Fault identification method and device based on electric vehicle thermal management system

Abstract

The invention provides a fault identification method and device based on an electric vehicle thermal management system, and relates to the technical field of electric automobiles. The method comprises the steps that the vehicle temperature, the water loop water flow value and the water loop pressure peak value are obtained; calculating to obtain a water pump target duty ratio and a water loop target water flow value, calculating to obtain an initial water flow deviation value according to the water loop target water flow value and the water loop water flow value, and obtaining a correction coefficient corresponding to the initial water flow deviation value according to a first preset relation; a corrected water pump duty ratio is calculated according to the water pump target duty ratio and the correction coefficient, and a corrected water flow deviation value is calculated according to the corrected water pump duty ratio; whether the corrected water flow deviation value is larger than a water flow deviation threshold value or not is judged; judging whether the water pump target duty ratio is greater than a water pump duty ratio preset threshold value or not and judging whether the water loop pressure deviation value is greater than a water loop pressure preset threshold value or not. The fault state of the vehicle water loop can be identified, and an alarm is triggered to carry out maintenance prompting.

Description

Technical Field

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

[0002] The electric vehicle thermal management system is one of the important systems to ensure the normal operation of electric vehicles. The thermal management system is generally controlled by controlling the water pump operation through the vehicle controller to achieve cooling of components that need cooling, such as motors and motor controllers.

[0003] The existing control method of the thermal management system of an electric vehicle generally controls the duty cycle of the electronic water pump by collecting the temperature of the vehicle components that need to be cooled, so as to control the electronic water pump to cool the vehicle components that need to be cooled, or controls the electronic water pump based on the working conditions of the vehicle components that need to be cooled, such as motor speed, motor torque and other working condition information. However, when a water circuit failure problem occurs in the thermal management system, such as a problem in which the water circuit of the thermal management system is blocked by foreign matter or bubbles are attached to the wall of the water circuit, resulting in a reduction in water flow, the existing control method of the thermal management system of an electric vehicle cannot provide sufficient cooling capacity, and it is easy for the motor temperature to exceed the threshold and trigger the over-temperature protection. At the same time, the existing control method of the thermal management system of an electric vehicle cannot identify the water circuit failure state of the thermal management system, and cannot give the driver a maintenance prompt. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a fault identification method and device based on an electric vehicle thermal management system, aiming to solve the technical problem that the control method of the electric vehicle thermal management system in the prior art cannot provide sufficient cooling capacity when a water circuit failure occurs in the thermal management system, and it is easy for the motor temperature to exceed the threshold and trigger the over-temperature protection. In addition, the water circuit failure state of the thermal management system cannot be identified, and the driver cannot be given maintenance prompts.

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

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

[0007] Calculating a target duty cycle of the water pump according to the vehicle temperature, obtaining a target water flow value of the water circuit according to the vehicle temperature and the target duty cycle of the water pump, calculating an initial water flow deviation value according to the target water flow value of the water circuit and the water flow value of the water circuit, obtaining a correction coefficient corresponding to the initial water flow deviation value according to a first preset relationship, calculating a corrected water pump duty cycle according to the target duty cycle of the water pump and the correction coefficient, and calculating a corrected water flow deviation value according to the corrected water pump duty cycle;

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

[0009] If the corrected water flow deviation value is greater than the water flow deviation threshold, it is determined that the vehicle water circuit is faulty and an alarm is triggered;

[0010] If the corrected 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;

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

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

[0013] Compared with the prior art, the beneficial effect of the fault identification method based on the electric vehicle thermal management system of the present invention is that it can analyze the fault state of the vehicle's water circuit through parameter analysis of the vehicle temperature, the water flow value of the water circuit and the peak pressure of the water circuit, and correct the speed of the electronic water pump to meet the cooling needs of the vehicle's components that need to be cooled, thereby effectively avoiding overheating of the vehicle's components that need to be cooled. In addition, the present application can identify the fault state of the vehicle's water circuit and trigger an alarm prompt 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 present invention may also have the following additional technical features:

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

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

[0017] 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;

[0018] A 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 a water pump target duty cycle.

[0019] Furthermore, the water circuit pressure peak value is the maximum value of the water circuit pressure collected by the pressure sensor within 2 seconds after the water pump is started.

