Electric drive cooling system fault monitoring method and device, electronic equipment and storage medium

Abstract

The invention provides an electric drive cooling system fault monitoring method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining the voltage of a DC bus, the current of thermal sensitive ceramic, and the temperature of a whole vehicle cooling liquid, and enabling the thermal sensitive ceramic to be connected with an electric drive; calculating the current thermal resistance of the thermal sensitive ceramic based on the direct current bus voltage, the current of the thermal sensitive ceramic and the whole vehicle cooling liquid temperature; and whether the electrically-driven cooling system breaks down or not is judged based on the current thermal resistance of the thermal sensitive ceramic. Whether the electrically-driven cooling system breaks down or not can be monitored. Meanwhile, the method has the advantage of high detection accuracy.

Description

Technical Field

[0001] The present application relates to the field of electric drive status monitoring, and in particular, to a method, device, electronic device and storage medium for monitoring faults in a cooling system of an electric drive. Background Art

[0002] The electric drive system of an electric vehicle needs to operate in harsh conditions such as high temperature and generate a lot of heat. If the electric drive cooling system fails, the temperature of the electric drive system will be too high, which may reduce its output capacity, efficiency and other performance indicators. In severe cases, it may lead to a reduction in system life, system damage, and even cause a fire, endangering the safety of drivers and passengers.

[0003] In order to ensure normal cooling of components such as motors and motor controllers, it is necessary to monitor the working status of the electric drive cooling system in real time so that the electric drive system can control the heat power in a timely and rapid manner according to the cooling system status to ensure that there is no risk of overheating in the electric drive system. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a method, device, electronic device and storage medium for monitoring the cooling system fault of an electric drive, so as to monitor whether the cooling system of the electric drive fails. At the same time, the present application has the advantage of high detection accuracy.

[0005] In a first aspect, the present invention provides a method for monitoring a cooling system fault of an electric drive, the method comprising:

[0006] Obtaining a DC bus voltage, a current of a thermistor ceramic, and a vehicle coolant temperature, wherein the thermistor ceramic is connected to an electric drive;

[0007] Calculating the current thermal resistance of the thermistor based on the DC bus voltage, the current of the thermistor and the vehicle coolant temperature;

[0008] It is determined whether a cooling system of the electric drive fails based on the current thermal resistance of the thermistor ceramic.

[0009] In an optional implementation, judging whether a cooling system of the electric drive fails based on the thermal resistance of the thermistor ceramic includes:

[0010] It is determined whether the current thermal resistance of the thermistor ceramic is greater than the fault threshold; if the current thermal resistance of the thermistor ceramic is greater than the fault threshold, it is determined that a fault occurs in the cooling system of the electric drive.

[0011] The method of the present application obtains the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, wherein the thermistor ceramic is connected to the electric drive, and then can calculate the current thermal resistance of the thermistor ceramic based on the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, and then can judge whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the present application can improve the accuracy of the cooling system fault detection of the electric drive.

[0012] In an optional embodiment, the method further comprises:

[0013] Calculating the thermal resistance of the thermistor ceramic under a target operating condition, wherein the target operating condition is that the cooling system of the electric drive operates normally based on a minimum flow rate;

[0014] The fault threshold is determined based on the thermal resistance of the thermistor ceramic under the target operating condition.

[0015] This optional implementation calculates the thermal resistance of the thermistor ceramic under the target operating condition, wherein the target operating condition is that the cooling system of the electric drive operates normally based on the minimum flow rate, and thus the fault threshold can be determined based on the thermal resistance of the thermistor ceramic under the target operating condition. In an optional implementation, the current thermal resistance of the thermistor ceramic is calculated based on the DC bus voltage, the current of the thermistor ceramic and the vehicle coolant temperature, including:

[0016] Calculating the resistance of the thermistor ceramic based on the DC bus voltage and the current of the thermistor ceramic;

[0017] calculating the temperature of the thermistor based on the resistance of the thermistor;

[0018] The current thermal resistance of the thermistor ceramic is calculated based on the temperature of the thermistor ceramic, the vehicle coolant temperature, the DC bus voltage, and the current of the thermistor ceramic.

