΩ, then the contact resistance of the main positive relay is less than the first resistance threshold, and the resistance value of the main positive relay is normal.

[0215] In some specific embodiments, when the high-voltage circuit meets the first preset condition, the contact resistance R of the main negative relay is calculated according to the voltage of the main negative relay and the current in the high-voltage circuit S3 ; when the contact resistance R of the main negative relay S3 is greater than the first resistance threshold In the case where (that is, when R S3 >) ), it is determined that the resistance value of the main negative relay is abnormal; when the contact resistance R S3 of the main negative relay is less than or equal to the first resistance threshold (that is, when R S3 ≤ ), it is determined that the resistance value of the main negative relay is normal.

[0216] Exemplarily, if the voltage of the main negative relay is 3V and the current of the high-voltage circuit is 200A, then the contact voltage R S1 of the main positive relay = 3V / 200A = 15mΩ. If the first resistance threshold can be 10 mΩ for example, then the contact resistance of the main negative relay is greater than the first resistance threshold, and it is determined that the resistance value of the main negative relay has abnormally increased.

[0217] Exemplarily, the preset conditions may include that the main positive relay and the main negative relay are closed, and the current of the high-voltage circuit is greater than the second preset current. Considering that the contact resistance of the main positive relay or the main negative relay is usually below 0.5mΩ, when the current of the high-voltage circuit is small, the voltage drop of the main positive relay or the main negative relay is very small, and it is difficult to detect whether the resistance value of the main positive relay or the main negative relay is abnormal. Therefore, when the current of the high-voltage circuit is less than the second preset current, it is detected whether the resistance value of the main positive relay or the main negative relay is abnormal.

[0218] The first preset condition may further include that the high-voltage circuit has an abnormality. Considering that when the high-voltage circuit has an abnormality, the measured value of the resistance of the main positive relay or the main negative relay at a certain current may suddenly become extremely large (for example, a mutation from mΩ to Ω occurs), and at this time, there will be a significant voltage drop in the main positive relay or the main negative relay without the current being greater than the second preset current. Therefore, when the high-voltage circuit has an abnormality, it is not required that the current of the high-voltage circuit is greater than the second preset current, and the contact resistance of the main positive relay or the main negative relay is immediately measured. The high-voltage circuit having an abnormality may be, for example, a failure of the main positive relay to have a high-voltage power-off after pre-charging is completed.

[0219] Exemplarily, the second preset current can be set according to the sensitivity of the voltage detection module and the size of the contact resistance of the relay, and can be, for example, above 20A.

[0220] In a specific embodiment, when it is first determined that the resistance value of the fourth target relay has abnormally increased, the resistance value of the fourth target relay is detected again. The fourth target relay includes the main positive relay and / or the main negative relay; when it is determined that the resistance value of the fourth target relay is abnormal within the fourth preset number of times, a fourth warning message is issued; when it is not determined that the resistance value of the fourth target relay is abnormal within the fourth preset number of times, the detection times of the abnormal resistance value are cleared.

[0221] Exemplarily, when the contact resistance of the relay is detected to be in an abnormal increase state for the first time, the system does not give a warning signal. At this time, the signal is fed back to the control module for multiple detections after the detection conditions are met; if the relay is in the continuous N 2 times of detection, the fourth preset number of times (1 / 3N 2 ~1 / 2N 2 , and the result is taken as a natural integer) or more are all in an abnormal increase state, then the system gives a warning signal that the contact resistance of the relay is abnormally increased. Otherwise, at the N 2 +1th detection, the number of times of abnormal increase state detection that has occurred is cleared. Among them, N 2 can be an integer between 2 and 10. Clearing the number of times of abnormal increase state detection is for the state evaluation circuit, and all the monitoring data itself will not be cleared for subsequent fault analysis.

[0222] For example, if the main negative relay is detected 10 times continuously, and the actual measurement shows that 6 times are in an abnormal increase state, meeting the judgment condition that 4 times or more are in an abnormal increase state, then the system gives a warning signal that the contact resistance of the main negative relay is abnormally increased. If the main negative relay is detected 10 times continuously, and the actual measurement shows that only 2 times are in an abnormal increase state, then the system does not give a warning signal that the contact resistance of the main negative relay is abnormally increased. At the 11th detection, the number of times of abnormal increase state detection that has occurred is cleared. Here, clearing the number of times of abnormal increase state detection is for the state evaluation circuit, and all the monitoring data itself will not be cleared for subsequent fault analysis.

[0223] Exemplarily, except for extreme situations such as short-circuit current, usually the contact resistances of the main positive relay and the main negative are not detected as abnormal at the same time; when the main positive relay and the main negative relay are detected 10 times continuously, and 5 times or more both relays are detected in an abnormal increase state at the same time, then the system gives a warning signal of abnormal relay state detection circuit and abnormally increased relay contact resistance.

[0224] In order to reduce the error caused by the difference in synchronization during the sampling process of current and voltage values, it is best to directly use the signal control voltage detection module to collect voltage, and at the same time use the signal control current sensor to collect current. In addition, during the relay switch detection process, avoid connecting additional loads to keep the current in the circuit unchanged.

[0225] S103. When the vehicle is in the high-voltage power-off stage, determine whether at least one relay in the high-voltage switch is abnormal according to the current in the high-voltage circuit.