[0020] Furthermore, the first preset relationship is the relationship between the initial water flow deviation value and the 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 factor is 1.2;

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

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

[0025] Further, after determining whether the target duty cycle of the water pump is greater than a preset threshold value of the water pump duty cycle, the method further includes:

[0026] If the target duty cycle of the water pump is not greater than the preset threshold value of the water pump duty cycle, it is determined that the water circuit pressure deviation value is unreliable and no alarm is triggered.

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

[0028] An acquisition module, used to acquire the vehicle temperature, water flow value of the water circuit, and peak pressure of the water circuit after the electric vehicle is started;

[0029] a calculation module, configured to calculate a target duty cycle of the water pump according to the vehicle temperature, obtain a target water flow value of the water circuit according to the vehicle temperature and the target duty cycle of the water pump, calculate an initial water flow deviation value according to the target water flow value of the water circuit and the water flow value of the water circuit, 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 target duty cycle of the water pump 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, used to judge whether the corrected water flow deviation value is greater than a water flow deviation threshold;

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

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

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

[0034] The third execution module is used to determine that the vehicle water circuit is faulty 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 present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the aforementioned fault identification method based on the thermal management system of an electric vehicle is implemented.

[0036] The present invention also provides a data processing device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the aforementioned fault identification method based on the thermal management system of an electric vehicle when executing the program. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A flowchart of a fault identification method based on an electric vehicle thermal management system of the present invention;

[0038] Figure 2 A structural block diagram of a thermal management system for an electric vehicle provided in an embodiment of the present invention;

[0039] Figure 3 It is a structural block diagram of a fault identification device based on an electric vehicle thermal management system of the present invention;

[0040] Figure 4 A block diagram of a data processing device according to the present invention.

[0041] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented 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 present invention more thorough and comprehensive.

[0043] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0045] In order to solve the problem of water circuit failure in the thermal management system of electric vehicles in the prior art, such as the problem of reduced water flow caused by foreign matter blocking the thermal management water circuit or bubbles attached to the water circuit pipe wall, the existing control method of the thermal management system of electric vehicles cannot provide sufficient cooling capacity, and it is easy for the motor temperature to exceed the threshold and trigger the over-temperature protection. At the same time, the existing control method of the thermal management system of electric vehicles cannot identify the water circuit failure state of the thermal management system and cannot give the driver maintenance prompts. The fault identification method and device based on the thermal management system of electric vehicles provided in the present application can analyze the fault state of the vehicle water circuit through parameter analysis of the vehicle temperature, the water flow value of the water circuit and the peak pressure of the water circuit, and correct the speed of the electronic water pump to meet the cooling requirements of the vehicle components that need to be cooled, thereby effectively avoiding the overheating of the vehicle components that need to be cooled. In addition, the present application can identify the fault state of the vehicle water circuit and trigger an alarm prompt to achieve the purpose of giving the driver maintenance prompts.

[0046] To facilitate understanding of the present invention, the specific implementation of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0047] See also Figure 1 , which is a flow chart of a fault identification method based on an electric vehicle thermal management system of the present invention, the fault identification method based on an electric vehicle thermal management system of the present invention comprises the following steps S101 to S107:

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

[0049] See also Figure 2 The electric vehicle thermal management system in the present application includes a control execution assembly and a signal acquisition assembly, wherein the control execution assembly includes a vehicle controller and an electronic water pump connected to the vehicle controller through a communication signal line, and the vehicle controller is used to receive the vehicle components to be cooled and the signals sent by the signal acquisition assembly and calculate the duty cycle of the electronic water pump. In this embodiment, the vehicle components to be cooled include a motor, a motor controller, a DC-DC (direct current-to-direct current converter) and an OBC (on-board charger); the signal acquisition assembly includes an all-in-one controller, a flow sensor and a pressure sensor.

[0050] Specifically, the vehicle controller receives the communication signal of the all-in-one controller to obtain the vehicle temperature, which includes the motor temperature, the motor controller temperature, the DC-DC converter temperature, and the on-board charger temperature. The vehicle controller receives the communication signal of the flow sensor to obtain the water flow value of the water circuit. The vehicle controller receives the communication signal of the pressure sensor to obtain the water circuit pressure peak value. In this embodiment, the water circuit pressure peak value is the maximum water circuit pressure collected by the pressure sensor within 2 seconds after the electronic water pump is started.

