Method for determining main insulation resistance of motor, early warning method, device and system

Abstract

The invention is suitable for the field of vehicles, and provides a method for determining the main insulation resistance of a motor, and an early warning method, device and system, and the method comprises the steps: obtaining a first insulation resistance value, detected by a battery management system, of a target electrode of a drive motor system to the ground; acquiring a second insulation resistance value, detected by the battery management system, of a target electrode of the driving motor system to the ground; and the resistance value of the main insulation resistor of the motor is determined based on the first insulation resistance value and the second insulation resistance value, so that the resistance value of the main insulation resistor of the motor of the electric vehicle can be detected in situ on the basis of not disassembling and assembling the motor of the electric vehicle. The detected resistance value of the main insulation resistor can be sent to the cloud end, and the cloud end outputs early warning information when determining that the main insulation resistor of the motor has a failure risk based on the early warning method, so that a user can arrange maintenance in time before the motor fails.

Description

Technical Field

[0001] The present application belongs to the technical field of electric vehicles, and in particular, relates to a method for determining the main insulation resistance of a motor, an early warning method, a device and a system. Background Art

[0002] At present, the voltage level of new energy electric vehicles has gradually developed from 400V to 800V. The motor is a key part of new energy vehicles, and the increase in voltage brings new challenges to the insulation design of the motor. Motor insulation failure will not only cause damage to the equipment, but also affect driving safety in serious cases.

[0003] Existing motor fault monitoring mainly includes post-maintenance and preventive maintenance. Post-maintenance will incur high costs, the motor will be damaged in the fault, and the loss of power during driving will cause driving safety problems. Currently, periodic preventive maintenance is widely used. Commonly used AC motor detection methods include insulation resistance and absorption ratio of windings, DC resistance of windings, leakage current and DC withstand voltage test of stator windings, AC withstand voltage test of stator windings, etc. Periodic preventive maintenance requires driving the vehicle to a specific maintenance site, removing the motor from the vehicle or disconnecting the high-voltage power supply line, and then having professionals use detection instruments to conduct detection; each detection may cause damage to the motor equipment, and unnecessary detection is not conducive to the health of the motor equipment. Summary of the invention

[0004] In response to the above-mentioned problems, the embodiments of the present application provide a method, an early warning method, an apparatus and a system for determining the main insulation resistance of a motor, which are used to detect the resistance value of the main insulation resistance of the motor of an electric vehicle in situ without disassembling or assembling the motor of the electric vehicle.

[0005] In a first aspect, an embodiment of the present application provides a method for determining a main insulation resistance of a motor, the method comprising:

[0006] Obtaining a first insulation resistance value of a target electrode of a drive motor system to ground detected by a battery management system, wherein the target electrode is a positive electrode or a negative electrode of the drive motor system; the first insulation resistance value is an insulation resistance value of the target electrode to ground when a motor controller of the drive motor system disconnects a motor winding and a battery;

[0007] Acquire a second insulation resistance value of the target electrode to ground of the drive motor system detected by the battery management system; the second insulation resistance value is the insulation resistance value of the target electrode to ground when the motor controller realizes electrical connection between the winding of the motor and the battery;

[0008] A resistance value of a main insulation resistor of the motor is determined based on the first insulation resistance value and the second insulation resistance value.

[0009] In some embodiments, the method further comprises:

[0010] The three-phase upper bridge arm and the three-phase lower bridge arm of the inverter unit in the motor controller of the electric vehicle are controlled to be in a non-conducting state so that the motor controller disconnects the winding of the motor and the battery, and the motor controller communicates with the battery management system.

[0011] In some embodiments, the method further comprises:

[0012] Control at least one switch device of the three-phase upper bridge arm of the inverter unit in the motor controller of the electric vehicle to be turned on and all the switch devices of the three-phase lower bridge arm to be turned off so that the motor controller can realize the electrical connection between the winding of the motor and the battery, or control all the switch devices of the three-phase upper bridge arm to be turned off and at least one switch device of the three-phase lower bridge arm to be turned on so that the motor controller can realize the electrical connection between the winding of the motor and the battery, wherein, when at least one switch device of the three-phase upper bridge arm is turned on and all the switch devices of the three-phase lower bridge arm are turned off, the target electrode is the positive electrode, and when all the switch devices of the three-phase upper bridge arm are turned off and at least one switch device of the three-phase lower bridge arm is turned on, the target electrode is the negative electrode, and the motor controller communicates with the battery management system.

[0013] In some embodiments, determining the value of the main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value includes:

[0014] Multiplying the first insulation resistance value by the second insulation resistance value to obtain a first calculation result;

[0015] Subtracting the second insulation resistance value from the first insulation resistance value to obtain a second calculation result;

[0016] The resistance value of the main insulation resistance of the motor is determined according to the first calculation result and the second calculation result. For example, the first calculation result is divided by the second calculation result to obtain the resistance value of the main insulation resistance of the motor.

[0017] In some embodiments, the method further comprises:

[0018] Acquire data of one or more influencing factors at a moment corresponding to the resistance value of the main insulation resistor;

[0019] The resistance value of the main insulation resistor and data of one or more of the influencing factors are sent.

[0020] In a second aspect, an embodiment of the present application provides a device for determining the main insulation resistance of a motor, comprising:

[0021] A first acquisition module is used to acquire a first insulation resistance value of a target electrode of a drive motor system to ground detected by a battery management system, wherein the target electrode is a positive electrode or a negative electrode of the drive motor system; the first insulation resistance value is an insulation resistance value of the target electrode to ground when a motor controller of the drive motor system disconnects the motor and the battery;

[0022] A second acquisition module is used to acquire a second insulation resistance value of the target electrode of the drive motor system to the ground detected by the battery management system; the second insulation resistance value is the insulation resistance value of the target electrode to the ground when the motor controller turns on the motor and the battery;

[0023] A determination module is used to determine a main insulation resistance of the motor based on the first insulation resistance and the second insulation resistance.

[0024] It is understandable that the device for determining the main insulation resistance of the motor may be an electric vehicle, or may be a chip or a processing / control device applied to the electric vehicle.

[0025] In a third aspect, an embodiment of the present application provides an electric vehicle, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any of the above methods when executing the computer program.

[0026] In a fourth aspect, an embodiment of the present application provides an early warning method, including:

[0027] Acquire detection information of a first electric vehicle, wherein the detection information includes at least: a resistance value of a main insulation resistor of a motor of the first electric vehicle; calculate an insulation failure judgment value based at least on the resistance value of the main insulation resistor; and output warning information when it is determined that the main insulation resistor has a failure risk based on the insulation failure judgment value.

[0028] In some embodiments, the resistance value of the main insulation resistor is determined based on the method for determining the main insulation resistance of the motor described in any one of the first aspects.

[0029] In some embodiments, the step of calculating the insulation failure judgment value based at least on the resistance value of the main insulation resistor comprises:

[0030] Obtaining a preset insulation failure value and an initial resistance value of the main insulation resistance of the motor;

[0031] Calculating the insulation failure judgment value based on the preset insulation failure value, the initial resistance value of the main insulation resistance of the motor, and the resistance value of the main insulation resistance;

[0032] Wherein, when the insulation failure judgment value exceeds a first preset threshold range, it is determined that there is a failure risk of the main insulation resistance.

[0033] In some embodiments, the resistance value of the main insulation resistor includes multiple resistance values ​​of the main insulation resistor within a first preset period, the detection information also includes: a numerical range of one or more influencing factors when detecting the main insulation resistance within the first preset period, and the insulation failure judgment value is calculated at least based on the resistance value of the main insulation resistor, including:

[0034] Determine a first resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical subintervals corresponding to any of the influencing factors within the first preset period; the plurality of numerical subintervals are obtained by dividing the numerical interval;

[0035] Determine a second resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical subintervals corresponding to any of the influencing factors in a second preset period; wherein the second preset period is before the first preset period and is adjacent to the first preset period;

[0036] The insulation failure judgment value corresponding to each numerical subinterval of each of the influencing factors is determined according to the first resistance statistical parameter and the second resistance statistical parameter corresponding to the same numerical subinterval of the influencing factor.

[0037] In some embodiments, determining the insulation failure judgment value corresponding to each numerical subinterval of each influencing factor according to the first resistance statistical parameter and the second resistance statistical parameter corresponding to the same numerical subinterval of the influencing factor includes:

[0038] For any numerical subinterval of the influencing factors, determine a first insulation failure judgment value, a second insulation failure judgment value and a third insulation failure judgment value of the numerical subinterval of any influencing factors, wherein the first insulation failure judgment value is determined based on a first resistance minimum value and a second resistance minimum value, the second insulation failure judgment value is determined based on a first resistance middle value and a second resistance middle value, the third insulation failure judgment value is determined by a first resistance average value and a second resistance average value, the first resistance statistical parameter includes: the first resistance minimum value, the first resistance middle value and the first resistance average value, and the second resistance statistical parameter includes: the second resistance minimum value, the second resistance middle value and the second resistance average value;

[0039] The maximum value among the first insulation failure judgment value, the second insulation failure judgment value and the third insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors is determined as the insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors, wherein, when the insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors is not within the preset threshold range corresponding to the influencing factor interval, it is determined that the main insulation resistance has a failure risk.

