A fault identification method and device based on an electric vehicle thermal management system

Abstract

The application provides a kind of based on the fault identification method and device of electric vehicle thermal management system, it is related to electric vehicle technical field, method includes: obtaining vehicle temperature, water circuit water flow value and water circuit pressure peak value;Water pump target duty cycle, water circuit target water flow value are calculated, initial water flow deviation value is calculated according to water circuit target water flow value and water circuit water flow value, correction coefficient corresponding to initial water flow deviation value is obtained according to first preset relationship, corrected water pump duty cycle is calculated according to water pump target duty cycle and correction coefficient, and corrected water flow deviation value is calculated according to corrected water pump duty cycle;Whether corrected water flow deviation value is greater than water flow deviation threshold value is judged;Whether water pump target duty cycle is greater than water pump duty cycle preset threshold value is judged and whether water circuit pressure deviation value is greater than water circuit pressure preset threshold value is judged.The application can identify the fault state of vehicle water circuit and trigger alarm to carry out maintenance prompt.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicles, in particular to a fault identification method and device based on an electric vehicle thermal management system. BACKGROUND

[0002] The electric vehicle thermal management system is one of the important systems to ensure the normal operation of the electric vehicle, and the working control of the thermal management system is generally to control the water pump operation through the vehicle controller to cool the cooling components such as the motor and the motor controller.

[0003] The existing control method of the electric vehicle thermal management system is generally to control the duty cycle of the electronic water pump by collecting the temperature of the vehicle cooling components, so as to control the electronic water pump to cool the vehicle cooling components, or to control the electronic water pump based on the working conditions of the vehicle cooling components, such as motor speed, motor torque and other condition information, however, when the water circuit fault problem of the thermal management system occurs, such as the water flow reduction problem caused by the foreign matter blockage of the water circuit of the thermal management system or the bubble attached to the wall of the water circuit, the existing control method of the electric vehicle thermal management system cannot provide sufficient cooling capacity, and it is easy to trigger the over-temperature protection when the motor temperature exceeds the threshold value, at the same time, the existing control method of the electric vehicle thermal management system cannot identify the water circuit fault state of the thermal management system, and cannot give the driver maintenance prompt. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a fault identification method and device based on an electric vehicle thermal management system, which aims to solve the technical problems that the existing control method of the electric vehicle thermal management system cannot provide sufficient cooling capacity when the water circuit fault problem of the thermal management system occurs, it is easy to trigger the over-temperature protection when the motor temperature exceeds the threshold value, and it cannot identify the water circuit fault state of the thermal management system and cannot give the driver maintenance prompt.

[0005] One aspect of the present application is to provide a fault identification method based on an electric vehicle thermal management system, comprising:

[0006] Obtaining the vehicle temperature, the water circuit water flow value and the water circuit pressure peak value after the electric vehicle starts;

[0007] According to the vehicle temperature, the target duty cycle of the water pump is calculated, the target water flow value of the water circuit is obtained according to the vehicle temperature and the target duty cycle of the water pump, the initial water flow deviation value is calculated according to the target water flow value of the water circuit and the water flow value, the correction coefficient corresponding to the initial water flow deviation value is obtained according to the first preset relationship, the corrected water pump duty cycle is calculated according to the target duty cycle of the water pump and the correction coefficient, and the corrected water flow deviation value is calculated according to the corrected water pump duty cycle.

[0008] determining whether the corrected water flow deviation value is greater than a water flow deviation threshold value;

[0009] if the corrected water flow deviation value is greater than the water flow deviation threshold value, it is determined that the vehicle water circuit has a fault, and an alarm prompt is triggered;

[0010] if the corrected water flow deviation value is not greater than the water flow deviation threshold value, a water circuit pressure deviation value is calculated according to the water circuit pressure peak value and the water circuit rated pressure value;

[0011] determining whether the water pump target duty cycle is greater than a water pump duty cycle preset threshold value, and determining whether the water circuit pressure deviation value is greater than a water circuit pressure preset threshold value;

[0012] if the water pump target duty cycle is greater than the water pump duty cycle preset threshold value, and the water circuit pressure deviation value is greater than the water circuit pressure preset threshold value, it is determined that the vehicle water circuit has a fault, and an alarm prompt is triggered.