[0051] S102. Calculate the target duty cycle of the water pump according to the vehicle temperature, obtain the target water flow value of the water circuit according to the vehicle temperature and the target duty cycle of the water pump, calculate the initial water flow deviation value according to the target water flow value of the water circuit and the water flow value of the water circuit, 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 target duty cycle of the water pump and the correction coefficient, and calculate the corrected water flow deviation value according to the corrected water pump duty cycle.

[0052] Specifically, the target duty cycle R of the water pump is calculated according to the vehicle temperature. tar The steps include:

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

[0056] Pump target duty cycle R tar The corresponding water flow is the target water flow value L of the water circuit tar , by the target duty cycle R of the water pump in this embodiment tar , vehicle temperature T and water circuit target water flow value L tar The parameter corresponding table is looked up in Table 1, that is, the target duty cycle of the water pump R tar As the X-axis (horizontal axis), the vehicle temperature as the Y-axis (vertical axis), corresponding to the values ​​in Table 1 below to obtain the target water flow value L of the water circuit tar The target water flow rate of the water circuit obtained under different vehicle temperatures and different water pump target duty cycles is different. It should be understood that the target water flow rate of the water circuit in this embodiment is L tar Determined by the design state of the water circuit in the thermal management system of the electric vehicle, the parameters in Table 1 are only an example in this application. The water circuit design states corresponding to the water circuits of different vehicles are different. It should be calibrated according to the specific conditions of the vehicle and is not limited to the parameter values ​​in Table 1 below. .

[0057] Table 1 Pump target duty cycle R tar , vehicle temperature T, water circuit target water flow value L tar Parameter correspondence 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] Furthermore, the vehicle controller receives the signal from the flow sensor to obtain the current water flow value L of the water circuit. cur , and according to the water circuit target water flow L found in Table 1 above tar Calculate the initial water flow deviation value L dev Specifically, the initial water flow deviation value is L dev =L tar -L cur .

[0060] Furthermore, the initial water flow deviation value L obtained by the above calculation is dev , and look up the table according to the first preset relationship to obtain the corresponding correction coefficient C dev , where the first preset relationship is the initial water flow deviation value L dev and correction factor C dev Specifically, the relationship between can be:

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

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

[0063] When the initial water flow deviation value L dev When the flow rate is 1.5L / min, the correction factor C dev 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 is 2.

[0065] As a specific example, in this embodiment, the first preset relationship, that is, the initial water flow deviation value L dev and correction factor C dev The relationship between them is shown in Table 2.

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

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

[0068] From Table 2 above, we can see that when the calculated initial water flow deviation value L dev When it is smaller, the calculated initial water flow deviation value L dev When it is 0L / min-0.5L / min, it can be considered that the current water circuit water flow value L cur To meet the cooling requirements of vehicle components, there is no need to correct the water pump control at this time; when the calculated initial water flow deviation value L dev When it is larger, the calculated initial water flow deviation value L dev When it is greater than 0.5L / min, it can be considered that the current water circuit water flow value L cur It cannot meet the cooling requirements of vehicle parts. In this case, the correction factor C is required. dev Correct the pump operation duty cycle to obtain the corrected pump duty cycle R out , and 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 is the target duty cycle of the water pump calculated by the vehicle controller based on the vehicle temperature, C dev It should be understood that the parameter settings in the first preset relationship in the present 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] Furthermore, the corrected water pump duty cycle R obtained by the above calculation is out , from Table 1 above, obtain the corrected water circuit target water flow value L corresponding to the current vehicle temperature tar ', and recalculate the corresponding corrected water flow deviation value L dev '=L tar '-L cur , where L cur It is the current water flow value of the water circuit.

[0070] S103: Determine whether the corrected water flow deviation value is greater than a water flow deviation threshold.

[0071] Specifically, the corrected water flow deviation value L is calculated in step S102: dev ', and compare it with the preset water flow deviation threshold. In this embodiment, the water flow deviation threshold is 0.5L / min.

[0072] S104: If the corrected water flow deviation value is greater than the water flow deviation threshold, it is determined that a fault occurs in the vehicle water circuit, and an alarm is triggered.

[0073] Specifically, if the calculated corrected water flow deviation value L dev ' is greater than 0.5L / min, it is determined that the vehicle's water circuit is faulty, that is, the vehicle's water circuit is blocked by foreign matter or bubbles are attached to the pipe wall. The water flow is reduced, and it is easy for vehicle parts to be insufficiently cooled and cause overheating. At this time, the vehicle controller will trigger an alarm to prompt the driver to perform maintenance work.

