Permanent magnet synchronous motor temperature rise control method and device, electronic equipment, computer readable storage medium, computer program product and vehicle

Abstract

The application discloses a permanent magnet synchronous motor temperature rise control method, which comprises the following steps: when the motor temperature is less than a temperature threshold value, and the difference between the motor temperature and the temperature threshold value is less than a preset difference value, the current constraint value of the motor is reduced to control the motor temperature to be not higher than the temperature threshold value. The application can effectively avoid motor overheating.

Description

Technical Field

[0001] This application relates to the field of motor temperature control technology, and in particular to a method and device for controlling the temperature rise of a permanent magnet synchronous motor, electronic equipment, computer-readable storage medium, computer program product, and vehicle. It is especially suitable for application scenarios with high requirements for motor overheat protection, such as electric power steering (EPS) systems, steer-by-wire systems, brake-by-wire systems, and electric drive systems. Background Technology

[0002] Permanent magnet synchronous motors are widely used in many fields due to their high efficiency and high power density, such as electric power steering (EPS) systems in automobiles. In such applications, the motor (such as the EPS motor) is usually installed in environments with limited space and lack of active cooling equipment (such as inside a car cabin). Therefore, overheating problems are prone to occur when the motor operates continuously or under high load.

[0003] In order to control the temperature rise of motors (especially motors without active cooling devices such as EPS motors), related technologies limit the motor's heat generation power by reducing the motor's operating current. However, the motor temperature can still easily exceed the temperature threshold, leading to the risk of overheating. Summary of the Invention

[0004] This application proposes a method for controlling the temperature rise of a permanent magnet synchronous motor. This method can accurately control the motor temperature below a temperature threshold, thereby reducing the risk of motor overheating.

[0005] According to one embodiment of this application, a method for controlling the temperature rise of a permanent magnet synchronous motor is proposed, which includes: when the motor temperature is less than a temperature threshold and the difference between the motor temperature and the temperature threshold is less than a preset difference, reducing the current constraint value of the motor to control the motor temperature not to exceed the temperature threshold.

[0006] In some implementations, the preset difference is determined based on the current motor current and / or the historical temperature change rate of the motor.

[0007] In some implementations, the higher the current motor current, the larger the preset difference, and / or the greater the historical temperature change rate of the motor, the larger the preset difference.

[0008] In some implementations, the preset difference is greater than 20°C.

[0009] In some embodiments, reducing the current constraint value of the motor to control the motor temperature not to exceed the temperature threshold includes:

[0010] The current operating parameters of the motor are obtained, including at least the current motor temperature, motor current, and ambient temperature. Based on the current operating parameters, the current constraint value of the motor is dynamically adjusted.

[0011] In some implementations, the current constraint value of the motor is dynamically adjusted based on the current operating parameters, including:

[0012] Based on the current operating parameters and the pre-established motor temperature rise model, the temperature change trend of the motor in the future prediction time is predicted to obtain the future predicted motor temperature sequence.

[0013] Based on the predicted motor temperature sequence, the overheating risk level of the motor is determined;

[0014] The current constraint value of the motor is dynamically adjusted according to the overheating risk level.

[0015] In some implementations, predicting the temperature change trend of the motor over a future predicted time period includes:

[0016] Set the forecast time and forecast step size;

[0017] An iterative calculation method is used to predict the motor temperature for the next time step based on the current motor current, ambient temperature, and motor temperature at the current time step, combined with the motor temperature rise model, until the prediction time ends, thus forming the predicted motor temperature sequence.

[0018] In some implementations, the iterative calculation includes:

[0019] In the previous time step, the predicted motor temperature for the next time step was calculated using the following formula:

[0020]

[0021] Where k is the time step within the prediction time, and T p[k+1] For the predicted motor temperature at the next time step, when k = 0, the initial step T... p[0] To obtain the current motor temperature, when k > 0, T p[k] I is the motor temperature predicted in the previous time step iteration. s R is the current of the motor. s C1 represents the motor phase resistance parameter in the motor temperature rise model, and R represents the parameter related to the first thermal capacitor in the motor temperature rise model. 13 The thermal resistance related to heat conduction between the first and second thermal capacitors in the motor temperature rise model is given by T, where Δt is the prediction step size. c[k] The intermediate temperature variable is determined according to the following formula:

[0022]

[0023] Where k is the time step within the prediction time, and when k = 0, the initial step T is... c[0] The current temperature of the motor controller or the motor housing temperature, and the relevant parameters of the second thermal capacitor in the motor temperature rise model described in C3, R. 3e T is the thermal resistance related to heat conduction between the second thermal capacitor and the environment in the motor temperature rise model. e This represents the current ambient temperature.

[0024] In some embodiments, the method further includes obtaining the parameters of the motor temperature rise model by the following methods:

[0025] The motor is controlled to run within a preset speed and torque range for a specified first duration, and during the operation and for a specified second duration after the motor stops running, the motor temperature, motor current and ambient temperature are continuously and synchronously collected.

[0026] The phase resistance R of the motor was measured using an electrical parameter measuring instrument. s ;

[0027] Based on motor current, ambient temperature, motor temperature, and motor phase resistance, and using a preset transfer function, other parameters of the motor temperature rise model are identified, including parameters C1 and C3 related to heat capacity and parameter R related to thermal resistance. 13 R 3e .

[0028] In some implementations, determining the overheating risk level of the motor includes:

[0029] Multiple temperature thresholds are set, including an overheating threshold and a severe overheating threshold, wherein the overheating threshold is lower than the severe overheating threshold;

[0030] Each predicted motor temperature in the predicted motor temperature sequence is compared with the plurality of temperature thresholds:

[0031] If the predicted motor temperature does not exceed the overheating threshold, it is determined to be a low overheating risk level.

[0032] If there are predicted motor temperatures exceeding the overheating threshold, but none exceeding the severe overheating threshold, the motor is classified as having a medium overheating risk level.

[0033] If the predicted motor temperature exceeds the severe overheating threshold, it is determined to be at a high overheating risk level.

[0034] In some implementations, the current constraint value of the motor is dynamically adjusted according to the overheating risk level, including:

[0035] When the overheating risk level is low, the current constraint value of the motor is gradually increased;

[0036] When the overheating risk level is medium or high, the current constraint value of the motor is gradually reduced.

[0037] In some embodiments, the method further includes:

[0038] When gradually increasing or decreasing the current constraint value of the motor, the adjustment amount ΔI of the current constraint value is calculated according to the following formula. lim :

[0039]

[0040] Among them, risk levels 0, 1, and 2 correspond to low overheat risk, medium overheat risk, and high overheat risk, respectively. th1 For the overheating threshold, T p To predict the motor temperature sequence, Idx1 represents the predicted motor temperature sequence T. p The data sequence number in the prediction that the motor temperature first exceeds the overheat threshold, Idx2 is the predicted motor temperature sequence T. p The data sequence number when the predicted motor temperature first exceeds the severe overheating threshold is used, and Const1, Const2, Const3, Const4, Const5, and Const6 are preset coefficients.

[0041] In some implementations, the motor is used in an electric power steering (EPS) system, a steer-by-wire system, a brake-by-wire system, or an electric drive system.