[0226] Among them, the high-voltage power-off stage refers to the stage when the vehicle goes from the high-voltage operation stage to complete power-off. When the vehicle is in the high-voltage power-off stage, the main positive relay, the main negative relay, and the pre-charge relay are disconnected.

[0227] In some alternative embodiments, in response to the high-voltage power-off signal, after the main positive relay and the main negative relay are disconnected and before the high-voltage discharge module is started, when the current in the high-voltage circuit is greater than the third preset current, it is determined that one of the main positive relay and the pre-charge relay, and the main negative relay are simultaneously stuck, that is, the main positive relay and the main negative relay are simultaneously stuck, or the pre-charge relay and the main negative relay are simultaneously stuck; when the current in the high-voltage circuit is less than or equal to the third preset current, it is determined that one of the main positive relay and the pre-charge relay, and the main negative relay are not simultaneously stuck, that is, the main positive relay and the main negative relay are not simultaneously stuck, or the pre-charge relay and the main negative relay are not simultaneously stuck, so that it is possible to more accurately determine whether the high-voltage switch is abnormal according to the current in the high-voltage circuit during the high-voltage power-off stage, and improve the accuracy of the abnormal detection of the high-voltage switch.

[0228] Exemplarily, the high-voltage circuit may further include a discharge module, the discharge module is connected in parallel with the capacitor. After the main positive relay and the main negative relay are disconnected in response to the high-voltage power-off signal and before the discharge module is started, if the current in the high-voltage circuit is greater than the third preset current, it is determined that one of the main positive relay and the pre-charge relay is simultaneously stuck with the main negative relay. The third preset current may be a value close to 0, such as 0.

[0229] In some alternative embodiments, according to the time when the current in the high-voltage circuit first continuously equals the third preset current, and the time when the power-off control signal is first given in the main positive relay and the main negative relay, the high-voltage power-off time is determined; according to the high-voltage power-off time, it is determined whether the relay that first receives the power-off control signal is delayed in disconnection, so that it is possible to relatively accurately determine whether the relay that first receives the power-off control signal is delayed in disconnection.

[0230] In some specific embodiments, when the high-voltage power-off time is greater than or equal to the second preset time, it is determined that the relay that first receives the power-off control signal is delayed in disconnection; when the high-voltage power-off time is less than the second preset time, it is determined that the relay that first receives the power-off control signal is normally disconnected.

[0231] Exemplarily, the relay that first receives the power-off control signal may be the main positive relay or the main negative relay.

[0232] Exemplarily, the time when the main positive relay and the main negative relay first receive the power-off control signal can be recorded, as well as the time when the current in the high-voltage circuit continuously equals the third preset current (for example, the time when the current in the high-voltage circuit equals 0 for the first detection). The time difference between the two is used as the high-voltage power-off time. If the high-voltage power-off time (for example, 50 ms) is greater than or equal to the second preset time (for example, 10 ms), the disconnection delay of the relay that first receives the power-off control signal is determined; if the high-voltage power-off time is less than the second preset time, it is determined that the relay that first receives the power-off control signal disconnects normally.

[0233] Exemplarily, the second preset time can be determined according to the release time of the relay when it leaves the factory, and the second preset time is greater than the release time. Different relays have corresponding release times. If the relay that first receives the power-off control signal is the main positive relay, the second preset time can be determined according to the release time of the main positive relay. If the relay that first receives the power-off control signal is the main negative relay, the second preset time can be determined according to the release time of the main negative relay.

[0234] In a specific implementation manner, when the disconnection delay of the fifth target relay is determined for the first time, it is detected again whether the fifth target relay has a disconnection delay. The fifth target relay includes the relay that first gives the power-off control signal among the main positive relay and the main negative relay; when the disconnection delay of the fifth target relay is determined within the fifth preset number of times, the fifth warning message is issued.

[0235] Exemplarily, during the high-voltage power-off process, when the relay is first detected to be in an abnormal state of disconnection delay, the system does not give a warning signal; if the relay is detected to be in an abnormal state of disconnection delay in subsequent consecutive fifth preset number of times (for example, an integer between 2 and 10), the system gives a warning signal for the disconnection delay of the relay. For example, if the relay is detected to be in an abnormal state of disconnection delay in subsequent consecutive 5 normal power-off processes, the system gives a warning signal for the disconnection delay of the relay.

[0236] In some optional implementation manners, when the discharge circuit meets the second preset condition, it is determined whether the main positive relay and the pre-charge relay are stuck according to the current in the discharge circuit, so that it can be more accurately determined whether the main positive relay and the pre-charge relay are stuck. Among them, the sticking may be caused by reasons such as uneven contact surfaces, dirt or oxides between contacts, the adsorptivity of contact materials, etc., or may be due to excessive current passing through the contacts, resulting in an increase in the contact temperature, exceeding the melting point of the material, and causing the contacts to melt and solidify together.

[0237] Exemplarily, the discharge circuit may include a power battery, a main positive relay, a main negative relay, and a discharge module, and the discharge module is connected between the main positive relay and the main negative relay. Before the discharge module is turned on, the current of the high-voltage circuit can be obtained, and after the discharge module is turned on, the current of the discharge circuit can be obtained.

[0238] Exemplarily, after the main positive relay and the main negative relay are disconnected, due to the existence of the capacitor, there may be residual voltage in the high-voltage circuit. After the discharge module is turned on and before the residual voltage is completely discharged, it is determined whether the main positive relay and the pre-charge relay are stuck according to the current of the discharge circuit. For example, within 0 to 3 s after the discharge module is turned on, for example, at 50 ms, it is determined whether the main positive relay and the pre-charge relay are stuck according to the current of the discharge circuit.

