Vehicle motor controller temperature acquisition method and system

Abstract

The invention relates to a vehicle motor controller temperature obtaining method and system. The method comprises the steps that S1, the heating power of a vehicle motor and the sampling temperature of a controller used for controlling the vehicle motor are obtained; s2, determining an estimated temperature of the controller according to the heating power and the sampling temperature; and S3, determining a temperature correction coefficient according to the rotating speed and the torque of the vehicle motor, and determining the final temperature of the controller according to the estimated temperature and the temperature correction coefficient. According to the method, on the basis of the estimated temperature determined according to the heating power and the sampling temperature, the estimated temperature is corrected by using the temperature correction coefficient determined according to the rotating speed and the torque of the motor, and the precision is high.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a method and system for acquiring temperature of an automotive motor controller. Background Technology

[0002] In existing technologies, temperature sensors are typically installed in the power devices of motors and controllers in electric drive systems to detect the current temperature of the motor or power device. However, due to certain inherent characteristics of temperature sensors, they can only be placed around the chip of the power device, maintaining a certain installation distance from the heat-generating wafer. This results in a delay and difference between the temperature detected by the temperature sensor and the actual wafer temperature, leading to low accuracy in temperature detection.

[0003] Those skilled in the art have been seeking solutions to the above problems. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide a method and system for acquiring temperature of an automotive motor controller, addressing the deficiencies of the prior art.

[0005] To achieve the above objectives, this application employs the following technical solution:

[0006] This application provides a method for obtaining the temperature of an automotive motor controller, including the following steps:

[0007] S1. Obtain the heating power of the vehicle motor and the sampling temperature of the controller used to control the vehicle motor;

[0008] S2. Determine the estimated temperature of the controller based on the heating power and the sampling temperature;

[0009] S3. Determine the temperature correction coefficient based on the speed and torque of the vehicle motor, and determine the final temperature of the controller based on the estimated temperature and the temperature correction coefficient.

[0010] Optionally, step S1 includes: calculating the heat generation power of the vehicle motor based on the vehicle motor's speed, torque, switching transistor parameters, and efficiency.

[0011] Optionally, step S2 includes:

[0012] Establish a thermal resistance model for the controller;

[0013] The reference temperature is determined based on the heating power in the thermal resistance model.

[0014] The difference between the reference temperature and the sampling temperature is compared with a preset temperature difference threshold.

[0015] If the difference between the reference temperature and the sampling temperature does not exceed the temperature difference threshold, then the reference temperature is determined as the estimated temperature of the controller.

[0016] Optionally, determining the temperature correction coefficient based on the speed and torque of the vehicle motor includes:

[0017] Establish a table of temperature correction coefficients corresponding to the speed and torque of the vehicle motor;

[0018] Based on the currently obtained speed and torque of the vehicle motor, the corresponding temperature correction coefficient is retrieved from the temperature correction coefficient table.

[0019] Optionally, establishing the temperature correction coefficient table corresponding to the speed and torque of the vehicle motor includes:

[0020] Determine the current speed and torque of the vehicle motor, and maintain the current torque unchanged during a preset test period;

[0021] During the test period, the difference between the test sampling temperature and the estimated temperature is obtained, and the difference is determined as the temperature correction coefficient;

[0022] The temperature correction table is established based on the correspondence between the current rotational speed, the current torque, and the temperature correction coefficient.

[0023] Optionally, the step of establishing a temperature correction coefficient table corresponding to the speed and torque of the vehicle motor further includes:

[0024] After determining the difference as the temperature correction coefficient, the current torque is compared with a preset torque threshold.

[0025] If the current torque is less than the torque threshold, the current torque is increased by a preset torque increase rate, and the process returns to the step of determining the current speed and current torque of the vehicle motor and maintaining the current torque unchanged within a preset test period.

[0026] Optionally, comparing the current torque with a preset torque threshold further includes:

[0027] If the current torque is greater than the torque threshold, then determine whether the current rotational speed is greater than a preset rotational speed threshold;

[0028] If the current rotational speed is less than the rotational speed threshold, the current rotational speed is increased by a preset rotational speed increase, and the process returns to the step of determining the current rotational speed and current torque of the vehicle motor and maintaining the current torque unchanged within a preset test period.

[0029] If the current rotational speed is greater than the rotational speed threshold, then the temperature correction table is completed.