[0019] This optional implementation can calculate the resistance of the thermistor based on the DC bus voltage and the current of the thermistor, and further can calculate the temperature of the thermistor based on the resistance of the thermistor, and further can calculate the current thermal resistance of the thermistor based on the temperature of the thermistor, the vehicle coolant temperature, the DC bus voltage and the current of the thermistor.

[0020] In an optional embodiment, the calculating the temperature of the thermistor based on the resistance of the thermistor comprises:

[0021] Obtaining a resistance-temperature characteristic curve of the thermistor ceramic;

[0022] The temperature of the thermistor ceramic is calculated based on the resistance of the thermistor ceramic and a resistance-temperature characteristic curve of the thermistor ceramic.

[0023] This optional implementation manner can obtain the resistance-temperature characteristic curve of the thermistor ceramic, and further can calculate the temperature of the thermistor ceramic based on the resistance of the thermistor ceramic and the resistance-temperature characteristic curve of the thermistor ceramic.

[0024] In an optional embodiment, the calculating the current thermal resistance of the thermistor based on the temperature of the thermistor, the vehicle coolant temperature, the DC bus voltage and the current of the thermistor comprises:

[0025] Calculating the difference between the vehicle coolant temperature and the temperature of the thermistor ceramic;

[0026] The current thermal resistance of the thermistor is calculated based on the difference, the DC bus voltage and the current of the thermistor.

[0027] This optional implementation calculates the difference between the vehicle coolant temperature and the temperature of the thermistor ceramic, and then can calculate the current thermal resistance of the thermistor ceramic based on the difference, the DC bus voltage and the current of the thermistor ceramic.

[0028] In an optional implementation manner, the calculation formula corresponding to the current thermal resistance of the thermistor ceramic is calculated based on the difference, the DC bus voltage and the current of the thermistor ceramic:

[0029] R th =(T ptc -T w ) / (U dc I ptc );

[0030] Among them, R th represents the current thermal resistance of the thermistor ceramic, T ptc represents the temperature of the thermistor ceramic, T w Indicates the vehicle coolant temperature, U dc represents the DC bus voltage, I ptc represents the current of the thermistor ceramic.

[0031] This optional implementation can accurately calculate the current thermal resistance of the thermistor ceramic through the above calculation formula.

[0032] In a second aspect, the present invention provides a cooling system fault monitoring device for an electric drive, the device comprising:

[0033] An acquisition module, used to acquire the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, wherein the thermistor ceramic is connected to the electric drive;

[0034] A calculation module, used for calculating the current thermal resistance of the thermistor based on the DC bus voltage, the current of the thermistor and the vehicle coolant temperature;

[0035] A judgment module is used to judge whether a cooling system of the electric drive fails based on the current thermal resistance of the thermistor ceramic.

[0036] The device of the present application can obtain the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature by executing the electric drive cooling system fault monitoring method, wherein the thermistor ceramic is connected to the electric drive, and then the current thermal resistance of the thermistor ceramic can be calculated based on the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, and then it can be determined whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the present application can improve the accuracy of the electric drive cooling system fault detection.

[0037] In a third aspect, the present invention provides an electronic device, comprising:

[0038] Processor; and

[0039] The memory is configured to store machine-readable instructions, and when the instructions are executed by the processor, the method for monitoring the cooling system fault of the electric drive as described in any one of the aforementioned embodiments is executed.

[0040] The electronic device of the present application can obtain the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature by executing the cooling system fault monitoring method of the electric drive, wherein the thermistor ceramic is connected to the electric drive, and then the current thermal resistance of the thermistor ceramic can be calculated based on the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, and then it can be determined whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the present application can improve the accuracy of the cooling system fault detection of the electric drive.