[0239] In some specific embodiments, when the current of the discharge circuit is greater than a third preset current, it is determined that the main positive relay or the pre-charge relay is stuck, that is, there is a stuck relay among the main positive relay and the pre-charge relay; when the current of the discharge circuit is less than or equal to the third preset current, it is determined that the main positive relay and the pre-charge relay are not stuck, so that it can be determined whether there is a stuck relay among the main positive relay and the pre-charge relay.

[0240] In some specific embodiments, the second preset condition includes that the discharge module is equivalently grounded or the main negative relay is closed. Exemplarily, when the discharge module is equivalently grounded (the discharge circuit has a ground point or an equivalent ground point), it can be determined whether the main positive relay and the pre-charge relay are stuck according to the current of the discharge module; when the discharge module is not equivalently grounded, even if the main positive relay or the pre-charge relay is stuck, the current of the discharge circuit is still less than or equal to the third preset current, and the main negative relay can be closed, and then it is determined whether the main positive relay and the pre-charge relay are stuck according to the current of the discharge circuit.

[0241] In some specific examples, when the current of the discharge circuit is greater than a third preset current, it is determined that the main positive relay or the pre-charge relay is stuck, and considering that the resistance value of the pre-charge resistor is much larger than the contact resistance of the main positive relay and the main negative relay (for example, the resistance value of the pre-charge resistor is between 80 Ω and 200 Ω, and the contact resistance of the main positive relay and the main negative relay is at the mΩ level), therefore, it can be determined which specific relay among the main positive relay and the pre-charge relay is stuck according to the voltage of the positive electrode switch to locate the abnormal relay.

[0242] Exemplarily, when the voltage of the positive electrode switch (e.g., 3.5 mV) is less than the second preset voltage (e.g., 20 V), it is determined that the main positive relay is stuck; when the voltage of the positive electrode switch (e.g., 50 V) is greater than or equal to the second preset voltage (e.g., 20 V), it is determined that the pre-charge relay is stuck. It can be understood that when the main positive relay is stuck, the voltage of the positive electrode switch is close to 0, and when the pre-charge relay is stuck, the voltage of the positive electrode switch is greater than 0. Therefore, it can be determined whether the main positive relay or the pre-charge relay is stuck according to the voltage of the positive electrode switch.

[0243] Exemplarily, the second preset voltage can be determined according to the difference between the power battery voltage and the voltage across the capacitor, the high-voltage discharge speed, and the state detection time. For example, it can be a value greater than 0 and less than or equal to 60 V.

[0244] In some specific examples, when the current in the discharge circuit is greater than the third preset current, it is determined that the main positive relay or the pre-charge relay is stuck, and then it can be further determined which relay of the main positive relay and the pre-charge relay is stuck according to the current in the discharge circuit. When the current in the discharge circuit (e.g., 7 A) is greater than the third preset current (e.g., 0 A) and greater than or equal to the fourth preset current (e.g., 4 A), it is determined that the main positive relay is stuck; when the current in the discharge circuit (e.g., 1 A) is greater than the third preset current (e.g., 0 A) and less than the fourth preset current (e.g., 4 A), it is determined that the pre-charge relay is stuck.

[0245] Exemplarily, the fourth preset current refers to the discharge current set value, and the discharge current set value can be determined according to the power battery voltage, the voltage of the capacitor, the pre-charge resistor, and the resistance of the discharge circuit.

[0246] In some specific embodiments, when it is first determined that the sixth target relay is stuck, a third abnormal signal is sent to the control module so that the control module controls the sixth target relay to disconnect; the sixth target relay includes the main positive relay and / or the pre-charge relay; when it is determined that the sixth target relay is stuck for the sixth preset number of times, a sixth warning message is issued.

[0247] Exemplarily, during the high-voltage electrical process, when the abnormal state of relay adhesion is detected for the first time, the system will not give a warning signal. At this time, the signal is fed back to the control module for a second disconnection of the relay. If the relay fails to disconnect normally for six consecutive preset times (for example, an integer between 2 and 10), the system gives a warning signal indicating that the relay is adhered. Considering that some contact adhesions and sinterings can be self-disconnected during multiple disconnection operations, and the relay can still work normally after disconnection, this operation can significantly reduce the impact of such phenomena on electric vehicles. While reducing the number of relay repairs, it also avoids the spread of the impact of relay failures. For example, if the relay fails to disconnect normally for 4 consecutive times, the system gives a warning signal indicating that the relay is adhered / sintered.

[0248] The detection method of the high-voltage switch provided by the embodiment of the present application. When the high-voltage switch is abnormal, the operating parameters of the high-voltage circuit will be affected. Therefore, it is possible to determine whether the high-voltage switch is abnormal according to the operating parameters of the high-voltage circuit, improving the accuracy of abnormal detection of the high-voltage switch.

[0249] Figure 3 It is a schematic structural diagram of the control module provided by the present application. As Figure 3 shown, the control module 50 provided in this embodiment includes at least one processor 501 and a memory 502. Optionally, the control module 50 further includes a communication component 503. Among them, the processor 501, the memory 502, and the communication component 503 are connected through a bus.

