Adaptive boundary-finding method for driving the electro-thermal coupling safe operating boundary of a motor under test

Abstract

The application discloses a kind of self-adapting methods of driving motor electric-thermal coupling safety working boundary, it is related to the field of motor testing and control, first start test system and set target, controller controls load dynamometer to increase the electric load of motor to be measured with dynamic step gradient. After each loading, electric, thermal parameters are collected and real-time temperature change rate is calculated. The rate is compared with the preset safety threshold: if the boundary is touched, stop loading and record boundary data points; if not, use heuristic search method to adaptively adjust the step according to the temperature rise rate, and continue to load. Calibrate the boundary points under different conditions, and finally generate the safety working boundary map of the motor to be tested. The problem of conservative or aggressive, low precision and poor safety in the prior art is solved. The application can adaptively balance the efficiency and precision of boundary searching, and form a complete safety working boundary map of the motor to be tested.

Description

Technical Field

[0001] This invention relates to the field of testing and control of motors under test, and specifically to an adaptive edge-finding method for driving the safe working boundary of the electro-thermal coupling of the motor under test. Background Technology

[0002] The performance limits of motors under test (MUTs), especially permanent magnet synchronous motors used in new energy vehicles, are closely related to their thermal safety. When an MUT operates under overload, increased copper and iron losses can lead to a rapid rise in internal temperature, potentially causing serious malfunctions such as irreversible demagnetization of the permanent magnets, insulation aging, or even burnout. Therefore, accurately defining the safe operating boundaries of the MUT under different operating conditions is crucial for MUT design optimization, vehicle power domain control strategy development, and testing verification.

[0003] There are two main traditional methods for determining the safe operating boundary of a motor under test (TMT): The first is a combination of theoretical calculation and a fixed safety margin method. This method performs theoretical calculations based on the TTM's thermal model and standard operating conditions, reserving a large safety margin. While safe, it is overly conservative and cannot fully utilize the TTM's true performance potential; furthermore, model errors can lead to inaccurate boundaries. The second method is the stepped loading test method, which gradually increases the load in fixed steps until the temperature at a certain point reaches its absolute upper limit. This method is prone to overheating, demagnetization, or even damage to the TTM due to overshoot, and suffers from poor test accuracy and low reproducibility. Neither of these methods can calibrate the true safe operating boundary of the TTM under electro-thermal coupling conditions while ensuring its safety.

[0004] Therefore, an adaptive edge-finding method is needed to drive the safe working boundary of the electro-thermal coupling of the motor under test in order to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention discloses an adaptive edge-finding method for determining the safe operating boundary of the electric-thermal coupling of the motor under test. By dynamically adjusting the electrical load loading step size and monitoring the temperature rise rate of the motor under test in real time, the method uses whether the temperature rise rate exceeds a preset safety threshold as a criterion to efficiently and accurately calibrate the safe operating boundary of the motor under test under different operating conditions.

[0006] The present invention adopts the following technical solution:

[0007] An adaptive edge-finding method for the safe operating boundary of the electro-thermal coupling of a driven motor under test includes the following steps:

[0008] S1. Start the test system of the motor under test under the initial safe working conditions and set the edge finding target. The test system of the motor under test includes the motor under test, the load dynamometer, the data acquisition unit and the host computer. The data acquisition unit includes at least a current sensor, a voltage sensor, a torque sensor and a temperature sensor array deployed inside the motor under test. The host computer has a controller deployed inside.

[0009] S2. The controller controls the load dynamometer to apply an electrical load to the motor under test. The initial applied electrical load is L0, and then the applied electrical load to the motor under test is increased in a dynamic step size ΔL gradient, expressed by the formula: L k =L k-1 +ΔL, where k is the number of times the electrical load increases, L k This represents the electrical load applied to the tested motor after the k-th increase;

[0010] S3. After each electrical load is applied to the motor under test, the data acquisition unit collects the electrical and thermal parameters of the motor under test in real time, and calculates the real-time temperature change rate of the motor under test based on the collected parameters.