[0042] According to one embodiment of this application, a permanent magnet synchronous motor temperature rise control device is also proposed, comprising:

[0043] A sensor unit is used to acquire the current operating parameters of the motor, which include at least the current motor temperature, motor current, and ambient temperature.

[0044] The computing unit, connected to the sensor unit, is configured as follows:

[0045] Based on the current operating parameters and the pre-established motor temperature rise model, the temperature change trend of the motor in the future prediction time is predicted to obtain the future predicted motor temperature sequence.

[0046] Based on the predicted motor temperature sequence, the overheating risk level of the motor is determined;

[0047] Based on the overheating risk level, the current constraint value of the motor is dynamically calculated and generated;

[0048] A power unit, connected to the computing unit, is used to constrain the current of the motor according to the current constraint value generated by the computing unit;

[0049] The storage unit is used to store the current operating parameters, the parameters of the motor temperature rise model, the predicted motor temperature sequence, and the current constraint value.

[0050] In some implementations, the computing unit is configured to use an iterative calculation method when predicting the temperature change trend, predicting the motor temperature for the next time step at the previous time step within the prediction time using the following formula:

[0051]

[0052] Where k is the time step within the prediction time, and T p[k+1] For the predicted motor temperature at the next time step, when k = 0, the initial step T... p[0] To obtain the current motor temperature, when k > 0, T p[k] The initial step T is the motor temperature predicted in the previous time step iteration. p[0] To obtain the current motor temperature T m ,I s To obtain the motor current, R s Here, C1 represents the motor phase resistance parameter of the motor temperature rise model, and R represents the first thermal capacitance related parameter of the motor temperature rise model. 13 The thermal resistance related to heat conduction between the first and second thermal capacitors in the motor temperature rise model is given by Δt, where Δt is the preset prediction step size, and T is the thermal resistance. c[k] The intermediate temperature is determined according to the following formula:

[0053]

[0054] Where k is the time step within the prediction time, and when k = 0, the initial step T is... c[0] To obtain the current temperature of the motor controller or the motor housing temperature, C3 is the second thermal capacitance related parameter of the motor temperature rise model, and R... 3e For the thermal resistance related to the thermal conduction between the second thermal capacitor and the environment, T e The ambient temperature was obtained.

[0055] In some embodiments, the calculation unit is further configured to acquire and determine the parameters C1, C3, and R of the motor temperature rise model by the following methods. 13 R 3e :

[0056] The motor is controlled to run within a preset speed and torque range for a specified first duration, and during the operation and for a specified second duration after the motor stops running, the sensor unit is instructed to continuously and synchronously collect motor temperature, motor current and ambient temperature.

[0057] The phase resistance R of the motor was measured using an electrical parameter measuring instrument. s ;

[0058] Based on motor current, ambient temperature, motor temperature, and motor phase resistance, and using a preset transfer function, other parameters of the motor temperature rise model are identified, including heat capacity-related parameters C1 and C3, and thermal resistance-related parameter R. 13 R 3e ;

[0059] The acquired and identified model parameters are then stored in the storage unit.

[0060] In some implementations, the calculation unit is configured to: determine the overheating risk level and dynamically calculate and generate the current constraint value based on the overheating risk level.

[0061] Based on a preset set of multiple temperature thresholds, including an overheating threshold and a severe overheating threshold higher than the overheating threshold, each predicted motor temperature in the predicted motor temperature sequence is compared with the multiple temperature thresholds to determine whether the overheating risk level is a low overheating risk level, a medium overheating risk level, or a high overheating risk level.

[0062] When the overheating risk level is low, the current constraint value of the motor is gradually increased;

[0063] When the overheating risk level is medium or high, the current constraint value of the motor is gradually reduced;

[0064] When gradually increasing or decreasing the current constraint value of the motor, the adjustment amount ΔI of the current constraint value is calculated according to the following formula. lim :

[0065]

[0066] Among them, risk levels 0, 1, and 2 correspond to low overheat risk, medium overheat risk, and high overheat risk, respectively. th1 For the overheating threshold, T p To predict the motor temperature sequence, Idx1 represents the predicted temperature T in the predicted motor temperature sequence. p The data sequence number when the value first exceeds the overheat threshold, where Idx2 is the predicted motor temperature sequence T. pThe data sequence number when the predicted motor temperature first exceeds the severe overheating threshold is used, and Const1 to Const6 are preset coefficients.

[0067] In some embodiments, the apparatus further includes:

[0068] A power supply unit is used to supply power to the sensor unit, the computing unit, the power unit, and the storage unit;

[0069] The communication unit is used for data transmission between the sensor unit, the computing unit, the power unit, and the storage unit, as well as for data transmission between the device and an external system.

[0070] Compared with existing technologies, the permanent magnet synchronous motor temperature rise control method and device proposed in this application introduce a future temperature prediction mechanism based on a motor temperature rise model, and performs overheat risk assessment and current constraint adjustment based on the predicted future temperature rather than the current temperature, thereby bringing significant beneficial effects. Firstly, by predicting the temperature change trend of the motor over a future period, this invention can achieve early warning of potential overheating risks, overcoming the inherent lag of traditional current-temperature-based control. This allows the control system to intervene before the motor actually reaches an overheated state, thus more effectively avoiding the risk of performance degradation or damage to the motor due to excessive temperature, and significantly improving the operational safety of the system.

[0071] Secondly, this application dynamically adjusts the current constraint value based on the predicted future overheating risk level, achieving more precise and timely current control. Unlike existing technologies that use a preset fixed rate or fixed multiplier for current decay, this application can adjust the current limit step by step and finely according to the specific predicted temperature conditions, ensuring that only the necessary minimum current decay is performed to avoid overheating. This not only effectively avoids motor overheating but also minimizes unnecessary suppression of motor output performance caused by temperature control.

[0072] Furthermore, this application employs a dynamic closed-loop current constraint strategy: when an overheating risk is predicted, the system gradually reduces the motor current constraint value until the predicted overheating risk is reduced to an acceptable level; once the overheating risk decreases, the system gradually increases the motor current constraint value until a potential overheating trend is detected again. By dynamically seeking the optimal balance between "avoiding overheating" and "maximizing performance," this control method ensures that the motor is not damaged by overheating throughout the entire operation process, while continuously outputting the maximum current allowed under the current temperature rise conditions. This maximizes the functionality of the motor and the performance of the system (such as an EPS system), improving the user experience and the overall efficiency of the system.

[0073] According to one embodiment of this application, an electronic device is also provided, comprising:

[0074] Memory, on which computer programs / instructions are stored;

[0075] A processor is configured to execute the computer program / instructions in the memory to implement the steps of the aforementioned permanent magnet synchronous motor temperature rise control method.

[0076] According to one embodiment of this application, a computer-readable storage medium is also provided, on which a computer program / instruction is stored, which, when executed by a processor, implements the steps of the aforementioned permanent magnet synchronous motor temperature rise control method.

[0077] According to one embodiment of this application, a computer program product is also proposed, including a computer program / instructions that, when executed by a processor, implement the steps of the aforementioned permanent magnet synchronous motor temperature rise control method.