[0250] In the specific implementation process, at least one processor 501 executes the computer execution instructions stored in the memory 502, so that at least one processor 501 executes the above method.

[0251] For the specific implementation process of the processor 501, reference can be made to the above method embodiment. The implementation principle and technical effects are similar, and will not be elaborated here in this embodiment.

[0252] In the above embodiment, it should be understood that the processor can be a central processing unit (English: Central Processing Unit, abbreviated as: CPU), and can also be other general-purpose processors, digital signal processors (English: Digital Signal Processor, abbreviated as: DSP), application-specific integrated circuits (English: Application Specific Integrated Circuit, abbreviated as: ASIC), etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly embodied as being executed and completed by a hardware processor, or executed and completed by a combination of hardware and software modules in the processor.

[0253] The memory may include a random access memory (RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0254] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the buses in the drawings of this application are not limited to only one bus or one type of bus.

[0255] The embodiment of this application also provides a detection circuit for a high-voltage switch, as Figure 4 shown, this circuit may include:

[0256] A high-voltage switch, a voltage detection module 102, a current detection module 103, and the above control module 104;

[0257] The high-voltage switch includes a positive-pole switch 1011 and a negative-pole switch 1012; the first end of the positive-pole switch 1011 is connected to the positive pole of the power battery 30, and the second end of the positive-pole switch 1011 is connected to the first end of the high-voltage electrical device; the first end of the negative-pole switch 1012 is connected to the negative pole of the power battery 30, and the second end of the negative-pole switch 1012 is connected to the second end of the high-voltage electrical device.

[0258] The positive-pole switch 1011 includes a main positive relay S1, a pre-charge relay S2, and a pre-charge resistor R1; the first end of the main positive relay S1 is connected to the first end of the pre-charge relay S2 as the first end of the positive-pole switch 1011; the second end of the main positive relay S1 is connected to the second end of the pre-charge resistor R1 as the second end of the positive-pole switch 1011; the second end of the pre-charge relay S2 is connected to the first end of the pre-charge resistor R1. The negative-pole switch 1012 includes a main negative relay S3; the first end of the main negative relay S3 is used as the first end of the negative-pole switch 1012, and the second end of the main negative relay S3 is used as the second end of the negative-pole switch 1012.

[0259] The voltage detection module 102 is connected to the first end of the main positive relay S1, the second end of the main positive relay S1, the second end of the main negative relay S3, the first end of the main negative relay S3, the second end of the pre-charge relay S2, and the control module 103; the current detection module 103 is connected to the second end of the main positive relay S1, the first end of the high-voltage electrical device, and the control module 103.

[0260] Accordingly, the voltage detection module 102 can detect at least one of the voltage of the positive electrode switch 1011, the voltage of the main negative relay S3, the voltage of the pre-charge relay S2, and the voltage of the pre-charge resistor R1, and send it to the control module 103. The current detection module 103 can detect the current of the high-voltage circuit and send it to the control module 103. The control module 103 determines whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive electrode switch 1011, the voltage of the main negative relay S3, the voltage of the pre-charge relay S2, the voltage of the pre-charge resistor R1, and the current of the high-voltage circuit.

[0261] Exemplarily, the voltage detection module 102 can detect the voltage of the positive electrode switch 1011, the voltage of the main negative relay S3, the voltage of the pre-charge relay S2, and the voltage of the pre-charge resistor R1 when the vehicle is in the high-voltage power-on stage, and send it to the control module 103. The current detection module 103 can also detect the current of the high-voltage circuit when the vehicle is in the high-voltage power-on state and send it to the control module 103. Accordingly, the control module 103 can determine whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive electrode switch 1011, the voltage of the main negative relay S3, the voltage of the pre-charge relay S2, the voltage of the pre-charge resistor R1, and the current of the high-voltage circuit when the vehicle is in the high-voltage power-on stage;

[0262] Exemplarily, the voltage detection module 102 can detect the voltage of the positive electrode switch 1011 and the voltage of the main negative relay S3 when the vehicle is in the high-voltage operation stage, and send it to the control module 103. The current detection module 103 can also detect the current of the high-voltage circuit when the vehicle is in the high-voltage operation state and send it to the control module 103. Accordingly, the control module 103 can determine whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive electrode switch 1011, the voltage of the main negative relay S3, and the current of the high-voltage circuit when the vehicle is in the high-voltage operation stage;

[0263] Exemplarily, the current detection module 103 can detect the current of the high-voltage circuit when the vehicle is in the high-voltage power-off stage and send it to the control module 103. Accordingly, the control module 103 can determine whether at least one relay in the high-voltage switch is abnormal according to the current of the high-voltage circuit when the vehicle is in the high-voltage power-off stage.

[0264] In some specific embodiments, such as Figure 4As shown, the voltage detection module 102 includes a first interface 1, a second interface 2, a third interface 3, a fourth interface 4, and a fifth interface 5; the first interface 1 is connected to the first end of the main positive relay S1, and the second interface 2 is connected to the second end of the main positive relay S1; the third interface 3 is connected to the second end of the main negative relay S3, and the fourth interface 4 is connected to the first end of the main negative relay S3 and grounded; the fifth interface 5 is connected to the second end of the pre-charge relay S3. Accordingly, the voltage detection module 102 can detect the voltage of the main positive relay S1, the voltage of the main negative relay S3, the voltage of the pre-charge relay S2, and the voltage of the pre-charge resistor R1.