[0074] S105: If the corrected 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 corrected water flow deviation value L dev ' is not greater than 0.5L / min, then according to the peak water circuit pressure P max And the rated pressure value of the water circuit P tar Calculate the water circuit pressure deviation value P dev =P tar -P max , where the rated pressure of the water circuit is P tar It is determined by the capacity of the electronic water pump configured in the vehicle. As a specific example, in this embodiment, the rated pressure value P of the water circuit corresponding to the electronic water pump is tarIt should be noted that when the electronic water pump is in the shutdown state, the vehicle water circuit pressure is generally equal to the atmospheric pressure, that is, the vehicle water circuit pressure when the electronic water pump is in the shutdown state is 1.01 bar. When the electronic water pump is started, the pressure sensor collects the vehicle water circuit pressure value and takes the maximum water circuit pressure collected within 2 seconds after the electronic water pump is started as the water circuit pressure peak value P max , and then transmitted to the vehicle controller, which calculates the water circuit pressure deviation value P dev Therefore, it can be understood that the vehicle controller is responsible for the water circuit pressure deviation value P dev The calculation is only detected once when the electronic water pump starts from stop.

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

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

[0078] S107: If the target duty cycle of the water pump is greater than the preset threshold value of the water pump duty cycle and the water circuit pressure deviation value is greater than the preset threshold value of the water circuit pressure, it is determined that the vehicle water circuit is faulty and an alarm is triggered.

[0079] Specifically, if the target duty cycle R of the water pump calculated in step S102 is tar greater than 20%, and the water circuit pressure deviation value P calculated in step S105 dev If it is greater than 0.5bar, it is determined that the vehicle's water circuit is faulty. In other words, the vehicle's water circuit is blocked by foreign matter or bubbles are attached to the pipe wall. The water flow is reduced, and it is easy for vehicle parts to be insufficiently cooled and cause overheating. At this time, the vehicle controller will trigger an alarm to prompt the driver to perform maintenance work.

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

[0081] Specifically, if the target duty cycle R of the water pump calculated in step S102 is tar If it is not greater than 20%, it is determined to be the water circuit pressure deviation value P calculated in step S105. devIt is unreliable, and the vehicle controller does not trigger an alarm prompt at this time.

[0082] See also Figure 3 , which is a block diagram of a fault identification device based on a thermal management system of an electric vehicle according to the present invention, and the fault identification device based on a thermal management system of an electric vehicle according to the present invention comprises:

[0083] An acquisition module 21 is used to acquire the vehicle temperature, water flow value of the water circuit, and peak pressure of the water circuit after the electric vehicle is started;

[0084] a calculation module 22, configured to calculate a target duty cycle of the water pump according to the vehicle temperature, obtain a target water flow value of the water circuit according to the vehicle temperature and the target duty cycle of the water pump, calculate an initial water flow deviation value according to the target water flow value of the water circuit and the water flow value of the water circuit, 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 target duty cycle of the water pump and the correction coefficient, and calculate a corrected water flow deviation value according to the corrected water pump duty cycle;

[0085] A first judging module 23, used to judge whether the corrected water flow deviation value is greater than a water flow deviation threshold;

[0086] The first execution module 24 is used 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;

[0087] A second execution module 25 is used to calculate the water circuit pressure deviation value according to the water circuit pressure peak value and the water circuit 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 used to judge whether the target duty cycle of the water pump is greater than a preset threshold value of the water pump duty cycle, and to judge whether the water circuit pressure deviation value is greater than a preset threshold value of the water circuit pressure;

[0089] The third execution module 27 is used to determine that the vehicle water circuit is faulty and trigger an alarm prompt when the water pump target duty cycle is greater than the preset threshold value of the water pump duty cycle and the water circuit pressure deviation value is greater than the preset threshold value of the water circuit pressure.

[0090] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the aforementioned fault identification method based on the thermal management system of an electric vehicle is implemented.

[0091] See also Figure 4, shown is a block diagram of the data processing device of the present invention, including a memory 31, a processor 32, and a computer program stored in the memory 31 and executable on the processor 32, wherein the processor 32 implements the aforementioned fault identification method based on the thermal management system of an electric vehicle when executing the program.

