Control method and device of permanent magnet synchronous motor and motor control system

Abstract

The invention relates to a control method and device of a permanent magnet synchronous motor and a motor control system, motor parameter identification and winding temperature prediction form bidirectional closed-loop control, and real-time identification parameters are obtained according to real-time electrical parameters and temperature prediction values of the permanent magnet synchronous motor. The method fully considers the change of the real-time identification parameter of the motor caused by temperature rise, improves the parameter identification precision, further corrects the temperature prediction value according to the real-time identification parameter, and improves the accuracy of the temperature prediction data. Besides, the accuracy of the temperature prediction data is improved, the current control parameter of the permanent magnet synchronous motor obtained according to the temperature prediction data is more accurate, and the torque current of the permanent magnet synchronous motor is controlled according to the current control parameter, so that insulation failure of a motor winding caused by overheating of the motor can be avoided, and the reliability of the motor is improved. And moreover, the performance loss caused by premature derating of the motor can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor control, and in particular to a control method and device of a permanent magnet synchronous motor and a motor control system. BACKGROUND

[0002] In the operation process of the permanent magnet synchronous motor, the temperature of the motor needs to be monitored in real time, so as to make corresponding control strategy according to the motor temperature, to avoid the problems such as motor winding insulation failure and permanent demagnetization of permanent magnet caused by overheat of the motor due to high temperature rise of the motor. However, the current online monitoring method of motor winding temperature usually relies on stable motor parameters, resulting in inaccurate temperature detection value, and further affecting the control accuracy of motor current limit value. SUMMARY

[0003] Therefore, it is necessary to provide a control method and device of a permanent magnet synchronous motor and a motor control system.

[0004] In a first aspect, the present application provides a control method of a permanent magnet synchronous motor, comprising:

[0005] According to the input real-time electrical parameters and temperature prediction value of the permanent magnet synchronous motor, real-time identification parameters of the permanent magnet synchronous motor are obtained; the real-time identification parameters include resistance identification parameters, back electromotive force parameters and inductance identification parameters;

[0006] According to the real-time electrical parameters, the resistance identification parameters and the inductance identification parameters, temperature prediction data of the stator winding of the permanent magnet synchronous motor are obtained; the temperature prediction data at least includes the temperature prediction value;

[0007] At least according to the temperature prediction data, the current control parameters of the permanent magnet synchronous motor are output.

[0008] In one embodiment, according to the input real-time electrical parameters and temperature prediction value of the permanent magnet synchronous motor, the real-time identification parameters of the permanent magnet synchronous motor are obtained, comprising:

[0009] According to the temperature prediction value and the initialization parameters, temperature drift compensation processing is performed to obtain motor identification parameters after temperature drift compensation;

[0010] According to the motor identification parameters and the real-time electrical parameters, error compensation processing is performed to obtain the real-time identification parameters.

[0011] In one embodiment, the initialization parameters include initial resistance parameters, initial inductance parameters and initial back electromotive force constant; and the temperature drift compensation processing according to the temperature prediction value and the initialization parameters to obtain the motor identification parameters, comprising:

[0012] determining a temperature compensation value according to the temperature prediction value and the initial temperature value;

[0013] obtaining the motor identification parameter according to the temperature compensation value, the initial resistance parameter, the initial inductance parameter, the initial back electromotive force constant and a preset temperature drift coefficient; wherein the resistance identification parameter in the motor identification parameter is positively correlated with the initial resistance parameter, the inductance identification parameter is positively correlated with the initial inductance parameter, and the back electromotive force parameter is positively correlated with the initial back electromotive force constant.

[0014] In one of the embodiments, the real-time electric parameters at least include real-time torque voltage, real-time current and motor speed; error compensation processing is performed according to the motor identification parameter and the real-time electric parameters to obtain the real-time identification parameter, including:

[0015] obtaining a torque voltage prediction value according to the motor identification parameter, the real-time current and the motor speed;

[0016] obtaining an error compensation value according to the torque voltage prediction value and the real-time torque voltage;

[0017] obtaining the real-time identification parameter according to the error compensation value and a preset parameter identification model.

[0018] In one of the embodiments, the current control parameter at least includes a first current threshold; and outputting the current control parameter of the permanent magnet synchronous motor at least according to the temperature prediction data, including:

[0019] obtaining a torque current limiting parameter;

[0020] obtaining the first current threshold according to the torque current limiting parameter and the temperature prediction value in the temperature prediction data; the first current threshold is negatively correlated with the temperature prediction value.