[0265] Exemplarily, the current detection module 103 can be arranged outside the voltage detection circuit of the positive electrode switch 1011, between the capacitor 106 and the positive electrode switch 1011, to avoid the error caused by the internal resistance of the current detection module 103 itself.

[0266] In some other specific embodiments, when the current detection module 103 uses a non-direct contact sensor such as a current Hall sensor, since its internal resistance will not introduce errors, its installation position does not require being outside the voltage detection circuit of the positive electrode switch 1011.

[0267] In some specific embodiments, as Figure 5 shown, it further includes a first switch K1 and a second switch K2; the first end of the first switch K1 is connected to the first interface 1, and the second end of the first switch K1 is connected to the first end of the main positive relay S1; the first end of the second switch K2 is connected to the fourth interface 4, and the second end of the second switch K2 is connected to the first end of the main negative relay S2; the first switch K1 is used to control whether the first interface 1 and the first end of the main positive relay S1 are connected, so as to control whether the voltage detection module 102 detects the voltage of the main positive relay S1; the second switch K2 is used to control whether the fourth interface 4 and the first end of the main negative relay S2 are connected, so as to control whether the power supply detection module 102 can detect the voltage of the main negative relay S2.

[0268] In some specific embodiments, it further includes a discharge module 105; the first end of the discharge module 105 is connected to the second end of the main positive relay S1, and the second end of the discharge module 105 is connected to the second end of the main negative relay S2; the discharge module 105 is used to discharge the residual voltage of the high-voltage circuit when the vehicle is in the high-voltage power-off stage.

[0269] In some specific examples, the discharge module 105 includes a discharge component and a fourth switch S4; the first end of the fourth switch S4 serves as the first end of the discharge module 105, the second end of the fourth switch S4 is connected to the first end of the discharge component, and the second end of the discharge component serves as the second end of the discharge module 105. The fourth switch S4 is used to control whether the discharge module 105 is turned on, so as to control whether the discharge component can discharge the participating voltage of the high-voltage circuit. The discharge component can be, for example, a discharge resistor, etc.

[0270] The embodiment of the present application also provides a high-voltage system, including the detection circuit of the above-mentioned high-voltage switch, a power battery, and a high-voltage electrical device, and the detection circuit is connected to the power battery and the high-voltage electrical device.

[0271] The embodiment of the present application also provides a vehicle, including the above-mentioned high-voltage system.

[0272] The present application also provides a computer program product, including a computer program, and when the computer program is executed by a processor, the above-mentioned method is implemented.

[0273] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the processor executes the computer-executable instructions, the above-mentioned method is implemented.

[0274] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk or an optical disk. The readable storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0275] Finally, it should be noted that: After those skilled in the art consider the specification and practice the invention disclosed herein, other implementation manners of the present invention will be easily thought of. The present invention aims to cover any variations, uses, or adaptive changes of the present invention. These variations, uses, or adaptive changes follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field of the present invention that is not disclosed in the present invention. It is not limited to the exact structure described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A method for detecting a high voltage switch, characterized in that: The high-voltage switch includes a positive switch and a negative switch, the positive switch includes a main positive relay, a pre-charge relay and a pre-charge resistor, the negative switch includes a main negative relay, and the method includes: When the vehicle is in the high-voltage power-on stage, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit; When the vehicle is in a high-voltage operation stage, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, and the current of the high-voltage circuit; When the vehicle is in a high-voltage power-off stage, it is determined whether at least one relay in the high-voltage switch is abnormal according to the current of the high-voltage circuit.

2. The method according to claim 1, characterized in that The determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit comprises: According to the current of the high-voltage circuit, it is determined whether the main positive relay and the pre-charging relay are stuck.

3. The method according to claim 2, characterized in that The determining, based on the current of the high-voltage circuit, whether the main positive relay and the pre-charging relay are adhered comprises: After the main negative relay is closed and before the pre-charge relay is closed: When the current of the high-voltage circuit is greater than or equal to a first preset current and less than a maximum set current, determining that the pre-charging relay is stuck; When the current of the high-voltage circuit is greater than the maximum set current, determining that the main positive relay is stuck; When the current of the high-voltage circuit is less than the first preset current, it is determined that the main positive relay and the pre-charging relay are not stuck.

4. The method according to claim 1, characterized in that The determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit comprises: According to the current of the high-voltage circuit and the voltage of the positive switch, it is determined whether the pre-charging relay and the main negative relay are abnormally attracted.

5. The method according to claim 4, characterized in that The determining, based on the current of the high-voltage circuit and the voltage of the positive switch, whether the pre-charging relay and the main negative relay are abnormally attracted, comprises: Upon receiving the power-on signal of the pre-charging relay: Within a first preset time, when the current of the high-voltage circuit is greater than or equal to the first preset current and less than the maximum set current, determining that the pre-charging relay and the main negative relay are normally energized; When the current of the high-voltage circuit is less than the first preset current within the first preset time, it is determined that the pre-charging relay or the main negative relay is abnormally energized based on the voltage of the positive switch.

6. The method according to claim 5, characterized in that The determining, based on the voltage of the positive switch, that the pre-charging relay or the main negative relay is abnormally attracted, comprises: When the voltage of the positive switch is greater than or equal to the first preset voltage, determining that the pre-charging relay is abnormally closed; When the voltage of the positive switch is less than the first preset voltage, it is determined that the main negative relay is abnormally closed.