[0013] Compared with the prior art, the fault identification method based on the electric vehicle thermal management system has the beneficial effects that through parameter analysis of the vehicle temperature, the water circuit water flow value and the water circuit pressure peak value, the fault state of the vehicle water circuit can be analyzed, and the speed of the control electronic water pump can be corrected to meet the cooling demand of the vehicle cooling parts, thereby effectively avoiding the over-temperature phenomenon of the vehicle cooling parts, and the fault state of the vehicle water circuit can be identified, and an alarm prompt is triggered to achieve the purpose of giving the driver a maintenance prompt.

[0014] In addition, the fault identification method based on the electric vehicle thermal management system according to the above-mentioned application can also have the following additional technical features:

[0015] Further, the vehicle temperature includes motor temperature, motor controller temperature, DC-DC converter temperature, and on-board charger temperature.

[0016] Further, the step of calculating the water pump target duty cycle according to the vehicle temperature comprises:

[0017] calculating a first water pump duty cycle required by the motor according to the motor temperature, a second water pump duty cycle required by the motor controller according to the motor controller temperature, a third water pump duty cycle required by the DC-DC converter according to the DC-DC converter temperature, and a fourth water pump duty cycle required by the on-board charger according to the on-board charger temperature;

[0018] selecting a maximum value from the first water pump duty cycle, the second water pump duty cycle, the third water pump duty cycle, and the fourth water pump duty cycle as a water pump target duty cycle.

[0019] Further, the water circuit pressure peak value is a maximum value of the water circuit pressure collected by the pressure sensor within 2s after the water pump starts.

[0020] Further, the first preset relationship is a relationship between an initial water flow deviation value and a correction coefficient, wherein:

[0021] When the initial water flow deviation value is 0L / min-0.5L / min, the correction coefficient is 1;

[0022] When the initial water flow deviation value is 1L / min, the correction coefficient is 1.2;

[0023] When the initial water flow deviation value is 1.5L / min, the correction coefficient is 1.5;

[0024] When the initial water flow deviation value is 2L / min-10L / min, the correction coefficient is 2.

[0025] Further, after judging whether the water pump target duty cycle is greater than a water pump duty cycle preset threshold, the method further comprises:

[0026] If the water pump target duty cycle is not greater than the water pump duty cycle preset threshold, it is determined that the water circuit pressure deviation value is unreliable, and an alarm prompt is not triggered.

[0027] The application also provides a fault identification device based on an electric vehicle thermal management system, comprising:

[0028] An acquisition module is configured to acquire a vehicle temperature, a water circuit water flow value, and a water circuit pressure peak value after the electric vehicle starts;

[0029] A calculation module is configured to calculate a water pump target duty cycle according to the vehicle temperature, obtain a water circuit target water flow value according to the vehicle temperature and the water pump target duty cycle, calculate an initial water flow deviation value according to the water circuit target water flow value and the water circuit water flow value, obtain a correction coefficient corresponding to the initial water flow deviation value according to a first preset relationship, calculate a corrected water pump duty cycle according to the water pump target duty cycle and the correction coefficient, and calculate a corrected water flow deviation value according to the corrected water pump duty cycle.

[0030] A first judgment module is configured to judge whether the corrected water flow deviation value is greater than a water flow deviation threshold.

[0031] A first execution module is configured to determine that a vehicle water circuit has a fault and trigger an alarm prompt when the corrected water flow deviation value is greater than the water flow deviation threshold.

[0032] a second execution module configured to calculate a water circuit pressure deviation value according to the water circuit pressure peak value and a water circuit rated pressure value when the corrected water flow deviation value is not greater than a water flow deviation threshold value;

[0033] a second judgment module configured to judge whether the water pump target duty cycle is greater than a water pump duty cycle preset threshold value and whether the water circuit pressure deviation value is greater than a water circuit pressure preset threshold value;

[0034] a third execution module configured to determine that the vehicle water circuit has a fault and trigger an alarm prompt when the water pump target duty cycle is greater than the water pump duty cycle preset threshold value and the water circuit pressure deviation value is greater than the water circuit pressure preset threshold value.

[0035] The application further provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the aforementioned fault identification method based on the thermal management system of the electric vehicle.