[0030] This application also provides a temperature acquisition system for an automotive motor controller, including: a data acquisition module, a data analysis module, and a data integration module;

[0031] The data acquisition module is used to acquire the heating power of the vehicle motor and the sampling temperature of the controller used to control the vehicle motor;

[0032] The data analysis module is used to determine the estimated temperature of the controller based on the heating power and the sampling temperature, and to determine the temperature correction coefficient based on the speed and torque of the vehicle motor.

[0033] The data integration module is used to determine the final temperature of the controller based on the estimated temperature and the temperature correction coefficient.

[0034] Optionally, the data acquisition module is further configured to calculate the heat generation power of the vehicle motor based on the vehicle motor's speed, torque, switching transistor parameters, and efficiency.

[0035] Optionally, the data analysis module is further configured to establish a thermal resistance model for the controller, determine a reference temperature based on the heating power in the thermal resistance model, compare the difference between the reference temperature and the sampling temperature with a preset temperature difference threshold, and if the difference between the reference temperature and the sampling temperature does not exceed the temperature difference threshold, determine the reference temperature as the estimated temperature of the controller.

[0036] This application provides a method and system for obtaining temperature of an automotive motor controller. Based on the estimated temperature determined by the heating power and the sampled temperature, the estimated temperature is corrected using a temperature correction coefficient determined by the motor speed and torque, resulting in high accuracy.

[0037] To make the above and other objects, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0038] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments;

[0039] Figure 1 This is a schematic flowchart of a method for acquiring temperature of an automotive motor controller according to an embodiment of this application;

[0040] Figure 2 This is a functional structure diagram of a vehicle motor controller temperature acquisition system provided in one embodiment of this application;

[0041] Figure 3This is a schematic diagram of the structure of a test system for obtaining a temperature correction coefficient table according to an embodiment of this application. Detailed Implementation

[0042] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0043] Currently, electric drive systems consist of two parts: the motor itself and the controller, which includes a low-voltage control signal unit and a high-voltage power unit. As a key component in the automotive powertrain system, the electric drive system provides the power needed for electric vehicles to move forward. To meet the diverse performance requirements of electric vehicles, the drive motor has high requirements in terms of overload capacity, starting torque, and reliability. Overload capacity and starting torque of the electric drive system: When an overload occurs, the power device will carry a large current I. Since power devices have a certain on-resistance R, according to Joule's law, heat Q = I²Rt, a large amount of heat will be generated inside the power device per unit time, causing the device temperature to rise sharply. Each power device has its own temperature threshold; when the temperature exceeds a certain threshold, the reliability of the power device decreases, and it may even be damaged.

[0044] Based on the above, it is necessary to accurately monitor the real-time temperature of the power devices in the controller.

[0045] In electric drive systems, temperature sensors are typically installed in the power devices of the motor and controller to detect their current temperature. However, due to the inherent characteristics of the devices, temperature sensors can only be placed around the chip and are kept at a certain distance from the heat-generating wafer. This results in a delay and discrepancy between the temperature detected by the sensor and the actual wafer temperature. To correct this discrepancy, existing technologies employ temperature estimation schemes such as obtaining the current heat generation power through the switching and conduction characteristics of the device or by using an offline lookup table to assess the controller's efficiency, and then estimating the actual device temperature using a thermal resistance model. However, due to environmental factors and the complexity of the temperature model, discrepancies still exist between the estimated and actual temperatures under different operating conditions, requiring further correction.

[0046] Figure 1 This is a schematic flowchart of a method for acquiring the temperature of an automotive motor controller according to an embodiment of this application. Please refer to [link / reference]. Figure 1 This application provides a method for obtaining the temperature of an automotive motor controller, comprising the following steps:

[0047] S1. Obtain the heating power of the vehicle motor and the sampling temperature of the controller used to control the vehicle motor;

[0048] Optionally, step S1 includes: calculating the heat generation power of the vehicle motor based on the vehicle motor's speed, torque, switching transistor parameters, and efficiency.

[0049] S2. Determine the estimated temperature of the controller based on the heating power and the sampling temperature.

[0050] Optionally, step S2 includes:

[0051] Establish a thermal resistance model for the controller;

[0052] The reference temperature is determined based on the heating power in the thermal resistance model;

[0053] The difference between the reference temperature and the sampling temperature is compared with a preset temperature difference threshold.

[0054] If the difference between the reference temperature and the sampled temperature does not exceed the temperature difference threshold, the reference temperature will be determined as the estimated temperature of the controller.