7. The method according to claim 6, characterized in that When the voltage of the positive switch is greater than or equal to a first preset voltage, determining that the pre-charging relay is abnormally closed includes: When the voltage of the positive switch is greater than or equal to the first preset voltage, the pre-charging relay is determined to be delayed in closing, incorrectly closed, or non-conductive when closed based on the current of the high-voltage circuit after the first preset time.

8. The method according to claim 7, characterized in that The determining, based on the current of the high-voltage circuit after the first preset time, that the pre-charging relay is delayed in closing, incorrectly closed, or non-conductive when closed, includes: After the first preset time, when the current of the high-voltage circuit is greater than or equal to the first preset current, determining the pre-charging relay pick-up delay; After the first preset time, when the current of the high-voltage circuit is less than the first preset current, it is determined that the pre-charging relay is not correctly energized or is not conducting when energized.

9. The method according to claim 6, characterized in that When the voltage of the positive switch is less than the first preset voltage, determining that the main negative relay is abnormally closed includes: When the voltage of the positive switch is less than the first preset voltage, the main negative relay is determined to be delayed in closing, incorrectly closed, or non-conductive when closed based on the current of the high-voltage circuit after the first preset time.

10. The method according to claim 9, characterized in that The determining, based on the current of the high-voltage circuit after the first preset time, that the main negative relay is delayed in closing, incorrectly closed, or non-conductive when closed, includes: After the first preset time, when the current of the high-voltage circuit is greater than or equal to the first preset current, determining the main negative relay pick-up delay; After the first preset time, when the current of the high-voltage circuit is less than the first preset current, it is determined that the main negative relay is not correctly energized or is not conducting when energized.

11. The method according to claim 1, characterized in that The determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit comprises: Determining whether the resistance value of the pre-filling relay is abnormal according to the voltage of the pre-filling resistor and the voltage of the pre-filling relay; And / or, determining whether the resistance of the main negative relay is abnormal based on the voltage of the pre-charging resistor and the voltage of the main negative relay.

12. The method according to claim 11, characterized in that The determining whether the resistance value of the pre-charging relay is abnormal according to the voltage of the pre-charging resistor and the voltage of the pre-charging relay comprises: After the pre-charging relay is closed and before the pre-charging is completed, when the ratio of the voltage of the pre-charging relay to the voltage of the pre-charging resistor is greater than a first preset ratio, determining that the resistance of the pre-charging relay is abnormal; When the ratio of the voltage of the pre-charging relay to the voltage of the pre-charging resistor is less than or equal to the first preset ratio, it is determined that the resistance of the pre-charging relay is normal.

13. The method according to claim 11, characterized in that The determining whether the resistance value of the main negative relay is abnormal according to the voltage of the pre-charging resistor and the voltage of the main negative relay comprises: After the pre-charging relay is closed and before the pre-charging is completed, when the ratio of the voltage of the main negative relay to the voltage of the pre-charging resistor is greater than a first preset ratio, determining that the resistance of the main negative relay is abnormal; When the ratio of the voltage of the main negative relay to the voltage of the pre-charging resistor is less than or equal to the first preset ratio, it is determined that the resistance of the main negative relay is normal.

14. The method according to claim 1, characterized in that The determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit comprises: According to the current of the high-voltage circuit, it is determined whether the main positive relay is abnormally attracted.

15. The method according to claim 14, characterized in that The step of determining whether the main positive relay is abnormally attracted according to the current of the high-voltage circuit comprises: When the voltage across the capacitor reaches a preset value, the main positive relay is closed, and the pre-charge relay is disconnected, and the current of the high-voltage circuit is less than or equal to a fourth preset current within a third preset time, it is determined that the main positive relay is not correctly attracted or is not conductive when attracted; When the current of the high-voltage circuit is greater than the fourth preset current within the third preset time, it is determined that the main positive relay is normally energized.

16. The method according to claim 3, characterized in that The method further comprises: When it is determined for the first time that the first target relay is stuck, a first abnormal signal is sent to the control module, so that the control module controls the first target relay to be closed and disconnected for a first preset number of times; the first target relay is the main positive relay or the pre-charge relay; When it is determined that the first target relay is stuck within a second preset number of times, a first warning message is issued.

17. The method according to claim 12 or 13, characterized in that The method comprises: In the case where it is determined for the first time that the resistance value of the second target relay is abnormal, detecting again whether the resistance value of the second target relay is abnormal; the second target relay includes the pre-charge relay and / or the main negative relay; When it is determined that the resistance value of the second target relay is abnormal within a third preset number of times, a second warning message is issued.

18. The method according to any one of claims 7 to 10, characterized in that: The method further comprises: In the case of first determining the second target relay's pull-in delay, detecting again whether the second target relay has a pull-in delay; the second target relay includes the pre-charge relay and / or the main negative relay; When it is determined that the second target relay is delayed in closing within a third preset number of times, a third warning message is issued.

19. The method according to any one of claims 7 to 10 and 15, characterized in that: The method further comprises: When it is determined for the first time that the third target relay is not properly attracted or is not conductive when attracted, a second abnormal signal is sent to the control module so that the control module controls the third target relay to be attracted and disconnected for a first preset number of times; the third target relay is at least one of the main positive relay, the main negative relay and the pre-charge relay; When it is determined within the third preset number of times that the third target relay is not correctly attracted or is not conductive when attracted, a third warning message is issued.

