Motor thermal test method and device, motor controller and range extending control system
By outputting torque at 0.6 to 1 times the peak torque across the entire motor speed range, collecting the motor's real-time temperature and duration, plotting a MAP diagram, and generating comprehensive and accurate thermal parameters, the problem of insufficient control precision caused by incomplete motor thermal parameters is solved, thus achieving optimal motor performance and vehicle power optimization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LEADRIVE TECH (SHANGHAI) CO LTD
- Filing Date
- 2023-03-23
- Publication Date
- 2026-07-14
AI Technical Summary
The existing motor thermal parameters are not comprehensive enough, resulting in insufficient control precision and redundant motor performance, which prevents the motor from achieving its optimal performance.
By collecting real-time temperature and duration data at different torques and speeds across the entire motor speed range, using 0.6 to 1 times the peak torque as the output torque, and plotting a MAP diagram, comprehensive and accurate thermal parameters are generated for motor over-temperature protection and thermal management.
It improves the comprehensiveness and accuracy of motor thermal parameters, realizes the best performance of motor under different operating conditions, reduces performance redundancy, provides reliable data support, and provides a basis for the optimization of vehicle power control and range extension control system.
Smart Images
Figure CN116298875B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of motor control technology, and in particular to a method, apparatus, motor controller, and range extender control system for motor thermal testing. Background Technology
[0002] During operation, the stator windings of an induction motor will heat up. The operating temperature of the stator windings is an important parameter for the safe operation of the motor. If the operating temperature of the stator windings exceeds its limit temperature within a certain period of time, it will seriously affect the performance of the motor and cause damage to the motor.
[0003] Over-temperature protection for the motor stator windings is provided. When the stator winding temperature reaches a threshold, power output is reduced based on the motor's thermal parameters. Existing thermal parameters mostly only include the motor's continuously stable rated temperature rise and the peak temperature rise corresponding to the motor's peak torque. Based on this, under various operating conditions, when the rated or peak temperature rise is exceeded, the output torque is limited to protect the motor. For example, if the peak temperature threshold is set to 145°C, torque is limited at around 130°C. However, existing control methods rely on only two data points, which is incomplete and lacks control precision. This leads to torque limitation using the same data point under various operating conditions, resulting in different maximum temperatures that the motor stator windings can withstand under different conditions. This causes partial redundancy in motor performance, preventing it from achieving its optimal performance. Summary of the Invention
[0004] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide a method, device, motor controller and range extender control system for testing motor thermal parameters, so as to solve the problem that the existing motor thermal parameters are not comprehensive enough, which leads to insufficient control accuracy based on thermal parameters and causes redundancy in motor performance.
[0005] This invention discloses a method for thermal testing of an electric motor, comprising:
[0006] After the motor runs under rated conditions to a preset state, the real-time temperature of the motor stator winding is collected to obtain the temperature of the cooling medium. When the real-time temperature exceeds the temperature of the cooling medium, the test is started.
[0007] Obtain the full speed range and peak torque of the motor;
[0008] The motor was tested across its full speed range, with the output torque set at 0.6 to 1 times the peak torque, to determine the real-time temperature and duration of the motor at different torque and speed conditions.
[0009] The test ends when the motor is stopped after the real-time temperature determines that it has reached thermal stability or the preset threshold temperature.
[0010] A MAP diagram is plotted based on the real-time temperature and duration of the motor at different torques and speeds to output thermal parameters.
[0011] Preferably, when the real-time temperature does not change beyond the preset temperature value within a preset time period, the motor is determined to have reached thermal stability.
[0012] Preferably, the motor over-temperature protection function is turned off before the test is performed.
[0013] Preferably, a MAP is plotted based on the real-time temperature and duration of the motor at different torques and speeds, including:
[0014] The temperature change curve is determined based on the real-time temperature changes, and different labels are used to correspond to different temperatures to obtain an intermediate image containing temperature changes.
[0015] The duration at different real-time temperatures is determined, and a time-varying curve is plotted on the Z-axis based on the intermediate image to obtain a MAP plot containing temperature and time variations under different torques.