[0011] S4. Compare the real-time temperature change rate calculated in step S3 with the preset safety threshold. If the real-time temperature change rate is greater than or equal to the preset safety threshold, it is determined that the tested motor has reached the thermal safety boundary, and step S5 is executed. If the real-time temperature change rate is less than the preset safety threshold, it is determined that the tested motor has not reached the thermal safety boundary, and step S6 is executed.

[0012] S5. The controller controls the load dynamometer to stop applying electrical load to the motor under test, and records the current electrical and thermal parameters of the motor under test, calibrating them as data points on the safe operating boundary of the motor under test.

[0013] S6. Adaptively adjust the step size ΔL using a heuristic search method, and return to step S2. Increase the electrical load applied to the tested motor using the adjusted step size ΔL. The heuristic search method dynamically adjusts the loading step size according to the change in the temperature rise rate.

[0014] Furthermore, in step S1, the initial safe operating condition is determined based on the historical data of the motor under test under different operating conditions. The edge-finding target is to find the maximum output torque or current when the real-time temperature rise rate of the motor under test does not exceed the preset safety threshold at the preset speed or initial temperature.

[0015] Furthermore, the electrical parameters include current, voltage, torque, and speed, and the thermal parameters include at least the temperatures of the internal windings, magnets, and bearings of the motor under test.

[0016] Furthermore, in step S3, the method for calculating the real-time temperature change rate is as follows:

[0017] The temperature data of the internal windings, magnets and bearings of the motor under test, collected by the temperature sensor array, are filtered to eliminate noise interference and obtain a temperature time series. The temperature difference between the current moment and the previous moment in the temperature time series is calculated and divided by the time interval to obtain the real-time temperature change rate series. The maximum value in the real-time temperature change rate series is the real-time temperature change rate.

[0018] The filtering process employs one or more combinations of moving average filtering, median filtering, Kalman filtering, or Savitzky-Golay filtering.

[0019] Further, in step S6, the heuristic search method specifically includes:

[0020] When an electrical load is applied to the motor under test N times consecutively, and the calculated real-time temperature change rate is less than the preset safety threshold, and the change amplitude of the real-time temperature change rate is less than the preset first change threshold, the motor under test is determined to be in the thermally stable region. Then, the dynamic step size ΔL is increased by the preset scaling factor α, where N≥2; α>1.

[0021] When an electrical load is applied to the motor under test, if the calculated real-time temperature change rate is less than the preset safety threshold and the change amplitude of the real-time temperature change rate is greater than or equal to the preset second change threshold, it is determined that the motor under test is close to or touches the thermal safety boundary. Then, the dynamic step size ΔL is reduced by the preset scaling factor β, where 0 < β < 1.

[0022] The magnitude of the real-time temperature change rate is the change in the real-time temperature change rate after the current increase in electrical load compared to the previous increase in electrical load.

[0023] The first preset threshold is less than the second preset threshold.

[0024] Furthermore, in step S5, when the real-time temperature change rate is greater than or equal to the preset safety threshold, the controller controls the load dynamometer to stop applying electrical load and simultaneously controls the active cooling system to start until the real-time temperature change rate is less than the safety threshold.

[0025] The preset safety threshold is a curve or mapping table that is dynamically set based on at least one of the following factors: the current speed of the motor under test, the current temperature, or the material properties of the motor under test.

[0026] Further, after step S5, steps S1 to S5 are repeated to obtain data points on the safe operating boundary of the motor under test under different speeds or different initial temperatures, and curve fitting or interpolation algorithms are used to generate the safe operating boundary curve of the motor under test to form a safe operating boundary map of the motor under test.

[0027] Furthermore, in step S2, the electrical load applied to the motor under test is one or more of current, power, torque, or a combination thereof.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. The test system for the motor under test of this invention encompasses the motor under test, a load dynamometer, a data acquisition unit, and a host computer. The data acquisition unit further includes a current sensor, a voltage sensor, a torque sensor, and a temperature sensor array deployed inside the motor under test. This comprehensive configuration enables the simultaneous acquisition of the electrical and thermal parameters of the motor under test, as well as key information such as torque. This provides a rich data foundation for accurately analyzing the electro-thermal coupling characteristics of the motor under test and helps to fully understand the operating status of the motor under test under different working conditions.