[0055] Optionally, the temperature correction factor is determined based on the speed and torque of the vehicle motor, including:

[0056] Establish a table of temperature correction coefficients corresponding to the speed and torque of automotive motors;

[0057] Based on the current speed and torque of the vehicle motor, the corresponding temperature correction factor is retrieved from the temperature correction factor table.

[0058] Optionally, establishing a table of temperature correction factors corresponding to the speed and torque of the vehicle motor includes:

[0059] Establish a test system for obtaining a temperature correction factor table;

[0060] The test system determines the current speed and torque of the vehicle motor and maintains the current torque unchanged during the preset test period.

[0061] During the test period, the difference between the test sampling temperature and the estimated temperature is obtained, and the difference is determined as the temperature correction factor.

[0062] A temperature correction table is established based on the correspondence between the current speed, current torque, and temperature correction coefficient.

[0063] Optionally, establishing a table of temperature correction factors corresponding to the speed and torque of the vehicle motor also includes:

[0064] After determining the difference as a temperature correction factor, the current torque is compared with a preset torque threshold.

[0065] If the current torque is less than the torque threshold, the current torque is increased by a preset torque increase rate, and the process returns to the step of determining the current speed and torque of the vehicle motor and maintaining the current torque unchanged within a preset test period.

[0066] Optionally, comparing the current torque with a preset torque threshold also includes:

[0067] If the current torque is greater than the torque threshold, then determine whether the current speed is greater than the preset speed threshold.

[0068] If the current speed is less than the speed threshold, the current speed is increased by a preset speed increase amount, and the process returns to the step of determining the current speed and current torque of the vehicle motor and maintaining the current torque unchanged within the preset test period.

[0069] If the current speed is greater than the speed threshold, then the temperature correction table is completed.

[0070] S3. Determine the temperature correction coefficient based on the speed and torque of the vehicle motor, and determine the final temperature of the controller based on the estimated temperature and the temperature correction coefficient.

[0071] Figure 2 This is a functional structure diagram of a vehicle motor controller temperature acquisition system according to an embodiment of this application. Please refer to it. Figure 2 This application also provides a temperature acquisition system for an automotive motor controller, comprising: a data acquisition module A, a data analysis module B, and a data integration module C;

[0072] Data acquisition module A is used to acquire the heating power of the vehicle motor and the sampling temperature of the controller used to control the vehicle motor;

[0073] Data analysis module B is used to determine the estimated temperature of the controller based on the heating power and the sampling temperature, and to determine the temperature correction coefficient based on the speed and torque of the vehicle motor.

[0074] The data integration module C is used to determine the final temperature of the controller based on the estimated temperature and the temperature correction factor.

[0075] Optionally, the data acquisition module A is also used to calculate the heat generation power of the vehicle motor based on the motor's speed, torque, switching transistor parameters, and efficiency.

[0076] Optionally, the data analysis module B is also used to establish a thermal resistance model for the controller, determine a reference temperature based on the heat generation power in the thermal resistance model, compare the difference between the reference temperature and the sampling temperature with a preset temperature difference threshold, and determine the reference temperature as the estimated temperature of the controller if the difference between the reference temperature and the sampling temperature does not exceed the temperature difference threshold.

[0077] Figure 3This is a schematic diagram of a test system for obtaining a temperature correction coefficient table according to an embodiment of this application. Please refer to [link / reference]. Figure 3 The testing system in this embodiment includes: a microprocessor 10, a power device 20 disposed in the vehicle motor controller, a dynamometer controller 30, a motor 40, a coupling 50, an auxiliary motor 60, and an infrared thermometer 70.

[0078] The microprocessor 10 is electrically connected to the power device 20, the power device 20 is electrically connected to the motor 40, the microprocessor 10 is communicatively connected to the dynamometer controller 30, the dynamometer controller 30 is connected to the motor 40, the infrared thermometer 70 is communicatively connected to the microprocessor 10 and is located on the side close to the power device 20, the auxiliary motor 60 is electrically connected to the dynamometer controller 30, and the auxiliary motor 60 is also connected to the motor 40 through the coupling 50.

[0079] The microprocessor 10 is used to obtain the heat output of the vehicle motor.

[0080] The infrared thermometer 70 is used to obtain the test sampling temperature of the motor controller.

[0081] Coupling 50 is used to connect the central shaft of motor 40 and auxiliary motor 60.

[0082] The auxiliary motor 60 is used to drive the motor 40 to rotate via the coupling 50.

