Method for detecting high-voltage switch, control module, circuit, system and vehicle

Abstract

The embodiment of the application provides a kind of high voltage switch detection method, control module, circuit, system and vehicle, in the case where vehicle is in different stage, with corresponding operating parameter, operating parameter can include the voltage and / or current of relay, when high voltage switch is abnormal, the operating parameter of high voltage loop will be affected, therefore, whether high voltage switch is abnormal can be determined according to the operating parameter of different stage, improve the accuracy of the abnormal detection of high voltage switch.

Description

TECHNICAL FIELD

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

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

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

[0004] The existing detection method mainly recycles the high-voltage distribution box and manually analyzes the abnormality of the high-voltage switch. This method is time-consuming and labor-intensive, and lacks preliminary abnormality positioning when the abnormality occurs, which makes it difficult to reproduce the abnormality and affects the accuracy of abnormality detection. SUMMARY

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

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

[0007] In the case that the vehicle is in a high-voltage power-on stage, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of a voltage of the positive switch, a voltage of the main negative relay, a voltage of the pre-charge relay, a voltage of the pre-charge resistor, and a current of the high-voltage loop;

[0008] In the case that the vehicle is in a high-voltage running stage, determining whether at least one relay in the high-voltage switch is abnormal according to at least one of a voltage of the positive switch, a voltage of the main negative relay, and a current of the high-voltage loop;

[0009] In the case that the vehicle is in a high-voltage power-off stage, determining whether at least one relay in the high-voltage switch is abnormal according to a current of the high-voltage loop.

[0010] In a possible implementation, 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 of the high-voltage loop comprises:

[0011] The determining whether the main positive relay and the pre-charge relay are stuck according to the current of the high-voltage loop comprises:

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

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

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

[0015] In a case where the current of the high-voltage loop is greater than the maximum set current, it is determined that the main positive relay is stuck;

[0016] In a case where the current of the high-voltage loop is less than the first preset current, it is determined that the main positive relay and the pre-charge relay are not stuck.

[0017] In a possible implementation, 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 of the high-voltage loop comprises:

[0018] The determining whether the pre-charge relay and the main negative relay are normally attracted according to the current of the high-voltage loop and the voltage of the positive electrode switch comprises:

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

[0020] In a case where the power-on signal of the pre-charge relay is received:

[0021] In a case where the current of the high-voltage loop is greater than or equal to a first preset current and less than a maximum set current within a first preset time, it is determined that the pre-charge relay and the main negative relay are normally attracted;

[0022] In a case that the current of the high-voltage loop is less than the first preset current within the first preset time, determining, according to the voltage of the positive electrode switch, whether the pre-charging relay or the main negative relay is attracted abnormally.

[0023] In a possible implementation, the determining, according to the voltage of the positive electrode switch, whether the pre-charging relay or the main negative relay is attracted abnormally comprises:

[0024] In a case that the voltage of the positive electrode switch is greater than or equal to a first preset voltage, determining that the pre-charging relay is attracted abnormally.

[0025] In a case that the voltage of the positive electrode switch is less than the first preset voltage, determining that the main negative relay is attracted abnormally.

[0026] In a possible implementation, the determining, in a case that the voltage of the positive electrode switch is greater than or equal to a first preset voltage, that the pre-charging relay is attracted abnormally comprises:

[0027] In a case that the voltage of the positive electrode switch is greater than or equal to a first preset voltage, determining, according to the current of the high-voltage loop after the first preset time, whether the pre-charging relay is attracted delayed, not correctly attracted or attracted not to conduct.

[0028] In a possible implementation, the determining, according to the current of the high-voltage loop after the first preset time, whether the pre-charging relay is attracted delayed, not correctly attracted or attracted not to conduct comprises:

[0029] In a case that the current of the high-voltage loop is greater than or equal to the first preset current after the first preset time, determining that the pre-charging relay is attracted delayed.

[0030] In a case that the current of the high-voltage loop is less than the first preset current after the first preset time, determining that the pre-charging relay is not correctly attracted or attracted not to conduct.

[0031] In a possible implementation, the determining, in a case that the voltage of the positive electrode switch is less than the first preset voltage, that the main negative relay is attracted abnormally comprises:

[0032] In a case that the voltage of the positive electrode switch is less than the first preset voltage, determining, according to the current of the high-voltage loop after the first preset time, whether the main negative relay is attracted delayed, not correctly attracted or attracted not to conduct.

[0033] In a possible implementation, the determining, according to the current of the high-voltage loop after the first preset time, whether the main negative relay is attracted delayed, not correctly attracted or attracted not to conduct comprises:

[0034] In a case where the current of the high-voltage loop is greater than or equal to the first preset current after the first preset time, it is determined that the main negative relay is attracted with delay;

[0035] In a case where the current of the high-voltage loop is less than the first preset current after the first preset time, it is determined that the main negative relay is not correctly attracted or is not attracted to be conductive.

[0036] In a possible implementation, the determination of 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 loop comprises:

[0037] According to the voltage of the pre-charge resistor and the voltage of the pre-charge relay, it is determined whether the resistance value of the pre-charge relay is abnormal.

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

[0039] In a possible implementation, the determination of 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 comprises: in a case where 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 after the pre-charge relay is closed and before pre-charging is completed, it is determined that the resistance value of the pre-charge relay is abnormal.

[0040] In a case where 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, it is determined that the resistance value of the pre-charge relay is normal.

[0041] In a possible implementation, the determination of 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 comprises:

[0042] In a case where 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 after the pre-charge relay is closed and before pre-charging is completed, it is determined that the resistance value of the main negative relay is abnormal.

[0043] In a case where 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, it is determined that the resistance value of the main negative relay is normal.

[0044] In a possible implementation, the determining whether the 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-charging relay, the voltage of the pre-charging resistor, and the current of the high-voltage loop includes:

[0045] The determining whether the main positive relay is normally attracted according to the current of the high-voltage loop includes:

[0046] In a possible implementation, the determining whether the main positive relay is normally attracted according to the current of the high-voltage loop includes:

[0047] In a case where the current of the high-voltage loop is less than or equal to a fourth preset current within a third preset time in a case where the voltage across the capacitor reaches a preset value, the main positive relay is closed, and the pre-charging relay is disconnected, it is determined that the main positive relay is not correctly attracted or is not attracted to be conductive.

[0048] In a case where the current of the high-voltage loop is greater than the fourth preset current within the third preset time, it is determined that the main positive relay is normally attracted.

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

[0050] In a case where it is determined for the first time that the first target relay is stuck, a first abnormal signal is sent to a control module, so that the control module controls the first target relay to be attracted and disconnected for a first preset number of times; the first target relay is the main positive relay or the pre-charging relay.