[0030] 2. This invention, by deploying a temperature sensor array inside the motor under test, can acquire temperature information from different parts of the motor in real time and accurately, rather than just the temperature at a single location. This is crucial for analyzing the temperature distribution inside the motor, providing a more precise reflection of the motor's thermal state during operation, and offering a reliable basis for determining whether the motor has reached its thermal safety boundaries.

[0031] 3. In this invention, when the load dynamometer applies an electrical load to the motor under test, an initial electrical load is used, which is then increased in a dynamic step-gradient manner. Compared to fixed-step loading, this loading method allows for flexible adjustment of the loading speed based on the actual response of the motor under test. When the motor under test is close to the safety boundary, a smaller step size can more accurately determine the boundary position, avoiding missing the boundary point due to an excessively large step size; while when it is far from the safety boundary, a larger step size can speed up the testing process and improve overall testing efficiency.

[0032] 4. This invention collects the electrical and thermal parameters of the tested motor in real time after each application of electrical load and calculates the real-time temperature change rate. By comparing the real-time temperature change rate with a preset safety threshold, it can promptly and accurately determine whether the tested motor has reached the thermal safety boundary. This method directly monitors and judges the key indicator of temperature change, which is closely related to the actual thermal safety state of the tested motor, thus improving the accuracy and reliability of boundary judgment.

[0033] 5. When this invention determines that the tested motor has not reached the thermal safety boundary, it employs a heuristic search method to adaptively adjust the step size ΔL. This heuristic search method dynamically adjusts the loading step size based on changes in the temperature rise rate, making the step size adjustment more intelligent and rational. For example, when the temperature rise rate changes rapidly, the step size is appropriately reduced to more accurately capture the boundary point; when the temperature rise rate changes slowly, the step size is increased to accelerate the test. This adaptive adjustment mechanism further optimizes the edge-finding process, improving test efficiency and the accuracy of boundary determination.

[0034] 6. When the present invention determines that the motor under test has reached the thermal safety boundary, the controller immediately controls the load dynamometer to stop applying electrical load to the motor under test, effectively preventing damage to the motor under test due to overheating and ensuring its safe operation. This measure is of great significance for protecting the motor under test and extending its service life. When the motor under test reaches the thermal safety boundary, the current electrical and thermal parameters of the motor under test are recorded and calibrated as data points on the safe operating boundary of the motor under test. These accurately recorded data points provide important reference for subsequent performance analysis, safety assessment, and optimization design of the motor under test, and help to gain a deeper understanding of the safe operating range and limitations of the motor under test. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall process of the present invention;

[0036] Figure 2 This is an architecture diagram of the test system for the motor under test in this invention. Detailed Implementation

[0037] The following will refer to the appendices in the embodiments of the present invention. Figure 1 To be continued Figure 2 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] This invention discloses an adaptive edge-finding method for determining the safe operating boundary of a motor under test (TMT) under electro-thermal coupling. The core of this method lies in dynamically adjusting the electrical load step size, monitoring the temperature rise rate of the TMT in real time, and using whether the temperature rise rate exceeds a preset safety threshold as a criterion to efficiently and accurately calibrate the safe operating boundary of the TMT under different operating conditions. This method can adaptively balance edge-finding efficiency and accuracy, and form a complete safe operating boundary map of the TMT, providing crucial basis for the safe control and optimized design of the TMT. (See attached diagram) Figure 1 This includes the following steps:

[0039] S1. System Initialization and Target Setting

[0040] The test system for the motor under test is started under initial safe operating conditions, and the edge-finding target is set. The test system mainly includes the motor under test, a load dynamometer capable of accurately applying load, a data acquisition unit, and a host computer. The data acquisition unit must be equipped with at least current, voltage, and torque sensors, and an array of temperature sensors should be arranged in key hot areas inside the motor under test (such as winding ends, slots, permanent magnets, and bearings). The host computer has a built-in controller responsible for the automated control and algorithm execution of the entire test process.