[0040] In some embodiments, the first insulation failure judgment value is obtained by subtracting the second resistance minimum value from the first resistance minimum value and dividing the result by the first resistance minimum value; the second insulation failure judgment value is obtained by subtracting the second resistance middle value from the first resistance middle value and dividing the result by the second resistance middle value; the third insulation failure judgment value is obtained by subtracting the second resistance average value from the first resistance average value and dividing the result by the second resistance average value.

[0041] In some embodiments, the step of calculating the insulation failure judgment value based at least on the resistance value of the main insulation resistor comprises:

[0042] Determine a third resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical subintervals corresponding to any of the influencing factors within the first preset period;

[0043] An insulation failure judgment value is determined based on the third resistance statistical parameter.

[0044] In some embodiments, the plurality of numerical subintervals include: a first data subinterval and a second data subinterval, the third resistance statistical parameter corresponding to the first data subinterval includes: a third resistance minimum value, a third resistance middle value, and a third resistance average value, the third resistance statistical parameter corresponding to the second data subinterval includes: a fourth resistance minimum value, a fourth resistance middle value, and a fourth resistance average value, and determining the insulation failure judgment value based on the third resistance statistical parameter includes:

[0045] determining a seventh insulation failure judgment value, an eighth insulation failure judgment value, and a ninth insulation failure judgment value based on a fourth insulation failure judgment value, a fifth insulation failure judgment value, a sixth insulation failure judgment value, and a span value between a first data subinterval and a second data subinterval of any of the influencing factors, respectively; the fourth insulation failure judgment value is determined by the third minimum resistance value and the fourth minimum resistance value, the fifth insulation failure judgment value is determined by the third middle resistance value and the fourth middle resistance value, and the sixth insulation failure judgment value is determined by the third average resistance value and the fourth average resistance value;

[0046] A maximum value and a minimum value are selected from the seventh insulation failure judgment value, the eighth insulation failure judgment value and the ninth insulation failure judgment value to obtain an insulation failure judgment value, wherein, when the maximum value and the minimum value are not within a second preset threshold range, it is determined that the main insulation resistance has a failure risk.

[0047] In some embodiments, the determining of the fourth insulation failure judgment value based on the third resistance minimum value and the fourth resistance minimum value, the determining of the fifth insulation failure judgment value based on the third resistance intermediate value and the fourth resistance intermediate value, and the determining of the sixth insulation failure judgment value based on the third resistance average value and the fourth resistance average value include: obtaining the fourth insulation failure judgment value by subtracting the fourth resistance minimum value from the third resistance minimum value and dividing the result by the third resistance minimum value; obtaining the fifth insulation failure judgment value by subtracting the fourth resistance intermediate value from the third resistance intermediate value and dividing the result by the third resistance intermediate value; obtaining the sixth insulation failure judgment value by subtracting the fourth resistance average value from the third resistance average value and dividing the result by the third resistance average value;

[0048] The determining of the seventh insulation failure judgment value, the eighth insulation failure judgment value and the ninth insulation failure judgment value based on the fourth insulation failure judgment value, the fifth insulation failure judgment value, the sixth insulation failure judgment value and the span value between the first data sub-interval and the second data sub-interval, respectively, comprises: dividing the fourth insulation failure judgment value, the fifth insulation failure judgment value and the sixth insulation failure judgment value by the span value between the first data sub-interval and the second data sub-interval, respectively obtaining the seventh insulation failure judgment value, the eighth insulation failure judgment value and the ninth insulation failure judgment value.

[0049] In some embodiments, the method further comprises:

[0050] Dividing the numerical interval of any influencing factor within the first preset period to obtain a plurality of numerical sub-intervals corresponding to any influencing factor;

[0051] Determine a decrease prediction formula of the main insulation resistance corresponding to the multiple numerical subintervals corresponding to any influencing factor based on the resistance values ​​of the main insulation resistance corresponding to the multiple numerical subintervals corresponding to any influencing factor and the time of detecting the resistance value of the main insulation resistance, wherein the decrease prediction formula includes: a calculation relationship between time and the resistance value of the main insulation resistance;

[0052] Determining a predicted resistance value of the main insulation resistance within a preset time period based on the decline prediction formula;

[0053] Obtaining the failure time based on the predicted resistance value within a preset time period and a preset failure main insulation resistance threshold;

[0054] When the failure time is within the preset time period, a failure warning is issued.

[0055] In some embodiments, the method further comprises:

[0056] Obtaining a resistance value of a main insulation resistance of at least one motor of a second electric vehicle;

[0057] Determining an average value of the main insulation resistance based on the resistance value of the main insulation resistance of the motor of the first electric vehicle and the resistance value of the main insulation resistance of the motor of at least one second electric vehicle;

[0058] Accordingly, an insulation failure judgment value is determined based at least on the resistance value of the main insulation resistor;

[0059] The deviation value between the resistance value of the main insulation resistance of the motor of the first electric vehicle and the average value is used as an insulation failure judgment value. If the deviation value is greater than a preset deviation value, it is determined that there is a failure risk in the main insulation resistance of the first electric vehicle.

[0060] In a fifth aspect, an embodiment of the present application provides an early warning device, for example, the early warning device may be an electronic device or a chip or circuit used in an electronic device, and the early warning device includes:

[0061] A third acquisition module is used to acquire detection information of the first electric vehicle, wherein the detection information at least includes: a resistance value of a main insulation resistance of the motor;

[0062] A calculation module, used for calculating an insulation failure judgment value based at least on the resistance value of the main insulation resistor;

[0063] The early warning module is used to output early warning information when it is determined that the main insulation resistance has a failure risk based on the insulation failure judgment value.

[0064] In a sixth aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, an early warning method provided in the fourth aspect is implemented.

[0065] In a seventh aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements an early warning method provided in the fourth aspect above.

[0066] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements a method for determining the main insulation resistance of a drive motor system provided in the first aspect above.

[0067] In a ninth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes an early warning method provided in the fourth aspect above.

[0068] In a tenth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes a method for determining the main insulation resistance of a drive motor system provided in the first aspect above.

[0069] In an eleventh aspect, an embodiment of the present application provides a communication system, comprising the electric vehicle and the electronic device described above, wherein the electric vehicle is communicatively connected to the electronic device. The electric vehicle is used to execute a method for determining the main insulation resistance of a drive motor system provided in the first aspect, and the electronic device is used to execute an early warning method provided in the fourth aspect. For example, the electronic device may be a server.

[0070] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0071] The method for determining the main insulation resistance of a motor provided in an embodiment of the present application obtains a first insulation resistance value of a target electrode of a drive motor system to ground detected by a battery management system, wherein the target electrode is a positive electrode or a negative electrode of the drive motor system; the first insulation resistance value is the insulation resistance value of the target electrode to ground when a motor controller of the drive motor system disconnects the motor and the battery; obtains a second insulation resistance value of the target electrode of the drive motor system to ground detected by the battery management system; the second insulation resistance value is the insulation resistance value of the target electrode to ground when the motor controller connects the motor and the battery; the resistance value of the main insulation resistance of the motor is determined based on the first insulation resistance value and the second insulation resistance value, so that the resistance value of the main insulation resistance of the motor of the electric vehicle can be detected in situ without disassembling the motor of the electric vehicle.

[0072] It can be understood that the beneficial effects of the second to ninth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0074] Figure 1A schematic diagram of a method for determining the main insulation resistance of a motor provided for the implementation of the present application;

[0075] Figure 2 A schematic diagram of a circuit for detecting a first insulation resistance provided in an embodiment of the present application;

[0076] Figure 3 A schematic diagram of a circuit for detecting a second insulation resistance provided in an embodiment of the present application;

[0077] Figure 4 A schematic diagram of the implementation process of an early warning method provided for the implementation of this application;

[0078] Figure 5 A schematic diagram of the structure of a device for determining the main insulation resistance of a motor provided in an embodiment of the present application;

[0079] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0080] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0081] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0082] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0083] As used in the specification of this application and the appended claims, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting" depending on the context. Similarly, the phrases "if it is determined" or "if it is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce detected" or "in response to detecting" depending on the context.

[0084] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0085] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0086] Based on the technical problems of the related art, the embodiment of the present application provides a method for determining the main insulation resistance of a motor that can be applied to electric vehicles. For example, a method for determining the main insulation resistance of a motor can be applied to an on-board device in an electric vehicle. The on-board device may include a motor controller in an electric vehicle, or a vehicle domain controller or a vehicle machine of an electric vehicle. Of course, a method for determining the main insulation resistance of a motor in an embodiment of the present application can also be performed by an electronic device that communicates with an electric vehicle. For example, an electric vehicle may include: a mobile phone, a tablet computer, a wearable device, an augmented reality (AR) / virtual reality (VR) device, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a personal digital assistant (PDA), and other electronic devices. The embodiment of the present application does not impose any restrictions on the specific type of electronic device.