[0051] In a case where it is determined for a second preset number of times that the first target relay is stuck, first warning information is sent.

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

[0053] In a case where it is determined for the first time that the resistance value of a second target relay is abnormal, the resistance value of the second target relay is detected again; the second target relay includes the pre-charging relay and / or the main negative relay.

[0054] In a case where it is determined for a third preset number of times that the resistance value of the second target relay is abnormal, second warning information is sent.

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

[0056] In a case where it is determined for the first time that the second target relay is attracted with a delay, whether the second target relay is attracted with a delay is detected again; the second target relay includes the pre-charging relay and / or the main negative relay.

[0057] In a case where the second target relay is determined to have a third preset number of pull-in delays, a third warning information is sent out.

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

[0059] In a case where the third target relay is determined to have a first preset number of pull-in and opening operations and is not correctly pulled in or pulled in without conduction, a second abnormal signal is sent to the control module to control the third target relay to perform a first preset number of pull-in and opening operations; the third target relay is at least one of the main positive relay, the main negative relay, and the pre-charge relay;

[0060] In a case where the third target relay is determined to have a third preset number of pull-in delays, a third warning information is sent out.

[0061] In a possible implementation, the determination of 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 of the high-voltage loop comprises:

[0062] The resistance value of the main positive relay is determined to be abnormal according to the voltage of the positive electrode switch and the current of the high-voltage loop.

[0063] In a possible implementation, the determination of whether the resistance value of the main positive relay is abnormal according to the voltage of the positive electrode switch and the current of the high-voltage loop comprises:

[0064] In a case where the high-voltage loop meets a first preset condition, the contact resistance of the main positive relay is determined according to the voltage of the positive electrode switch and the current of the high-voltage loop.

[0065] In a case where the contact resistance of the main positive relay is greater than a first resistance threshold, it is determined that the resistance value of the main positive relay is abnormal.

[0066] In a case where 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.

[0067] In a possible implementation, the determination of 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 of the high-voltage loop comprises:

[0068] The resistance value of the main negative relay is determined to be abnormal according to the voltage of the main negative relay and the current of the high-voltage loop.

[0069] In a possible implementation, the 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 loop comprises:

[0070] In a case where the high-voltage switch satisfies a first preset condition, the contact resistance of the main negative relay is determined according to the voltage of the main negative relay and the current of the high-voltage loop.

[0071] In a case where the contact resistance of the main negative relay is greater than a first resistance threshold, it is determined that the resistance value of the main negative relay is abnormal.

[0072] In a case where 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.

[0073] In a possible implementation, the first preset condition comprises 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 loop is greater than a second preset current.

[0075] The high-voltage loop is abnormal.

[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 comprises:

[0079] In a case where the resistance value of the fourth target relay is determined to be abnormal for the first time, it is detected again whether the resistance value of the fourth target relay is abnormal; the fourth target relay comprises the main positive relay and / or the main negative relay.

[0080] In a case where the resistance value of the fourth target relay is determined to be abnormal for a fourth preset number of times, fourth warning information is sent.

[0081] In a case where the resistance value of the fourth target relay is not determined to be abnormal for the fourth preset number of times, the number of times of detection of abnormal resistance value is cleared.

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

[0083] In a case where the current of the high-voltage loop is greater than a third preset current, it is determined that one of the main positive relay and the pre-charge relay, and the main negative relay, is stuck.

[0084] In a case where the current of the high-voltage loop 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 do not simultaneously stick.

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

[0086] According to a time during which the current of the high-voltage loop is equal to the third preset current for the first time, and a time during which the power-off control signal is given first in the main positive relay and the main negative relay, a high-voltage power-off time is determined.

[0087] According to the high-voltage power-off time, it is determined whether the relay that receives the power-off control signal first is disconnected with delay.

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

[0089] In a case where the high-voltage power-off time is greater than or equal to a second preset time, it is determined that the relay that receives the power-off control signal first is disconnected with delay.

[0090] In a case where the high-voltage power-off time is less than the second preset time, it is determined that the relay that receives the power-off control signal first is disconnected normally.

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

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

[0093] In a case where the bleeder loop meets a second preset condition, it is determined, according to a current of the bleeder loop, whether the main positive relay and the pre-charge relay stick.

[0094] In a possible implementation, the determining whether the main positive relay and the pre-charge relay stick according to the current of the bleeder loop includes:

[0095] In a case where the current of the bleeder loop is greater than a third preset current, it is determined that the main positive relay or the pre-charge relay sticks.

[0096] In a case where the current of the bleeder loop is less than or equal to the third preset current, it is determined that the main positive relay and the pre-charge relay do not stick.

[0097] In a possible implementation, the bleeder loop includes a bleeder module connected between the main positive relay and the main negative relay.

[0098] The second preset condition comprises: the bleed module is equivalent to ground, or the main negative relay is closed.

[0099] In a possible implementation, the method further comprises:

[0100] In a possible implementation, the method further comprises:

[0101] In a possible implementation, the method further comprises:

[0102] In a possible implementation, the method further comprises:

[0103] In a possible implementation, the method further comprises:

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

[0105] In a possible implementation, the method further comprises:

[0106] In a possible implementation, the method further comprises:

[0107] In a possible implementation, the method further comprises:

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

[0109] In a possible implementation, the method further comprises:

[0110] In a possible implementation, the method further comprises:

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

[0112] In a case where the sixth target relay is determined to be stuck for the first time, a third abnormal signal is sent to the control module to make the control module control the sixth target relay to be opened; the sixth target relay includes the main positive relay and / or the pre-charge relay;

[0113] In a case where the sixth target relay is determined to be stuck for the sixth preset number of times, sixth warning information is sent.

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

[0115] In a case where the high-voltage switch is determined to be abnormal, the operating parameters of the high-voltage loop are stored, the operating parameters including 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 loop.

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

[0117] In a case where the vehicle is in a high-voltage power-on stage, 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 loop is acquired;

[0118] In a case where the vehicle is in a high-voltage running stage, at least one of the voltage of the positive switch, the voltage of the main negative relay, and the current of the high-voltage loop is acquired;

[0119] In a case where the vehicle is in a high-voltage power-off stage, the current of the high-voltage switch is acquired.

[0120] In a second aspect, the 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 of the first aspect.