[0016] Preferably, the cooling medium temperature is set to 65℃±5℃; the flow rate is 8L / min;
[0017] The test will begin when the real-time temperature reaches 70°C.
[0018] Preferably, the full speed range includes the lowest speed to the highest speed;
[0019] Adjust the speed according to the output torque.
[0020] Preferably, it further includes: generating a motor power reduction strategy based on the thermal parameters output by the MAP diagram, so that the motor can perform real-time output torque control according to the power reduction command;
[0021] And / or, generate a thermal management strategy based on the thermal parameters to enable thermal management cooling control of the motor.
[0022] The present invention also provides a motor thermal testing device, comprising:
[0023] The startup module is used to collect the real-time temperature of the motor stator winding and obtain the temperature of the cooling medium. When the real-time temperature exceeds the temperature of the cooling medium, the test is started.
[0024] The processing module is used to obtain the full speed range and peak torque of the motor; within the full speed range of the motor, the motor is tested with an output torque of 0.6 to 1 times the peak torque to determine the real-time temperature and duration of the motor at different torques and speeds; when the real-time temperature determines that the motor has reached thermal stability or has reached a preset threshold temperature, the test is stopped and the test ends.
[0025] The output module is used to draw a MAP based on the real-time temperature and duration of the motor at different torques and speeds, so as to output thermal parameters.
[0026] The present invention also provides a motor control system.
[0027] Obtain the thermal parameters output by the aforementioned motor thermal testing device;
[0028] The motor power reduction strategy is updated in real time based on the thermal parameters.
[0029] The present invention also provides a range-extended motor control system for use in range-extended vehicles;
[0030] Obtain the thermal parameters output by the motor thermal testing device as described above;
[0031] The range extender is matched, controlled, and optimized based on the thermal parameters.
[0032] Compared with existing technologies, the above technical solution has the following advantages:
[0033] In this application, the motor is operated, and the real-time temperature of the motor's stator windings is collected. A thermal test is performed on the motor with a continuous and stable output of 0.6 to 1 times the peak torque / peak power across the entire speed range. Real-time temperature and duration at different torques and speeds are obtained. Based on this, thermal parameters are output. Unlike existing methods that only set a predetermined temperature value as thermal parameters, this method improves the comprehensiveness and accuracy of the obtained thermal parameters from two sources. It allows for a comprehensive test of the motor's output capability. Based on these thermal parameters, a torque-limiting strategy / power-saving strategy for motor over-temperature protection is implemented, maximizing the motor's capabilities. This solves the problem of insufficient comprehensiveness of existing motor thermal parameters, which leads to insufficient control precision and performance redundancy. Attached Figure Description
[0034] Figure 1 This is a flowchart of an embodiment of the motor thermal testing method, apparatus, and motor control system described in this invention;
[0035] Figure 2 The MAP output in Embodiment 1 of the motor thermal testing method, device and motor control system of the present invention includes a reference graph of temperature change curve;
[0036] Figure 3 This is a reference diagram showing the time-varying curves in the MAP output of the motor thermal testing method, device, and motor control system according to Embodiment 1 of the present invention.
[0037] Figure 4 This is a schematic diagram of a module in Embodiment 2 of the motor thermal testing method, device and motor control system of the present invention.
[0038] Figure label:
[0039] 6-Motor thermal testing device; 61-Start-up module; 62-Processing module; 63-Output module. Detailed Implementation
[0040] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.
[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.
[0042] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.
[0043] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information 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 disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."
[0044] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0045] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0046] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.
[0047] Example 1: This invention discloses a method for thermal testing of a motor, used to obtain the temperature and duration of multiple stator windings of the motor at different speeds and torques, thereby obtaining comprehensive and accurate thermal parameters. This differs from existing technologies that only obtain rated temperature rise and peak temperature rise for torque output control. This allows the motor performance to be fully utilized under different operating conditions, improving the overall vehicle power output efficiency and providing reliable data support for the vehicle's VCU (Vehicle Control Unit) power control and decision-making. Furthermore, it can be applied to range-extended motor control systems for rapid matching and optimization of motor-based range extenders. For details, please refer to [link to relevant documentation]. Figure 1 This includes the following steps:
[0048] S100: After the motor runs under rated conditions to a preset state, the real-time temperature of the motor stator winding is collected to obtain the temperature of the cooling medium. When the real-time temperature exceeds the temperature of the cooling medium, the test is started.