[0087] The embodiment of the present application provides a detection and warning system, which may include: a vehicle-side detection module and a cloud module, wherein the vehicle-side detection module may be deployed on an electric vehicle, and the vehicle-side detection module may include a vehicle domain controller, a motor controller, and a battery management system. Optionally, the electric vehicle may also include a drive motor system, the drive motor system includes: a motor and a motor controller, the motor is used to drive the vehicle, the motor has a main insulation resistor, the cloud module is used to judge the failure risk based on the resistance value of the main insulation resistor, and outputs a warning message when it is determined that the main insulation resistor has a failure risk based on the insulation failure judgment value.

[0088] In an embodiment of the present application, the vehicle domain controller is used to control the battery management system to detect the first insulation resistance value and the second insulation resistance value.

[0089] The motor controller can control the switch device in the inverter unit in the motor controller so that the battery and the motor winding are electrically connected or disconnected. For example, the motor controller has an inverter unit, which includes: three upper bridge arms, three lower bridge arms, and multiple capacitors. The three upper bridge arms and the three lower bridge arms form an IGBT module, and the multiple capacitors form a filter circuit and are connected in parallel with the IGBT module.

[0090] The battery management system has the functions of real-time monitoring of battery parameters, estimating the state of charge, performing battery balancing, performing fault diagnosis and protection, managing the charging and discharging process, regulating thermal management, communication and data recording, and remote monitoring. The battery management system includes an insulation resistance detection module, which is used to detect the insulation resistance value of the positive and negative electrodes of the drive motor system to the ground.

[0091] Based on the aforementioned early warning system, the function implemented by the method for determining the main insulation resistance of the motor provided in the embodiment of the present application can be implemented by calling the program code by the processor of the electronic device, wherein the program code can be stored in a computer storage medium.

[0092] The present application embodiment provides a method for determining the main insulation resistance of a motor, which can be performed by an electric vehicle, and specifically can be implemented by a motor controller or a vehicle domain controller in the electric vehicle. Figure 1 Taking an electric vehicle as an execution subject to perform a method for determining the main insulation resistance of a motor as an example, a method for determining the main insulation resistance of a motor provided by the present application is described, such as Figure 1 As shown, the method includes:

[0093] Step S101, the electric vehicle obtains a first insulation resistance value of a target electrode of a drive motor system to ground detected by a battery management system.

[0094] The target electrode is a positive electrode or a negative electrode of the drive motor system. The first insulation resistance value is an insulation resistance value of the target electrode to ground when a motor controller of the drive motor system disconnects the motor from the battery.

[0095] In an embodiment of the present application, the electric vehicle includes: a battery, a battery management system and a drive motor system. The drive motor system is connected to the battery through a DC bus, and the battery and the winding of the motor in the drive motor system can be disconnected or electrically connected by controlling the motor controller.

[0096] Insulation resistance is an important indicator of the insulation performance of the motor, reflecting the ability of the insulating material to prevent current leakage. It is usually expressed as a resistance value (such as Ω), and the target electrode can be a positive electrode or a negative electrode.

[0097] In the embodiment of the present application, the motor controller can obtain the first insulation resistance value of the target electrode of the drive motor system to the ground through the detection circuit in the battery management system. The detection circuit can also be called an insulation detection circuit, and the detection circuit can include: multiple resistors and switches, and the detection circuit is composed of resistors and switches. In the embodiment of the present application, the detection circuit of the battery management system is reused, and no additional detection device is required.

[0098] The above step S101 can be specifically implemented by the motor controller in the electric vehicle. For example, step S101 can be specifically implemented in the following manner: the vehicle domain controller in the electric vehicle can send a detection instruction of the first insulation resistance value to the battery management system, and the battery management system can control the motor controller to work after receiving the detection instruction. At this time, the motor controller turns off the switch device in the inverter unit in the motor controller, so that the battery is disconnected from the winding of the motor, and then the battery management system uses the detection circuit to detect the voltage on the DC bus, thereby obtaining the voltage of the target electrode to the ground, and the first insulation resistance value can be determined by the detected voltage through the voltage division principle, and then the first insulation resistance value is sent to the motor controller.

[0099] Step S102 : the electric vehicle obtains a second insulation resistance value of a target electrode of a drive motor system to ground detected by a battery management system.

[0100] The second insulation resistance value is the insulation resistance value of the target electrode to the ground when the motor controller realizes the electrical connection between the winding of the motor and the battery.

[0101] In the embodiment of the present application, the motor controller can be connected to the battery management system for communication, and the second insulation resistance value of the target electrode of the drive motor system to the ground can be obtained through the detection circuit in the battery management system.

[0102] The above step S102 can be specifically implemented by the motor controller in the electric vehicle. In some embodiments, the vehicle controller in the electric vehicle can send a detection instruction of the second insulation resistance value to the battery management system, and the battery management system controls the motor controller according to the detection instruction so that the battery is electrically connected to the winding of the motor, and then the battery management system detects the second insulation resistance value of the target electrode to the ground. When the second insulation resistance value is detected, the battery management system sends the second insulation resistance value to the motor controller through a message, so that the motor controller obtains the second insulation resistance value.

[0103] Specifically, the battery management system controls the inverter unit of the motor controller to enter different control modes through message interaction to achieve electrical connection between the battery and the motor winding. Then, the existing insulation resistance detection circuit in the battery management system can be called to perform voltage detection on the DC bus to obtain the voltage of the target electrode to the ground. The second insulation resistance value can be determined by the detected voltage and the voltage division principle.

[0104] In the embodiment of the present application, step S101 and step S102 may not distinguish the order of precedence. That is, the vehicle domain controller in the electric vehicle may first send a detection instruction of the first insulation resistance value to the battery management system, so that the battery management system controls the motor controller to disconnect the windings of the battery and the motor, and the battery management system detects the first insulation resistance value of the target electrode to the ground. Then the vehicle domain controller in the electric vehicle may send a detection instruction of the second insulation resistance value to the battery management system, so that the battery management system controls the motor controller to electrically connect the windings of the battery and the motor, and then the battery management system detects the second insulation resistance value of the target electrode to the ground.

[0105] Alternatively, the vehicle controller in the electric vehicle can first send a detection instruction for the second insulation resistance value to the battery management system, so that the battery management system controls the motor controller to achieve electrical connection between the battery and the motor windings according to the detection instruction for the second insulation resistance value, and the battery management system detects the second insulation resistance value of the target electrode to the ground. Then, the vehicle controller in the electric vehicle can send a detection instruction for the first insulation resistance value to the battery management system, so that the battery management system controls the motor controller to achieve disconnection between the battery and the motor windings, and the battery management system detects the first insulation resistance value of the target electrode to the ground.

[0106] Step S103: The electric vehicle determines a resistance value of a main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value.

[0107] The above step S103 can be implemented by a motor controller in the electric vehicle. Based on the above example, the motor controller can calculate the main insulation resistance of the motor by using the first insulation resistance value and the second insulation resistance value, thereby obtaining the main insulation resistance of the motor.

[0108] In the embodiment of the present application, the first insulation resistance value and the second insulation resistance value are combined to obtain the main insulation resistance, which can reflect the overall insulation performance of the motor.

[0109] As an example, if the executor of the embodiment of the present application is a vehicle domain controller, then when the battery management system detects the second insulation resistance value of the target electrode to the ground or the first insulation resistance value of the target electrode to the ground based on the detection instruction of the vehicle domain controller, the second insulation resistance value and the first insulation resistance value can be provided to the vehicle domain controller. In this case, the vehicle domain controller can determine the resistance value of the main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value. In some embodiments, if the executor is a motor controller, the motor controller can determine the resistance value of the main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value, which may include: the vehicle domain controller sends the first insulation resistance value and the second insulation resistance value to the motor controller, and then the motor controller determines the resistance value of the main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value.

[0110] The method provided in the embodiment of the present application obtains a first insulation resistance value of a target electrode of the drive motor system to ground detected by a battery management system, wherein the target electrode is a positive electrode or a negative electrode of the drive motor system; the first insulation resistance value is the insulation resistance value of the target electrode to ground when a motor controller of the drive motor system disconnects the winding of the motor from a battery; obtains a second insulation resistance value of the target electrode of the drive motor system to ground detected by the battery management system; the second insulation resistance value is the insulation resistance value of the target electrode to ground when the motor controller electrically connects the winding of the motor to the battery; and determines the resistance value of the main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value, so as to detect the resistance value of the main insulation resistance of the motor of the electric vehicle in situ without disassembling or assembling the motor of the electric vehicle.

[0111] In some embodiments, the winding of the motor and the battery are disconnected or electrically connected by the states of the switch devices in the three-phase upper bridge arm and the three-phase lower bridge arm of the inverter unit in the motor controller.

[0112] For example, all the switching devices in the three-phase upper bridge arm and the three-phase lower bridge arm of the inverter unit in the motor controller of the electric vehicle are in a non-conducting state, so that the motor controller can disconnect the motor winding and the battery, and the motor controller communicates with the battery management system.