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

[0124] The high-voltage switch, the voltage detection module, the current detection module, and the control module of the second aspect;

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

[0126] The positive electrode switch comprises a main positive relay, a pre-charging relay and a pre-charging resistor, and the negative electrode switch comprises a main negative relay;

[0127] A first end of the main positive relay is connected to a first end of the pre-charging relay as a first end of the positive electrode switch, a second end of the main positive relay is connected to a second end of the pre-charging resistor as a second end of the positive electrode switch, a second end of the pre-charging relay is connected to the second end of the pre-charging resistor, a first end of the main negative relay is connected to a second end of the main negative relay as a first end of the negative electrode switch, and a second end of the main negative relay is connected to a second end of the main negative relay as a second end of the negative electrode 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-charging 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 a voltage of the positive electrode switch, a voltage of the main negative relay, a voltage of the pre-charging relay and a voltage of the pre-charging resistor, and send the voltage to the control module;

[0131] The current detection module is configured to detect a current of a high-voltage loop, and send the current 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 electrode 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 loop.

[0133] In a possible implementation, the voltage detection module comprises 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, the first switch and the second switch are further included.

[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 configured to control whether the first interface and the first end of the main positive relay are in communication.

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

[0142] In a possible implementation, the bleed module is further included.

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

[0144] The bleed module is configured to bleed the residual voltage of the high-voltage loop when the vehicle is in the high-voltage charging stage.

[0145] In a possible implementation, the bleed module includes a bleed assembly and a fourth switch.

[0146] The first end of the fourth switch is the first end of the bleed module, the second end of the fourth switch is connected to the first end of the bleed assembly, and the second end of the bleed assembly is the second end of the bleed module.

[0147] In a fourth aspect, the application provides a high-voltage system, including the detection circuit of the high-voltage switch, 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] In a fifth aspect, the application provides a vehicle including the high-voltage system of the fourth aspect.

[0150] In a sixth aspect, the application provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a processor, the computer-executable instructions are configured to implement the first aspect and / or various possible implementation manners of the first aspect.

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

[0152] The detection method, control module, circuit, system and vehicle provided by the embodiment of the present application have corresponding operating parameters in different stages of the vehicle, and the operating parameters can include the voltage and / or current of the relay. When the high-voltage switch is abnormal, the operating parameters of the high-voltage loop will be affected, so whether the high-voltage switch is abnormal can be determined according to the operating parameters in different stages, and the accuracy of abnormal detection of the high-voltage switch is improved. BRIEF DESCRIPTION OF DRAWINGS

[0153] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the application and, together with the description, serve to explain the principles of the application.

[0154] Figure 1 A structural schematic diagram of the high-voltage loop provided by the present application is shown in the figure;

[0155] Figure 2 A flowchart of the detection method of the high-voltage switch provided by the present application is shown in the figure;

[0156] Figure 3 A structural schematic diagram of the control device provided by the present application is shown in the figure;

[0157] Figure 4 A structural schematic diagram of the detection circuit of the high-voltage switch provided by the present application is shown in the figure;

[0158] Figure 5 A circuit schematic diagram of the detection circuit of the high-voltage switch provided by the present application is shown in the figure.

[0159] Through the above-mentioned drawings, the specific embodiments of the present application have been shown, and more detailed descriptions will be given hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0160] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The following description is only one of the embodiments consistent with the present application, and is not intended to represent all embodiments consistent with the present application. Rather, 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, the high-voltage loop includes the power battery 30, the high-voltage distribution box 10, and the high-voltage electrical equipment 20. The high-voltage distribution box 10 includes a high-voltage switch for controlling the on-off of the high-voltage loop. Abnormalities of the high-voltage switch will affect the safety, stability, and reliability of the high-voltage loop. Due to the lack of operation monitoring data of the high-voltage switch (such as positive relay, main negative relay, and pre-charge relay), the high-voltage distribution box 10 is currently recycled, and then whether the high-voltage switch is abnormal is analyzed manually. This way is time-consuming and laborious, and lacks preliminary abnormality positioning when the abnormality occurs. When analyzing the abnormality of the high-voltage switch, it is difficult to reproduce the abnormality again due to factors such as environment, condition, and operation mode, which affects the accuracy of the abnormality detection of the high-voltage switch.

[0162] Therefore, the application provides a detection method of a high-voltage switch. When the high-voltage switch is abnormal, the operation parameters (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 loop) of the high-voltage loop will be affected. Therefore, whether the high-voltage switch is abnormal can be determined according to the operation parameters of the high-voltage loop, and the accuracy of the abnormality detection of the high-voltage switch is improved.

[0163] The technical solutions of the application and how the technical solutions solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the application will be described below with reference to the drawings.

[0164] Figure 2 Flowchart of the detection method of the high-voltage switch provided by the application Figure 1 As shown in the flowchart, the method includes the following steps. Figure 2

[0165] S101, in the case that the vehicle is in a high-voltage power-up 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-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage loop.

[0166] The high-voltage power-up stage refers to the stage in which the vehicle is switched 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, and 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 loop, so as to control whether to supply power to the high-voltage electrical equipment.

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

[0169] In some optional embodiments, the high-voltage circuit includes a power battery, a high-voltage switch, and a high-voltage electrical device, and the high-voltage switch connects the power battery and the high-voltage electrical device.

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

[0171] For example, the high-voltage electrical equipment may include a drive motor, an electric compressor, a DC-DC converter, an on-board charger, and the like.

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

[0173] Accordingly, when the vehicle is in the high-voltage power-up phase, the pre-charge relay and the main negative relay are closed, and the main positive relay is opened to charge the capacitor. When the voltage across the capacitor reaches the preset value of the battery voltage, the main positive relay is closed, the pre-charge relay is opened, and the vehicle is ready for the high-voltage operation phase. The preset value can be any value between 90% and 95%.

[0174] For example, 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 of the pre-charge resistor may be 100 Ω.

[0175] For example, the abnormality of the relay may include sticking, delayed energization, incorrect energization, non-conduction during energization, etc. Among them, delayed energization, incorrect energization, and non-conduction during energization may be referred to as abnormal energization.

[0176] In some optional embodiments, whether the main positive relay and the pre-fill relay are stuck is determined based on the current of the high-voltage circuit. It is understandable that if the main positive relay or the pre-fill relay is stuck, it will affect the current of the high-voltage circuit. For example, if the main positive relay is stuck, the current of the high-voltage circuit will be large, and if the pre-fill relay is stuck, the current of the high-voltage circuit will be small. Therefore, it is possible to more accurately determine whether the main positive relay and the pre-fill relay are stuck based on the current of the high-voltage circuit during the high-voltage power-on stage.