[0049] As an explanation, the motor is operated under rated conditions to a preset state. Specifically, it is preferable to operate the motor in a hot state and run it under rated conditions until thermal stability is achieved, and then quickly reduce the speed to a preset speed / no-load state. Pre-operating the motor to a preset state can be regarded as allowing the motor to run in a hot state for a period of time, so that the motor's operating state is more consistent with the actual operating state, thereby making the subsequent thermal test results more accurate and more consistent with the actual operating conditions.
[0050] In the above steps, the motor continues to run, and the temperature of the motor stator windings is collected by sensors. It should be noted that the highest temperature point on the motor stator windings is used to determine the real-time temperature; that is, the test is conducted at the highest temperature point on the motor. This ensures accurate thermal parameters are obtained subsequently, which are then used to control the motor output and reduce damage caused by exceeding this temperature limit. The bus voltage is the rated voltage during the test.
[0051] For the same type of motor, the test method provided in this embodiment can be pre-executed once to obtain the following comprehensive and accurate thermal parameters, and then used for multiple motors; that is, only the thermal parameters need to be obtained. However, different types of motors have different applicable application scenarios, and the dimensions of various modules and the temperature of the cooling medium are different. Therefore, it is necessary to perform the thermal test of this embodiment on each type of motor. The aforementioned cooling medium temperature requirements are different for different motors. In this embodiment, as an example, the inlet temperature of the cooling medium is set to 65℃±5℃; the flow rate is 8L / min; the cooling medium temperature is set to be consistent with the actual operating conditions, thereby making the execution of this thermal test method match the actual operating conditions, thereby further improving the accuracy of the obtained thermal parameters. When the real-time temperature reaches 70℃, the test begins, that is, the test is executed when the real-time temperature is higher than the cooling medium temperature (or exceeds a certain range). When the real-time temperature is lower than the cooling medium temperature, there is no need to execute the motor over-temperature protection, and therefore no need to limit the torque output.
[0052] In this embodiment, in order to obtain comprehensive and accurate thermal parameters of the motor, the temperature of the cooling medium and the start-up of the test are set to be as consistent as possible with the actual operating conditions. Therefore, the motor over-temperature protection function is turned off before the test, that is, there is no need to trigger the command to limit the torque of the motor according to the existing set rated temperature rise or peak temperature rise. The purpose of the test method in this embodiment is to obtain comprehensive thermal parameters. When the motor over-temperature protection function is turned on, it may be possible that the motor cannot stop after reaching the preset temperature during the test. At this time, the actual motor has some performance redundancy, which affects the comprehensiveness of the test results.
[0053] S200: Obtain the full speed range and peak torque of the motor;
[0054] In the above steps, the full speed range refers to the range from the lowest operating speed to the highest operating speed, including the rated speed, which is the stable output speed of the motor under actual rated operating conditions. The speed is affected by torque. In the testing method of this embodiment, the motor needs to operate under multiple torque and speed conditions. The speed can also be adjusted according to the output torque. For example, as the torque output gradually increases, the speed change increases, and then the torque output stabilizes. The maximum output torque of a vehicle generally occurs in the low to medium speed range. As the speed increases, the torque will decrease. During this process, various operating conditions with different torques and speeds will occur. The peak torque is the maximum torque output, which represents the optimal output capability of the motor and is obtained in advance based on different motor parameters.
[0055] S300: The motor is tested at 0.6 to 1 times the peak torque as the output torque across the entire speed range to determine the real-time temperature and duration of the motor at different torques and speeds.