20. The method according to claim 1, characterized in that The determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, and the current of the high-voltage circuit comprises: Whether the resistance of the main positive relay is abnormal is determined based on the voltage of the positive switch and the current of the high-voltage circuit.

21. The method according to claim 20, characterized in that The determining whether the resistance of the main positive relay is abnormal according to the voltage of the positive switch and the current of the high-voltage circuit includes: When the high-voltage circuit meets the first preset condition, determining the contact resistance of the main positive relay according to the voltage of the positive switch and the current of the high-voltage circuit; When the contact resistance of the main positive relay is greater than a first resistance threshold, determining that the resistance value of the main positive relay is abnormal; When the contact resistance of the main positive relay is less than or equal to the first resistance threshold, it is determined that the resistance value of the main positive relay is normal.

22. The method according to claim 1, characterized in that The determining whether at least one relay in the high-voltage switch is abnormal according to at least one of the voltage of the positive switch, the voltage of the main negative relay, and the current of the high-voltage circuit comprises: Whether the resistance value of the main negative relay is abnormal is determined according to the voltage of the main negative relay and the current of the high-voltage circuit.

23. The method according to claim 22, characterized in that The determining whether the resistance of the main negative relay is abnormal according to the voltage of the main negative relay and the current of the high-voltage circuit includes: When the high-voltage switch meets the first preset condition, determining the contact resistance of the main negative relay according to the voltage of the main negative relay and the current of the high-voltage circuit; When the contact resistance of the main negative relay is greater than a first resistance threshold, determining that the resistance value of the main negative relay is abnormal; When the contact resistance of the main negative relay is less than or equal to the first resistance threshold, it is determined that the resistance value of the main negative relay is normal.

24. The method according to claim 21 or 23, characterized in that The first preset condition includes at least one of the following: The main positive relay and the main negative relay are closed, and the current of the high-voltage circuit is greater than a second preset current; An abnormality occurred in the high-voltage circuit.

25. The method according to claim 21 or 23, characterized in that The first resistance threshold is less than 50 mΩ.

26. The method according to claim 24, characterized in that The second preset current is greater than 20A.

27. The method according to claim 21 or 23, characterized in that The method further comprises: In the case where it is determined for the first time that the resistance value of the fourth target relay is abnormal, detecting again whether the resistance value of the fourth target relay is abnormal; the fourth target relay includes the main positive relay and / or the main negative relay; When it is determined that the resistance value of the fourth target relay is abnormal within a fourth preset number of times, issuing a fourth warning message; When the resistance value of the fourth target relay is not determined to be abnormal within the fourth preset number of times, the number of detection times of the abnormal resistance value is reset to zero.

28. The method according to claim 1, characterized in that The step of determining whether at least one relay in the high-voltage switch is abnormal based on the current of the high-voltage circuit comprises: When the current of the high-voltage circuit is greater than a third preset current, determining that one of the main positive relay and the pre-charge relay, and the main negative relay are stuck; When the current of the high-voltage circuit is less than or equal to the third preset current, it is determined that one of the main positive relay and the pre-charge relay, and the main negative relay are not simultaneously stuck.

29. The method according to claim 28, characterized in that The method further comprises: Determine the high voltage power-off time according to the time when the current of the high voltage circuit is equal to the third preset current for the first time, and the time when the main positive relay and the main negative relay first give a power-off control signal; It is determined according to the high voltage power-off time whether the relay which first receives the power-off control signal disconnects the delay.

30. The method according to claim 25, characterized in that The step of determining whether the relay that first receives the power-off control signal is disconnected and delayed according to the high voltage power-off time includes: In the case where the high voltage power-off time is greater than or equal to the second preset time, determining the disconnection delay of the relay that first receives the power-off control signal; When the high voltage power-off time is less than the second preset time, it is determined that the relay that first receives the power-off control signal is normally disconnected.

31. The method according to claim 30, characterized in that The second preset time is greater than the release time of the relay.

32. The method according to claim 1, characterized in that The method further comprises: When the discharge circuit meets the second preset condition, it is determined whether the main positive relay and the pre-charging relay are stuck according to the current of the discharge circuit.

33. The method according to claim 32, characterized in that The determining, according to the current of the discharge circuit, whether the main positive relay and the pre-charge relay are stuck, comprises: When the current of the discharge circuit is greater than a third preset current, determining that the main positive relay or the pre-charge relay is stuck; When the current of the discharge circuit is less than or equal to the third preset current, it is determined that the main positive relay and the pre-charging relay are not stuck.

34. The method according to claim 33, characterized in that The discharge circuit includes a discharge module, and the discharge module is connected between the main positive relay and the main negative relay; The second preset condition includes: the discharge module is equivalently grounded, or the main negative relay is closed.

35. The method according to claim 34, characterized in that Determining that the main positive relay or the pre-charge relay is stuck; According to the voltage of the positive switch, it is determined that the main positive relay or the pre-charging relay is stuck.

36. The method according to claim 35, characterized in that The determining, based on the voltage of the positive switch, that the main positive relay or the pre-charge relay is stuck, includes: When the voltage of the positive switch is less than the second preset voltage, determining that the main positive relay is stuck; When the voltage of the positive switch is greater than or equal to a second preset voltage, it is determined that the pre-charging relay is stuck.