[0041] According to the design requirements, correctly connect the drive motor under test, the load dynamometer, the data acquisition unit, and the host computer. Ensure that the current sensor, voltage sensor, torque sensor, and the temperature sensor array deployed inside the motor under test are accurately positioned to accurately collect the required parameters. Debug the load dynamometer to ensure it can accurately apply electrical load according to control commands and has stable operating performance. Check the communication interface between the data acquisition unit and the host computer to ensure that data can be transmitted to the host computer in real time and accurately.

[0042] Deploy controller software within the host computer and configure relevant parameters such as control algorithm and sampling frequency. Develop data acquisition and processing software to receive data from the data acquisition unit in real time and perform operations such as filtering and temperature change rate calculation. Configure relevant parameters for the edge-finding target, including preset speed or initial temperature and preset safety threshold. The preset safety threshold can be determined as a curve or mapping table through experimentation or theoretical analysis based on factors such as the current speed, current temperature, or material properties of the motor under test, and then input into the software system.

[0043] In step S1, the initial safe operating condition is determined based on the historical data of the motor under test under different operating conditions. Based on the historical operating data or simulation data of the motor under test, a known stable operating point (such as medium speed and low torque) far from the thermal boundary is selected as the test starting point to ensure that the edge finding process starts in the safe area.

[0044] The goal of edge finding is to locate the maximum output torque or current of the motor under test at a preset speed or initial temperature, where the real-time temperature rise rate does not exceed a preset safety threshold. The specific objective of this edge finding is clearly defined, for example: at a certain preset speed (or initial temperature), find the maximum torque (or maximum current) that the motor under test can output while ensuring that the real-time temperature rise rate just does not exceed a preset safety threshold. This threshold is the core criterion for edge finding.

[0045] Based on historical data of the motor under test under different operating conditions, the operating status of the motor under test under various conditions is analyzed to determine the initial safe operating condition. For example, by analyzing the temperature changes of the motor under test at different speeds and loads in historical data, a relatively safe operating condition is selected as the initial operating condition. The test system for the motor under test is started under the determined initial safe operating condition. At this time, the motor under test is in a state of waiting for testing, the load dynamometer has not applied any electrical load, and the data acquisition unit begins to collect the initial electrical and thermal parameters.

[0046] S2, Gradient electrical load loading

[0047] The controller controls the load dynamometer to apply an electrical load to the motor under test. The initial applied electrical load is L0, and then the applied electrical load to the motor under test is increased in a dynamic step size ΔL gradient, expressed by the formula: L k =L k-1 +ΔL, where k is the number of times the electrical load increases, L k Let L be the electrical load applied to the motor under test after the k-th increase; the controller instructs the dynamometer to apply gradient loading to the motor under test starting from the initial safe load, with dynamic step sizes. The total electrical load after each loading is L. k =L k-1 +ΔL. In step S2, an electrical load is applied to the motor under test, which is one or more of current, power, torque, or a combination thereof.

[0048] The controller controls the load dynamometer to apply an electrical load to the motor under test based on a preset initial electrical load. The magnitude of the initial electrical load can be reasonably set according to the rated parameters and initial safe operating conditions of the motor under test, for example, it can be set as a certain percentage of the rated current or torque of the motor under test.

[0049] S3. Real-time parameter acquisition and temperature change rate calculation

[0050] Each time an electrical load is applied to the motor under test, the data acquisition unit collects the electrical and thermal parameters of the motor under test in real time, and calculates the real-time temperature change rate of the motor under test based on the collected parameters.

[0051] Electrical parameters include current, voltage, torque, and speed, while thermal parameters include at least the temperature of the internal windings, magnets, and bearings of the motor being tested.

[0052] In step S3, the method for calculating the real-time temperature change rate is as follows:

[0053] The temperature data of the internal windings, magnets and bearings of the motor under test, collected by the temperature sensor array, are filtered to eliminate noise interference and obtain a temperature time series. The temperature difference between the current moment and the previous moment in the temperature time series is calculated and divided by the time interval to obtain the real-time temperature change rate series. The maximum value in the real-time temperature change rate series is the real-time temperature change rate.