[0113] Figure 2 A schematic diagram of a circuit for detecting a first insulation resistance value provided in an embodiment of the present application is shown in FIG. Figure 2As shown, the switch devices Q1, Q2, Q3, Q4, Q5, and Q6 in the motor controller are in a non-conducting state. When all the switch devices in the motor controller are in a non-conducting state, the battery and the motor winding are disconnected. By controlling S1 to be turned on and S2 to be turned off in the detection circuit, and then controlling S1 to be turned off and S2 to be turned on in the insulation detection circuit, the resistance value of DC_RP and the resistance value of DC_RN can be calculated. The resistance value of DC_RP or the resistance value of DC_RN can be considered as the first insulation resistance value obtained, and the resistance value of DC_RN can be recorded as DCRstncN. DC_RN can be considered as the resistance of the negative electrode to the ground, and the resistance value of DC_RP can be considered as the resistance of the positive electrode to the ground, which is the first insulation resistance value.

[0114] In some embodiments, the method provided by the embodiments of the present application also includes: at least one switching device of the three-phase upper bridge arm of the inverter unit in the electric vehicle control motor controller is turned on, and all the switching devices of the three-phase lower bridge arm are not turned on, or, all the switching devices of the three-phase upper bridge arm are not turned on, and at least one switching device of the three-phase lower bridge arm is turned on, so that the motor controller realizes the electrical connection between the winding of the motor and the battery.

[0115] Among them, when at least one switching device of the three-phase upper bridge arm of the inverter unit is turned on and all the switching devices of the three-phase lower bridge arm are not turned on, the target electrode is the positive electrode; when all the switching devices of the three-phase upper bridge arm of the inverter unit are not turned on and at least one switching device of the three-phase lower bridge arm is turned on, the target electrode is the negative electrode, and the motor controller communicates with the battery management system.

[0116] In the embodiment of the present application, at least one may be 1, 2 or 3. Taking 3 as an example, Figure 3 A schematic diagram of a circuit for detecting a second insulation resistance value provided in an embodiment of the present application is shown in FIG. Figure 3As shown, the switch devices Q1, Q2, and Q3 in the motor controller are in a non-conducting state, and the switch devices Q4, Q5, and Q6 are in a conducting state. At this time, the battery is electrically connected to the winding of the motor, and the battery supplies power to the winding of the motor. Control S1 in the insulation detection circuit to turn on, S2 to turn off, then S2 to turn on, S1 to turn off, and the resistance value of DC_RN in parallel with Rg can be calculated, thereby obtaining a second insulation resistance value, which can be expressed as: ACRstncN, Rg is the resistance value of the main insulation resistance of the motor, or the switch devices Q1, Q2, and Q3 in the motor controller are in a conducting state, and the switch devices Q4, Q5, and Q6 are in a non-conducting state, and control S1 in the insulation detection circuit to turn off, S2 to turn on, then S1 to turn on, S2 to turn off, and the resistance value of DC_RP in parallel with Rg can be calculated, thereby obtaining a second insulation resistance value.

[0117] In the embodiment of the present application, when the resistance value of DC_RN connected in parallel with Rg is obtained, the target electrode is the negative electrode. When the resistance value of DC_RP connected in parallel with Rg is calculated, the target electrode is the positive electrode.

[0118] In the embodiment of the present application, when the first insulation resistance value is the insulation resistance value corresponding to the negative electrode, the second insulation resistance value is also the insulation resistance value corresponding to the negative electrode. When the first insulation resistance value is the insulation resistance value corresponding to the positive electrode, the second insulation resistance value is also the insulation resistance value corresponding to the positive electrode.

[0119] In some embodiments, step S103 can be implemented by the following steps:

[0120] Step S1031: multiply the first insulation resistance value by the second insulation resistance value to obtain a first calculation result.

[0121] Step S1032: Subtract the second insulation resistance value from the first insulation resistance value to obtain a second calculation result.

[0122] Step S1033: Obtain the resistance value of the main insulation resistance of the motor according to the first calculation result and the second calculation result. For example, the first calculation result is divided by the second calculation result to obtain the resistance value of the main insulation resistance of the motor.

[0123] As an example, the above step S103 can be implemented by the following formula:

[0124] Rg = (first insulation resistance value × second insulation resistance value) / (first insulation resistance value - second insulation resistance value);

[0125] Wherein, Rg represents the resistance value of the main insulation resistor.

[0126] Based on the foregoing embodiments, the embodiments of the present application further provide an example of a method for determining the main insulation resistance of a motor. The following explanation is given using an example in which the execution subject is a vehicle domain controller in an electric vehicle. Before the high voltage of the vehicle is powered on, the motor controller enters a non-conducting state by default.

[0127] The first is the detection phase of the first insulation resistance value. In this phase, the vehicle domain controller sends a detection instruction for the first insulation resistance value to the battery management system. After the battery management system receives the instruction, the detection circuit in the battery management system starts to detect the insulation resistance of the target electrode of the drive motor system to the ground. The motor controller remains in a non-conductive state. At this time, the battery is disconnected from the winding of the motor. The battery management system controls S1 to turn on and S2 to turn off in the insulation detection circuit. Then S1 is turned off and S2 is turned on. After a period of time, the insulation detection of the target electrode of the drive motor system to the ground is completed, and the calculated first insulation resistance value of the negative electrode of the drive motor to the ground is sent to the vehicle domain controller through a message. The vehicle domain controller receives the message and latches the first insulation resistance value, recorded as DCRstncN.

[0128] Then comes the second insulation resistance value detection phase. In this phase, the vehicle domain controller sends a second insulation resistance value detection instruction to the battery management system. After the battery management system receives the instruction, the detection circuit in the battery management system starts to detect the insulation resistance of the target electrode of the drive motor system to the ground, and sends a message to the motor controller. After receiving the message, the motor controller enters the three-phase lower bridge arm conduction state, at which time the battery is electrically connected to the motor winding. S1 in the insulation detection circuit in the battery management system is turned on, S2 is turned off, then S1 is turned off, and S2 is turned on. After a period of time, the insulation detection of the target electrode of the drive motor system to the ground is completed, and the calculated second insulation resistance value is sent to the vehicle domain controller through a message. The vehicle domain controller receives the message and latches the resistance value, which is recorded as ACRstncN.

[0129] From the circuit schematic, we can know that the second insulation resistance value is derived from the main insulation resistance of the DC_RN parallel motor. Therefore, based on DCRstncN and ACRstncN, the main insulation resistance of the motor can be calculated, which is recorded as Rg. The calculation formula can be expressed as:

[0130] Rg=(DCRstncN×ACRstncN) / (DCRstncN-ACRstncN).

[0131] The method provided in the embodiment of the present application can realize the calculation of the resistance value of the main insulation resistance in situ of the electric vehicle, so that there is no need to go to the maintenance site for testing. The main insulation resistance can be tested once each time the vehicle completes a driving cycle, and the main insulation data can be accumulated over a long period of time.

[0132] Based on the technical problems of related technologies, the embodiments of the present application provide an early warning method that can be applied to electronic devices such as mobile phones, tablet computers, wearable devices, augmented reality (AR) / virtual reality (VR) devices, laptops, ultra-mobile personal computers (UMPC), netbooks, personal digital assistants (PDA), etc. The embodiments of the present application do not impose any restrictions on the specific types of electronic devices. The electronic device can be a server in the cloud. In the embodiments of the present application, the processing is performed by the server, and there is no need to add additional data processing and storage modules for electric vehicles.

[0133] The functions implemented by the information processing method provided in the embodiments of the present application can be implemented by calling program codes by a processor of an electronic device, wherein the program codes can be stored in a computer storage medium.

[0134] The present application embodiment provides an early warning method. Figure 4 A schematic diagram of the implementation process of an early warning method provided for the implementation of this application is as follows: Figure 4 As shown, the early warning methods include:

[0135] Step S401, acquiring detection information of a first electric vehicle, wherein the detection information at least includes: a resistance value of a main insulation resistance of a motor.

[0136] In the embodiment of the present application, the resistance value of the main insulation resistance may be determined by the method for determining the main insulation resistance of the motor in the above embodiment. The first electric vehicle may be any electric vehicle.

[0137] In some embodiments, the detection information also includes: data of influencing factors corresponding to the detection of the resistance value of the main insulation resistor, and the influencing factors may include: motor stator temperature, ambient temperature, motor coolant temperature, ambient air pressure, ambient humidity, etc.

[0138] Step S402: Calculate an insulation failure judgment value based at least on the resistance value of the main insulation resistor.

[0139] In the embodiment of the present application, the insulation failure judgment value can be calculated based on the resistance value of the main insulation resistor. In some embodiments, the insulation failure judgment value can be calculated based on the data of the influencing factors and the resistance value of the main insulation resistor. The insulation failure judgment value is used to evaluate whether the motor can still work effectively.

[0140] Step S403: when it is determined based on the insulation failure judgment value that the main insulation resistance has a failure risk, outputting warning information.

[0141] In the embodiment of the present application, an insulation judgment failure threshold can be set, and the insulation failure judgment value and the insulation judgment failure threshold can be compared to determine whether there is a failure risk of the main insulation resistance. If the insulation failure judgment value is greater than the insulation judgment failure threshold or is not within the range of the insulation judgment failure threshold, it is determined that there is a failure risk of the main insulation resistance. On the contrary, if the insulation failure judgment value is less than the insulation judgment failure threshold or is within the range of the insulation judgment failure threshold, it is determined that there is no failure risk of the main insulation resistance.