[0041] In a fourth aspect, the present invention provides a storage medium storing a computer program, wherein the computer program is executed by a processor as described in any one of the aforementioned embodiments for monitoring the fault of a cooling system of an electric drive.

[0042] The storage medium of the present application can obtain the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature by executing the cooling system fault monitoring method of the electric drive, wherein the thermistor ceramic is connected to the electric drive, and then the current thermal resistance of the thermistor ceramic can be calculated based on the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, and then it can be determined whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the present application can improve the accuracy of the cooling system fault detection of the electric drive. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a flow chart of a method for monitoring a cooling system fault of an electric drive disclosed in an embodiment of the present application;

[0045] Figure 2 is a schematic diagram of a motor system cooling circuit disclosed in an embodiment of the present application;

[0046] Figure 3 It is a structural schematic diagram of a cooling system fault monitoring device for an electric drive disclosed in an embodiment of the present application;

[0047] Figure 4 It is a structural schematic diagram of an electronic device disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0049] Embodiment 1

[0050] See also Figure 1 , Figure 1 is a flow chart of a method for monitoring a cooling system fault of an electric drive disclosed in an embodiment of the present application, such as Figure 1 As shown, the method of the embodiment of the present application includes the following steps:

[0051] 101. Obtain the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, wherein the thermistor ceramic is connected to the electric drive;

[0052] 102. Calculate the current thermal resistance of the thermistor ceramic based on the DC bus voltage, the current of the thermistor ceramic and the vehicle coolant temperature;

[0053] 103. Determine whether a cooling system of the electric drive fails based on the current thermal resistance of the thermistor ceramic.

[0054] In an optional implementation, judging whether a cooling system of an electric drive fails based on the thermal resistance of the thermistor ceramic includes:

[0055] It is determined whether the current thermal resistance of the thermistor ceramic is greater than a fault threshold. If the current thermal resistance of the thermistor ceramic is greater than the fault threshold, it is determined that a fault occurs in the cooling system of the electric drive.

[0056] The method of the embodiment of the present application obtains the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, wherein the thermistor ceramic is connected to the electric drive, and then the current thermal resistance of the thermistor ceramic can be calculated based on the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, and then it can be determined whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the embodiment of the present application can improve the accuracy of the cooling system fault detection of the electric drive.

[0057] In the embodiment of the present application, since the thermistor ceramic is connected to the electric drive, the embodiment of the present application can use the relationship between the thermal resistance of the thermistor ceramic and the coolant to determine whether the cooling system of the electric drive has a fault. When the cooling system of the electric drive fails, the coolant decreases and the thermal resistance of the thermistor ceramic increases. When the thermal resistance of the thermistor ceramic is greater than the fault threshold, it can be determined that the cooling system of the electric drive has a fault.

[0058] With respect to the embodiments of the present application, the embodiments of the present application do not directly rely on the detection results of the temperature sensor to determine whether the system has failed, but determine whether the system has failed by the thermal resistance of the thermistor ceramic directly connected to the system, and thus are not subject to the arrangement limitations of the temperature sensor, thereby avoiding the hysteresis of fault detection. In comparison, the prior art is subject to the arrangement limitations of the temperature sensor, and cannot directly measure the maximum water temperature through the temperature sensor, so there is a detection delay. For example, since the maximum temperature is not detected in real time, the current detection result shows that the system has not failed, but in fact the system has failed.

[0059] In the embodiment of the present application, the electric drive refers to a motor system.

[0060] In the embodiment of the present application, as an optional implementation, the method of the embodiment of the present application further includes the following steps:

[0061] Calculate the thermal resistance of the thermistor ceramic under the target operating condition, where the target operating condition is that the cooling system of the electric drive operates normally based on the minimum flow rate;

[0062] The fault threshold is determined based on the thermal resistance of the thermistor ceramic under target operating conditions.