[0054] The filtering process employs one or more combinations of moving average filtering, median filtering, Kalman filtering, or Savitzky-Golay filtering.

[0055] The acquired raw temperature data (especially the temperature time series) is filtered (e.g., Kalman filtering, moving average filtering) to suppress noise interference and improve the signal-to-noise ratio. For the filtered temperature time series, the difference between the current moment and the previous moment is calculated, and then divided by the sampling time interval to obtain the real-time temperature change rate sequence for each measuring point. The maximum value among all the real-time temperature change rates is selected as the "real-time temperature change rate" representing the overall thermal state of the tested motor, for subsequent judgment.

[0056] The data acquisition unit collects the electrical parameters (current, voltage, torque, and speed) and thermal parameters (temperature of the internal windings, magnets, and bearings) of the motor under test in real time. The acquisition frequency can be set according to actual needs; generally, a higher frequency is selected to ensure the real-time performance and accuracy of the data.

[0057] The temperature data acquired by the temperature sensor array is filtered. One or more combinations of moving average filtering, median filtering, Kalman filtering, or Savitzky-Golay filtering can be used. For example, median filtering can be used first to remove significant noise interference, followed by Kalman filtering to further smooth the data and obtain the temperature time series.

[0058] Calculate the temperature difference between the current and previous time points in the temperature time series, and divide it by the time interval to obtain the real-time temperature change rate series. Then, find the maximum value in the real-time temperature change rate series as the real-time temperature change rate at the current time.

[0059] S4. Safety Boundary Judgment

[0060] The real-time temperature change rate calculated in step S3 is compared with the preset safety threshold. If the real-time temperature change rate is greater than or equal to the preset safety threshold, it is determined that the tested motor has reached the thermal safety boundary, and step S5 is executed. If the real-time temperature change rate is less than the preset safety threshold, it is determined that the tested motor has not reached the thermal safety boundary, and step S6 is executed.

[0061] The calculated real-time temperature rise rate is compared with a preset safety threshold. This threshold can be a fixed value or a curve or mapping table that dynamically adjusts according to the current speed, temperature, or material properties of the motor under test, providing greater adaptability. If the real-time temperature rise rate is greater than or equal to the preset safety threshold: the motor under test has reached or is about to exceed the thermal safety boundary. Immediately execute S5. If the real-time temperature rise rate is less than the preset safety threshold: the motor under test is still within the safe zone. Proceed to S6 to adjust the step size and prepare for the next round of loading.

[0062] The preset safety threshold is a curve or mapping table that is dynamically set based on at least one of the following factors: the current speed of the motor under test, the current temperature, or the material properties of the motor under test.

[0063] S5. When the thermal safety boundary is reached, record the event.

[0064] The controller controls the load dynamometer to stop applying electrical load to the motor under test, and records the current electrical and thermal parameters of the motor under test, calibrating them as data points on the safe operating boundary of the motor under test;

[0065] In step S5, when the real-time temperature change rate is greater than or equal to a preset safety threshold, the controller controls the load dynamometer to stop applying electrical load and simultaneously controls the activation of the active cooling system until the real-time temperature change rate is less than the safety threshold. The controller instructs the dynamometer to immediately stop increasing the electrical load to prevent the tested motor from overheating and being damaged. Protection activation: Simultaneously, the active cooling system (such as a fan or liquid cooling pump) can be triggered to accelerate heat dissipation until the temperature rise rate drops below the safety threshold, ensuring the safety of the test process. All electrical parameters (such as speed, torque, current, and voltage) and thermal parameters (such as temperature at various points, maximum temperature, and temperature rise rate) are recorded at this moment. This set of data is calibrated as a safe operating boundary point under this specific operating condition (such as the current speed).

[0066] After step S5, steps S1 to S5 are repeated to obtain data points on the safe working boundary of the motor under test under different speeds or different initial temperatures. Curve fitting or interpolation algorithms are used to generate the safe working boundary curve of the motor under test to form a safe working boundary map of the motor under test.