[0142] In the embodiment of the present application, if it is determined that the main insulation resistance has a risk of failure, the early warning mechanism is triggered, and the early warning information can be sent to relevant personnel via text messages, emails, monitoring systems, etc.

[0143] The method provided in the embodiment of the present application obtains detection information of a first electric vehicle, wherein the detection information includes at least: the resistance value of a main insulation resistor of the first electric vehicle; calculates an insulation failure judgment value based at least on the resistance value of the main insulation resistor; and outputs warning information when it is determined that the main insulation resistor has a failure risk based on the insulation failure judgment value, so that the user can take timely action and improve the user experience.

[0144] In some embodiments, step S402 may be implemented by the following steps:

[0145] Step S4021, obtaining a preset insulation failure value and an initial resistance value of the main insulation resistance of the motor.

[0146] For example, the initial resistance value of the main insulation resistance may be the resistance value of the main insulation resistance when the motor leaves the factory.

[0147] In the embodiment of the present application, the model of the motor can be obtained, and the preset insulation failure value of the motor and the initial resistance value of the main insulation resistance can be obtained through the model.

[0148] In some embodiments, the electronic device may also pre-store a preset insulation failure value of the motor and an initial resistance value of the main insulation resistor.

[0149] Step S4022, calculating the insulation failure judgment value based on the preset insulation failure value, the initial resistance value of the main insulation resistance of the motor, and the resistance value of the main insulation resistance.

[0150] Wherein, when the insulation failure judgment value exceeds the first preset threshold range, it is determined that there is a failure risk of the main insulation resistance.

[0151] In the embodiment of the present application, the insulation failure judgment value is calculated based on the preset insulation failure value, the initial resistance value of the main insulation resistance of the motor, and the resistance value of the main insulation resistance, which can be expressed by the following formula:

[0152] Q1=A*Rg+B*R0+C*R1;

[0153] Among them, the main insulation detection value is Rg, the initial resistance value is R0, the insulation failure judgment value is Q1, R1 is the preset insulation failure value, A, B, and C are weight coefficients, which can be adjusted according to actual conditions.

[0154] The method provided in the embodiment of the present application can more comprehensively reflect the true state of motor insulation by calculating the insulation failure judgment value based on the preset insulation failure value, the initial resistance value of the main insulation resistance and the main insulation resistance. A single measurement value may be affected by temporary factors, and combining multiple values ​​can improve the accuracy and reliability of the judgment. Combining multiple values ​​can provide a more comprehensive insulation status assessment, taking into account the changes in historical performance (initial resistance value at the time of leaving the factory) and current conditions (current main insulation resistance), making the judgment result more scientific.

[0155] In some embodiments, step S402 may be implemented by the following steps:

[0156] The insulation failure judgment value is determined based on the main insulation resistance and influencing factor data.

[0157] In the embodiment of the present application, a mathematical model or a standardized evaluation formula can be constructed based on the characteristics and influencing factors of the motor. For example, regression analysis, machine learning algorithms or expert experience rules can be used to comprehensively consider the influence of these factors on the insulation performance, thereby obtaining an insulation failure judgment value.

[0158] When considering the influencing factor data, a single influencing factor or multiple influencing factors may be combined. When multiple influencing factors are combined, a machine learning algorithm may be used to determine the insulation failure judgment value.

[0159] The method provided in the embodiments of the present application can improve the accuracy and reliability of judgment by combining influencing factor data.

[0160] In some embodiments, the resistance value of the main insulation resistor includes multiple resistance values ​​of the main insulation resistor within a first preset period, and the detection information also includes: a numerical range of one or more influencing factors when detecting the main insulation resistance within the first preset period, and calculating the insulation failure judgment value based at least on the resistance value of the main insulation resistor can be achieved by the following steps:

[0161] Step S1, determining a first resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical sub-intervals corresponding to any of the influencing factors within the first preset period; the plurality of numerical sub-intervals are obtained by dividing the numerical interval.

[0162] In an embodiment of the present application, the first preset period can be set, and exemplarily, can be set to T1. The influencing factor here can be any influencing factor, and exemplarily, the influencing factor can be one of the motor stator temperature, ambient temperature, motor coolant temperature, ambient air pressure, and ambient humidity.

[0163] In the embodiment of the present application, multiple numerical sub-intervals may be preset, so that the numerical interval of the influencing factor is divided to obtain multiple numerical sub-intervals corresponding to any of the influencing factors.

[0164] In the embodiment of the present application, the first resistance statistical parameters include: a first resistance minimum value, a first resistance middle value, and a first resistance average value.

[0165] Step S2, determining a second resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical subintervals corresponding to any of the influencing factors in a second preset period; wherein the second preset period is before the first preset period and adjacent to the first preset period.

[0166] In an embodiment of the present application, the duration of the second preset period is the same as that of the first preset period, and the numerical interval of the influencing factors within the second preset period can be divided by using the multiple numerical sub-intervals corresponding to the above-mentioned preset influencing factors to obtain multiple numerical sub-intervals corresponding to any of the influencing factors within the second preset period.

[0167] In an embodiment of the present application, the main insulation resistance in multiple numerical sub-intervals corresponding to any of the influencing factors in the second preset period can be statistically analyzed to obtain a second resistance statistical parameter, and the second resistance statistical parameter includes: a second resistance minimum value, a second resistance intermediate value, and a second resistance average value.

[0168] Step S3, determining the insulation failure judgment value corresponding to each numerical sub-interval of each of the influencing factors according to the first resistance statistical parameter and the second resistance statistical parameter corresponding to the same numerical sub-interval of the influencing factor.

[0169] In an embodiment of the present application, for a numerical sub-interval of any of the influencing factors, a first insulation failure judgment value, a second insulation failure judgment value, and a third insulation failure judgment value of the numerical sub-interval of any of the influencing factors are determined, wherein the first insulation failure judgment value is determined based on a first resistance minimum value and a second resistance minimum value, the second insulation failure judgment value is determined based on a first resistance intermediate value and a second resistance intermediate value, the third insulation failure judgment value is determined by a first resistance average value and a second resistance average value, the first resistance statistical parameter includes: the first resistance minimum value, the first resistance intermediate value, and the first resistance average value, and the second resistance statistical parameter includes: the second resistance minimum value, the second resistance intermediate value, and the second resistance average value; the maximum value among the first insulation failure judgment value, the second insulation failure judgment value, and the third insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors is determined as the insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors, wherein, when the insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors is not within a preset threshold range corresponding to the influencing factor interval, it is determined that the main insulation resistance has a failure risk.

[0170] In the embodiment of the present application, the first insulation failure judgment value is obtained by subtracting the second resistance minimum value from the first resistance minimum value and dividing the result by the first resistance minimum value; the second insulation failure judgment value is obtained by subtracting the second resistance middle value from the first resistance middle value and dividing the result by the second resistance middle value; the third insulation failure judgment value is obtained by subtracting the second resistance average value from the first resistance average value and dividing the result by the second resistance average value.

[0171] Exemplarily, taking the influencing factor of the motor stator temperature as an example, the motor stator temperature intervals of different ranges are divided. The main insulation resistance Rg accumulated in this first preset period is grouped according to the motor stator temperature to obtain each motor stator temperature interval. The resistance value of the main insulation resistance in each temperature interval is counted, and for the first preset period T1, the minimum value Rg_min_T1, median Rg_mid_T1, and average value Rg_ave_T1 corresponding to each motor stator temperature interval are obtained. For the second preset period T0, the same method is used to obtain the minimum value Rg_min_T0, median Rg_mid_T0, and average value Rg_ave_T0 corresponding to each stator temperature interval.

[0172] The statistical data of each same temperature interval of the first preset period T1 and the second preset period T0 are processed as follows:

[0173]

[0174] Wherein, Q2 is the insulation failure judgment value corresponding to any numerical sub-interval of the stator temperature.

[0175] In the embodiment of the present application, the insulation failure judgment value corresponding to the numerical sub-interval of any influencing factor can be compared with the threshold value corresponding to the numerical sub-interval of any influencing factor to determine whether there is a failure risk of the main insulation resistance.

[0176] In some embodiments, calculating the insulation failure judgment value based at least on the resistance value of the main insulation resistor can be achieved by the following steps:

[0177] Step S11, determining a third resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical sub-intervals corresponding to any of the influencing factors within the first preset period.

[0178] Step S12: determining an insulation failure judgment value based on the third resistance statistical parameter.

[0179] In the embodiment of the present application, the third resistance statistical parameter may include: a minimum resistance value, a middle resistance value, and an average resistance value.

[0180] In an embodiment of the present application, multiple numerical sub-intervals include: a first data sub-interval and a second data sub-interval, the third resistance statistical parameters corresponding to the first data sub-interval include: a third resistance minimum value, a third resistance middle value and a third resistance average value, the third resistance statistical parameters corresponding to the second data sub-interval include: a fourth resistance minimum value, a fourth resistance middle value and a fourth resistance average value, and the insulation failure judgment value is determined based on the third resistance statistical parameters.