[0063] This optional implementation calculates the thermal resistance of the thermistor ceramic under a target operating condition, wherein the target operating condition is that the cooling system of the electric drive operates normally based on a minimum flow rate, and thus the fault threshold can be determined based on the thermal resistance of the thermistor ceramic under the target operating condition.

[0064] In the embodiment of the present application, as an optional implementation, the step of calculating the current thermal resistance of the thermistor ceramic based on the DC bus voltage, the current of the thermistor ceramic and the vehicle coolant temperature includes the following sub-steps:

[0065] Calculate the resistance of the thermistor ceramic based on the DC bus voltage and the current of the thermistor ceramic;

[0066] calculating the temperature of the thermistor ceramic based on the resistance of the thermistor ceramic;

[0067] The current thermal resistance of the thermistor ceramic is calculated based on the temperature of the thermistor ceramic, the vehicle coolant temperature, the DC bus voltage, and the current of the thermistor ceramic.

[0068] This optional implementation can calculate the resistance of the thermistor based on the DC bus voltage and the current of the thermistor, and further calculate the temperature of the thermistor based on the resistance of the thermistor, and further calculate the current thermal resistance of the thermistor based on the temperature of the thermistor, the vehicle coolant temperature, the DC bus voltage and the current of the thermistor.

[0069] In the embodiment of the present application, as an optional implementation, calculating the temperature of the thermistor ceramic based on the resistance of the thermistor ceramic includes the following sub-steps:

[0070] Obtain the resistance-temperature characteristic curve of thermistor ceramics;

[0071] Based on the resistance of the thermistor ceramic and the resistance-temperature characteristic curve of the thermistor ceramic, the temperature of the thermistor ceramic is calculated.

[0072] This optional implementation manner can obtain the resistance-temperature characteristic curve of the thermistor ceramic, and further can calculate the temperature of the thermistor ceramic based on the resistance of the thermistor ceramic and the resistance-temperature characteristic curve of the thermistor ceramic.

[0073] In the embodiment of the present application, as an optional implementation, based on the temperature of the thermistor ceramic, the vehicle coolant temperature, the DC bus voltage and the current of the thermistor ceramic, the current thermal resistance of the thermistor ceramic is calculated, including the following steps:

[0074] Calculate the difference between the vehicle coolant temperature and the temperature of the thermistor ceramic;

[0075] Based on the difference, the DC bus voltage and the current of the thermistor ceramic, the current thermal resistance of the thermistor ceramic is calculated.

[0076] This optional implementation calculates the difference between the vehicle coolant temperature and the temperature of the thermistor ceramic, and can then calculate the current thermal resistance of the thermistor ceramic based on the difference, the DC bus voltage, and the current of the thermistor ceramic.

[0077] In the embodiment of the present application, as an optional implementation, based on the difference, the DC bus voltage and the current of the thermistor ceramic, the calculation formula corresponding to the current thermal resistance of the thermistor ceramic is calculated as follows:

[0078] R th =(T ptc -T w ) / (U dc I ptc );

[0079] Among them, R th represents the current thermal resistance of the thermistor ceramic, T ptc Indicates the temperature of the thermistor ceramic, T w Indicates the vehicle coolant temperature, U dc Indicates the DC bus voltage, I ptc Indicates the current of the thermistor ceramic.

[0080] This optional implementation can accurately calculate the current thermal resistance of the thermistor ceramic through the above calculation formula.

[0081] For the embodiments of this application, as an example, please refer to Figure 2 , Figure 2 Schematic diagram of a cooling circuit of a motor system disclosed in an embodiment of the present application. Figure 1 As shown, the motor system cooling circuit includes a motor system, a PTC, a water pump, a water temperature sensor, a radiator, a multi-way valve, and a cooler component, wherein the motor system is electrically driven. When the motor system cooling system is abnormal, the thermal parameters of the PTC will change and be reflected, especially when the coolant does not flow or there is no coolant, the thermal parameters of the PTC will change significantly. Therefore, by utilizing the characteristics of the PTC thermal parameters changing with the cooling conditions, fault monitoring of the cooling system can be achieved.