[0067] Repeat steps S1 to S5, and obtain a series of boundary points by changing the initial conditions (such as different target speeds or different initial temperatures). By processing these discrete points using curve fitting (such as polynomial fitting or spline fitting) or interpolation algorithms (such as linear interpolation or Kriging interpolation), a continuous and complete safe operating boundary curve or three-dimensional map (such as torque-speed-temperature boundary surface) of the tested motor can be generated.

[0068] S6. Thermal safety boundary not reached, step size adaptive adjustment and cycling.

[0069] A heuristic search method is used to adaptively adjust the step size ΔL, and the process returns to step S2. The electrical load applied to the tested motor is increased using the adjusted step size ΔL. The heuristic search method dynamically adjusts the loading step size based on the change in the temperature rise rate. This step is the core of the "adaptive" edge finding, aiming to optimize the search process: rapidly approaching the boundary when far away, and finely probing when approaching the boundary.

[0070] In step S6, the heuristic search method specifically includes:

[0071] When an electrical load is applied to the motor under test N times consecutively, and the calculated real-time temperature change rate is less than a preset safety threshold, and the change amplitude of the real-time temperature change rate is less than a preset first change threshold, the motor under test is determined to be in the thermally stable region. Then, the dynamic step size ΔL is increased by a preset scaling factor α, where N≥2; α>1; for example, ΔL is increased to 1.2 times the original value.

[0072] When an electrical load is applied to the motor under test, if the calculated real-time temperature change rate is less than the preset safety threshold and the change amplitude of the real-time temperature change rate is greater than or equal to the preset second change threshold, it is determined that the motor under test is close to or touches the thermal safety boundary. Then, the dynamic step size ΔL is reduced by the preset scaling factor β, where 0 < β < 1; for example, ΔL is reduced to 0.8 times the original value.

[0073] The magnitude of the real-time temperature change rate is the change in the real-time temperature change rate after the current increase in electrical load compared to the previous increase in electrical load.

[0074] The first preset threshold is less than the second preset threshold.

[0075] Using the adjusted step size ΔL, the electrical load applied to the motor under test is increased according to the formula, and then the process returns to step S3 to continue data acquisition and safety boundary judgment.

[0076] This method enables a shift from "static, offline, and coarse" boundary estimation to "dynamic, online, and accurate" boundary self-identification, which is of great significance for improving the safety and performance potential of high-density drive electric systems such as electric vehicles and aerospace.

[0077] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, any equivalent modifications or substitutions made by those skilled in the art to the relevant technical features will fall within the scope of protection of the present invention.

Claims

1. An adaptive edge-finding method for the safe operating boundary of the electro-thermal coupling of a driven motor under test, characterized in that, Includes the following steps: S1. Start the test system of the motor under test under the initial safe working conditions and set the edge finding target. The test system of the motor under test includes the motor under test, the load dynamometer, the data acquisition unit and the host computer. The data acquisition unit includes at least a current sensor, a voltage sensor, a torque sensor and a temperature sensor array deployed inside the motor under test. The host computer has a controller deployed inside. S2. The controller controls the load dynamometer to apply an electrical load to the motor under test. The initial applied electrical load is L0, and then the applied electrical load to the motor under test is increased in a dynamic step size ΔL gradient, expressed by the formula: L k =L k-1 +ΔL, where k is the number of times the electrical load increases, L k This represents the electrical load applied to the tested motor after the k-th increase; S3. After each electrical load is applied to the motor under test, the data acquisition unit collects the electrical and thermal parameters of the motor under test in real time, and calculates the real-time temperature change rate of the motor under test based on the collected parameters. S4. Compare the real-time temperature change rate calculated in step S3 with the preset safety threshold. If the real-time temperature change rate is greater than or equal to the preset safety threshold, it is determined that the tested motor has reached the thermal safety boundary, and step S5 is executed. If the real-time temperature change rate is less than the preset safety threshold, it is determined that the tested motor has not reached the thermal safety boundary, and step S6 is executed. S5. The controller controls the load dynamometer to stop applying electrical load to the motor under test, and records the current electrical and thermal parameters of the motor under test, calibrating them as data points on the safe operating boundary of the motor under test. S6. Adaptively adjust the step size ΔL using a heuristic search method, and return to step S2. Increase the electrical load applied to the tested motor using the adjusted step size ΔL. The heuristic search method dynamically adjusts the loading step size according to the change in the temperature rise rate.