[0056] In this embodiment, unlike existing methods that only use rated temperature rise and peak temperature rise as thermal parameters, real-time temperature and duration of the motor at different torques and speeds are obtained after thermal testing, thereby increasing the comprehensiveness of thermal parameters. Specifically, to achieve multiple torque and speed operating states, the output torque is set to 0.6 to 1 times the peak torque. The larger the output torque, the greater the speed change, and the faster the temperature change of the motor stator winding. Therefore, the output is set to more than 0.6 times the peak torque, considering that an output below 0.6 times has little impact on temperature changes and would lead to increased workload; and it will not exceed 1 times the peak torque. As mentioned above, the peak torque is the optimal output capability of the motor. The motor is controlled at an output torque of 0.6 to 1 times the peak torque from the lowest operating speed to the highest operating speed, and the real-time temperature and duration at each temperature are collected accordingly. This provides comprehensive thermal parameters, all of which simulate the actual operation of the motor under real-world conditions, resulting in high accuracy.
[0057] S400: The test ends when the motor stops and the temperature reaches thermal stability or the preset threshold temperature, based on the real-time temperature.
[0058] In the above steps, as mentioned above, the over-temperature protection function is turned off before the test to prevent the motor from automatically reducing its output torque if the test is not completed. To protect the motor and avoid damage caused by excessively high temperatures due to continuous torque and speed output, the test is stopped after reaching a preset threshold temperature (the maximum safe operating temperature can be defined, i.e., the preset threshold temperature is 145 ℃). This preset threshold temperature is the highest temperature that the motor can withstand (which can be obtained in advance from the motor parameters). It also allows the motor to reach a thermally stable state. Specifically, it should be noted that the condition for determining the thermally stable state is: when the real-time temperature does not change beyond the preset temperature value within a preset time period, the motor is considered to have reached thermal stability. For example, when the real-time temperature collected by the motor does not change by more than 2 ℃ within 1 hour, it is determined that the motor has reached a thermally stable state. That is, at this time, the motor temperature will no longer have a large temperature rise, and it can be considered that the motor has reached its maximum operating temperature, and the test can be ended.
[0059] S500: Based on the real-time temperature and duration of the motor at different torques and speeds, a MAP diagram is plotted to output thermal parameters.
[0060] In step S400 above, the real-time temperature and duration are obtained by collecting the output of different torques and speeds, which are the thermal parameters of the motor required by this test method. In order to further facilitate the visualization of the data, a MAP diagram is drawn based on the collected data as the output thermal parameters.
[0061] Specifically, a MAP is plotted based on the real-time temperature and duration of the motor at different torques and speeds. This includes: determining the temperature change curve based on the real-time temperature changes, and using different labels to correspond to different temperatures to obtain an intermediate image containing temperature changes; determining the duration at different real-time temperatures, and plotting the time change curve on the Z-axis based on the intermediate image to obtain a MAP containing temperature and time changes at different torques.
[0062] In the steps described above for generating a MAP map, isotherms can be plotted (see reference). Figure 2 The 145℃ isotherm above indicates temperature changes. Different labels can be used to represent different temperatures, such as different colors: blue for below 100℃, green for 100-110℃, and red for above 120℃; or different fills for different temperature ranges, etc., to clearly display temperature changes and the corresponding torque and speed ranges at each temperature. This allows for a comprehensive assessment of the motor's output capabilities. Furthermore, duration can be added as a new dimension (see reference). Figure 3 The MAP plot (with a 60-minute timeline) allows for multi-dimensional display. Time-varying curves can be plotted in this reference plot, making the output thermal parameters accurate and easy to obtain.
[0063] Furthermore, after the above testing process is completed and the thermal parameters in the form of a MAP are output, the method further includes: generating a motor power reduction strategy based on the thermal parameters output by the MAP, so that the motor can perform real-time output torque control according to the power reduction command. Specifically, based on the actual operating torque and speed of the motor, the corresponding temperature and duration are obtained from the thermal parameters. When the temperature exceeds the preset maximum temperature that the motor can withstand, the output torque is reduced before the time limit is exceeded (e.g., when the preset temperature value is reached, the existing method immediately performs power reduction when the temperature is about to be reached, but the actual motor can still run for a period of time. According to the thermal parameters output by this application, the power reduction can be precisely controlled after running for a period of time, thereby increasing the efficiency of the motor). This allows the motor performance to be fully utilized.