[0036] The application further provides a data processing device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the aforementioned fault identification method based on the thermal management system of the electric vehicle when executing the program. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 a flow chart of the fault identification method based on the thermal management system of the electric vehicle of the application;

[0038] Figure 2 a structure block diagram of the thermal management system of the electric vehicle provided in the embodiment of the application;

[0039] Figure 3 a structure block diagram of the fault identification device based on the thermal management system of the electric vehicle of the application;

[0040] Figure 4 a block diagram of the data processing device of the application.

[0041] The following specific embodiments will further illustrate the application in combination with the above-mentioned drawings. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the application, the application will be described more fully below with reference to the related drawings. The drawings show several embodiments of the application. However, the application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the application more thorough and comprehensive.

[0043] It is to be understood that where an element such as a layer, region or substrate is described as being "on" another element, it can be directly on the other element or intervening elements can also be present. Where an element such as a layer, region or substrate is described as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] In order to solve the problem that the control method of the existing electric vehicle thermal management system cannot provide sufficient cooling capacity when the thermal management system has a water circuit fault problem, such as a decrease in water flow caused by foreign matter blocking the thermal management water circuit or bubbles adhering to the water circuit pipe wall, and easily triggers an over-temperature protection condition when the motor temperature exceeds the threshold value, and the control method of the existing electric vehicle thermal management system cannot identify the water circuit fault state of the thermal management system and cannot provide a maintenance prompt to the driver, the fault identification method and device based on the electric vehicle thermal management system provided by the present application can analyze the fault state of the vehicle water circuit by analyzing the vehicle temperature, water circuit water flow value and water circuit pressure peak value, correct the speed of the control electronic water pump to meet the cooling demand of the vehicle cooling components, thereby effectively avoiding the over-temperature phenomenon of the vehicle cooling components, and the application can identify the fault state of the vehicle water circuit and trigger an alarm prompt to achieve the purpose of providing a maintenance prompt to the driver.

[0046] In order to facilitate the understanding of the present application, the specific implementation manner of the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific implementation manner described herein is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application.

[0047] Referring to Figure 1 , a flowchart of the fault identification method based on the electric vehicle thermal management system of the present application is shown, and the fault identification method based on the electric vehicle thermal management system of the present application includes the following steps S101-S107:

[0048] S101, obtaining the vehicle temperature, water circuit water flow value and water circuit pressure peak value after the electric vehicle starts.

[0049] Referring toFigure 2 The electric vehicle thermal management system in the application comprises a control execution assembly and a signal collection assembly, wherein the control execution assembly comprises a vehicle controller and an electronic water pump connected with the vehicle controller through a communication signal line, the vehicle controller is used for receiving signals sent by vehicle cooling components and the signal collection assembly and calculating a duty cycle of the electronic water pump, in the embodiment, the vehicle cooling components comprise a motor, a motor controller, a DC-DC (direct current-direct current converter) and an OBC (on-board charger), the signal collection assembly comprises a multi-in-one controller, a flow sensor and a pressure sensor.

[0050] Specifically, the vehicle temperature is obtained by receiving a communication signal of the multi-in-one controller through the vehicle controller, the vehicle temperature comprises a motor temperature, a motor controller temperature, a DC-DC converter temperature and an on-board charger temperature, the water circuit flow value is obtained by receiving a communication signal of the flow sensor through the vehicle controller, and the water circuit pressure peak value is obtained by receiving a communication signal of the pressure sensor through the vehicle controller, wherein in the embodiment, the water circuit pressure peak value is the maximum water circuit pressure value collected by the pressure sensor within 2s after the electronic water pump starts.

[0051] S102, a water pump target duty cycle is calculated according to the vehicle temperature, a water circuit target water flow value is obtained according to the vehicle temperature and the water pump target duty cycle, an initial water flow deviation value is calculated according to the water circuit target water flow value and the water circuit water flow value, a correction coefficient corresponding to the initial water flow deviation value is obtained according to a first preset relationship, a corrected water pump duty cycle is calculated according to the water pump target duty cycle and the correction coefficient, and a corrected water flow deviation value is calculated according to the corrected water pump duty cycle.

[0052] Specifically, the water pump target duty cycle R tar is calculated according to the vehicle temperature, and the steps comprise:

[0053] a first water pump duty cycle required by the motor is calculated according to the motor temperature, a second water pump duty cycle required by the motor controller is calculated according to the motor controller temperature, a third water pump duty cycle required by the DC-DC converter is calculated according to the DC-DC converter temperature, and a fourth water pump duty cycle required by the on-board charger is calculated according to the on-board charger temperature.