37. The method according to claim 36, characterized in that The second preset voltage is set based on the difference between the power battery voltage and the voltage across the capacitor, the high voltage discharge speed and the state detection time.

38. The method according to claim 33, characterized in that The determining that the main positive relay or the pre-charging relay is stuck includes: When the current of the discharge circuit is greater than or equal to a fourth preset current, determining that the main positive relay is stuck; When the current of the discharge circuit is less than the fourth preset current, it is determined that the pre-charging relay is stuck.

39. The method according to claim 30, characterized in that The method further comprises: In the case of first determining the disconnection delay of the fifth target relay, detecting again whether the fifth target relay has a disconnection delay; the target relay includes the relay that first gives a power-off control signal among the main positive relay and the main negative relay; In the case where the fifth target relay opening delay is determined within a fifth preset number of times, a fifth warning message is issued.

40. The method according to any one of claims 33 to 37, characterized in that The method further comprises: When it is determined for the first time that the sixth target relay is stuck, a third abnormal signal is sent to the control module so that the control module controls the sixth target relay to be disconnected; the sixth target relay includes the main positive relay and / or the pre-charge relay; When it is determined that the sixth target relay is stuck a sixth preset number of times, a sixth warning message is issued.

41. The method according to claim 1, characterized in that The method further comprises: When it is determined that the high-voltage switch is abnormal, the operating parameters of the high-voltage circuit are stored, and the operating parameters include at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit.

42. The method according to claim 1, characterized in that The method further comprises: When the vehicle is in a high-voltage power-on stage, obtaining at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit; When the vehicle is in a high-voltage operation stage, obtaining at least one of a voltage of the positive switch, a voltage of the main negative relay, and a current of the high-voltage circuit; When the vehicle is in a high-voltage power-down stage, a current of the high-voltage switch is obtained.

43. A control module, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 42.

44. A detection circuit for a high voltage switch, characterized in that: include: A high voltage switch, a voltage detection module, a current detection module, and a control module as claimed in claim 43; The high-voltage switch includes a positive switch and a negative switch, wherein the first end of the positive switch is connected to the positive electrode of the battery, the second end of the positive switch is connected to the first end of the high-voltage electrical equipment, the first end of the negative switch is connected to the negative electrode of the battery, and the second end of the positive switch is connected to the second end of the high-voltage electrical equipment; The positive switch includes a main positive relay, a pre-charge relay and a pre-charge resistor, and the negative switch includes a main negative relay; The first end of the main positive relay is connected to the first end of the pre-charging relay as the first end of the positive switch, the second end of the main positive relay is connected to the second end of the pre-charging resistor as the second end of the positive switch, the second end of the pre-charging relay is connected to the second end of the pre-charging resistor, the first end of the main negative relay serves as the first end of the negative switch, and the second end of the main negative relay serves as the second end of the negative switch. The voltage detection module is connected to the first end of the main positive relay, the second end of the main positive relay, the second end of the main negative relay, the first end of the main negative relay, the second end of the pre-charge relay, and the control module; The current detection module is connected to the second end of the main positive relay, the first end of the high-voltage electrical equipment and the control module; The voltage detection module is used to detect at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay and the voltage of the pre-charging resistor, and send the voltage to the control module; The current detection module is used to detect the current of the high-voltage circuit and send it to the control module; The control module is used to determine whether at least one relay in the high-voltage switch is abnormal based on at least one of the voltage of the positive switch, the voltage of the main negative relay, the voltage of the pre-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage circuit.

45. The circuit according to claim 44, characterized in that The voltage detection module includes a first interface, a second interface, a third interface, a fourth interface and a fifth interface; The first interface is connected to a first end of the main positive relay, and the second interface is connected to a second end of the main positive relay; The third interface is connected to the second end of the main negative relay, and the fourth interface is connected to the first end of the main negative relay and is grounded; The fifth interface is connected to the second end of the pre-charging relay.

46. ​​The circuit according to claim 45, characterized in that Also includes a first switch and a second switch; A first end of the first switch is connected to the first interface, and a second end of the first switch is connected to a first end of the main positive relay; A first end of the second switch is connected to the fourth interface, and a second end of the second switch is connected to a first end of the main negative relay; The first switch is used to control whether the first interface is connected to the first end of the main positive relay; The second switch is used to control whether the fourth interface is connected to the first end of the main negative relay.

47. The circuit according to any one of claims 44 to 46, characterized in that Also included is a bleed module; The first end of the discharge module is connected to the second end of the main positive relay, and the second end of the discharge module is connected to the second end of the main negative relay; The discharge module is used to discharge the residual voltage of the high-voltage circuit when the vehicle is in a high-voltage power-down stage.

48. The circuit according to claim 47, characterized in that The discharge module includes a discharge component and a fourth switch; The first end of the fourth switch serves as the first end of the discharge module, the second end of the fourth switch is connected to the first end of the discharge component, and the second end of the discharge component serves as the second end of the discharge module.

49. A high-voltage system, characterized in that: A detection circuit for a high-voltage switch, a power battery and a high-voltage electrical device comprising the detection circuit for a high-voltage switch according to claims 44 to 48; The detection circuit is connected to the power battery and the high-voltage electrical equipment.

50. A vehicle, characterized in that: Includes the high pressure system of claim 49.

51. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method according to any one of claims 1 to 42.

52. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 42 when being executed by a processor.

Images