[0177] It should be noted that, considering that the high current generated by the main positive relay sticking can damage circuit components, the main positive relay can be checked for sticking during the high-voltage power-up phase. Furthermore, to reduce the impact of the brief high current during the main positive relay sticking detection process, sticking detection can be prioritized during the high-voltage power-down phase.

[0178] In some specific embodiments, the current It1 in the high voltage circuit is greater than or equal to the first preset current I1 and less than the maximum set current I 1max In the case of (that is, I1≤It1<I 1max ), confirm that the pre-charge relay is stuck; when the current It1 of the high-voltage circuit is greater than the maximum set current I 1max In the case of (that is, I t1 >I 1max ), determine that the main positive relay is stuck; when the current It1 of the high-voltage circuit is less than the first preset current I1 (ie I t1 <I1), it is determined that the main positive relay and the pre-charge relay are not adhered, so that it can be determined whether the main positive relay and the pre-charge relay are adhered based on the current of the high-voltage circuit.

[0179] For example, 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-fill relay can be closed. Therefore, the current of the high-voltage circuit can be detected after the main negative relay is closed and before the pre-fill relay is closed. 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, it is determined that the pre-fill relay is stuck; when the current of the high-voltage circuit is greater than the maximum set current, it is determined 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-fill relay are not stuck. The first preset current can be determined based on the difference between the power battery voltage and the voltage across the capacitor, the capacitor, the pre-fill resistance, and the high-voltage circuit resistance, for example, it can be 0~10A, for example, 0.2A. The maximum set current can be 10A, for example. In this example, the current of the high-voltage circuit can be 1.2A, for example.

[0180] It should be noted that the main negative relay needs to be closed during the high-voltage power-on stage and the high-voltage operation stage. Therefore, it is not necessary to detect whether the main negative relay is stuck during the high-voltage power-on stage and the high-voltage operation stage.

[0181] In some specific implementations, after it is determined that the main positive relay is stuck, the main negative relay may be disconnected immediately to prevent excessive pre-charge current from damaging circuit components (eg, capacitors).

[0182] In some specific embodiments, when the first target relay is determined to be stuck, a first abnormality signal is sent to a control module (e.g., a battery management system (BMS) or a vehicle control unit (VCU)), causing the control module to control the first target relay to be closed and opened a first preset number of times. If the first target relay is determined to be stuck within a second preset number of times, a first warning message is issued. The first target relay may include a main positive relay or a pre-charge relay; closing and opening constitute a single operation; the first preset number of times can be determined based on actual conditions, and the second preset number of times can be, for example, 3 to 5.

[0183] For example, during the high-voltage power-on process, when the abnormal state of the relay sticking is detected for the first time, the system will not give a warning signal; at this time, the signal will be fed back to the control module for multiple closing and opening actions of the relay and then tested again. If the relay is detected as sticking for 3-5 consecutive times, the system will give a corresponding warning signal of relay sticking.

[0184] In some optional embodiments, whether the pre-fill relay and the main negative relay are abnormally engaged can be determined based on the current in the high-voltage circuit and the voltage of the positive switch. Abnormal engagement of the pre-fill relay or the main negative relay will affect the current in the high-voltage circuit, and abnormal engagement of the pre-fill relay will also affect the voltage of the positive switch. Therefore, based on the current in the high-voltage circuit and the voltage of the positive switch, it can be more accurately determined whether the pre-fill relay and the main negative relay are abnormally engaged.

[0185] In some optional examples, 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 within the first preset time, it is determined that the pre-charge 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 there is a relay with abnormal energization among the pre-charge relay and the main negative relay, and then which relay among the pre-charge relay and the main negative relay is abnormally energized is determined based on the voltage of the positive pole switch.

[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 based on the pull-in time of the relay when it leaves the factory and the pre-charge time under normal circumstances. For example, if the pull-in time is 14ms and the pre-charge time is 200ms, the first preset time can be 14+200×0.5=114ms. 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 based on actual conditions.

[0187] For example, when the power-on signal of the pre-charging relay is received, the pre-charging relay is closed. The current of the high-voltage circuit can be detected within the first preset time of the closure of the pre-charging relay. 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-charging relay and the main negative relay are normally energized. 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-charging relay or the main negative relay is abnormally energized.

[0188] In some specific embodiments, during the first preset time, the current I t1 is less than the first preset current I1 and the voltage U of the positive switch t1 When the voltage is greater than or equal to the first preset voltage U1 (ie I t1 <I1,U t1 ≥U1), determine that the pre-charge relay is abnormal; within the first preset time, the current I t1 is less than the first preset current I1 and the voltage U of the positive switch t1 When the voltage is less than the first preset voltage U1 (i.e. I t1 <I1,U t1 <U1), determining that the main negative relay is abnormally engaged, thereby determining that the pre-charge relay or the main negative relay is abnormally engaged based on the current of the high-voltage circuit and the voltage of the positive switch. The first preset voltage can be 300V. In this embodiment, the voltage of the positive switch can be, for example, 350V or 0V.

[0189] In some specific examples, when the current of the high-voltage circuit (for example, 0A) is less than the first preset current (for example, 0.2A) and the voltage of the positive switch is greater than or equal to the first preset voltage within the first preset time, the current of the high-voltage circuit after the first preset time determines that the pre-charge relay is delayed in closing, incorrectly closed, or not conducting when closed.

[0190] For example, when the current of the high-voltage circuit (for example, 1A) is greater than or equal to the first preset current after a first preset time, it is determined that the pre-charging relay is delayed in closing; when the current of the high-voltage circuit (for example, 0A) is less than the first preset current after a first preset time, it is determined that the pre-charging relay is not correctly closed or is not conductive when closed.

[0191] In some specific examples, when the current of 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 within the first preset time, the current of the high-voltage circuit after the first preset time determines that the main negative relay is delayed in closing, incorrectly closed, or not conducting when closed.

[0192] For example, in a case where the current of the high-voltage loop is greater than or equal to the first preset current after the first preset time, it is determined that the main negative relay is delayed in being attracted; in a case where the current of the high-voltage loop is less than the first preset current after the first preset time, it is determined that the main negative relay is not correctly attracted or is not attracted to be conductive.

[0193] In a specific embodiment, in a case where the second target relay is determined to be delayed in being attracted for the first time, it is detected again whether the second target relay is delayed in being attracted, the second target relay including the pre-charge relay and / or the main negative relay; in a case where the second target relay is determined to be delayed in being attracted for a third preset number of times, a third warning information is given. The third preset number of times may, for example, be 2-10.