[0078] According to one embodiment of this application, a vehicle is also provided, wherein the aforementioned electronic equipment, or the aforementioned computer-readable storage medium, or the aforementioned permanent magnet synchronous motor temperature rise control device is also provided.

[0079] In summary, this application effectively solves the problems of lag in temperature control and inaccurate current decay in the prior art by predicting the temperature in advance and adjusting the current dynamically, providing a more reliable and optimized technical solution for the safe and efficient operation of permanent magnet synchronous motors. Attached Figure Description

[0080] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this specification and, together with the description, serve to explain the principles of this specification.

[0081] Figure 1 This is a flowchart of a method for controlling the temperature rise of a permanent magnet synchronous motor according to an embodiment of this application;

[0082] Figure 2 This is a schematic diagram of a motor temperature prediction process according to an exemplary embodiment of this application;

[0083] Figure 3 This is a schematic diagram of a motor overheating risk level determination process according to an exemplary embodiment of this application;

[0084] Figure 4 This is a schematic diagram illustrating the process of calculating and adjusting motor current constraint values ​​according to an exemplary embodiment of this application;

[0085] Figure 5This is a structural block diagram of a permanent magnet synchronous motor temperature rise control device according to an exemplary embodiment of this application;

[0086] Figure 6 This is a schematic diagram illustrating the changes in relevant parameters according to an exemplary embodiment of this application. Detailed Implementation

[0087] 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 numbers 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 application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0088] This application provides a method for controlling the temperature rise of a permanent magnet synchronous motor. When the motor temperature is below a temperature threshold, and when the difference between the motor temperature and the temperature threshold is less than a preset difference, the current constraint value of the motor is reduced to control the motor temperature so that it does not exceed the temperature threshold. The current constraint value is the maximum output current value set by the controller. Reducing the motor current constraint value when the current motor temperature is below the temperature threshold and the difference between the current motor temperature and the temperature threshold is less than a preset difference can effectively prevent the motor temperature from exceeding the temperature threshold, accurately control the motor temperature, and prevent the motor from overheating. When reducing the motor current constraint value, the current constraint value typically decreases by more than 20%.

[0089] In related technologies, motor temperature is typically controlled based on the current temperature. The applicant discovered that if the current is reduced only after the motor temperature has exceeded a temperature threshold, the motor temperature does not immediately decrease but continues to rise for a period before decreasing, still resulting in overheating. This application addresses this by reducing the current constraint value when the motor temperature is below the temperature threshold by a certain amount, effectively reducing the risk of motor overheating.

[0090] The temperature threshold is a set value. If the temperature threshold is obtained through testing, it can be achieved using the following methods:

[0091] 1) Test the product's maximum current at room temperature, for example, 120A. 2) Place the product in an adjustable temperature chamber and slowly increase the chamber temperature within a certain range. For example, start at 70℃ and increase by 10℃ per hour until reaching 145℃. 3) During the temperature rise, briefly run the product at regular intervals to test its maximum current at different temperatures. For example, run it for 15 seconds every 6 minutes and take the average current over those 15 seconds as the maximum current at that temperature. 4) After testing all temperatures, plot the curve of maximum current versus temperature. The temperature at which the maximum current begins to continuously decrease is the product's temperature threshold.

[0092] In some implementations, the preset difference is determined based on the current motor current and / or the historical rate of change of motor temperature. By determining the magnitude of the preset difference based on the dynamic trend of motor temperature change, and considering the current motor current and the historical rate of change of motor temperature, the timing of the current constraint value reduction can be more accurately determined, allowing for precise control of motor temperature. This effectively avoids motor overheating while maximizing the normal operation of motor output performance and system functions.

[0093] In some implementations, the higher the current motor current, the larger the preset difference, and / or the greater the historical temperature change rate of the motor, the larger the preset difference. A higher current motor current and a greater historical temperature change rate indicate a more pronounced upward trend in motor temperature, requiring an earlier (larger preset difference) reduction of the motor current constraint value to prevent the motor temperature from exceeding the temperature threshold. Conversely, a lower current motor current and a smaller historical temperature change rate indicate a weaker upward trend in motor temperature, requiring a later (smaller preset difference) reduction of the motor current constraint value to prevent the motor temperature from exceeding the temperature threshold while ensuring the normal operation of motor output performance and system functions.

[0094] In some implementations, the preset temperature difference is greater than 20°C. When the preset temperature difference is greater than 20°C, it is possible to effectively avoid motor overheating while maximizing the normal operation of motor output performance and system functions.

[0095] In some implementations, reducing the motor's current constraint value to control the motor temperature below a temperature threshold includes:

[0096] Obtain the current operating parameters of the motor, which must include at least the current motor temperature T. m Motor current I s and ambient temperature T e Based on current operating parameters, the motor current constraint value is dynamically adjusted. This is based on the current motor temperature T. m Motor current I s and ambient temperature T e By analyzing the dynamic temperature change trend of the motor under the influence of various factors and dynamically adjusting the current constraint value of the motor, the motor temperature can be controlled more precisely, reducing the risk of motor overheating.

[0097] In some implementations, such as Figure 1 As shown, by accurately predicting the future temperature of the motor, early warning of the risk of motor overheating and precise current control are achieved, thereby maximizing the motor's performance output while avoiding overheating. As shown in the figure, this method includes the following steps 1 to 4.

[0098] Step 1: Obtain the current operating parameters of the motor. The current operating parameters should include at least the current motor temperature T. m Motor current I s and ambient temperature T e .

[0099] Step 1 is used to collect the basic data required for subsequent motor temperature rise prediction and control decisions. Current operating parameters include at least the current motor temperature T. m Motor current I s and ambient temperature T e .

[0100] Current motor temperature T m The temperature can be obtained through either direct measurement or indirect estimation. Direct measurement methods, for example, involve using temperature sensors (such as thermistors or thermocouples) installed in specific locations on the motor body (such as windings, core, or casing) to monitor and read temperature values ​​in real time. Indirect estimation methods utilize existing temperature information from the motor (such as temperature information from the motor controller), eliminating the need for additional temperature sensors on the motor body. The motor temperature is estimated using specific algorithms or models (such as thermal network models or closed-loop observers). Those skilled in the art can choose the method of obtaining the motor temperature based on specific application requirements regarding cost, size, accuracy, etc. This application does not impose any limitations on this.

[0101] Motor current I s This refers to the actual current flowing through the motor windings, which can usually be accurately measured using a current sensor (such as a Hall effect sensor or a sampling resistor) inside the motor controller. This current value is a major factor contributing to Joule heating in the motor.

[0102] Ambient temperature T e This refers to the temperature of the operating environment of the motor. This parameter can be obtained through a temperature sensor located near the motor or that represents the motor's operating environment. Ambient temperature is an important boundary condition affecting the motor's heat dissipation capacity.

[0103] These current operating parameters, once collected, will serve as input for subsequent steps.

[0104] Step 2: Based on the current operating parameters and the pre-established motor temperature rise model, predict the temperature change trend of the motor in the future prediction time to obtain the future predicted motor temperature sequence.