[0054] The maximum value is selected from the first water pump duty cycle, the second water pump duty cycle, the third water pump duty cycle and the fourth water pump duty cycle as the water pump target duty cycle R tar .

[0055] Further, the step of obtaining the water circuit target water flow value according to the vehicle temperature and the water pump target duty cycle is specifically:

[0056] Water pump target duty ratio R tar The corresponding water flow is the water circuit target water flow value L tar , through the water pump target duty ratio R tar , vehicle temperature T and water circuit target water flow value L tar of the parameter corresponding table in this embodiment, that is, Table 1 below, the water pump target duty ratio R tar as the X axis (horizontal axis), the vehicle temperature as the Y axis (vertical axis), the water circuit target water flow value L tar corresponding to the value in Table 1 below is obtained, the water circuit target water flow value obtained under different vehicle temperature and different water pump target duty ratio is different, it should be understood that the water circuit target water flow value L tar in this embodiment is determined by the design state of the water circuit in the electric vehicle thermal management system, the parameters in Table 1 are only an example in this application, the water circuit design state corresponding to the water circuit of different vehicles is different, and the parameters can be calibrated according to the specific situation of the vehicle, and are not limited to the parameter values in Table 1 below.

[0057] Table 1 water pump target duty ratio R tar , vehicle temperature T, water circuit target water flow value L tar Parameter Corresponding Table

[0058] 10％ 20％ 30％ 40％ 50％ 60％ 70％ 80％ 90％ 100％ -30℃ 2.15 2.65 3.31 4.14 4.65 5.34 5.80 6.94 7.44 8.33 -15℃ 2.92 3.50 4.27 5.25 5.84 6.64 7.26 8.44 9.03 10.10 0℃ 3.36 3.99 4.83 5.89 6.53 7.38 8.24 9.29 9.88 11.03 15℃ 3.64 4.30 5.19 6.27 6.93 7.80 8.66 9.75 10.31 11.47 30℃ 3.82 4.49 5.37 6.48 7.15 8.04 8.94 10.08 10.66 11.84 60℃ 4.00 4.69 5.62 6.78 7.48 8.41 9.34 10.49 11.07 12.29

[0059] Further, the vehicle controller receives the signal sent by the flow sensor to obtain the current water circuit water flow value L cur , and calculates the initial water flow deviation value L dev according to the water circuit target water flow L tar found in Table 1 above. Specifically, the initial water flow deviation value is L dev =L tar -L cur .

[0060] Further, the initial water flow deviation value L dev obtained by the above calculation, and according to the first preset relationship, the corresponding correction coefficient C dev is obtained by looking up table, wherein the first preset relationship is the relationship between the initial water flow deviation value L dev and the correction coefficient C dev , specifically, it can be:

[0061] When the initial water flow deviation value L dev is 0L / min-0.5L / min, the correction coefficient C dev is 1;

[0062] When the initial water flow deviation value Ldev When the flow rate is 1 L / min, the correction factor C dev It is 1.2;

[0063] When the initial water flow deviation value L dev When the flow rate is 1.5 L / min, the correction factor C dev It is 1.5;

[0064] When the initial water flow deviation value L dev When the flow rate is 2L / min-10L / min, the correction factor C dev The value is 2.

[0065] As a specific example, in this embodiment, the first preset relationship is also known as the initial water flow deviation value L. dev With correction factor C dev The relationships between them are shown in Table 2 below.

[0066] Table 2 Initial water flow deviation value L dev With correction factor C dev Parameter correspondence table

[0067] Initial water flow deviation value L dev (L / min) 0 0.5 1 1.5 2 3 5 10 Correction factor C dev ]] 1 1 1.2 1.5 2 2 2 2