[0194] For example, in a high-voltage power-on process, in a case where the pre-charge (high-voltage power-on) is still successful, when the pre-charge relay and / or the main negative relay is detected to be delayed in being attracted for the first time, the system does not give a warning signal and does not perform multiple attraction operations; if the relay is detected to be delayed in being attracted for a third preset number of times (for example, an integer between 2 and 10) continuously, the system gives a corresponding abnormal state warning signal, so that excessive maintenance work caused by occasional relay delay in being attracted can be reduced.

[0195] In some optional embodiments, whether the resistance value of the pre-charge relay is abnormal can be determined according to the voltage of the pre-charge resistor and the voltage of the pre-charge relay, and whether the resistance value of the main negative relay is abnormal can be determined according to the voltage of the pre-charge resistor and the voltage U S3 of the main negative relay, so that whether the resistance value of the pre-charge relay and whether the resistance value of the main negative relay are abnormal can be determined more accurately according to the voltage of the relay in the high-voltage power-on stage.

[0196] In a specific embodiment, after the pre-charge relay is closed, in a case where 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 a first preset ratio P1 (i.e., U S2 / U R1 >P1), it is determined that the resistance value of the pre-charge relay is abnormal; in a case where the ratio of the voltage U S2 of the pre-charge relay to the voltage U R1 of the pre-charge resistor 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, in a case where the ratio of the voltage (for example, 6V) of the pre-charge relay to the voltage (for example, 30V) of the pre-charge resistor (for example, 0.2) is greater than a first preset ratio (for example, 0.1), it is determined that the resistance value of the pre-charge relay is abnormally increased.

[0198] In a specific embodiment, after the pre-charge relay is closed, before the pre-charge is completed, the voltage U S3 of the main negative relay is greater than the voltage U R1 of the pre-charge resistor, it is determined that the resistance of the main negative relay is abnormal; when the voltage U S3 of the main negative relay is less than or equal to the voltage U R1 of the pre-charge resistor, it is determined that the resistance of the main negative relay is normal. S3 R1 S3 R1

[0199] For example, the voltage of the pre-charge resistor can be obtained by calculating the difference between the voltage of the positive switch and the voltage of the pre-charge relay, or directly measuring the voltage of the pre-charge relay.

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

[0201] In a specific embodiment, when it is determined for the first time that the resistance of the second target relay is abnormal, the resistance of the second target relay is detected again to determine whether it is abnormal, the second target relay including the pre-charge relay and / or the main negative relay; when it is determined for the third preset number of times that the resistance of the second target relay is abnormal, a second warning information is sent.

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

[0203] In some optional 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 disconnected to charge the capacitor; when the voltage across the capacitor reaches a preset value (for example, 90%-95% of the battery voltage) of the battery voltage, the main positive relay is closed, the pre-charge relay is disconnected, and the vehicle is ready for the high-voltage operation stage. When the pre-charge relay is disconnected and the main positive relay is closed, if the main positive relay is abnormal, it will affect the current of the high-voltage loop. Therefore, whether the main positive relay is abnormal can be determined according to the current of the high-voltage loop.

[0204] ​​​​In a specific embodiment, in the case that the voltage across the capacitor reaches the preset value, the main positive relay is closed and the pre-charge relay is disconnected, and the current of the high-voltage loop 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 properly attracted or is not attracted to it. In the case that the current of the high-voltage loop is greater than the fourth preset current within the third preset time, it is determined that the main positive relay is normally attracted. The fourth preset current may be, for example, a value close to 0, for example, 0. The third preset time may be determined according to actual conditions and is not limited here.

[0205] For example, in the case that the current of the high-voltage loop is continuously equal to 0, it is determined that the main positive relay is not properly attracted or is not attracted to it; in the case that the current of the high-voltage loop is greater than 0, it is determined that the main positive relay is normally attracted.

[0206] In a specific embodiment, in the case that the third target relay is determined to be not properly attracted or not attracted to it for the first time, second abnormal information is sent to the control module to control the third target relay to be attracted and disconnected for a first preset number of times, the third target relay being at least one of the main positive relay, the main negative relay and the pre-charge relay; in the case that the third target relay is determined to be not properly attracted or not attracted to it in the third preset number of times, third warning information is issued.

[0207] For example, during the high-voltage power-on process, when the relay is first detected to be in an abnormal state of not being properly attracted or not being attracted to it, the first pre-charge fails at this time and cannot successfully power on. The system does not give a warning signal at this time, and the signal is fed back to the control module for multiple attractings of the relay. If the relay is continuously detected to be abnormal for a third preset number of times (for example, an integer between 2 and 10), the system gives a corresponding abnormal state warning signal, thereby reducing the excessive maintenance work caused by the occasional pre-charge relay not being properly attracted or not being attracted to it.

[0208] S102, in the case that the vehicle is in a high-voltage running phase, at least one relay in the high-voltage switch is determined to be abnormal according to 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 loop.

[0209] The high-voltage running phase refers to a phase in which the high-voltage electrical equipment of the vehicle is normally powered and the vehicle can normally run and be used. In the case that the vehicle is in the high-voltage running phase, the main positive relay and the main negative relay are closed, and the pre-charge relay is disconnected.

[0210] In an optional embodiment, it is possible to determine whether the resistance of the main positive relay is abnormal based on the voltage of the positive switch and the current of the high-voltage circuit, thereby more accurately determining whether the main positive relay is abnormal based on the current of the high-voltage circuit during the high-voltage operation stage and the voltage of the positive switch.

[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 switch and the current of the high-voltage circuit. S1 ; Contact resistance R of the main positive relay S1 Greater than the first resistance threshold In the case of R S1 > ), determine the resistance of the main positive relay is abnormal; the contact resistance R S1 Less than or equal to the first resistance threshold In the case of R S1 ≤ ), confirm that the resistance of the main positive relay is normal.

[0212] For example, foreign matter on the contacts, oxidation of the contacts, etc. may cause abnormal resistance of the relay.

[0213] For example, the first resistance threshold value may be set according to the model of the relay, and is generally less than 50 mΩ.

[0214] For example, if the voltage of the positive switch is 100mV and the current of the high voltage circuit is 200A, the contact voltage R of the main positive relay is S1 =100mV / 200A=0.5mΩ. The first resistance threshold may be, for example, 10mΩ. 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 based on the voltage of the main negative relay and the current of the high-voltage circuit. S3 ; Contact resistance R of the main negative relay S3 Greater than the first resistance threshold In the case of R S3 > ), determine the resistance of the main negative relay is abnormal; the contact resistance R S3 Less than or equal to the first resistance threshold In the case of R S3 ≤ ), confirm that the resistance of the main negative relay is normal.