2. The adaptive edge-finding method for the safe working boundary of the electro-thermal coupling of the driven motor under test according to claim 1, characterized in that, In step S1, the initial safe operating condition is determined based on the historical data of the motor under test under different operating conditions. The edge-finding target is to find the maximum output torque or current when the real-time temperature rise rate of the motor under test does not exceed the preset safety threshold at the preset speed or initial temperature.

3. The adaptive edge-finding method for the safe working boundary of the electro-thermal coupling of the driven motor under test according to claim 1, characterized in that, The electrical parameters include current, voltage, torque, and speed, and the thermal parameters include at least the temperatures of the internal windings, magnets, and bearings of the motor under test.

4. The adaptive edge-finding method for the safe working boundary of the electro-thermal coupling of the driven motor under test according to claim 1, characterized in that, In step S3, the method for calculating the real-time temperature change rate is as follows: The temperature data of the internal windings, magnets and bearings of the motor under test, collected by the temperature sensor array, are filtered to eliminate noise interference and obtain a temperature time series. The temperature difference between the current moment and the previous moment in the temperature time series is calculated and divided by the time interval to obtain the real-time temperature change rate series. The maximum value in the real-time temperature change rate series is the real-time temperature change rate. The filtering process employs one or more combinations of moving average filtering, median filtering, Kalman filtering, or Savitzky-Golay filtering.

5. The adaptive edge-finding method for the safe working boundary of the electro-thermal coupling of the driven motor under test according to claim 1, characterized in that, In step S6, the heuristic search method specifically includes: When an electrical load is applied to the motor under test N times consecutively, and the calculated real-time temperature change rate is less than the preset safety threshold, and the change amplitude of the real-time temperature change rate is less than the preset first change threshold, the motor under test is determined to be in the thermally stable region. Then, the dynamic step size ΔL is increased by the preset scaling factor α, where N≥2; α>1. When an electrical load is applied to the motor under test, if the calculated real-time temperature change rate is less than the preset safety threshold and the change amplitude of the real-time temperature change rate is greater than or equal to the preset second change threshold, it is determined that the motor under test is close to or touches the thermal safety boundary. Then, the dynamic step size ΔL is reduced by the preset scaling factor β, where 0 < β < 1. The magnitude of the real-time temperature change rate is the change in the real-time temperature change rate after the current increase in electrical load compared to the previous increase in electrical load. The first preset threshold is less than the second preset threshold.

6. The adaptive edge-finding method for the safe working boundary of the electro-thermal coupling of the driven motor under test according to claim 1, characterized in that, In step S5, when the real-time temperature change rate is greater than or equal to the preset safety threshold, the controller controls the load dynamometer to stop applying electrical load and simultaneously controls the active cooling system to start until the real-time temperature change rate is less than the safety threshold. The preset safety threshold is a curve or mapping table that is dynamically set based on at least one of the following factors: the current speed of the motor under test, the current temperature, or the material properties of the motor under test.

7. The adaptive edge-finding method for the safe working boundary of the electro-thermal coupling of the driven motor under test according to claim 1, characterized in that, After step S5, steps S1 to S5 are repeated to obtain data points on the safe working boundary of the motor under test under different speeds or different initial temperatures. Curve fitting or interpolation algorithms are used to generate the safe working boundary curve of the motor under test to form a safe working boundary map of the motor under test.

8. The adaptive edge-finding method for the safe working boundary of the electro-thermal coupling of the driven motor under test according to claim 1, characterized in that, In step S2, the electrical load applied to the motor under test is one or more of current, power, torque, or a combination thereof.

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