[0068] As shown in Table 2 above, when the calculated initial water flow deviation value L... dev When it is small, that is, the calculated initial water flow deviation value L dev When the flow rate is 0 L / min to 0.5 L / min, the current water circuit flow rate L can be considered as... cur To meet the cooling requirements of vehicle components, no correction control of the water pump is required at this time; when the calculated initial water flow deviation value L... dev When it is large, that is, the calculated initial water flow deviation value L dev When the flow rate is greater than 0.5 L / min, the current water circuit flow rate L can be considered to be... cur If the cooling requirements of vehicle components cannot be met, then a correction factor C is needed. dev The pump duty cycle is corrected to obtain the corrected pump duty cycle R. out This is output as the final duty cycle of the electronic water pump in this embodiment. Specifically, the corrected water pump duty cycle R... out =R tar *C dev , where R tar C represents the target duty cycle of the water pump calculated by the vehicle controller based on the vehicle temperature. dev This is the correction factor for water pump control. It should be understood that the parameter settings in the first preset relationship in this application can be calibrated according to the specific conditions of the vehicle, and are not limited to the parameter values ​​in Table 2 above.

[0069] Further, the modified water pump duty ratio R out The modified water circuit target water flow value L corresponding to the current vehicle temperature is obtained from the above table 1 tar The corresponding modified water flow deviation value L dev ' is calculated again tar ' = L cur ' - L cur , where L dev is the current water circuit water flow value.

[0070] S103, determine whether the modified water flow deviation value is greater than the water flow deviation threshold.

[0071] Specifically, the modified water flow deviation value L dev ' is calculated by step S102, and compared with the preset water flow deviation threshold. In this embodiment, the water flow deviation threshold is 0.5 L / min.

[0072] S104, if the modified water flow deviation value is greater than the water flow deviation threshold, it is determined that the vehicle water circuit has a fault, and an alarm prompt is triggered.

[0073] Specifically, if the calculated modified water flow deviation value L dev ' is greater than 0.5 L / min, it is determined that the vehicle water circuit has a fault at this time, that is, the vehicle water circuit has problems such as foreign matter blockage or bubble attachment on the pipe wall, the water flow is reduced, and the vehicle parts are prone to insufficient cooling and overheating. At this time, the vehicle controller will trigger an alarm prompt to prompt the driver to perform maintenance work.

[0074] S105, if the modified water flow deviation value is not greater than the water flow deviation threshold, the water circuit pressure deviation value is calculated according to the water circuit pressure peak value and the water circuit rated pressure value.

[0075] Specifically, if the calculated modified water flow deviation value L max ' is not greater than 0.5 L / min, the water circuit pressure deviation value P dev is calculated according to the obtained water circuit pressure peak value P tar and the water circuit rated pressure value P tar = P max , where the water circuit rated pressure value P tar is determined by the capacity of the electronic water pump configured by the vehicle. As a specific example, in this embodiment, the water circuit rated pressure value P tar corresponding to the electronic water pump is 0.5 MPa.2.1 bar. It should be noted that when the electronic water pump is in a stopped state, the vehicle water circuit pressure is generally equal to the atmospheric pressure, i.e. the vehicle water circuit pressure in the stopped state of the electronic water pump is 1.01 bar, when the electronic water pump is started, the pressure sensor collects the vehicle water circuit pressure value, and the maximum value of the water circuit pressure collected within 2s after the electronic water pump is started is taken as the water circuit pressure peak P max , which is transmitted to the vehicle controller, and the vehicle controller calculates the water circuit pressure deviation value P dev , so it can be understood that the calculation of the water circuit pressure deviation value P dev by the vehicle controller is only detected once when the electronic water pump is started from the stopped state.

[0076] S106, judge whether the water pump target duty cycle is greater than the water pump duty cycle preset threshold value, and judge whether the water circuit pressure deviation value is greater than the water circuit pressure preset threshold value.

[0077] Specifically, the water pump target duty cycle R tar calculated in step S102 is compared with the water pump duty cycle preset threshold value, and at the same time, the water circuit pressure deviation value P dev calculated in step S105 is compared with the water circuit pressure preset threshold value, in this embodiment, the water pump duty cycle preset threshold value is 20%, and the water circuit pressure preset threshold value is 0.5 bar.

[0078] S107, if the water pump target duty cycle is greater than the water pump duty cycle preset threshold value, and the water circuit pressure deviation value is greater than the water circuit pressure preset threshold value, it is determined that the vehicle water circuit has a fault, and an alarm prompt is triggered.