[0216] For example, the voltage of the main negative relay is 3V, and the current of the high-voltage loop is 200A, the contact voltage R of the main positive relay is 3V / 200A=15mΩ. The first resistance threshold value can be 10mΩ, and the contact resistance of the main negative relay is greater than the first resistance threshold value, which determines that the resistance of the main negative relay is abnormally increased. S1

[0217] For example, the preset condition can include that the main positive relay and the main negative relay are closed, and the current of the high-voltage loop is greater than a 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 loop is small, the voltage drop of the main positive relay or the main negative relay is small, and it is difficult to detect whether the resistance of the main positive relay or the main negative relay is abnormal. Therefore, when the current of the high-voltage loop is less than the second preset current, whether the resistance of the main positive relay or the main negative relay is abnormal is detected.

[0218] The first preset condition can also include that the high-voltage loop is abnormal. Considering that when the high-voltage loop is abnormal, the resistance of the main positive relay or the main negative relay measured at a certain current can suddenly be particularly large (for example, a sudden change from mΩ to Ω), at this time, the main positive relay or the main negative relay will have a significant voltage drop without the current being greater than the second preset current. Therefore, when the high-voltage loop is abnormal, the contact resistance of the main positive relay or the main negative relay is immediately measured without requiring the current of the high-voltage loop to be greater than the second preset current. The high-voltage loop being abnormal can be, for example, a fault of the main positive relay losing power at high voltage after pre-charging is completed.

[0219] For example, 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, greater than 20A.

[0220] In a specific embodiment, when it is first determined that the resistance of the fourth target relay is abnormally increased, the resistance of the fourth target relay is detected again to determine whether the resistance of the fourth target relay is abnormally increased, the fourth target relay including the main positive relay and / or the main negative relay; when it is determined that the resistance of the fourth target relay is abnormal in a fourth preset number of times, a fourth warning information is issued; and when it is not determined that the resistance of the fourth target relay is abnormal in the fourth preset number of times, the number of times of detecting the abnormal resistance is cleared.

[0221] ​For example, when the contact resistance of the relay is detected to be in the abnormal increase state for the first time, the system does not give a warning signal, and the signal is fed back to the control module for multiple detections after the detection condition is met; if the relay is in the abnormal increase state for more than the fourth preset number of times (1 / 3N2~1 / 2N2, the result is a natural integer) in the continuous N2 detections, the system gives a warning signal that the contact resistance of the relay is abnormally increased. Otherwise, the number of abnormal increase state detections that have occurred is cleared at the N2+1th detection. N2 can be an integer between 2 and 10. The number of abnormal increase state detections is cleared for the state evaluation circuit, and all monitoring data itself is not cleared for subsequent fault analysis.

[0222] For example, if the main negative relay is detected to be in the abnormal increase state for 6 times in the continuous 10 detections, which meets the judgment condition that more than 4 times are in the abnormal increase state, 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 to be in the abnormal increase state for only 2 times in the continuous 10 detections, the system does not give a warning signal that the contact resistance of the main negative relay is abnormally increased. The number of abnormal increase state detections that have occurred is cleared at the 11th detection. The number of abnormal increase state detections is cleared for the state evaluation circuit, and all monitoring data itself is not cleared for subsequent fault analysis.

[0223] For example, in addition to encountering short-circuit current and other extreme situations, the contact resistance of the main positive relay and the main negative relay is not usually detected to be abnormal at the same time; when the main positive relay and the main negative relay are detected to be in the abnormal increase state for more than 5 times in the continuous 10 detections, the system gives a warning signal that the relay state detection circuit is abnormal and the contact resistance of the relay is abnormally increased.

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

[0225] S103, in the case that the vehicle is in the high-voltage power-off phase, determining whether at least one relay in the high-voltage switch is abnormal according to the current of the high-voltage circuit.

[0226] The high-voltage power-off phase refers to the phase from the high-voltage running phase of the vehicle to the complete power-off phase. In the case that the vehicle is in the high-voltage power-off phase, the main positive relay, the main negative relay and the pre-charging relay are disconnected.

[0227] In some optional embodiments, in response to the high-voltage de-energization signal, when the main positive relay and the main negative relay are disconnected, before the high-voltage discharge module is started, if the current of the high-voltage loop is greater than a third preset current, it is determined that one of the main positive relay and the pre-charging relay, and the main negative relay are stuck simultaneously, that is, the main positive relay and the main negative relay are stuck simultaneously, or the pre-charging relay and the main negative relay are stuck simultaneously; if the current of the high-voltage loop is less than or equal to the third preset current, it is determined that one of the main positive relay and the pre-charging relay, and the main negative relay are not stuck simultaneously, that is, the main positive relay and the main negative relay are not stuck simultaneously, or the pre-charging relay and the main negative relay are not stuck simultaneously, so that the abnormality of the high-voltage switch can be more accurately determined according to the current of the high-voltage loop in the high-voltage de-energization stage, and the accuracy of the abnormality detection of the high-voltage switch is improved.

[0228] For example, the high-voltage loop can further include a discharge module connected in parallel with the capacitor, and if the current of the high-voltage loop is greater than a third preset current before the discharge module is started after the main positive relay and the main negative relay are disconnected in response to the high-voltage de-energization signal, it is determined that one of the main positive relay and the pre-charging relay, and the main negative relay are stuck simultaneously. The third preset current can be a value close to 0, for example, 0.

[0229] In some optional embodiments, the high-voltage de-energization time is determined according to the time during which the current of the high-voltage loop is equal to the third preset current for the first time, and the time at which the de-energization control signal is first given in the main positive relay and the main negative relay, so that whether the relay that first receives the de-energization control signal is delayed in disconnection can be more accurately determined.

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

[0231] For example, the relay that first receives the de-energization control signal can be the main positive relay or the main negative relay.

[0232] For example, the time when the first of the main positive relay and the main negative relay receives the power-off control signal and the time when the current of the high-voltage loop is equal to the third preset current (for example, the time when the current of the high-voltage loop is equal to 0 is first detected) can be recorded, and the time difference between the two is taken 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), it is determined that the relay that first receives the power-off control signal is delayed in disconnection; 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 is normally disconnected.

[0233] For example, the second preset time can be determined according to the release time of the relay when it is shipped from 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 embodiment, in the case of determining the fifth target relay disconnection delay for the first time, it is detected again whether the fifth target relay is delayed in disconnection, the fifth target relay including the relay that first gives the power-off control signal among the main positive relay and the main negative relay; in the case of determining the fifth target relay disconnection delay for the fifth preset number of times, the fifth warning information is given.