[0181] In the embodiment of the present application, determining the insulation failure judgment value based on the third resistance statistical parameter may include:

[0182] determining a seventh insulation failure judgment value, an eighth insulation failure judgment value, and a ninth insulation failure judgment value based on a fourth insulation failure judgment value, a fifth insulation failure judgment value, a sixth insulation failure judgment value, and a span value between a first data subinterval and a second data subinterval of any of the influencing factors, respectively; the fourth insulation failure judgment value is determined by the third minimum resistance value and the fourth minimum resistance value, the fifth insulation failure judgment value is determined by the third middle resistance value and the fourth middle resistance value, and the sixth insulation failure judgment value is determined by the third average resistance value and the fourth average resistance value;

[0183] The maximum value and the minimum value are selected from the seventh insulation failure judgment value, the eighth insulation failure judgment value and the ninth insulation failure judgment value to obtain an insulation failure judgment value, wherein when the maximum value and the minimum value are not within the second preset threshold value range, it is determined that the main insulation resistance has a failure risk.

[0184] In an embodiment of the present application, the fourth insulation failure judgment value is determined based on the third resistance minimum value and the fourth resistance minimum value, and the fifth insulation failure judgment value is determined based on the third resistance intermediate value and the fourth resistance intermediate value, and the sixth insulation failure judgment value is determined based on the third resistance average value and the fourth resistance average value, including: subtracting the fourth resistance minimum value from the third resistance minimum value and dividing the result by the third resistance minimum value to obtain the fourth insulation failure judgment value; subtracting the fourth resistance intermediate value from the third resistance intermediate value and dividing the result by the third resistance intermediate value to obtain the fifth insulation failure judgment value; subtracting the fourth resistance average value from the third resistance average value and dividing the result by the fourth resistance average value. The method comprises: dividing the fourth insulation failure judgment value, the fifth insulation failure judgment value, and the sixth insulation failure judgment value by the third resistance average value to obtain a sixth insulation failure judgment value; determining the seventh insulation failure judgment value, the eighth insulation failure judgment value, and the ninth insulation failure judgment value based on the fourth insulation failure judgment value, the fifth insulation failure judgment value, the sixth insulation failure judgment value, and the span value between the first data sub-interval and the second data sub-interval, respectively, and comprising: dividing the fourth insulation failure judgment value, the fifth insulation failure judgment value, and the sixth insulation failure judgment value by the span value between the first data sub-interval and the second data sub-interval, respectively, to obtain the seventh insulation failure judgment value, the eighth insulation failure judgment value, and the ninth insulation failure judgment value.

[0185] Still taking the motor stator temperature as an example, the stator temperature intervals of different ranges are divided. The main insulation resistance Rg accumulated in this period is grouped according to the motor stator temperature. The resistance values ​​of the main insulation resistance in each temperature interval are counted to obtain the minimum value Rg_min, median Rg_mid, and average value Rg_ave in each temperature interval. Among them, the first data sub-interval can be a high temperature interval, and the second data sub-interval can be a low temperature interval. The minimum value Rg_min_H, median Rg_mid_H, and average value Rg_ave_H in the high temperature zone, the minimum value Rg_min_L, median Rg_mid_L, and average value Rg_ave_L in the low temperature interval, and the span of the high temperature interval and the low temperature interval is △ST.

[0186] The following processing is performed on the statistical parameters of the third resistor in different temperature ranges:

[0187]

[0188] When Q3 and Q4 exceed the preset threshold range, it is determined that the main resistor is at risk of failure.

[0189] In some embodiments, after step S403, the method further includes:

[0190] Step S404, dividing the numerical interval of any influencing factor within the first preset period to obtain a plurality of numerical sub-intervals corresponding to any influencing factor;

[0191] Step S405, based on the resistance values ​​of the main insulation resistance corresponding to the multiple numerical sub-intervals corresponding to any influencing factor and the time of detecting the resistance value of the main insulation resistance, determine a decrease prediction formula for the main insulation resistance corresponding to the multiple numerical sub-intervals corresponding to any influencing factor, wherein the decrease prediction formula includes: a calculation relationship between time and the resistance value of the main insulation resistance.

[0192] In the embodiment of the present application, a fitting algorithm can be used to obtain a prediction formula for the decrease of the main insulation resistance corresponding to each temperature interval. The fitting algorithm may include: least square method, polynomial fitting method, regression algorithm, Fourier series algorithm, etc.

[0193] Step S406, determining a predicted resistance value of the main insulation resistance within a preset time period based on the decrease prediction formula.

[0194] Step S407, obtaining the failure time based on the predicted resistance value within the preset time period and the preset failure main insulation resistance threshold.

[0195] In an embodiment of the present application, a failure main insulation resistance threshold can be set, and it can be determined whether the predicted main insulation resistance within a preset time period will be lower than the threshold. If it is lower than the threshold, the time corresponding to the time below the threshold is determined as the failure time.

[0196] Step S408: When the expiration time is within the preset time period, a failure warning is issued.

[0197] In the embodiment of the present application, a failure warning may be issued to prompt relevant personnel to perform inspection or maintenance. If it is not within the preset time, monitoring and evaluation will continue.

[0198] The method provided in the embodiment of the present application predicts failure of the main insulation, thereby arranging maintenance before the main insulation of the motor fails, reducing motor insulation failures and improving user experience.

[0199] In some embodiments, the method further comprises:

[0200] Step S409, obtaining the resistance value of the main insulation resistance of at least one motor of the second electric vehicle.

[0201] In the embodiment of the present application, the main insulation resistance values ​​of the motors of different second electric vehicles are collected to form a data set. For example, the test results of the main insulation resistance of the motors of multiple electric vehicles under the same conditions can be obtained.

[0202] Step S410: determining an average value of the main insulation resistance based on the resistance value of the main insulation resistance of the motor of the first electric vehicle and the resistance value of the main insulation resistance of at least one motor of the second electric vehicle.

[0203] Continuing with the above example, the average value of the average main insulation resistance is calculated based on the collected main insulation resistance values.

[0204] In the embodiment of the present application, the insulation failure judgment value is determined based on at least the resistance value of the main insulation resistor;

[0205] The deviation value between the resistance value of the main insulation resistance of the motor of the first electric vehicle and the average value is used as an insulation failure judgment value. If the deviation value is greater than a preset deviation value, it is determined that there is a failure risk in the main insulation resistance of the first electric vehicle.

[0206] In the embodiment of the present application, the deviation between the resistance value of the main insulation resistance of the motor of the first electric vehicle and the average value can be determined, and the main insulation resistance can be subtracted from the average value to obtain the deviation value. In the embodiment of the present application, a preset deviation value can be set, and if the deviation value is greater than the preset deviation value, it is determined that the main insulation resistance of the first electric vehicle has a failure risk.

[0207] The method provided in the embodiment of the present application can effectively monitor the insulation status of electric vehicle motors, timely identify motors with insulation failure risks, and issue early warnings to them, which helps to improve the safety of electric vehicles, reduce the risk of failure, and ensure the reliable operation of vehicles.

[0208] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0209] According to the aforementioned embodiments, the embodiments of the present application provide a device for determining the main insulation resistance of a motor. The modules included in the device and the units included in each module can be implemented by a processor in a computer device; of course, they can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU, Central Processing Unit), a microprocessor (MPU, Microprocessor Unit), a digital signal processor (DSP, Digital Signal Processing) or a field programmable gate array (FPGA, Field Programmable Gate Array), etc.

[0210] The present application provides a device for determining the main insulation resistance of a motor. Figure 5 A schematic diagram of a structure of a device for determining the main insulation resistance of a motor provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the device 500 for determining the main insulation resistance of a motor includes:

[0211] A first acquisition module 501 is used to acquire a first insulation resistance value of a target electrode of the drive motor system to ground detected by a battery management system, wherein the target electrode is a positive electrode or a negative electrode of the drive motor system; the first insulation resistance value is an insulation resistance value of the target electrode to ground when a motor controller of the drive motor system disconnects the winding of the motor from the battery;

[0212] A second acquisition module 502 is used to acquire a second insulation resistance value of the target electrode of the drive motor system to the ground detected by the battery management system; the second insulation resistance value is the insulation resistance value of the target electrode to the ground when the motor controller realizes the electrical connection between the winding of the motor and the battery;

[0213] The determination module 503 is used to determine the resistance value of the main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value.

[0214] In some embodiments, the apparatus 500 for determining the main insulation resistance of a motor includes:

[0215] The first control module is used to control all the switch devices in the three-phase upper bridge arm and the three-phase lower bridge arm of the inverter unit in the motor controller of the electric vehicle to be in a non-conducting state so that the motor controller can disconnect the motor winding and the battery, and the motor controller communicates with the battery management system.