[0021] In one of the embodiments, the current control parameter further includes a second current threshold, and the second current threshold and the first current threshold are respectively used to represent the upper limit value of the torque current of the permanent magnet synchronous motor;

[0022] outputting the current control parameter of the permanent magnet synchronous motor at least according to the temperature prediction data, further including:

[0023] obtaining the second current threshold according to the temperature change rate in the temperature prediction data; the second current threshold is exponentially related to the temperature change rate.

[0024] In one of the embodiments, the real-time electric parameters at least include bus voltage and motor speed;

[0025] The current control parameter further comprises a third current threshold value, the third current threshold value being used to represent an upper limit value of the excitation current of the permanent magnet synchronous motor;

[0026] The method further comprises:

[0027] The third current threshold value is obtained according to the inductance identification parameter, the back electromotive force parameter, the bus voltage and the motor speed.

[0028] In one of the embodiments, the temperature prediction data of the stator winding of the permanent magnet synchronous motor is obtained according to the real-time electrical parameter, the resistance identification parameter and the inductance identification parameter, comprising:

[0029] The copper loss power is obtained according to the real-time torque current and the real-time excitation current in the real-time electrical parameter and the resistance identification parameter; and / or,

[0030] The iron loss power is obtained according to the inductance identification parameter, the motor speed and the real-time excitation current in the real-time electrical parameter, and a preset iron loss coefficient; and / or,

[0031] The convection heat dissipation power is obtained according to the preset heat dissipation coefficient and the collected winding temperature and ambient temperature;

[0032] The temperature prediction data is obtained according to at least one of the copper loss power, the iron loss power and the convection heat dissipation power.

[0033] In a second aspect, the application further provides a control device of a permanent magnet synchronous motor, comprising: a temperature prediction module, a parameter identification module and a control module;

[0034] The parameter identification module is connected with the temperature prediction module, and the parameter identification module is used to output real-time identification parameters of the permanent magnet synchronous motor according to input real-time electrical parameters of the permanent magnet synchronous motor and a temperature prediction value output by the temperature prediction data; the real-time identification parameters comprise resistance identification parameters, back electromotive force parameters and inductance identification parameters;

[0035] The temperature prediction module is used to output temperature prediction data of the stator winding of the permanent magnet synchronous motor according to input real-time electrical parameters, resistance identification parameters and inductance identification parameters; the temperature prediction data at least comprises a temperature prediction value;

[0036] The control module is connected with the temperature prediction module and the parameter identification module respectively, and the control module is used to output current control parameters of the permanent magnet synchronous motor according to at least the temperature prediction data.

[0037] In a third aspect, the application further provides a motor control system, which comprises a permanent magnet synchronous motor and the control device of the permanent magnet synchronous motor according to any one of the above embodiments.

[0038] In the application, the real-time identification parameters of the permanent magnet synchronous motor are obtained according to the input real-time electrical parameters and temperature prediction values of the permanent magnet synchronous motor, and the temperature prediction data of the stator winding of the permanent magnet synchronous motor are obtained according to the real-time electrical parameters, the resistance identification parameters and the inductance identification parameters, so that the winding temperature is monitored by using a software algorithm, without the need to set a hardware structure such as a temperature sensor, thereby reducing the manufacturing cost of the permanent magnet synchronous motor. Moreover, the motor parameter identification and the winding temperature prediction form a bidirectional closed-loop control, on the one hand, the real-time identification parameters are obtained according to the real-time electrical parameters and the temperature prediction values of the permanent magnet synchronous motor, so that the change of the real-time identification parameters of the motor caused by the temperature rise is fully considered, thereby improving the parameter identification accuracy, on the other hand, the temperature prediction values are corrected according to the real-time identification parameters, thereby improving the accuracy of the temperature prediction data. In addition, since the accuracy of the temperature prediction data is improved, the current control parameters of the permanent magnet synchronous motor obtained according to the temperature prediction data are also more accurate, so that the dynamic and accurate control of the current of the permanent magnet synchronous motor according to the current control parameters can be realized, thereby improving the thermal protection performance of the permanent magnet synchronous motor, which can not only avoid the problems such as winding insulation failure and permanent demagnetization of the permanent magnet caused by overheating of the motor, but also reduce the performance loss caused by premature derating of the motor, thereby improving the performance of the motor. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0040] Figure 1 a structural block diagram of the control device of the permanent magnet synchronous motor according to an embodiment;

[0041] Figure 2 a data interaction diagram of each module in the control device of the permanent magnet synchronous motor according to an embodiment;

[0042] Figure 3 a flowchart of the control method of the permanent magnet synchronous motor according to an embodiment;

[0043] Figure 4 a flowchart of step S302 in the control method of the permanent magnet synchronous motor according to an embodiment;

[0044] Figure 5A flowchart of step S306 in a control method for a permanent magnet synchronous motor provided in one embodiment;

[0045] Figure 6 A flowchart of step S304 in a control method for a permanent magnet synchronous motor provided in one embodiment;

[0046] Figure 7 A flowchart of a control method for a permanent magnet synchronous motor provided in a more specific embodiment;

[0047] Figure 8 A timing diagram of each module in the control device of a permanent magnet synchronous motor provided in one embodiment;

[0048] Figure 9 An internal block diagram of a motor controller provided in one embodiment. Detailed Implementation

[0049] The 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 represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0050] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0051] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0052] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0053] The term "module" refers to any known or subsequently developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code that is capable of performing the functions associated with that element.