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

[0236] In some optional embodiments, in the case where the bleeder loop meets the second preset condition, whether the main positive relay and the pre-charging relay are stuck is determined according to the current of the bleeder loop, so that whether the main positive relay and the pre-charging relay are stuck can be more accurately determined. The sticking can be caused by uneven contact surface, dirt or oxide between contacts, adsorption of contact materials, etc. It can also be caused by too large current passing through the contact, causing the contact temperature to rise above the melting point of the material, causing the contact to melt and solidify together.

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

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

[0239] In some specific embodiments, in a case where the current of 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, that is, there is a stuck relay in the main positive relay and the pre-charge relay; in a case where 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 whether there is a stuck relay in the main positive relay and the pre-charge relay can be determined.

[0240] In some specific embodiments, the second preset condition includes that the discharge module is equivalent to ground or the main negative relay is closed. For example, in a case where the discharge module is equivalent to ground (the discharge circuit has a grounding point or an equivalent grounding point), whether the main positive relay and the pre-charge relay are stuck can be determined according to the current of the discharge module; in a case where the discharge module is not equivalent to ground, 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, the main negative relay can be closed, and then whether the main positive relay and the pre-charge relay are stuck can be determined according to the current of the discharge circuit.

[0241] In some specific examples, in a case where the current of 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 considering that the resistance value of the pre-charge resistor is much greater 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 80Ω-200Ω, and the contact resistance of the main positive relay and the main negative relay is in the mΩ level), so whether the main positive relay or the pre-charge relay is stuck can be determined according to the voltage of the positive switch to locate the abnormal relay.

[0242] For example, when the voltage of the positive 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 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 switch is close to 0, and when the pre-charge relay is stuck, the voltage of the positive switch is greater than 0, so the voltage of the positive switch can be used to determine whether the main positive relay or the pre-charge relay is stuck.

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

[0244] In some specific examples, when the current of the discharge loop is greater than a third preset current, it is determined that the main positive relay or the pre-charge relay is stuck, and then the current of the discharge loop can be further used to determine which of the main positive relay and the pre-charge relay is stuck. When the current of the discharge loop (e.g. 7 A) is greater than the third preset current (e.g. 0 A) and greater than or equal to a fourth preset current (e.g. 4 A), it is determined that the main positive relay is stuck; when the current of the discharge loop (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] For example, the fourth preset current refers to a discharge current setting value, which can be determined according to the voltage of the power battery, the voltage of the capacitor, the pre-charge resistor, and the resistance of the discharge loop.

[0246] In some specific embodiments, 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 to control 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 for the sixth preset number of times that the sixth target relay is stuck, a sixth warning information is sent.

[0247] For example, when the abnormal state of the sticking of the relay is detected for the first time in the electric process under high pressure, the system does not give a warning signal, at this time, the signal is fed back to the control module for the second disconnection of the relay, if the relay is disconnected for the sixth preset number of times (for example, it can be an integer between 2-10) in succession, the system gives a warning signal that the relay is stuck. Considering that part of the contact sticking and sintering can be disconnected by itself during multiple disconnection operations, and the relay can still work normally after disconnection, therefore, the operation can significantly reduce the impact of such phenomena on the electric vehicle. At the same time, the frequency of repairing the relay is reduced, and the spread of the influence of the relay failure is avoided. For example, if the relay is disconnected for 4 times in succession, the system gives a warning signal that the relay is stuck / sintered.

[0248] The detection method of the high-voltage switch provided in the embodiment of the application can determine whether the high-voltage switch is abnormal according to the operating parameter of the high-voltage loop when the high-voltage switch is abnormal, thereby improving the accuracy of the abnormal detection of the high-voltage switch.

[0249] Figure 3 The structure schematic diagram of the control module provided in the application is shown in FIG. 1. As shown in the figure, the control module 50 provided in the embodiment includes at least one processor 501 and a memory 502. Optionally, the control module 50 further includes a communication component 503. The processor 501, the memory 502 and the communication component 503 are connected through a bus. Figure 3

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

[0251] The specific implementation process of the processor 501 can refer to the method embodiments described above, which has similar implementation principles and technical effects, and will not be described here in detail.

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

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

[0254] The bus can be an industry standard architecture (ISA) bus, a peripheral component (PCI) bus, or 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 bus in the drawings of the present application does not limit to only one bus or one type of bus.

[0255] The embodiment of the present application also provides a detection circuit of a high-voltage switch, as shown in the figure, the circuit can include: Figure 4 as shown in the figure, the circuit can include:

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

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

[0258] The positive switch 1011 includes a main positive relay S1, a pre-charging relay S2, and a pre-charging resistor R1; the first end of the main positive relay S1 is connected to the first end of the pre-charging relay S2, as the first end of the positive switch 1011; the second end of the main positive relay S1 is connected to the second end of the pre-charging resistor R1, as the second end of the positive switch 1011; the second end of the pre-charging relay S2 is connected to the first end of the pre-charging resistor R1. The negative switch 1012 includes a main negative relay S3; the first end of the main negative relay S3 is the first end of the negative switch 1012, and the second end of the main negative relay S3 is the second end of the negative 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-charging 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 equipment, and the control module 103.

[0260] Accordingly, the voltage detection module 102 can detect at least one of the voltage of the positive 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 to the control module 103. The current detection module 103 can detect the current of the high-voltage loop, and send 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 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 loop.

[0261] For example, the voltage detection module 102 can detect the voltage of the positive 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 to the control module 103. The current detection module 103 can also detect the current of the high-voltage loop when the vehicle is in the high-voltage power-on stage, and send 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 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 loop when the vehicle is in the high-voltage power-on stage;

[0262] For example, the voltage detection module 102 can detect the voltage of the positive switch 1011 and the voltage of the main negative relay S3 when the vehicle is in the high-voltage running stage, and send to the control module 103. The current detection module 103 can also detect the current of the high-voltage loop when the vehicle is in the high-voltage running stage, and send 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 switch 1011, the voltage of the main negative relay S3, and the current of the high-voltage loop when the vehicle is in the high-voltage running stage;

[0263] For example, the current detection module 103 can detect the current of the high-voltage loop when the vehicle is in the high-voltage power-off stage, and send 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 loop when the vehicle is in the high-voltage power-off stage.

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

[0265] For example, the current detection module 103 may be disposed outside the voltage detection loop 1011 of the positive switch, between the capacitor 106 and the positive switch 1011 , to avoid errors caused by the internal resistance of the current detection module 103 itself.

[0266] In other specific embodiments, when the current detection module 103 uses a non-contact sensor such as a current Hall sensor, its installation position is not required to be outside the voltage detection loop of the positive switch 1011 because its own internal resistance will not introduce errors.