[0105] Step 2 uses a mathematical model to predict the temperature trend of the motor over a future period. In some implementations, predicting the temperature change trend of the motor over a predicted time period includes:

[0106] Set the forecast time and forecast step size;

[0107] An iterative calculation method is used, based on the current motor current I. s Ambient temperature T e The motor temperature T at the current time step p[k] Based on the motor temperature rise model, the predicted motor temperature T for the next time step is predicted. p[k+1] This continues until the prediction time ends, forming a predicted motor temperature sequence, where when k=0, the initial step T... p[0] To obtain the current motor temperature T m When k>0, T p[k] This is the motor temperature predicted in the previous time step iteration.

[0108] The prediction time refers to how long in the future the motor's temperature change is expected to be predicted. For example, it can be set to 5 seconds, 10 seconds or longer, depending on the application requirements and computing power.

[0109] The prediction step size Δt refers to the time interval during which the calculation advances in each iteration within the aforementioned prediction time. For example, it can be set to 0.1 seconds or 0.05 seconds. The length of the prediction time period should be an integer multiple of the prediction step size. Those skilled in the art can weigh prediction accuracy against computational load to select an appropriate step size. A step size that is too small will increase computational load, while a step size that is too large may reduce prediction accuracy.

[0110] At the start of each iteration, using the currently acquired motor current I... s and ambient temperature T e As a fixed input for this iteration, and based on the motor temperature T at the current time step k. p[k] Based on the pre-established motor temperature rise model, the motor temperature T at the next time step k+1 is predicted. p[k+1] T p[0] The current motor temperature T obtained at the start of the iteration m All predicted motor temperatures T p[1] T p[2] ... T p[N] Together they form a sequence for predicting motor temperature, where N is the sequence length.

[0111] In some implementations, the iterative calculation process described above may include:

[0112] At time step k (starting from k=0), the predicted motor temperature T for the next time step is calculated using the following formula. p[k+1] :

[0113]

[0114] Among them, I s R is the current motor current obtained at the start of the iteration and used for the entire current prediction sequence; sC1 represents the phase resistance parameters of the motor in the motor temperature rise model; C2 represents the parameters related to the first thermal capacitance in the motor temperature rise model, for example, the thermal capacity of the motor windings or main heat-generating parts; R 13 The thermal resistance related to heat conduction between the first and second thermal capacitors in the motor temperature rise model; Δt is the prediction step size; T c[k] For intermediate temperature variables, such as the temperature of the motor housing or the equivalent thermal capacity node associated with the controller, the intermediate temperature variable T can be determined according to the following formula. c[k] :

[0115]

[0116] Wherein, the initial step T c[0] The value of T can be determined based on the specific application scenario. For example, in an electric power steering (EPS) system, if the motor and controller are tightly assembled as one unit through a metal housing, the current temperature of the motor controller can be used as T. c[0] Otherwise, the current temperature of the motor casing can be used as T. c[0] In some examples, its value can be obtained through sensor measurement; C3 is the second thermal capacitance-related parameter in the motor temperature rise model, R 3e The thermal resistance T in the motor temperature rise model related to heat conduction between the second thermal capacitor and the environment. e This is the current ambient temperature, obtained at the start of the iteration and used throughout the prediction sequence.

[0117] At each time step, we can first use the T of the current time step. p[k] and T c[k] Calculate T for the next step p[k+1] and T c[k+1] The calculated T p[k+1] Stored as an element of the predicted motor temperature sequence, and T p[k+1] and T c[k+1] T is respectively used as the time step of the next iteration. p[k] and T c[k] This continues until the entire prediction period is completed.

[0118] Furthermore, in some embodiments, the parameters C1, C3, and R of the above-mentioned motor temperature rise model are... 13 R 3e This information can be obtained in advance through testing and identification to ensure the accuracy of the model. The acquisition method may include the following steps:

[0119] a. Experimental Data Acquisition: Control the permanent magnet synchronous motor to run within a preset speed range (e.g., 1000 rpm to 4000 rpm) and torque range (e.g., 0 Nm to 5 Nm, ensuring the motor output power does not exceed its rated value) for a specified first duration (e.g., 10 minutes). Then, stop the motor for a specified second duration (e.g., 20 minutes). Throughout the entire test (including the running phase and the cooling phase after stopping), continuously and synchronously acquire the motor phase current I using a digital recorder or similar equipment. s Ambient temperature T e and the measured temperature T of key parts of the motor m (For example, measured by a surface-mounted temperature sensor).

[0120] b. Motor phase resistance measurement: The phase resistance R of the motor is measured using an electrical parameter measuring instrument (such as an LCR meter or bridge) at a specific reference temperature (or considering temperature correction). s .

[0121] c. Identification of other model parameters: Based on the large amount of dynamic test data collected in step a (I s Sequence, T e Sequence, T m (Sequence) and the motor phase resistance R measured in step b. s Furthermore, using a pre-defined transfer function that characterizes the motor's thermal dynamics, the system identification algorithm (such as least squares method, maximum likelihood method, etc.) identifies other unknown parameters of the motor temperature rise model, specifically including parameters C1 and C3 related to heat capacity and parameter R related to thermal resistance. 13 R 3e These identified parameters were then incorporated into the motor temperature rise model for online temperature prediction.

[0122] For example, a transfer function can have the following form:

[0123]

[0124] Where s is the Laplace operator; a1, a2, a3, and a4 are simplified parameters, and these parameters are the same as the temperature rise model parameters R. s R 13 R 3e C1 and C3 have the following correspondence:

[0125]

[0126] Step 3: Determine the overheating risk level of the motor based on the predicted motor temperature sequence.

[0127] Step 3 is used to assess whether there is a risk of overheating in the motor and to classify the degree of risk.

[0128] In some implementations, the process of determining the overheat risk level includes:

[0129] Multiple temperature thresholds are set, including an overheat threshold and a severe overheat threshold, with the overheat threshold being lower than the severe overheat threshold.

[0130] Each predicted motor temperature in the predicted motor temperature sequence is compared with multiple temperature thresholds:

[0131] If the predicted motor temperature does not exceed the overheating threshold, it is judged as a low overheating risk level.

[0132] If there are predicted motor temperatures that exceed the overheating threshold, but none exceed the severe overheating threshold, the motor is classified as having a medium overheating risk level.

[0133] If the predicted motor temperature exceeds the severe overheating threshold, it is classified as a high overheating risk level.

[0134] When setting temperature thresholds, at least two key temperature thresholds should be set according to the motor's design specifications, material heat resistance rating, and safe operation requirements: "Overheat threshold," which can be represented by T. th1 For example, the overheating threshold can be set to 95°C; the "severe overheating threshold" can be represented by T. th2 This indicates, for example, that the severe overheating threshold can be set to 125°C. These thresholds represent the temperature points at which the motor should not be operated for extended periods or should be avoided.

[0135] When comparing the predicted motor temperature with the threshold and determining the risk level, each predicted motor temperature in the predicted motor temperature sequence obtained in step 2 can be traversed.