[0064] And / or, a thermal management strategy is generated based on the thermal parameters, enabling the motor to undergo thermal management cooling control. It should be noted that thermal management is the process of adjusting and controlling the temperature or temperature difference of a motor using heating or cooling methods according to control commands. Thermal management control can be performed based on the actual operating temperature and duration of the motor obtained from the thermal parameters, adjusting the thermal management strategy, including but not limited to increasing the output of the cooling module, or it can also be applied to systems such as range-extended thermal management systems. Based on the comprehensive and accurate thermal parameters provided in this embodiment, real-time torque output control of the motor is achieved, solving the problem that existing methods rely solely on rated temperature rise and peak temperature rise to determine power reduction strategies, resulting in insufficient control precision and redundant motor performance.
[0065] In this embodiment, the motor is run, and the real-time temperature of the motor's stator windings is collected. When the real-time temperature exceeds the temperature of the cooling medium, the test begins. Specifically, the test is conducted with a continuous and stable output of 0.6 to 1 times the peak torque / peak power across the entire speed range. The real-time temperature and duration at different torques and speeds are obtained, and then a MAP diagram is plotted as the thermal parameter output. This differs from existing methods that only set the rated temperature rise / peak temperature rise as thermal parameters. This method improves the comprehensiveness and accuracy of the thermal parameters obtained from two thermal parameters, allowing for a comprehensive assessment of the motor's output capability. This provides reliable data support for the power control and decision-making of the vehicle's VCU. Based on these thermal parameters, the torque limiting strategy / power reduction strategy for motor over-temperature protection is executed, maximizing the motor's capability, protecting the motor, and maximizing its utilization rate.
[0066] Example 2: This example provides a motor thermal testing device 6, see reference. Figure 4 ,include:
[0067] The startup module 61 is used to collect the real-time temperature of the motor stator winding and obtain the temperature of the cooling medium. When the real-time temperature exceeds the temperature of the cooling medium, the test is started.
[0068] In the startup module, the motor runs. It should be noted that the real-time temperature is determined by the highest temperature point on the motor stator windings. During testing, the bus voltage is the rated voltage, and the inlet temperature of the cooling medium is set to 65℃±5℃; the flow rate is 8L / min. Setting the cooling medium temperature to match the actual operating conditions ensures that the thermal testing method is matched to actual operating conditions, thereby further improving the accuracy of the obtained thermal parameters. When the real-time temperature reaches 70℃, the test begins, and the over-temperature protection function is disabled before the test.
[0069] Processing module 62 is used to acquire the full speed range and peak torque of the motor; within the full speed range of the motor, the motor is tested with an output torque of 0.6 to 1 times the peak torque to determine the real-time temperature and duration of the motor at different torques and speeds; when the motor is determined to have reached thermal stability or a preset threshold temperature based on the real-time temperature, the test is stopped and terminated.
[0070] The processing module is used to perform thermal testing of the motor. Specifically, after the thermal test, the real-time temperature and duration of the motor under different torques and speeds are obtained, thereby increasing the comprehensiveness of the thermal parameters. Specifically, in order to achieve multiple torque and speed operating states, the output torque is set to 0.6 to 1 times the peak torque. The test ends after the preset threshold temperature is reached (the maximum safe operating temperature can be defined, i.e., the preset threshold temperature is 145 ℃). It can also make the motor reach a thermally stable state. For example, when the real-time temperature of the motor collected does not change by more than 2 ℃ within 1 hour, it is determined that a thermally stable state has been reached, thereby stopping the test and obtaining thermal parameters. These thermal parameters, relative to the existing two-point data, include surface-type data, i.e., data of multiple different torques and speeds.
[0071] Output module 63 is used to draw a MAP based on the real-time temperature and duration of the motor at different torques and speeds, so as to output thermal parameters.