[0079] Specifically, if the water pump target duty cycle R tar calculated in step S102 is greater than 20%, and the water circuit pressure deviation value P dev calculated in step S105 is greater than 0.5 bar, it is determined that the vehicle water circuit has a fault at this time, that is, there is a problem such as foreign matter blockage or bubble attachment on the pipe wall in the vehicle water circuit, the water flow is reduced, and it is easy to cause overheating due to insufficient cooling of vehicle parts, at this time the vehicle controller will trigger an alarm prompt to prompt the driver to perform maintenance work.

[0080] Also includes: if the water pump target duty cycle is not greater than the water pump duty cycle preset threshold value, it is determined that the water circuit pressure deviation value is unreliable, and no alarm prompt is triggered.

[0081] Specifically, if the water pump target duty cycle R tar calculated in step S102 is not greater than 20%, it is determined that the water circuit pressure deviation value P devUnreliable, at this time the vehicle controller does not trigger alarm prompt.

[0082] Please refer to Figure 3 , as shown in the block diagram of the fault identification device based on the electric vehicle thermal management system of the present application, the fault identification device based on the electric vehicle thermal management system of the present application comprises:

[0083] The acquisition module 21 is configured to acquire the vehicle temperature, the water loop water flow value, and the water loop pressure peak value after the electric vehicle starts;

[0084] The calculation module 22 is configured to calculate the water pump target duty cycle according to the vehicle temperature, calculate the water loop target water flow value according to the vehicle temperature and the water pump target duty cycle, calculate the initial water flow deviation value according to the water loop target water flow value and the water loop water flow value, obtain the correction coefficient corresponding to the initial water flow deviation value according to a first preset relationship, calculate the corrected water pump duty cycle according to the water pump target duty cycle and the correction coefficient, and calculate the corrected water flow deviation value according to the corrected water pump duty cycle.

[0085] The first judgment module 23 is configured to judge whether the corrected water flow deviation value is greater than a water flow deviation threshold value.

[0086] The first execution module 24 is configured to determine that the vehicle water loop has a fault and trigger an alarm prompt when the corrected water flow deviation value is greater than the water flow deviation threshold value.

[0087] The second execution module 25 is configured to calculate the water loop pressure deviation value according to the water loop pressure peak value and a water loop rated pressure value when the corrected water flow deviation value is not greater than the water flow deviation threshold value.

[0088] The second judgment module 26 is configured to judge whether the water pump target duty cycle is greater than a water pump duty cycle preset threshold value and whether the water loop pressure deviation value is greater than a water loop pressure preset threshold value.

[0089] The third execution module 27 is configured to determine that the vehicle water loop has a fault and trigger an alarm prompt when the water pump target duty cycle is greater than the water pump duty cycle preset threshold value and the water loop pressure deviation value is greater than the water loop pressure preset threshold value.

[0090] The present application also provides a computer readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the aforementioned fault identification method based on the electric vehicle thermal management system.

[0091] Please refer to Figure 4, as shown in the figure is a block diagram of the data processing device of the application, comprising a memory 31, a processor 32, and a computer program stored in the memory 31 and capable of running on the processor 32, and the processor 32 implements the foregoing fault identification method based on the thermal management system of the electric vehicle when executing the program.

[0092] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0093] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as the limitation of the scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for identifying a fault based on an electric vehicle thermal management system, characterized by, The method comprises the following steps: obtaining the vehicle temperature after the electric vehicle starts, the water circuit water flow value, and the water circuit pressure peak value; calculating the water pump target duty cycle according to the vehicle temperature, obtaining the water circuit target water flow value according to the vehicle temperature and the water pump target duty cycle, calculating the initial water flow deviation value according to the water circuit target water flow value and the water circuit water flow value, obtaining the correction coefficient corresponding to the initial water flow deviation value according to a first preset relationship, calculating the corrected water pump duty cycle according to the water pump target duty cycle and the correction coefficient, and calculating the corrected water flow deviation value according to the corrected water pump duty cycle; determining whether the corrected water flow deviation value is greater than a water flow deviation threshold value; if the corrected water flow deviation value is greater than the water flow deviation threshold value, it is determined that the vehicle water circuit has a fault, and an alarm prompt is triggered; if the corrected water flow deviation value is not greater than the water flow deviation threshold value, calculating the water circuit pressure deviation value according to the water circuit pressure peak value and a water circuit rated pressure value; determining whether the water pump target duty cycle is greater than a water pump duty cycle preset threshold value and whether the water circuit pressure deviation value is greater than a water circuit pressure preset threshold value; if the water pump target duty cycle is greater than the water pump duty cycle preset threshold value and the water circuit pressure deviation value is greater than the water circuit pressure preset threshold value, it is determined that the vehicle water circuit has a fault, and an alarm prompt is triggered.