[0136] If none of the predicted motor temperatures in the predicted motor temperature sequence exceed the overheating threshold T th1 If the current motor overheating risk level is determined to be low (or risk level 0), it means that the probability of the motor overheating is low within the predicted time period.

[0137] If the predicted motor temperature sequence contains a predicted motor temperature exceeding the overheating threshold T th1 However, none of the predicted motor temperatures exceeded the severe overheating threshold T. th2 If the current motor overheating risk level is determined to be medium overheating risk level (or risk level 1), it indicates that the motor has a certain risk of overheating in the future, requiring attention or appropriate control measures.

[0138] If the predicted motor temperature sequence contains a predicted motor temperature exceeding the severe overheating threshold T th2If the current motor overheating risk level is determined to be high (or risk level 2), it means that there is a high probability that the motor will experience severe overheating in the future, and control measures must be taken immediately.

[0139] When assessing risk levels, it is generally advisable to focus on whether the peak temperature in the future temperature prediction sequence exceeds the corresponding threshold. Simultaneously, the time point when the predicted temperature first exceeds a certain threshold (e.g., the corresponding data sequence number, such as Idx1 and Idx2) can be recorded; this information can be used for subsequent, more refined current control.

[0140] Step 4: Dynamically adjust the motor current constraint value according to the overheating risk level.

[0141] This step, based on the aforementioned overheat risk assessment, dynamically adjusts the upper limit of the motor's allowable operating current to achieve temperature rise control.

[0142] In one implementation, a strategy for dynamically adjusting the current constraint value based on the determined overheating risk level includes:

[0143] When the overheating risk level is determined to be low, it indicates that the motor is currently operating safely and is not expected to overheat in the near future. At this time, the current constraint value of the motor can be gradually increased (i.e., the motor is allowed to output greater current and torque) to fully utilize the motor performance.

[0144] When the overheating risk level is determined to be medium or high, it indicates that the motor is at risk of overheating or severe overheating in the future. In this case, the current constraint value of the motor can be gradually reduced to reduce the motor's heat generation power, thereby suppressing further temperature rise.

[0145] The adjustment of the current constraint value is cumulative, meaning that the adjustment of the current constraint value in the current control cycle is based on the calculation results of the previous cycle.

[0146] In one example, when gradually increasing or decreasing the motor's current constraint value, the adjustment amount ΔI of the current constraint value can be calculated according to the following formula. lim :

[0147]

[0148] Among them, risk levels 0, 1, and 2 correspond to low overheat risk, medium overheat risk, and high overheat risk, respectively; T th1 The overheating threshold set in step 3 is the temperature threshold used to classify low-risk and medium-risk conditions; T p The predicted motor temperature sequence obtained in step 2, max(T) p ) indicates taking the maximum predicted motor temperature in the sequence; Idx1 is the predicted motor temperature sequence Tp The data sequence number at which the predicted motor temperature first exceeds the overheating threshold represents the predicted time point when the motor begins to enter the medium-risk phase; Idx2 is the predicted motor temperature sequence T. p The data sequence number when the predicted motor temperature first exceeds the severe overheating threshold represents the predicted time point when the motor begins to enter a high-risk state. Const1, Const2, Const3, Const4, Const5, and Const6 are all preset coefficients, which are usually obtained from experimental testing or simulation calibration. These coefficients determine the rate and magnitude of increase or decrease in current constraint values ​​under different risk levels.

[0149] For example, for risk level 0, the adjustment amount ΔI lim A positive value indicates an increase in the current constraint value. Its magnitude depends on the margin (T) between the highest temperature in the current predicted motor temperature sequence and the overheat threshold. th1 -max(T p The larger the margin, the greater the increase that can be made, and it is constrained by Const1 and Const2. Const1 can be regarded as a fixed minimum increase.

[0150] For example, for risk levels 1 and 2, the adjustment is negative, indicating a reduction in the current constraint value. The magnitude of this reduction is related to the predicted over-temperature time point Idx1 or Idx2 and the coefficients Const3, Const4 or Const5, Const6. Generally, the earlier the over-temperature occurs or the higher the risk level, the greater the reduction. Const4 and Const6 represent the minimum current reduction at the corresponding risk level.

[0151] The adjustment amount ΔI is calculated using the above formula. lim In each control cycle, it is used to update the total motor current constraint value I. lim The current constraint value I lim It can be limited to a reasonable range, that is, not lower than the minimum current value required to maintain the basic function of the motor, and not higher than the maximum physical current value that the motor or drive system can withstand. Ultimately, the dynamically adjusted current constraint value I lim The current circle used to limit permanent magnet synchronous motors satisfies:

[0152]

[0153] Among them, I d I represents the d-axis current amplitude. q This represents the q-axis current amplitude.

[0154] By using the dynamic current constraint adjustment method based on future temperature prediction and risk level assessment, this application can maximize the motor's performance by allowing the motor to output a larger current while ensuring that the motor does not overheat.

[0155] The following are combined with Figure 2 , Figure 3 and Figure 4 Several exemplary control flows of the permanent magnet synchronous motor temperature rise control method provided in this application will be described separately.

[0156] Figure 2 This is a schematic diagram of a motor temperature prediction process according to an exemplary embodiment of this application. Figure 2 As shown, in step 201, the prediction time and step size are first set. The initial time step k = 0. Next, proceed to step 202 to predict the motor temperature for the next time step. In step 203, the predicted motor temperature and intermediate temperature variables are stored in the storage unit. Step 4, determine if the prediction time has ended. If so, proceed to step 205 and output the motor temperature prediction result, i.e., the predicted motor temperature sequence within the prediction time. If the prediction time has not ended, the current step size is incremented by 1, i.e., k = k + 1, and the process returns to step 202 until the prediction time ends.

[0157] Figure 3 This is a schematic diagram of a motor overheating risk level determination process according to an exemplary embodiment of this application, used to process the obtained predicted motor temperature sequence. Figure 3 As shown, after the process starts, the kth temperature data is read first, that is, a predicted motor temperature is read from the predicted motor temperature sequence. Then, the predicted motor temperature is compared with a preset threshold 1 (e.g., an overheat threshold).

[0158] If the judgment result is negative, meaning the predicted motor temperature is not greater than the threshold 1, then it further checks whether the end of the data has been reached. If the end has not been reached, the current time step is incremented by 1, i.e., k = k + 1, and the next predicted motor temperature in the predicted motor temperature sequence is read, and the above judgment is executed again. If the end of the data has been reached, meaning that after traversing the predicted motor temperature sequence within the prediction time, it is determined that all predicted temperatures have not exceeded the threshold 1, then the overheating risk level 0 is output, indicating a low overheating risk.

[0159] If the predicted motor temperature is greater than the preset threshold 1, the current data sequence number is recorded as Idx1. Next, it is further determined whether the predicted motor temperature is greater than the threshold 2 (e.g., the severe overheating threshold).

[0160] If the predicted motor temperature is also greater than the threshold 2, then record the current data sequence number as Idx2 and execute the operation of outputting overheat risk level 2, indicating a high overheat risk.