[0092] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0093] The above-described embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of application of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention application shall be subject to the attached claims.

Claims

1. A fault identification method based on an electric vehicle thermal management system, characterized in that: include: Obtaining the vehicle temperature, water flow value of the water circuit, and peak pressure of the water circuit after the electric vehicle is started; Calculating a target duty cycle of the water pump according to the vehicle temperature, obtaining a target water flow value of the water circuit according to the vehicle temperature and the target duty cycle of the water pump, calculating an initial water flow deviation value according to the target water flow value of the water circuit and the water flow value of the water circuit, obtaining a correction coefficient corresponding to the initial water flow deviation value according to a first preset relationship, calculating a corrected water pump duty cycle according to the target duty cycle of the water pump and the correction coefficient, and calculating a corrected water flow deviation value according to the corrected water pump duty cycle; Determine whether the corrected water flow deviation value is greater than the water flow deviation threshold; If the corrected water flow deviation value is greater than the water flow deviation threshold, it is determined that the vehicle water circuit is faulty and an alarm is triggered; If the corrected 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; Determine whether the target duty cycle of the water pump is greater than a preset threshold value of the water pump duty cycle, and determine whether the water circuit pressure deviation value is greater than a preset threshold value of the water circuit pressure; If the water pump target duty cycle is greater than the water pump duty cycle preset threshold, and the water circuit pressure deviation value is greater than the water circuit pressure preset threshold, it is determined that the vehicle water circuit has a fault and an alarm is triggered.

2. The fault identification method based on the electric vehicle thermal management system according to claim 1 is characterized in that: The vehicle temperature includes motor temperature, motor controller temperature, DC-DC converter temperature, and on-board charger temperature.

3. The fault identification method based on the electric vehicle thermal management system according to claim 2 is characterized in that: The step of calculating the target duty cycle of the water pump according to the vehicle temperature comprises: 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; A 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 a water pump target duty cycle.

4. The fault identification method based on the electric vehicle thermal management system according to claim 1 is characterized in that: The water circuit pressure peak value is the maximum water circuit pressure value collected by the pressure sensor within 2 seconds after the water pump is started.

5. The fault identification method based on the electric vehicle thermal management system according to claim 1 is characterized in that: The first preset relationship is the relationship between the initial water flow deviation value and the correction coefficient, where: 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 factor is 1.2; When the initial water flow deviation value is 1.5L / min, the correction factor is 1.5; When the initial water flow deviation value is 2L / min-10L / min, the correction coefficient is 2.

6. The fault identification method based on the electric vehicle thermal management system according to claim 1 is characterized in that: After determining whether the target duty cycle of the water pump is greater than the preset threshold value of the water pump duty cycle, the following steps are further included: If the target duty cycle of the water pump is not greater than the preset threshold value of the water pump duty cycle, it is determined that the water circuit pressure deviation value is unreliable and no alarm is triggered.

7. A fault identification device based on an electric vehicle thermal management system, characterized in that: include: An acquisition module, used to acquire the vehicle temperature, water flow value of the water circuit, and peak pressure of the water circuit after the electric vehicle is started; a calculation module, configured to calculate a target duty cycle of the water pump according to the vehicle temperature, obtain a target water flow value of the water circuit according to the vehicle temperature and the target duty cycle of the water pump, calculate an initial water flow deviation value according to the target water flow value of the water circuit and the water flow value of the water circuit, 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 target duty cycle of the water pump and the correction coefficient, and calculate a corrected water flow deviation value according to the corrected water pump duty cycle; A first judgment module, used to judge whether the corrected water flow deviation value is greater than a water flow deviation threshold; A first execution module, configured to determine that a vehicle water circuit fails and trigger an alarm prompt when the corrected water flow deviation value is greater than a water flow deviation threshold; A second execution module is used to calculate the water circuit pressure deviation value according to the water circuit pressure peak value and the water circuit rated pressure value when the corrected water flow deviation value is not greater than the water flow deviation threshold value; The second judgment module is used to judge whether the target duty cycle of the water pump is greater than a preset threshold value of the water pump duty cycle, and to judge whether the water circuit pressure deviation value is greater than a preset threshold value of the water circuit pressure; The third execution module is used to determine that the vehicle water circuit is faulty 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.

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

9. A data processing device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the fault identification method based on the electric vehicle thermal management system as described in any one of claims 1 to 6 is implemented.

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