[0083] In embodiments of this application, the power device 20 includes a wafer, and the power device 20 is configured to have an open cover to expose the wafer.

[0084] In this embodiment, on one hand, the microprocessor 10 outputs a speed control signal to the dynamometer controller 30 via a communication line connected to the dynamometer controller 30. The dynamometer controller 30 controls the motor 40 to rotate at a certain speed according to the speed control signal. On the other hand, the microprocessor 10 outputs a torque control signal to the power device 20 via a communication line connected to the power device 20. The power device 20 controls the motor 40 to move with a certain torque according to the torque control signal. By outputting speed control signals to the dynamometer controller 30 and torque control signals to the power device 20, the microprocessor 10 can achieve independent control of the torque and speed of the motor 40, thus enabling the acquisition of a temperature correction coefficient table through this testing system.

[0085] In a specific embodiment of this application, after the test system is initialized, the microprocessor 10 outputs a torque control signal to the power device 20 to adjust the current torque of the motor 40 to T = Tmin0, and outputs a speed control signal to the dynamometer controller 30 to adjust the current speed of the motor 40 to V = v0. Based on this, the current torque Tmin0 is maintained unchanged for a preset test period (e.g., 1 hour, 5 hours). After the test period ends, the infrared thermometer 70 acquires the test sampling temperature, and obtains the difference between the test sampling temperature and the estimated temperature acquired by the microprocessor 10. This difference is determined as a first temperature correction coefficient. The microprocessor 10 then defines the torque Tmin0, speed v0, and the first temperature correction coefficient as first state parameters and stores them in a temperature correction table.

[0086] After storing the first state parameter, the microprocessor 10 compares the current torque Tmin0 with a preset torque threshold. If the current torque Tmin0 is less than the torque threshold, the current torque T is increased by a preset torque increase amount (e.g., 1Tmin0, 2Tmin0) to T = 2Tmin0. Based on this, the current speed v0 and current torque 2Tmin0 of the vehicle motor are determined, and the current torque 2Tmin0 is kept unchanged during the preset test period. After the test period ends, the infrared thermometer 70 acquires the test sampling temperature and the difference between the test sampling temperature and the estimated temperature acquired by the microprocessor 10. This difference is determined as the temperature correction coefficient. The microprocessor 10 then defines the torque 2Tmin0, speed v0, and the first temperature correction coefficient as the second state parameter and stores them in the temperature correction table.

[0087] After storing the first state parameters, the microprocessor 10 compares the current torque Tmin0 with a preset torque threshold. If the current torque Tmin0 is greater than the torque threshold, it determines whether the current speed v0 is greater than the preset speed threshold. If the current speed v0 is less than the speed threshold, it increases the current speed V by a preset speed increase increment (e.g., 1v0, 2v0) to V = 2v0. Based on this, it determines the current speed 2v0 and the current torque Tmin0 of the vehicle motor and maintains the current speed 2v0 unchanged during the preset test period. After the test period ends, the infrared thermometer 70 acquires the test sampling temperature and obtains the difference between the test sampling temperature and the estimated temperature acquired by the microprocessor 10. This difference is determined as the third temperature correction coefficient. The microprocessor 10 then defines the torque Tmin0, speed 2v0, and the third temperature correction coefficient as the third state parameters and stores them in the temperature correction table. After storing the first state parameters, if the current speed v0 is greater than the speed threshold, the temperature correction table is completed.

[0088] In the embodiments of this application, the temperature correction table obtained according to the above process is stored in the microprocessor. When the controller temperature is measured during actual driving, the calculated estimated temperature is revised according to the stored temperature correction table to obtain a more accurate final temperature. If the torque or speed cannot find the corresponding temperature correction coefficient, it can be obtained by interpolation.

[0089] This application provides a method and system for obtaining temperature of an automotive motor controller. Based on the estimated temperature determined by the heating power and the sampled temperature, the estimated temperature is corrected using a temperature correction coefficient determined by the motor speed and torque, resulting in high accuracy.

[0090] The solution proposed in this application can also be applied to the following scenarios: 1) for motor temperature estimation coefficient calibration; 2) for torque estimation coefficient correction calibration; 3) for system efficiency, controller efficiency, and motor efficiency calibration; and manual calibration using a thermometer without establishing communication.

[0091] The solution proposed in this application has the following beneficial effects:

[0092] 1. By correcting the estimated junction temperature under different operating conditions, the most accurate temperature is achieved;

[0093] 2. By using a customized open-cover power module, the actual temperature can be obtained, enabling closed-loop control and high reliability;

[0094] 3. By establishing a communication connection, the system can complete automated testing, reducing manual intervention and improving efficiency and consistency.