[0161] If the predicted motor temperature is not greater than threshold 2, then it is determined whether the end of the data has been reached. If the end has not been reached, the current time step is incremented by 1, i.e., k = k + 1, and the next predicted motor temperature in the predicted motor temperature sequence is read and compared with threshold 2, until a predicted motor temperature greater than threshold 2 is found and an overheating risk level of 2 is output. Alternatively, if no predicted motor temperature greater than threshold 2 is found until the end of the data is reached, an overheating risk level of 1 is output, indicating a moderate overheating risk.

[0162] This process involves performing two-level threshold judgments on each data point in the predicted motor temperature sequence, and recording the corresponding data sequence number based on the first occurrence of a specific threshold, ultimately obtaining the overheating risk level of the predicted motor temperature sequence within the prediction time.

[0163] Figure 4 This is a schematic diagram illustrating the process of calculating and adjusting the motor current constraint value according to an exemplary embodiment of this application. Figure 4 As shown, after the process begins, the existing current constraint value of the motor is first read. Next, branching processing is performed based on the input overheat risk level. If the overheat risk level is level 0 (low overheat risk), the motor current constraint value is increased. If the overheat risk level is level 1 (medium overheat risk) or level 2 (high overheat risk), the motor current constraint value is decreased. After either the increase or decrease operation is completed, the newly calculated motor current constraint value is stored for use by the motor control system in the next control cycle. This process is executed within each overheat protection calculation cycle, achieving dynamic constraint on the motor current through successive adjustments.

[0164] Figure 5 This is a schematic diagram of a permanent magnet synchronous motor temperature rise control device 500 provided in one embodiment of this application. This device can be applied to applications requiring precise temperature rise control of the permanent magnet synchronous motor, such as electric power steering (EPS) systems, steer-by-wire systems, brake-by-wire systems, or electric drive systems.

[0165] like Figure 5 As shown, the permanent magnet synchronous motor temperature rise control device 500 mainly includes a sensor unit 502, a computing unit 503, a power unit 504, a storage unit 505, and optionally, a power supply unit 501 and a communication unit 506.

[0166] The power supply unit 501 is used to provide a stable and suitable power supply for the other units of the permanent magnet synchronous motor temperature rise control device 500. For example, in automotive applications, the power supply unit 501 can convert the vehicle power supply (such as 12V or 24V DC power) into the low-voltage operating power (such as 5V, 3.3V, 1.2V, etc.) required by the various electronic components (such as computing units, sensors, etc.) within the device 500.

[0167] Sensor unit 502 is used to acquire the current operating parameters of the permanent magnet synchronous motor, which are the basis for performing temperature rise prediction and control decisions. Sensor unit 502 can be configured to acquire the current motor temperature T using a temperature sensor (such as a thermistor, PTC, NTC element, etc.) integrated inside or on the surface of the motor. m The effective or instantaneous value of the motor phase current is monitored in real time by using a current sensor built into the motor controller (such as a Hall sensor, a shunt in conjunction with a sampling circuit) to obtain the motor current I. s The ambient temperature T is obtained by using temperature sensors installed in the environment where the device is located or at locations that represent the motor's operating environment. e .

[0168] In addition, the sensor unit 502 can also acquire other parameters related to motor operation as needed, such as motor speed and bus voltage. These parameters may also be used as auxiliary inputs for the motor temperature rise model or for more precise control.

[0169] The sensor unit 502 transmits the collected current operating parameter data to the computing unit 503 for processing.

[0170] The computing unit 503 is typically composed of a microcontroller (MCU), digital signal processor (DSP), or application-specific integrated circuit (ASIC). It is connected to the sensor unit 502 and the storage unit 505, and is configured to: predict the temperature change trend of the motor within a predicted future timeframe based on current operating parameters and a pre-established motor temperature rise model, to obtain a predicted motor temperature sequence; determine the motor's overheating risk level based on the predicted motor temperature sequence; and dynamically calculate and generate the motor's current constraint value based on the overheating risk level. Specific implementation details can be found in the relevant descriptions above and will not be repeated here.

[0171] The power unit 504 is the final actuator for the motor current; it can be part of a motor controller, such as an inverter and its drive circuit. The power unit 504 is connected to the calculation unit 503 and receives the dynamically adjusted current constraint value I generated by the calculation unit 503. lim The power unit 504 limits the actual output current of the permanent magnet synchronous motor based on this current constraint value, ensuring that the actual operating current of the motor does not exceed the I given by the calculation unit 503.lim This achieves the purpose of controlling motor heat generation and preventing overheating.

[0172] Storage unit 505 is used to store various data and programs required for the operation of this device. The stored content may include: temporary values ​​of current operating parameters collected by sensor unit 502, program code for temperature rise control algorithm executed by calculation unit 503, structure and parameters of pre-established motor temperature rise model, and temperature threshold T used to determine the overheat risk level. th1 T th2 The coefficients Const1 to Const6 used to calculate the current adjustment; intermediate data generated during the calculation process, such as the predicted motor temperature sequence, intermediate temperature variables, recorded Idx1 and Idx2 values, and the currently determined overheat risk level; and the dynamically adjusted motor current constraint value I. lim wait.

[0173] The communication unit 506 is responsible for data exchange between the various units within the device 500 and between the device 500 and external systems. Internal communication may include the sensor unit 502 transmitting data to the computing unit 503, the computing unit 503 transmitting instructions (such as current constraint values) to the power unit 504, and data reading and writing between the computing unit 503 and the storage unit 505. External communication may include communication between the permanent magnet synchronous motor temperature rise control device 500 proposed in this application and other control units of the vehicle (such as the vehicle control unit, body control module, etc.) or diagnostic equipment to receive external instructions (such as operating mode switching), report motor status or fault information, or perform parameter calibration and software upgrades.

[0174] Through the coordinated operation of the above-mentioned units, the permanent magnet synchronous motor temperature rise control device provided in the embodiments of this application can effectively execute the aforementioned temperature rise control method, realize accurate prediction and active management of motor temperature, thereby ensuring the safe operation of the motor while optimizing its performance.

[0175] In one implementation, such as Figure 6 As shown, when the car is stationary, the driver rapidly rotates the steering wheel back and forth, assuming an amplitude of 300° and a frequency of 0.3Hz. The motor's threshold 1 (overheat threshold) is set to 95℃, and threshold 2 (severe overheat threshold) is set to 125℃. First, the motor's current constraint is set to 150A, at which point the driver can easily operate the steering wheel and the steering is quick. During the driver's steering operation, step 1 uses a thermocouple installed in the motor to monitor the motor's temperature in real time.

[0176] When the heat generated per unit time during motor operation exceeds the heat dissipation, the motor temperature T m The temperature increases; conversely, when the motor's heat dissipation rate is higher than its heat generation rate, the motor temperature T increases. mThen it decreases. In the initial stage of operation, due to the large current, the motor temperature rises rapidly. After temperature rise control begins, the motor temperature T... m Eventually, a dynamic equilibrium point is reached where the heat generation power equals the heat dissipation power, and the temperature response eventually converges. Initial ambient temperature T e At a temperature of 30℃, when the motor runs continuously at a maximum current of 150A for 60 seconds, the motor temperature T... m The temperature rises rapidly, then triggers temperature rise control; motor temperature T m The rate of increase gradually decreases, and the motor temperature T m Finally, it can be stabilized at 95℃.