[0082] Furthermore, the motor controller receives a DC bus voltage sensor signal U dc , vehicle coolant temperature signal T w , PTC current sensor signal I ptc .

[0083] Furthermore, the motor controller calculates the resistance R of the PTC ptc .

[0084] Furthermore, the motor controller calculates the PTC temperature T according to the PTC resistance-temperature correspondence. ptc .

[0085] Furthermore, the motor controller calculates the PTC thermal resistance R th .

[0086] Furthermore, the motor controller compares the real-time PTC thermal resistance R th_RealTime and the preset maximum thermal resistance R th_Max , if R th_RealTime >R th_Max , it can be determined that the cooling system is faulty.

[0087] Embodiment 2

[0088] See also Figure 3 , Figure 3 is a schematic diagram of a structure of a cooling system fault monitoring device for an electric drive disclosed in an embodiment of the present application, such as Figure 3 As shown, the device of the embodiment of the present application includes the following functional modules:

[0089] The acquisition module 201 is used to acquire the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, wherein the thermistor ceramic is connected to the electric drive;

[0090] A calculation module 202, used to calculate the current thermal resistance of the thermistor ceramic based on the DC bus voltage, the current of the thermistor ceramic and the vehicle coolant temperature;

[0091] The judgment module 203 is used to judge whether the cooling system of the electric drive fails based on the current thermal resistance of the thermistor ceramic.

[0092] The device of the embodiment of the present application can obtain the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature by executing the cooling system fault monitoring method of the electric drive, wherein the thermistor ceramic is connected to the electric drive, and then the current thermal resistance of the thermistor ceramic can be calculated based on the DC bus voltage, the current of the thermistor ceramic and the vehicle coolant temperature, and then it can be determined whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the present application can improve the accuracy of the cooling system fault detection of the electric drive.

[0093] It should be noted that for other detailed descriptions of the device in the embodiment of the present application, please refer to the relevant description of the embodiment of the present application, and the embodiment of the present application will not go into details therein.

[0094] Embodiment 3

[0095] See also Figure 4 , Figure 4 is a schematic diagram of the structure of an electronic device disclosed in an embodiment of the present application, such as Figure 4 As shown, the electronic device of the embodiment of the present application includes:

[0096] Processor 301; and

[0097] The memory 302 is configured to store machine-readable instructions, and when the instructions are executed by the processor 301, the method for monitoring the cooling system fault of the electric drive according to any one of the aforementioned embodiments is executed.

[0098] The electronic device of the embodiment of the present application can obtain the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature by executing the cooling system fault monitoring method of the electric drive, wherein the thermistor ceramic is connected to the electric drive, and then the current thermal resistance of the thermistor ceramic can be calculated based on the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, and then it can be determined whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the present application can improve the accuracy of the cooling system fault detection of the electric drive.

[0099] Embodiment 4

[0100] An embodiment of the present application provides a storage medium, wherein the storage medium stores a computer program, and the computer program is executed by a processor as a method for monitoring faults in a cooling system of an electric drive according to any of the aforementioned implementations.

[0101] The storage medium of the embodiment of the present application can obtain the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature by executing the cooling system fault monitoring method of the electric drive, wherein the thermistor ceramic is connected to the electric drive, and then the current thermal resistance of the thermistor ceramic can be calculated based on the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, and then it can be determined whether the cooling system of the electric drive has a fault based on the current thermal resistance of the thermistor ceramic. Compared with the prior art, the present application can improve the accuracy of the cooling system fault detection of the electric drive.

[0102] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, 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 communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0103] In addition, 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.