[0054] The field-oriented control (FOC) system of a permanent magnet synchronous motor (PMSM) transforms the three-phase current of the motor from the rotating coordinate system to the dq coordinate system, obtaining two mutually perpendicular decoupled components: the excitation current (also known as the direct-axis current) and the torque current (also known as the quadrature-axis current). The rotor flux linkage of the motor is controlled by adjusting the excitation current, and the electromagnetic torque is controlled by adjusting the torque current. Then, the adjusted excitation current and torque current are transformed back from the dq coordinate system to the rotating coordinate system, and the corresponding pulse width modulation signal is output by the space vector pulse width modulator (SVPWM) to the inverter. The inverter outputs the corresponding drive signal to the PMSM based on the pulse width modulation signal, thus realizing closed-loop control of the PMSM.

[0055] The control method for permanent magnet synchronous motors provided in this application embodiment can be applied to, for example... Figure 1 The control device for the permanent magnet synchronous motor shown is described. This control device can acquire real-time electrical parameters of the motor from the FOC system and output current control parameters to the FOC system, enabling the FOC system to more accurately limit the torque current and excitation current of the permanent magnet synchronous motor based on the current control parameters. This control device can be integrated into the FOC system or set up independently. The control method for the permanent magnet synchronous motor provided in this application is applicable to permanent magnet synchronous motor control systems with high reliability requirements, such as those used in new energy vehicle drive systems, industrial frequency converters, and smart home appliances (e.g., variable frequency air conditioning compressors).

[0056] In some exemplary embodiments, such as Figure 2As shown, the control device includes a parameter identification module 102, a temperature prediction module 104, and a control module 106. The data interaction process between the parameter identification module 102, the temperature prediction module 104, the control module 106, and the FOC system is as follows: The parameter identification module 102 obtains real-time electrical parameters from the FOC system and temperature prediction data from the temperature prediction module 104, and outputs real-time identification parameters to the temperature prediction module 104; the temperature prediction module 104 obtains real-time identification parameters after temperature drift compensation from the parameter identification module 102, and outputs temperature prediction data to the control module 106; the control module 106 outputs current control parameters to the FOC system based on the temperature prediction data; the FOC system limits the motor current based on the current control parameters, and the limited motor current acts on the permanent magnet synchronous motor through SVPWM and the inverter, reducing the motor output current, output torque, and output power, thereby suppressing temperature rise; after the temperature rise is suppressed, the temperature prediction data predicted by the temperature prediction module 104 decreases, and the current control parameters output by the control module 106 may increase accordingly, increasing the motor current limit, thereby realizing dynamic current closed-loop control of the permanent magnet synchronous motor.

[0057] In one embodiment, such as Figure 3 As shown, a control method for a permanent magnet synchronous motor is provided, which can be applied to applications such as... Figure 1 Taking the control device shown as an example, the method includes the following steps S302-S306.

[0058] S302: Based on the input real-time electrical parameters and temperature prediction values ​​of the permanent magnet synchronous motor, obtain the real-time identification parameters of the permanent magnet synchronous motor.

[0059] The real-time electrical parameters of the permanent magnet synchronous motor (PMSM) represent various electrical parameters during its operation. Optionally, these real-time electrical parameters may include at least one of the motor's real-time current, real-time voltage, motor speed, and bus voltage. The parameter identification module can be connected to measuring devices such as current meters and voltage meters. It measures the motor's real-time current using the current meter, and the motor's real-time voltage and bus voltage using the voltage meter. The motor speed is then estimated from the real-time current and bus voltage. Alternatively, real-time electrical parameters can be obtained through interaction with the field-oriented control system. The temperature prediction value is the stator winding temperature predicted by the temperature prediction module. The parameter identification module can obtain the temperature prediction value through interaction with the temperature prediction module.

[0060] Real-time identification parameters include resistance identification parameters, back electromotive force (EMF) parameters, and inductance identification parameters. Resistance identification parameters refer to the stator winding resistance value in a permanent magnet synchronous motor. Back EMF parameters refer to the amplitude of the back EMF generated in the stator winding when the rotor rotates at a certain speed. Inductance identification parameters refer to the direct-axis inductance value of the permanent magnet synchronous motor.