[0177] After obtaining the predicted motor temperature, step 3 compares the predicted temperature with the temperature threshold, such as... Figure 5 As shown. Before 60 seconds, the predicted temperature is below threshold 1, at which point step 3 outputs an overheating risk level of 0. From 60 to 100 seconds, the predicted temperature is mostly above threshold 1 but below threshold 2. During this period, step 3 outputs an overheating risk level of 1 for most of the time and an overheating risk level of 0 for a small portion of the time, resulting in an overall value of 1. After 100 seconds, the predicted temperature returns to near threshold 1, fluctuating up and down. At this point, step 3 frequently switches between overheating risk levels 0 and 1.

[0178] After obtaining the overheating risk level, step 4 dynamically adjusts the motor current constraint value. For example... Figure 6 As shown, before 60 seconds, the overheating risk level is 0, so the motor current constraint value is maintained at 150A during this stage. Between 60 and 100 seconds, the overheating risk level is 1 overall, at which point step 4 gradually reduces the motor current constraint value from... Figure 6 As can be seen, the motor constraint value gradually decreases, eventually reaching approximately 110A. After 100 seconds, the overheat risk level frequently switches between 0 and 1. Step 4 involves frequently increasing and decreasing the motor current limit around 110A, and the actual motor current also remains around 110A. Ultimately, in this embodiment, the motor temperature T... m As the current stabilizes, the motor temperature remains below the temperature threshold (threshold 1).

[0179] This invention also provides an electronic device, comprising:

[0180] Memory, on which computer programs / instructions are stored;

[0181] The processor is used to execute computer programs / instructions in memory to implement the steps of the aforementioned permanent magnet synchronous motor temperature rise control method.

[0182] This invention also provides a computer-readable storage medium storing a computer program / instructions thereon, which, when executed by a processor, implements the steps of the aforementioned permanent magnet synchronous motor temperature rise control method.

[0183] This invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the aforementioned permanent magnet synchronous motor temperature rise control method.

[0184] The present invention also provides a vehicle, including the aforementioned electronic device, or the aforementioned computer-readable storage medium, or the aforementioned permanent magnet synchronous motor temperature rise control device.

[0185] For the above-described embodiments of the permanent magnet synchronous motor temperature rise control device, electronic device, computer-readable storage medium, and computer program, the steps used to implement the aforementioned permanent magnet synchronous motor temperature rise control method and achieve the same technical effect are not repeated here to avoid repetition. For relevant details, please refer to the description of the embodiments of the permanent magnet synchronous motor temperature rise control method.

[0186] For the above vehicle embodiments, it includes the aforementioned permanent magnet synchronous motor temperature rise control device, electronic device, and computer-readable storage medium, and can achieve the same technical effect. To avoid repetition, it will not be described again here. For relevant details, please refer to the description of the permanent magnet synchronous motor temperature rise control method embodiments.

[0187] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any invention or the scope of the claims, but rather are primarily intended to describe features of specific embodiments of a particular invention. Certain features described in the various embodiments herein may also be implemented in combination in a single embodiment. Conversely, various features described in a single embodiment may also be implemented separately in various embodiments or in any suitable sub-combination. Furthermore, while features may function in certain combinations as described above and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and a claimed combination may refer to a sub-combination or a variation thereof.

[0188] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or requiring all illustrated operations to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system modules and components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0189] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings are not necessarily shown in a specific order or sequence to achieve the desired result. In some implementations, multitasking and parallel processing may be advantageous.

[0190] The above description is merely a preferred embodiment of one or more embodiments of this specification and is not intended to limit the scope of one or more embodiments of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification should be included within the protection scope of one or more embodiments of this specification.

Claims

1. A method for controlling the temperature rise of a permanent magnet synchronous motor, characterized in that, When the motor temperature is lower than the temperature threshold, and the difference between the motor temperature and the temperature threshold is less than a preset difference, the current constraint value of the motor is reduced to control the motor temperature to not exceed the temperature threshold.

2. The method according to claim 1, characterized in that, The preset difference is determined based on the current motor current and / or the historical temperature change rate of the motor.

3. The method according to claim 2, characterized in that, The higher the current motor current, the larger the preset difference; and / or, the greater the historical temperature change rate of the motor, the larger the preset difference.

4. The method according to claim 1, characterized in that, The preset difference is greater than 20°C.

5. The method according to claim 1, characterized in that, The step of reducing the current constraint value of the motor to control the motor temperature to not exceed the temperature threshold includes: The current operating parameters of the motor are obtained, including at least the current motor temperature, motor current, and ambient temperature. Based on the current operating parameters, the current constraint value of the motor is dynamically adjusted.

6. The method according to claim 5, characterized in that, Based on the current operating parameters, dynamically adjust the current constraint value of the motor, including: Based on the current operating parameters and the pre-established motor temperature rise model, the temperature change trend of the motor in the future prediction time is predicted to obtain the future predicted motor temperature sequence. Based on the predicted motor temperature sequence, the overheating risk level of the motor is determined; The current constraint value of the motor is dynamically adjusted according to the overheating risk level.

7. The method according to claim 6, characterized in that, Predicting the temperature change trend of the motor over a future predicted time period includes: Set the forecast time and forecast step size; An iterative calculation method is used to predict the motor temperature for the next time step based on the current motor current, ambient temperature, and motor temperature at the current time step, combined with the motor temperature rise model, until the prediction time ends, thus forming the predicted motor temperature sequence.

8. The method according to claim 7, characterized in that, The iterative calculation includes: In the previous time step, the predicted motor temperature for the next time step was calculated using the following formula: Where k is the time step within the prediction time, and T p[k+1] For the predicted motor temperature at the next time step, when k = 0, the initial step T... p[0] To obtain the current motor temperature, when k > 0, T p[k] I is the motor temperature predicted in the previous time step iteration. s R is the current of the motor. s C1 represents the motor phase resistance parameter in the motor temperature rise model, and R represents the parameter related to the first thermal capacitor in the motor temperature rise model. 13 The thermal resistance related to heat conduction between the first and second thermal capacitors in the motor temperature rise model is given by T, where Δt is the prediction step size. c[k] The intermediate temperature variable is determined according to the following formula: Where k is the time step within the prediction time, and when k = 0, the initial step T is... c[0] C3 represents the current temperature of the motor controller or the motor casing temperature, and R represents the relevant parameter of the second thermal capacitor in the motor temperature rise model. 3e T is the thermal resistance related to heat conduction between the second thermal capacitor and the environment in the motor temperature rise model. e This represents the current ambient temperature.

9. The method according to claim 8, characterized in that, The method further includes obtaining the parameters of the motor temperature rise model through the following methods: The motor is controlled to run within a preset speed and torque range for a specified first duration, and during the operation and for a specified second duration after the motor stops running, the motor temperature, motor current and ambient temperature are continuously and synchronously collected. The phase resistance of the motor was measured using an electrical parameter measuring instrument; Based on motor current, ambient temperature, motor temperature, and motor phase resistance, and using a preset transfer function, other parameters of the motor temperature rise model are identified, including parameters C1 and C3 related to heat capacity and parameter R related to thermal resistance. 13 R 3e .