[0267] In some specific embodiments, such as Figure 5 As shown, it also 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 detection module 102 can detect the voltage of the main negative relay S2.

[0268] In some specific embodiments, a discharge module 105 is further included; a first end of the discharge module 105 is connected to the second end of the main positive relay S1, and a 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 bleeding module 105 comprises a bleeding component and a fourth switch S4; a first end of the fourth switch S4 is the first end of the bleeding module 105, a second end of the fourth switch S4 is connected to a first end of the bleeding component, and a second end of the bleeding component is the second end of the bleeding module 105. The fourth switch S4 is used to control whether the bleeding module 105 is opened or not, so as to control whether the bleeding component can bleed the participation voltage of the high-voltage loop or not. The bleeding component may, for example, be a bleeding resistor or the like.

[0270] The embodiment of the present application further provides a high-voltage system comprising the detection circuit of the high-voltage switch, the power battery and the high-voltage electrical equipment.

[0271] The embodiment of the present application further provides a vehicle comprising the high-voltage system.

[0272] The present application further provides a computer program product comprising a computer program which, when executed by a processor, implements the method described above.

[0273] The present application further provides a computer-readable storage medium having computer-executable instructions stored therein, which, when executed by a processor, implement the method described above.

[0274] The above 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, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0275] Finally, it should be noted that: other embodiments of the application will be readily apparent to those skilled in the art with the consideration of the specification and practice of the application disclosed herein. The present application is intended to cover any variations, uses or adaptive changes of the application following the general principles of the application and including common knowledge or conventional technical means in the art which are not disclosed by the application, and is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application 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, and the negative switch includes a main negative relay. The method includes: When the vehicle is in a high-voltage power-on stage, determining 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-charge relay, the voltage of the pre-charge 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 based on 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 based on 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 based on 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 includes: Determine whether adhesion occurs between the main positive relay and the pre-charge relay based on the current of the high-voltage circuit.

3. The method according to claim 2, characterized in that The determining, based on the current of the high-voltage circuit, whether adhesion occurs between the main positive relay and the pre-charge relay includes: 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-charge relay are not stuck.

4. The method according to claim 1, wherein The determining 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-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit includes: 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-charge relay and the main negative relay are abnormally attracted, includes: Upon receiving the power-on signal of the pre-charge 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-charge relay and the main negative relay are normally attracted; 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-charge relay or the main negative relay is abnormally attracted 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-charge relay or the main negative relay is abnormally attracted, includes: 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; 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-charge 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-charge relay is delayed in closing, incorrectly closed, or non-conductive when closed, includes: After the first preset time, if the current of the high-voltage circuit is greater than or equal to the first preset current, determining the pre-charge relay pick-up delay; If the current of the high-voltage circuit is less than the first preset current after the first preset time, it is determined that the pre-charging relay is not correctly attracted or is not conducting when attracted.

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 after closing, includes: After the first preset time, if the current of the high-voltage circuit is greater than or equal to the first preset current, determining the main negative relay pickup delay; If the current of the high-voltage circuit is less than the first preset current after the first preset time, 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 based on 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 includes: determining whether the resistance 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 of the pre-filling relay is abnormal according to the voltage of the pre-filling resistor and the voltage of the pre-filling relay includes: After the pre-charging relay is closed and before pre-charging is completed, if 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 of the main negative relay is abnormal according to the voltage of the pre-charging resistor and the voltage of the main negative relay includes: After the pre-charging relay is closed and before pre-charging is completed, if 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, wherein The determining 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-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit includes: Determine whether the main positive relay is abnormally attracted based on the current of the high-voltage circuit.

15. The method according to claim 14, characterized in that The determining, based on the current of the high-voltage circuit, whether the main positive relay is abnormally attracted, includes: 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 opened 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 closing delay, detecting again whether the second target relay has a closing 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 correctly 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; If it is determined within the third preset number of times that the third target relay is not correctly energized or is not conductive when energized, a third warning message is issued.

20. The method according to claim 1, wherein The determining 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, and the current of the high-voltage circuit includes: 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 based on the voltage of the positive switch and the current of the high-voltage circuit includes: When the high-voltage circuit meets a 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, wherein The determining 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, and the current of the high-voltage circuit includes: Whether the resistance 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 a 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; issuing a fourth warning message when it is determined that the resistance value of the fourth target relay is abnormal within a fourth preset number of times; If the resistance abnormality of the fourth target relay is not determined within the fourth preset number of times, the number of detection times of the resistance abnormality is reset to zero.

28. The method according to claim 1, wherein The determining, based on the current of the high-voltage circuit, whether at least one relay in the high-voltage switch is abnormal includes: 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: Determining a high voltage power-off time based on the time when the current of the high voltage circuit first continuously equals the third preset current 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 that first receives the power-off control signal is disconnected and delayed.

30. The method according to claim 29, wherein The determining, based on the high voltage power-off time, whether the relay that first receives the power-off control signal is disconnected and delayed includes: When the high voltage power-off time is greater than or equal to a second preset time, determining a 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, wherein The second preset time is greater than the release time of the relay.

32. The method according to claim 1, wherein The method further comprises: 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 of the discharge circuit.

33. The method according to claim 32, characterized in that The determining whether adhesion occurs between the main positive relay and the pre-charge relay according to the current of the discharge circuit includes: 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-charge relay are not stuck.

34. The method according to claim 33, wherein 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, wherein 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-charge relay is stuck.

36. The method according to claim 35, characterized in that The determining, based on the voltage of the positive switch, whether the main positive relay or the pre-charge relay is stuck includes: When the voltage of the positive switch is less than a 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, wherein 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 status detection time.

38. The method according to claim 33, wherein The determining that the main positive relay or the pre-charge 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, wherein 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 fifth target relay includes the relay that first gives the 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 a fifth preset number of times, a fifth warning message is issued.

40. The method according to any one of claims 33 to 37, wherein 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, wherein 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-charge relay, the voltage of the pre-charge resistor, and the current of the high-voltage circuit.

42. The method according to claim 1, wherein 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-charge relay, the voltage of the pre-charge 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-off 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 the control module according to 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-charge relay, serving 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, serving 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 serves as the first end of the negative switch; 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-charge relay and the voltage of the pre-charge resistor, and send the detected 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-charge relay, the voltage of the pre-charge 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 the first end of the main positive relay, and the second interface is connected to the 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 comprising 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 the 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 bleeder 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 the 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-pressure system, characterized in that A detection circuit, a power battery, and a high-voltage electrical device comprising the high-voltage switch according to any one of 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 executed by a processor.

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