2. The method for identifying a fault based on an electric vehicle thermal management system according to claim 1, characterized in that, The vehicle temperature comprises a motor temperature, a motor controller temperature, a DC-DC converter temperature, and a vehicle-mounted charger temperature.

3. The method for identifying a fault based on an electric vehicle thermal management system according to claim 2, characterized in that, The step of calculating the water pump target duty cycle according to the vehicle temperature comprises the following steps: calculating a first water pump duty cycle required by the motor according to the motor temperature, calculating a second water pump duty cycle required by the motor controller according to the motor controller temperature, calculating a third water pump duty cycle required by the DC-DC converter according to the DC-DC converter temperature, and calculating a fourth water pump duty cycle required by the vehicle-mounted charger according to the vehicle-mounted charger temperature; selecting the maximum value from the first water pump duty cycle, the second water pump duty cycle, the third water pump duty cycle, and the fourth water pump duty cycle as the water pump target duty cycle.

4. The method for identifying a fault based on an electric vehicle thermal management system according to claim 1, characterized by, The water circuit pressure peak value is the maximum water circuit pressure value collected by a pressure sensor within 2s after the water pump starts.

5. The method for identifying faults based on an electric vehicle thermal management system according to claim 1, characterized in that, The first preset relationship is the relationship between the initial water flow deviation value and the correction coefficient, wherein: when the initial water flow deviation value is 0L / min-0.5L / min, the correction coefficient is 1; when the initial water flow deviation value is 1L / min, the correction coefficient is 1.2; when the initial water flow deviation value is 1.5L / min, the correction coefficient is 1.5; when the initial water flow deviation value is 2L / min-10L / min, the correction coefficient is 2.

6. The method for identifying a fault based on an electric vehicle thermal management system according to claim 1, wherein, After determining whether the water pump target duty cycle is greater than the water pump duty cycle preset threshold value, the method further comprises the following step: if the water pump target duty cycle is not greater than the water pump duty cycle preset threshold value, it is determined that the water circuit pressure deviation value is unreliable, and no alarm prompt is triggered.

7. An electric vehicle thermal management system based fault identification apparatus, characterized by, The method comprises the following steps: an obtaining module, configured to obtain the vehicle temperature after the electric vehicle starts, the water circuit water flow value, and the water circuit pressure peak value; The computing module is configured to calculate a water pump target duty ratio according to the vehicle temperature, calculate a water circuit target water flow value according to the vehicle temperature and the water pump target duty ratio, calculate an initial water flow deviation value according to the water circuit target water flow value and the water circuit water flow value, obtain a correction coefficient corresponding to the initial water flow deviation value according to a first preset relationship, calculate a corrected water pump duty ratio according to the water pump target duty ratio and the correction coefficient, and calculate a corrected water flow deviation value according to the corrected water pump duty ratio. The first judging module is configured to judge whether the corrected water flow deviation value is greater than a water flow deviation threshold value. The first executing module is configured to determine that the vehicle water circuit is faulty and trigger an alarm prompt when the corrected water flow deviation value is greater than the water flow deviation threshold value. The second executing module is configured to calculate a water circuit pressure deviation value according to the water circuit pressure peak value and a water circuit rated pressure value when the corrected water flow deviation value is not greater than the water flow deviation threshold value. The second judging module is configured to judge whether the water pump target duty ratio is greater than a water pump duty ratio preset threshold value and whether the water circuit pressure deviation value is greater than a water circuit pressure preset threshold value. The third executing module is configured to determine that the vehicle water circuit is faulty and trigger an alarm prompt when the water pump target duty ratio is greater than the water pump duty ratio preset threshold value and the water circuit pressure deviation value is greater than the water circuit pressure preset threshold value.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the fault identification method based on the electric vehicle thermal management system according to any one of claims 1-6.

9. A data processing device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the fault identification method based on the electric vehicle thermal management system according to any one of claims 1-6.

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