[0216] In some embodiments, the apparatus 500 for determining the main insulation resistance of a motor includes:

[0217] Control at least one switch device of the three-phase upper bridge arm of the inverter unit in the motor controller of the electric vehicle to be turned on and all the switch devices of the three-phase lower bridge arm to be turned off so that the motor controller can realize the electrical connection between the winding of the motor and the battery, or control all the switch devices of the three-phase upper bridge arm to be turned off and at least one switch device of the three-phase lower bridge arm to be turned on so that the motor controller can realize the electrical connection between the winding of the motor and the battery, wherein, when at least one switch device of the three-phase upper bridge arm of the inverter unit is turned on and all the switch devices of the three-phase lower bridge arm are turned off, the target electrode is the positive electrode, and when all the switch devices of the three-phase upper bridge arm of the inverter unit are turned off and at least one switch device of the three-phase lower bridge arm is turned on, the target electrode is the negative electrode, and the motor controller communicates with the battery management system.

[0218] In some embodiments, determining the value of the main insulation resistance of the motor based on the first insulation resistance value and the second insulation resistance value includes:

[0219] Multiplying the first insulation resistance value by the second insulation resistance value to obtain a first calculation result;

[0220] Subtracting the second insulation resistance value from the first insulation resistance value to obtain a second calculation result;

[0221] The first calculation result is divided by the second calculation result to obtain the main insulation resistance of the motor.

[0222] In some embodiments, the apparatus 500 for determining the main insulation resistance of the motor includes:

[0223] An influencing factor acquisition module, used to acquire data of influencing factors at a time corresponding to the resistance value of the main insulation resistor;

[0224] The sending module is used to send the resistance value of the main insulation resistor and the data of the influencing factors.

[0225] in addition, Figure 5 The device 500 for determining the main insulation resistance of a motor shown may be a software unit, a hardware unit, or a combination of software and hardware units built into an existing vehicle, or may be integrated into the vehicle as an independent pendant, or may exist as an independent terminal device.

[0226] An embodiment of the present application provides an early warning device, and the modules included in the device and the units included in the modules can be implemented by a processor in a computer device; of course, they can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU, Central Processing Unit), a microprocessor (MPU, Microprocessor Unit), a digital signal processor (DSP, Digital Signal Processing) or a field programmable gate array (FPGA, Field Programmable Gate Array), etc.

[0227] The present application embodiment further provides an early warning device, including:

[0228] A third acquisition module is used to acquire detection information of the first electric vehicle, wherein the detection information at least includes: a resistance value of a main insulation resistance of the motor;

[0229] A calculation module, used for calculating an insulation failure judgment value based at least on the resistance value of the main insulation resistor;

[0230] The early warning module is used to output early warning information when it is determined that the main insulation resistance has a failure risk based on the insulation failure judgment value.

[0231] In some embodiments, the resistance value of the main insulation resistance is determined by the electric vehicle based on the method for determining the main insulation resistance of the motor provided in the above embodiments.

[0232] In some embodiments, the computing module includes:

[0233] A first acquisition unit, used to acquire a preset insulation failure value and an initial resistance value of a main insulation resistance of the motor;

[0234] The first calculation unit is used to calculate the insulation failure judgment value based on the preset insulation failure value, the initial resistance value of the main insulation resistance of the motor and the resistance value of the main insulation resistance, wherein when the insulation failure judgment value exceeds a first preset threshold range, it is determined that the main insulation resistance has a failure risk.

[0235] In some embodiments, the resistance value of the main insulation resistor includes multiple resistance values ​​of the main insulation resistor within a first preset period, and the detection information also includes: a numerical range of one or more influencing factors when detecting the main insulation resistance within the first preset period, and the calculation module includes:

[0236] A first determination unit is used to determine a first resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical subintervals corresponding to any of the influencing factors within the first preset period; the plurality of numerical subintervals are obtained by dividing the numerical interval;

[0237] A second determination unit, used to determine a second resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical subintervals corresponding to any of the influencing factors in a second preset period; wherein the second preset period is before the first preset period and is adjacent to the first preset period;

[0238] A first calculation unit, configured to determine an insulation failure judgment value corresponding to each numerical subinterval of each of the influencing factors according to the first resistance statistical parameter and the second resistance statistical parameter corresponding to the same numerical subinterval of the influencing factor;

[0239] In some embodiments, the first computing unit includes:

[0240] A first determination subunit is used to determine, for a numerical subinterval of any of the influencing factors, a first insulation failure judgment value, a second insulation failure judgment value and a third insulation failure judgment value of the numerical subinterval of any of the influencing factors, wherein the first insulation failure judgment value is determined based on a first resistance minimum value and a second resistance minimum value, the second insulation failure judgment value is determined based on a first resistance middle value and a second resistance middle value, the third insulation failure judgment value is determined by a first resistance average value and a second resistance average value, the first resistance statistical parameter includes: the first resistance minimum value, the first resistance middle value and the first resistance average value, and the second resistance statistical parameter includes: the second resistance minimum value, the second resistance middle value and the second resistance average value.

[0241] The second determination subunit is used to determine the maximum value of the first insulation failure judgment value, the second insulation failure judgment value and the third insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors as the insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors, wherein, when the insulation failure judgment value corresponding to the numerical sub-interval of any influencing factor is not within the preset threshold range corresponding to the influencing factor interval, it is determined that the main insulation resistance has a failure risk.

[0242] In some embodiments, the first insulation failure judgment value is obtained by subtracting the second resistance minimum value from the first resistance minimum value and dividing the result by the first resistance minimum value; the second insulation failure judgment value is obtained by subtracting the second resistance middle value from the first resistance middle value and dividing the result by the second resistance middle value; the third insulation failure judgment value is obtained by subtracting the second resistance average value from the first resistance average value and dividing the result by the second resistance average value.

[0243] In some embodiments, the resistance value of the main insulation resistor includes multiple resistance values ​​of the main insulation resistor within a first preset period, and the detection information also includes: a numerical range of one or more influencing factors when detecting the main insulation resistance within the first preset period, and the calculation module includes:

[0244] A third determination unit, used to determine a third resistance statistical parameter corresponding to the main insulation resistance in a plurality of numerical sub-intervals corresponding to any of the influencing factors within the first preset period;

[0245] The second calculation unit is used to determine the insulation failure judgment value based on the third resistance statistical parameter.

[0246] In some embodiments, the plurality of numerical subintervals include: a first data subinterval and a second data subinterval, the third resistance statistical parameter corresponding to the first data subinterval includes: a third resistance minimum value, a third resistance middle value, and a third resistance average value, the third resistance statistical parameter corresponding to the second data subinterval includes: a fourth resistance minimum value, a fourth resistance middle value, and a fourth resistance average value, and the second calculation unit includes:

[0247] a second calculation subunit, configured to determine a seventh insulation failure judgment value, an eighth insulation failure judgment value, and a ninth insulation failure judgment value based on a fourth insulation failure judgment value, a fifth insulation failure judgment value, a sixth insulation failure judgment value, and a span value between a first data subinterval and a second data subinterval of any of the influencing factors, respectively; the fourth insulation failure judgment value is determined by the third minimum resistance value and the fourth minimum resistance value, the fifth insulation failure judgment value is determined by the third middle resistance value and the fourth middle resistance value, and the sixth insulation failure judgment value is determined by the third average resistance value and the fourth average resistance value;

[0248] The third determination subunit is used to select a maximum value and a minimum value from the seventh insulation failure judgment value, the eighth insulation failure judgment value and the ninth insulation failure judgment value to obtain an insulation failure judgment value, wherein when the maximum value and the minimum value are not within a second preset threshold range, it is determined that the main insulation resistance has a failure risk.

[0249] In some embodiments, the second calculation subunit is used to obtain a fourth insulation failure judgment value by subtracting the fourth resistance minimum value from the third resistance minimum value and dividing the result by the third resistance minimum value; obtain a fifth insulation failure judgment value by subtracting the fourth resistance middle value from the third resistance middle value and dividing the result by the third resistance middle value; obtain a sixth insulation failure judgment value by subtracting the fourth resistance average value from the third resistance average value and dividing the result by the third resistance average value;

[0250] The determining of the seventh insulation failure judgment value, the eighth insulation failure judgment value and the ninth insulation failure judgment value based on the fourth insulation failure judgment value, the fifth insulation failure judgment value, the sixth insulation failure judgment value and the span value between the first data sub-interval and the second data sub-interval, respectively, comprises: dividing the fourth insulation failure judgment value, the fifth insulation failure judgment value and the sixth insulation failure judgment value by the span value between the first data sub-interval and the second data sub-interval, respectively obtaining the seventh insulation failure judgment value, the eighth insulation failure judgment value and the ninth insulation failure judgment value.

[0251] In some embodiments, the early warning device further comprises:

[0252] A division module, used for dividing the numerical interval of any influencing factor within the first preset period to obtain a plurality of numerical sub-intervals corresponding to any influencing factor;

[0253] A first determination module is used to determine a decrease prediction formula of the main insulation resistance corresponding to a plurality of numerical subintervals corresponding to any influencing factor based on the resistance values ​​of the main insulation resistance corresponding to a plurality of numerical subintervals corresponding to any influencing factor and the time of detecting the resistance value of the main insulation resistance, wherein the decrease prediction formula includes: a calculation relationship between time and the resistance value of the main insulation resistance;

[0254] A second determination module, configured to determine a predicted resistance value of the main insulation resistance within a preset time period based on the decline prediction formula;

[0255] A third determination module is used to obtain a failure time based on a predicted resistance value within a preset time period and a preset failure main insulation resistance threshold;

[0256] The failure warning module is used to issue a failure warning when the failure time is within a preset time period.