[0104] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0105] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM) random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0106] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0107] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for monitoring faults in a cooling system of an electric drive, characterized in that: The method comprises: Obtaining a DC bus voltage, a current of a thermistor ceramic, and a vehicle coolant temperature, wherein the thermistor ceramic is connected to an electric drive; Calculating the current thermal resistance of the thermistor based on the DC bus voltage, the current of the thermistor and the vehicle coolant temperature; It is determined whether a cooling system of the electric drive fails based on the current thermal resistance of the thermistor ceramic.

2. The method according to claim 1, characterized in that The determining whether a cooling system of the electric drive fails based on the thermal resistance of the thermistor ceramic comprises: It is determined whether the current thermal resistance of the thermistor ceramic is greater than a fault threshold; if the current thermal resistance of the thermistor ceramic is greater than the fault threshold, it is determined that a fault occurs in the cooling system of the electric drive.

3. The method according to claim 2, characterized in that The method further comprises: Calculating the thermal resistance of the thermistor ceramic under a target operating condition, wherein the target operating condition is that the cooling system of the electric drive operates normally based on a minimum flow rate; The fault threshold is determined based on the thermal resistance of the thermistor ceramic under the target operating condition.

4. The method according to claim 1, characterized in that The calculating the current thermal resistance of the thermistor based on the DC bus voltage, the current of the thermistor and the vehicle coolant temperature includes: Calculating the resistance of the thermistor ceramic based on the DC bus voltage and the current of the thermistor ceramic; calculating the temperature of the thermistor based on the resistance of the thermistor; The current thermal resistance of the thermistor ceramic is calculated based on the temperature of the thermistor ceramic, the vehicle coolant temperature, the DC bus voltage, and the current of the thermistor ceramic.

5. The method according to claim 4, characterized in that The step of calculating the temperature of the thermistor based on the resistance of the thermistor comprises: Obtaining a resistance-temperature characteristic curve of the thermistor ceramic; The temperature of the thermistor ceramic is calculated based on the resistance of the thermistor ceramic and a resistance-temperature characteristic curve of the thermistor ceramic.

6. The method according to claim 4, characterized in that The calculating the current thermal resistance of the thermistor based on the temperature of the thermistor, the vehicle coolant temperature, the DC bus voltage and the current of the thermistor comprises: Calculating the difference between the vehicle coolant temperature and the temperature of the thermistor ceramic; The current thermal resistance of the thermistor is calculated based on the difference, the DC bus voltage and the current of the thermistor.

7. The method according to claim 6, characterized in that The calculation formula corresponding to the current thermal resistance of the thermistor ceramic based on the difference, the DC bus voltage and the current of the thermistor ceramic is: R th =(T ptc -T w ) / (U dc ·I ptc ); Among them, R th represents the current thermal resistance of the thermistor ceramic, T ptc represents the temperature of the thermistor ceramic, T w Indicates the vehicle coolant temperature, U dc represents the DC bus voltage, I ptc represents the current of the thermistor ceramic.

8. A cooling system fault monitoring device for an electric drive, characterized in that: The device comprises: An acquisition module, used to acquire the DC bus voltage, the current of the thermistor ceramic, and the vehicle coolant temperature, wherein the thermistor ceramic is connected to the electric drive; A calculation module, used for calculating the current thermal resistance of the thermistor based on the DC bus voltage, the current of the thermistor and the vehicle coolant temperature; A judgment module is used to judge whether a cooling system of the electric drive fails based on the current thermal resistance of the thermistor ceramic.

9. An electronic device, characterized in that: include: processor; as well as A memory configured to store machine-readable instructions, wherein when the instructions are executed by the processor, the method for monitoring faults of a cooling system of an electric drive according to any one of claims 1 to 7 is executed.

10. A storage medium, characterized in that: The storage medium stores a computer program, and the computer program is executed by a processor to implement the method for monitoring faults in a cooling system of an electric drive as described in any one of claims 1 to 7.

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