[0072] In the above output module, isotherms can be used to represent temperature changes, different labels can be used to display different temperatures, and time-dimensional time change curves can be added to form a MAP data that can be displayed in multiple dimensions, thereby improving the visualization of the data display.
[0073] In this embodiment, the real-time temperature of the motor stator winding is acquired in the startup module, and the test is started. The over-temperature protection function is turned off before the test. The thermal test is executed in the processing module. The motor is tested with an output torque of 0.6 to 1 times the peak torque across the entire speed range to determine the real-time temperature and duration of the motor at different torques and speeds. The test ends when the motor reaches thermal stability or a preset threshold temperature. The thermal parameters in the output module are output in the form of a MAP graph based on the acquired temperature and duration at different torques and speeds. This differs from existing methods that only set the rated temperature rise / peak temperature rise as thermal parameters, thus improving the comprehensiveness and accuracy of the obtained thermal parameters from two thermal parameters.
[0074] Based on the output of the aforementioned output module, the temperature and duration of the motor stator windings under multiple different torques and speeds can be obtained. This allows for a motor power reduction strategy, enabling real-time torque control based on the power reduction command. This addresses the problem of insufficient comprehensive thermal parameters in existing motors, which leads to insufficient control accuracy and performance redundancy. Testing the motor's output capability across the entire range of these output thermal parameters provides reliable data support and improves motor utilization.
[0075] Example 3: This example provides a motor control system that obtains thermal parameters output by applying the motor thermal testing device in Example 2 to perform the thermal testing method described in Example 1; updates the motor power reduction strategy in real time based on the thermal parameters; and also includes other devices or components that enable the motor control system to operate normally.
[0076] In this embodiment, the thermal parameters output by the aforementioned motor thermal testing device include the real-time temperature and duration of the motor at different torques and speeds. Unlike the prior art which only uses point data as thermal parameters, the aforementioned thermal testing device outputs thermal parameters in the form of area data, and outputs them in the form of a MAP diagram, which is comprehensive, accurate and clear. Based on this, the torque output of the motor under different operating conditions can be controlled. When the motor reaches a certain temperature, the output thermal parameters can be used to determine whether to execute torque limiting and / or the time of executing torque limiting command response, reducing the redundancy in motor performance caused by power reduction after setting a certain predetermined temperature rise.
[0077] Example 4: This invention also provides a range extender control system applicable to range-extended vehicles; it acquires thermal parameters output by at least one motor thermal testing device as described in Example 2; and performs matching, control, and optimization of the range extender based on these thermal parameters. That is, it can help range-extended vehicles quickly match the maximum power generation across various speed ranges. Specifically, the motor's torque output and temperature changes can be determined based on the thermal parameters output by this application. By using the temperature rise map of the motor across all speed and torque ranges (i.e., obtaining the maximum capacity of the motor at each speed and torque using the thermal testing method in Example 1), the selection of the motor in the range extender can be quickly completed, achieving the matching of the range extender management system.
[0078] It should also be noted that the range extender in the aforementioned range-extended motor control system or range-extended vehicle only participates in power generation and does not participate in driving. Driving is still achieved by the vehicle's own drive system, and the output power of the generated electricity is based on the power request of the vehicle's VCU. Since the range-extended control system needs to combine the current remaining charge of the generator battery with power generation, the maximum power generation capacity of the range extender depends not only on the engine but also on the generator and controller. Therefore, once the engine in the range-extended system is determined, the selection of the controller and generator is also crucial. Based on the aforementioned thermal parameters, the optimally matched generator can be selected, thereby achieving optimal range-extended control.
[0079] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.