[0095] Obviously, those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of this application. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; however, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0096] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0097] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, these elements should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this document, a first element may also be referred to as a second element, and similarly, a second element may also be referred to as a first element. Depending on the context, as used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms, unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, step, operation, element, component, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are to be interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C.” An exception to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0098] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for acquiring temperature in an automotive motor controller, characterized in that, Includes the following steps: S1. Obtain the heating power of the vehicle motor and the sampling temperature of the controller used to control the vehicle motor; S2. Determine the estimated temperature of the controller based on the heating power and the sampling temperature; S3. Determine the temperature correction coefficient based on the speed and torque of the vehicle motor, and determine the final temperature of the controller based on the estimated temperature and the temperature correction coefficient.

2. The method as described in claim 1, characterized in that, Step S1 includes: calculating the heat generation power of the vehicle motor based on the vehicle motor's speed, torque, switching transistor parameters, and efficiency.

3. The method as described in claim 2, characterized in that, Step S2 includes: Establish a thermal resistance model for the controller; The reference temperature is determined based on the heating power in the thermal resistance model. The difference between the reference temperature and the sampling temperature is compared with a preset temperature difference threshold. If the difference between the reference temperature and the sampling temperature does not exceed the temperature difference threshold, then the reference temperature is determined as the estimated temperature of the controller.

4. The method as described in claim 2, characterized in that, The determination of the temperature correction coefficient based on the speed and torque of the vehicle motor includes: Establish a table of temperature correction coefficients corresponding to the speed and torque of the vehicle motor; Based on the currently obtained speed and torque of the vehicle motor, the corresponding temperature correction coefficient is retrieved from the temperature correction coefficient table.

5. The method as described in claim 4, characterized in that, The establishment of the temperature correction coefficient table corresponding to the speed and torque of the vehicle motor includes: Establish a test system for obtaining the temperature correction coefficient table; The test system determines the current speed and torque of the vehicle motor and maintains the current torque unchanged during a preset test period. During the test period, the difference between the test sampling temperature and the estimated temperature is obtained, and the difference is determined as the temperature correction coefficient; The temperature correction table is established based on the correspondence between the current rotational speed, the current torque, and the temperature correction coefficient.

6. The method as described in claim 5, characterized in that, The establishment of the temperature correction coefficient table corresponding to the speed and torque of the vehicle motor also includes: After determining the difference as the temperature correction coefficient, the current torque is compared with a preset torque threshold. If the current torque is less than the torque threshold, the current torque is increased by a preset torque increase rate, and the process returns to the step of determining the current speed and current torque of the vehicle motor and maintaining the current torque unchanged within a preset test period.

7. The method as described in claim 6, characterized in that, The comparison of the current torque with a preset torque threshold also includes: If the current torque is greater than the torque threshold, then determine whether the current rotational speed is greater than a preset rotational speed threshold; If the current rotational speed is less than the rotational speed threshold, the current rotational speed is increased by a preset rotational speed increase, and the process returns to the step of determining the current rotational speed and current torque of the vehicle motor and maintaining the current torque unchanged within a preset test period. If the current rotational speed is greater than the rotational speed threshold, then the temperature correction table is completed.

8. A temperature acquisition system for an automotive motor controller, characterized in that, include: Data acquisition module, data analysis module, data integration module; The data acquisition module is used to acquire the heating power of the vehicle motor and the sampling temperature of the controller used to control the vehicle motor; The data analysis module is used to determine the estimated temperature of the controller based on the heating power and the sampling temperature, and to determine the temperature correction coefficient based on the speed and torque of the vehicle motor. The data integration module is used to determine the final temperature of the controller based on the estimated temperature and the temperature correction coefficient.

9. The system as described in claim 8, characterized in that, The data acquisition module is also used to calculate the heat generation power of the vehicle motor based on the vehicle motor's speed, torque, switching transistor parameters, and efficiency.

10. The system as described in claim 9, characterized in that, The data analysis module is also used to establish a thermal resistance model for the controller, determine a reference temperature based on the heating power in the thermal resistance model, compare the difference between the reference temperature and the sampling temperature with a preset temperature difference threshold, and if the difference between the reference temperature and the sampling temperature does not exceed the temperature difference threshold, determine the reference temperature as the estimated temperature of the controller.

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