10. The method according to claim 6, characterized in that, Determining the overheating risk level of the motor includes: Multiple temperature thresholds are set, including an overheating threshold and a severe overheating threshold, wherein the overheating threshold is lower than the severe overheating threshold; Each predicted motor temperature in the predicted motor temperature sequence is compared with the plurality of temperature thresholds: If the predicted motor temperature does not exceed the overheating threshold, it is determined to be a low overheating risk level. If there are predicted motor temperatures exceeding the overheating threshold, but none exceeding the severe overheating threshold, the motor is classified as having a medium overheating risk level. If the predicted motor temperature exceeds the severe overheating threshold, it is determined to be at a high overheating risk level.

11. The method according to claim 6, characterized in that, Based on the overheating risk level, the current constraint value of the motor is dynamically adjusted, including: When the overheating risk level is low, the current constraint value of the motor is gradually increased; When the overheating risk level is medium or high, the current constraint value of the motor is gradually reduced.

12. The method according to claim 11, characterized in that, The method further includes: When gradually increasing or decreasing the current constraint value of the motor, the adjustment amount ΔI of the current constraint value is calculated according to the following formula. lim : Among them, risk levels 0, 1, and 2 correspond to low overheat risk, medium overheat risk, and high overheat risk, respectively. th1 For the overheating threshold, T p To predict the motor temperature sequence, Idx1 represents the predicted motor temperature sequence T. p The data sequence number in the prediction that the motor temperature first exceeds the overheat threshold, Idx2 is the predicted motor temperature sequence T. p The data sequence number when the predicted motor temperature first exceeds the severe overheating threshold is used, and Const1, Const2, Const3, Const4, Const5, and Const6 are preset coefficients.

13. The method according to claim 1, characterized in that, The motor is used in electric power steering (EPS) systems, steer-by-wire systems, brake-by-wire systems, or electric drive systems.

14. A temperature rise control device for a permanent magnet synchronous motor, characterized in that, include: A sensor unit is used to acquire the current operating parameters of the motor, which include at least the current motor temperature, motor current, and ambient temperature. The computing unit, connected to the sensor unit, is configured as follows: Based on the current operating parameters and the pre-established motor temperature rise model, the temperature change trend of the motor in the future prediction time is predicted to obtain the future predicted motor temperature sequence. Based on the predicted motor temperature sequence, the overheating risk level of the motor is determined; Based on the overheating risk level, the current constraint value of the motor is dynamically calculated and generated; A power unit, connected to the computing unit, is used to constrain the current of the motor according to the current constraint value generated by the computing unit; The storage unit is used to store the current operating parameters, the parameters of the motor temperature rise model, the predicted motor temperature sequence, and the current constraint value.

15. The apparatus according to claim 14, characterized in that, When predicting the temperature change trend, the calculation unit is configured to use an iterative calculation method to predict the motor temperature for the next time step in the previous time step of the prediction time using the following formula: Where k is the time step within the prediction time, and T p[k+1] For the predicted motor temperature at the next time step, when k = 0, the initial step T... p[0] To obtain the current motor temperature, when k > 0, T p[k] The initial step T is the motor temperature predicted in the previous time step iteration. p[0] To obtain the current motor temperature, I s To obtain the motor current, R s Here, C1 represents the motor phase resistance parameter of the motor temperature rise model, and R represents the first thermal capacitance related parameter of the motor temperature rise model. 13 The thermal resistance related to heat conduction between the first and second thermal capacitors in the motor temperature rise model is given by Δt, where Δt is the preset prediction step size, and T is the thermal resistance. c[k] The intermediate temperature is determined according to the following formula: Where k is the time step within the prediction time, and when k = 0, the initial step T is... c[0] To obtain the current temperature of the motor controller or the motor housing temperature, C3 is the second thermal capacitance related parameter of the motor temperature rise model, and R... 3e For the thermal resistance related to the thermal conduction between the second thermal capacitor and the environment, T e The ambient temperature was obtained.

16. The apparatus according to claim 15, characterized in that, The calculation unit is also configured to acquire and determine the parameters C1, C3, and R of the motor temperature rise model by the following methods. 13 R 3e : The motor is controlled to run within a preset speed and torque range for a specified first duration, and during the operation and for a specified second duration after the motor stops running, the sensor unit is instructed to continuously and synchronously collect motor temperature, motor current and ambient temperature. The phase resistance of the motor was measured using an electrical parameter measuring instrument. Based on motor current, ambient temperature, motor temperature, and motor phase resistance, and using a preset transfer function, other parameters of the motor temperature rise model are identified, including heat capacity-related parameters C1 and C3, and thermal resistance-related parameter R. 13 R 3e ; The acquired and identified model parameters are then stored in the storage unit.

17. The apparatus according to claim 14, characterized in that, When the calculation unit performs the tasks of determining the overheating risk level and dynamically calculating and generating the current constraint value based on the overheating risk level, it is configured to: Based on a preset set of multiple temperature thresholds, including an overheating threshold and a severe overheating threshold higher than the overheating threshold, each predicted motor temperature in the predicted motor temperature sequence is compared with the multiple temperature thresholds to determine whether the overheating risk level is a low overheating risk level, a medium overheating risk level, or a high overheating risk level. When the overheating risk level is low, the current constraint value of the motor is gradually increased; When the overheating risk level is medium or high, the current constraint value of the motor is gradually reduced; When gradually increasing or decreasing the current constraint value of the motor, the adjustment amount ΔI of the current constraint value is calculated according to the following formula. lim : Among them, risk levels 0, 1, and 2 correspond to low overheat risk, medium overheat risk, and high overheat risk, respectively. th1 For the overheating threshold, T p To predict the motor temperature sequence, Idx1 represents the predicted temperature T in the predicted motor temperature sequence. p The data sequence number when the value first exceeds the overheat threshold, where Idx2 is the predicted motor temperature sequence T. p The data sequence number when the predicted motor temperature first exceeds the severe overheating threshold is used, and Const1 to Const6 are preset coefficients.

18. The apparatus according to claim 14, characterized in that, The device further includes: A power supply unit is used to supply power to the sensor unit, the computing unit, the power unit, and the storage unit; The communication unit is used for data transmission between the sensor unit, the computing unit, the power unit, and the storage unit, as well as for data transmission between the device and an external system.

19. An electronic device, characterized in that, include: Memory, on which computer programs / instructions are stored; A processor is configured to execute the computer program / instructions in the memory to implement the steps of the permanent magnet synchronous motor temperature rise control method according to any one of claims 1-13.

20. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the permanent magnet synchronous motor temperature rise control method according to any one of claims 1-13.

21. A computer program product, comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the permanent magnet synchronous motor temperature rise control method according to any one of claims 1-13.

22. A vehicle, characterized in that, The vehicle includes the electronic device as claimed in claim 19, or the computer-readable storage medium as claimed in claim 20, or the permanent magnet synchronous motor temperature rise control device as claimed in claims 14 to 18.

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