Claims
1. A method for thermal testing of an electric motor, characterized in that, include: After the motor operates under rated conditions to the preset state, the real-time temperature of the motor stator winding is collected, with the highest temperature point on the motor stator winding as the reference. The temperature of the cooling medium is obtained. When the real-time temperature exceeds the temperature of the cooling medium, the test is started. The operation of the motor under rated conditions to the preset state includes: the motor is operated under hot conditions and then operated under rated conditions until thermal stability is achieved. After that, the speed is reduced to the preset speed / no-load state so that the motor operates to the preset state. Before the test is performed, the motor over-temperature protection function is turned off, so as not to trigger the command to limit the torque of the motor according to the existing set rated temperature rise or peak temperature rise. Obtain the full speed range and peak torque of the motor; The motor was tested across its full speed range, with the output torque set at 0.6 to 1 times the peak torque, to determine the real-time temperature and duration of the motor at different torque and speed conditions. The test ends when the motor is stopped after the real-time temperature determines that it has reached thermal stability or the preset threshold temperature. A MAP diagram is plotted based on the real-time temperature and duration of the motor at different torques and speeds to output thermal parameters. It also includes: generating a motor power reduction strategy based on the thermal parameters output from the MAP diagram, enabling the motor to perform real-time output torque control; And / or, generate a thermal management strategy based on the thermal parameters to enable thermal management cooling control of the motor, wherein the corresponding temperature and duration are obtained from the thermal parameters based on the actual operating torque and speed of the motor, and when the temperature exceeds the preset maximum temperature that the motor can withstand, the output torque is reduced before the duration is exceeded.
2. The thermal testing method according to claim 1, characterized in that: If the real-time temperature does not change beyond the preset temperature value within the preset time period, the motor is considered to have reached thermal stability.
3. The thermal testing method according to claim 1, characterized in that: Turn off the motor over-temperature protection function before performing the test.
4. The thermal testing method according to claim 1, characterized in that, A MAP (Motor Map) is plotted based on the real-time temperature and duration of the motor at different torques and speeds, including: The temperature change curve is determined based on the real-time temperature changes, and different labels are used to correspond to different temperatures to obtain an intermediate image containing temperature changes. The duration at different real-time temperatures is determined, and a time-varying curve is plotted on the Z-axis based on the intermediate image to obtain a MAP plot containing temperature and time variations under different torques.
5. The thermal testing method according to claim 1, characterized in that: The cooling medium temperature is set to 65℃±5℃; the flow rate is 8L / min. The test will begin when the real-time temperature reaches 70°C.
6. The thermal testing method according to claim 1, characterized in that: The full speed range includes the lowest speed to the highest speed; Adjust the speed according to the output torque.
7. A thermal testing device for an electric motor, characterized in that, include: The startup module is used to collect the real-time temperature of the motor stator winding and obtain the temperature of the cooling medium. When the real-time temperature exceeds the temperature of the cooling medium, the test is started. The motor runs under rated conditions to a preset state, which includes: the motor is in a hot state and runs under rated conditions until thermal stability, and then the speed is reduced to a preset speed / no-load state, so that the motor runs to the preset state. Before the test is performed, the motor over-temperature protection function is turned off, so as not to trigger the command to limit the torque of the motor according to the existing set rated temperature rise or peak temperature rise. The processing module is used to obtain the full speed range and peak torque of the motor; within the full speed range of the motor, the motor is tested with an output torque of 0.6 to 1 times the peak torque to determine the real-time temperature and duration of the motor at different torques and speeds; when the real-time temperature determines that the motor has reached thermal stability or has reached a preset threshold temperature, the test is stopped and the test ends. The output module is used to draw a MAP based on the real-time temperature and duration of the motor at different torques and speeds, so as to output thermal parameters; It also includes: generating a motor power reduction strategy based on the thermal parameters output from the MAP diagram, enabling the motor to perform real-time output torque control; And / or, generate a thermal management strategy based on the thermal parameters to enable thermal management cooling control of the motor, wherein the corresponding temperature and duration are obtained from the thermal parameters based on the actual operating torque and speed of the motor, and when the temperature exceeds the preset maximum temperature that the motor can withstand, the output torque is reduced before the duration is exceeded.
8. A motor controller, characterized in that: Obtain the thermal parameters output by the motor thermal testing device described in claim 7 in advance; The motor power reduction strategy is updated in real time based on the thermal parameters.
9. A range extender control system, characterized in that: Applied in range-extended vehicles; Obtain the thermal parameters output by the motor thermal testing device described in claim 7 in advance; The range extender is matched, controlled, and optimized based on the thermal parameters.