[0257] In some embodiments, the early warning device further comprises:

[0258] A fourth acquisition module, used to acquire the resistance value of the main insulation resistance of at least one motor of the second electric vehicle;

[0259] Determining an average value of the main insulation resistance based on the resistance value of the main insulation resistance of the motor of the first electric vehicle and the resistance value of the main insulation resistance of the motor of at least one second electric vehicle;

[0260] A third determination module, configured to determine an average value of the main insulation resistance based on the resistance value of the main insulation resistance of the motor of the first electric vehicle and the resistance value of the main insulation resistance of the motor of at least one second electric vehicle;

[0261] The insulation failure judgment value is determined based at least on the resistance value of the main insulation resistor;

[0262] The deviation value between the resistance value of the main insulation resistance of the motor of the first electric vehicle and the average value is used as an insulation failure judgment value. If the deviation value is greater than a preset deviation value, it is determined that there is a failure risk in the main insulation resistance of the first electric vehicle.

[0263] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0264] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0265] An embodiment of the present application provides an electric vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for determining the main insulation resistance of the motor in the above embodiment is implemented.

[0266] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 6 As shown, the electronic device 3 of this embodiment may include: at least one processor 30 ( Figure 6 Only one processor 30 is shown in the figure), a memory 31, and a computer program 32 stored in the memory 31 and executable on at least one processor 30. When the processor 30 executes the computer program 32, the steps in any of the above-mentioned method embodiments are implemented; or, when the processor 30 executes the computer program 32, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0267] Exemplarily, the computer program 32 may be divided into one or more modules / units, one or more modules / units are stored in the memory 31, and are executed by the processor 30 to complete the present application. One or more modules / units may be a series of computer program 32 instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 32 in the electronic device 3.

[0268] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program 32. When the computer program 32 is executed by the processor 30, the steps in the above-mentioned method embodiments can be implemented.

[0269] An embodiment of the present application provides a computer program product. When the computer program product runs on an electronic device, the electronic device can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0270] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. According to this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program 32, and the computer program 32 can be stored in a computer-readable storage medium. When the computer program 32 is executed by the processor 30, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program 32 includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying the computer program code to the terminal, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), an electric carrier signal, a telecommunication signal and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0271] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0272] An embodiment of the present application further provides a vehicle, including: the electronic device provided in the above embodiment.

[0273] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0274] In the embodiments provided in the present application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0275] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0276] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

[0277] The relevant user personal information that may be involved in the various embodiments of this application is strictly in accordance with the requirements of laws and regulations, following the principles of legality, legitimacy and necessity, based on the reasonable purposes of business scenarios, to process the personal information that users actively provide during the use of products / services or generated due to the use of products / services, as well as the personal information obtained with the user's authorization.

[0278] The user personal information processed by the applicant will vary depending on the specific product / service scenario, and shall be based on the specific scenario in which the user uses the product / service, which may involve the user's account information, device information, driving information, vehicle information or other related information. The applicant will treat the user's personal information and its processing with a high degree of diligence.

[0279] The Applicant attaches great importance to the security of user personal information and has adopted reasonable and feasible security protection measures that comply with industry standards to protect user information and prevent personal information from being accessed, disclosed, used, modified, damaged or lost without authorization.

Claims

1. A method for determining the main insulation resistance of a motor, characterized in that The method comprises: Obtaining a first insulation resistance value of a target electrode of a drive motor system to ground detected by a battery management system, wherein the target electrode is a positive electrode or a negative electrode of the drive motor system; the first insulation resistance value is an insulation resistance value of the target electrode to ground when a motor controller of the drive motor system disconnects a motor winding and a battery; Acquire a second insulation resistance value of the target electrode to ground of the drive motor system detected by the battery management system; the second insulation resistance value is the insulation resistance value of the target electrode to ground when the motor controller realizes electrical connection between the winding of the motor and the battery; A resistance value of a main insulation resistor of the motor is determined based on the first insulation resistance value and the second insulation resistance value.

2. The method according to claim 1, characterized in that The method further comprises: All the switch devices in the three-phase upper bridge arm and the three-phase lower bridge arm of the inverter unit in the motor controller are controlled to be in a non-conducting state so that the motor controller can disconnect the winding and the battery of the motor, and the motor controller communicates with the battery management system.

3. The method according to claim 1, characterized in that The method further comprises: Controlling at least one switch device of the three-phase upper bridge arm of the inverter unit in the motor controller to be turned on and all the switch devices of the three-phase lower bridge arm to be turned off, so that the motor controller can realize the electrical connection between the winding of the motor and the battery; or controlling all the switch devices of the three-phase upper bridge arm to be turned off and at least one switch device of the three-phase lower bridge arm to be turned on so that the motor controller can realize the electrical connection between the winding of the motor and the battery; Among them, when at least one switching device of the three-phase upper bridge arm is turned on and all the switching devices of the three-phase lower bridge arm are not turned on, the target electrode is the positive electrode; when all the switching devices of the three-phase upper bridge arm are not turned on and at least one switching device of the three-phase lower bridge arm is turned on, the target electrode is the negative electrode, and the motor controller communicates with the battery management system.

4. An early warning method, characterized in that: include: Acquire detection information of the first electric vehicle, wherein the detection information at least includes: a resistance value of a main insulation resistance of a motor; determining an insulation failure judgment value based at least on the resistance value of the main insulation resistor; When it is determined based on the insulation failure judgment value that the main insulation resistance has a failure risk, warning information is output.

5. The method according to claim 4, characterized in that The resistance value of the main insulation resistor is determined by the method described in any one of claims 1 to 3.

6. The method according to claim 5, characterized in that The step of calculating the insulation failure judgment value based at least on the resistance value of the main insulation resistor comprises: Obtaining a preset insulation failure value and an initial resistance value of the main insulation resistance of the motor; Calculating the insulation failure judgment value based on the preset insulation failure value, the initial resistance value of the main insulation resistance of the motor, and the resistance value of the main insulation resistance; Wherein, when the insulation failure judgment value exceeds a first preset threshold range, it is determined that there is a failure risk of the main insulation resistance.

7. The method according to claim 5, characterized in that The resistance value of the main insulation resistor includes multiple resistance values ​​of the main insulation resistor within a first preset period, the detection information also includes: a numerical range of an influencing factor corresponding to the multiple resistance values ​​of each main insulation resistor within the first preset period, and the insulation failure judgment value is calculated at least based on the resistance value of the main insulation resistor, including: Determine a first resistance statistical parameter corresponding to the main insulation resistance in a plurality of value sub-intervals within the first preset period; the plurality of value sub-intervals are obtained by dividing the value interval of any of the influencing factors; Determine a second resistance statistical parameter corresponding to the main insulation resistance in a plurality of value subintervals in a second preset period; wherein the second preset period is before the first preset period and is adjacent to the first preset period; The insulation failure judgment value corresponding to each numerical subinterval of each of the influencing factors is determined according to the first resistance statistical parameter and the second resistance statistical parameter corresponding to the same numerical subinterval of the influencing factor.

8. The method according to claim 7, characterized in that The step of determining the insulation failure judgment value corresponding to each numerical subinterval of each influencing factor according to the first resistance statistical parameter and the second resistance statistical parameter corresponding to the same numerical subinterval of the influencing factor comprises: For any numerical subinterval of the influencing factors, determine a first insulation failure judgment value, a second insulation failure judgment value and a third insulation failure judgment value of the numerical subinterval of any influencing factors, wherein the first insulation failure judgment value is determined based on a first resistance minimum value and a second resistance minimum value, the second insulation failure judgment value is determined based on a first resistance middle value and a second resistance middle value, the third insulation failure judgment value is determined by a first resistance average value and a second resistance average value, the first resistance statistical parameter includes: the first resistance minimum value, the first resistance middle value and the first resistance average value, and the second resistance statistical parameter includes: the second resistance minimum value, the second resistance middle value and the second resistance average value; The maximum value among the first insulation failure judgment value, the second insulation failure judgment value and the third insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors is determined as the insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors, wherein, when the insulation failure judgment value corresponding to the numerical sub-interval of any of the influencing factors is not within the preset threshold range corresponding to the influencing factor interval, it is determined that the main insulation resistance has a failure risk.

9. An early warning device, characterized in that: include: A third acquisition module is used to acquire detection information of the first electric vehicle, wherein the detection information at least includes: a resistance value of a main insulation resistance of the motor; A calculation module, used for calculating an insulation failure judgment value based at least on the resistance value of the main insulation resistor; The early warning module is used to output early warning information when it is determined that the main insulation resistance has a failure risk based on the insulation failure judgment value.

10. A communication system, characterized in that: include: One or more electric vehicles and electronic devices, wherein any of the electric vehicles is used to execute the method described in any one of claims 1 to 3, and the electronic device is used to implement the method described in any one of claims 4 to 8.

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