[0061] In permanent magnet synchronous motors, changes in winding temperature can cause drift in real-time identification parameters. For example, as winding temperature increases, winding resistance and inductance increase, while back electromotive force decreases. Therefore, the parameter identification module can correct the real-time identification parameters of the permanent magnet synchronous motor based on temperature predictions, and fine-tune the corrected parameters according to real-time electrical parameters to ensure that the corrected parameters are closer to the true values.

[0062] S304 obtains the temperature prediction data of the stator winding of the permanent magnet synchronous motor based on real-time electrical parameters, resistance identification parameters, and inductance identification parameters.

[0063] Among them, the temperature prediction data is used to represent the temperature of the stator winding at a future preset time, and the temperature prediction data includes at least the temperature prediction value.

[0064] The temperature prediction module can obtain predicted temperature data of the stator windings of a permanent magnet synchronous motor based on real-time electrical parameters, resistance identification parameters, and inductance identification parameters. The temperature prediction module can connect to measuring devices such as current meters and voltage meters. It measures the motor's real-time current using the current meter and the motor's real-time voltage and bus voltage using the voltage meter, and estimates the motor speed by analyzing the real-time current and bus voltage. Alternatively, it can obtain real-time electrical parameters through interaction with the field-oriented control system. Furthermore, the temperature prediction module can also obtain resistance and inductance identification parameters through interaction with the parameter identification module.

[0065] A thermal network model of a permanent magnet synchronous motor can be pre-built and stored in the temperature prediction module. By simulating the generation, conduction, and dissipation of heat within the motor, the thermal network model abstracts the complex physical structure of the permanent magnet synchronous motor into an equivalent circuit network composed of equivalent thermal capacity, equivalent thermal resistance, and heat sources (primarily the windings). The temperature prediction module can then input real-time electrical parameters, resistance identification parameters, and inductance identification parameters into this pre-built thermal network model and obtain temperature prediction data through circuit calculations.

[0066] S306 outputs current control parameters for the permanent magnet synchronous motor, based at least on temperature prediction data.

[0067] Current control parameters can be used to limit the current of a permanent magnet synchronous motor. The current control parameters may include at least one of the upper limit of torque current and the upper limit of excitation current.

[0068] The control module can output current control parameters for the permanent magnet synchronous motor based at least on temperature prediction data. For example, if the temperature prediction data exceeds a set temperature threshold, the control module can reduce the current control parameters, thereby decreasing the upper limit of the permanent magnet synchronous current and preventing overload of the motor. Optionally, if the temperature prediction data does not exceed the set temperature threshold, the control module can also keep the current control parameters unchanged, thereby maintaining the upper limit of the permanent magnet synchronous current at its rated value to reduce motor performance loss.

[0069] In addition, the control module can output current control parameters for the permanent magnet synchronous motor based on motor identification parameters, such as inductance identification parameters and back electromotive force (EMF) parameters. As the winding temperature increases, the winding inductance increases, and the back EMF parameter decreases. The excitation current of the permanent magnet synchronous motor is related to the winding inductance and back EMF parameters. If the excitation current exceeds a certain value, the motor may be at risk of demagnetization. Therefore, the control module can output current control parameters for the permanent magnet synchronous motor based on the inductance identification parameters and back EMF parameters to limit the excitation current and prevent demagnetization of the permanent magnets.

[0070] In this embodiment, real-time identification parameters of the permanent magnet synchronous motor (PMSM) are obtained based on the input real-time electrical parameters and temperature prediction values. Furthermore, temperature prediction data for the stator windings of the PMSM is obtained based on the real-time electrical parameters, resistance identification parameters, and inductance identification parameters. Software algorithms are used to monitor the winding temperature, eliminating the need for hardware structures such as temperature sensors and reducing the manufacturing cost of the PMSM. Moreover, the motor parameter identification and winding temperature prediction form a bidirectional closed-loop control. On one hand, real-time identification parameters are obtained based on the real-time electrical parameters and temperature prediction values, fully considering the changes in real-time identification parameters caused by temperature rise, thus improving parameter identification accuracy. On the other hand, the temperature prediction values ​​are corrected based on the real-time identification parameters, further improving the accuracy of the temperature prediction data. Furthermore, due to the improved accuracy of temperature prediction data, the current control parameters of the permanent magnet synchronous motor obtained from the temperature prediction data are also more accurate. This enables dynamic and precise control of the torque current of the permanent magnet synchronous motor based on these current control parameters. This can avoid motor failures such as winding insulation failure and permanent demagnetization of permanent magnets caused by motor overheating, and can also reduce performance losses caused by premature derating of the motor.

[0071] In one embodiment, such as Figure 4 As shown, based on the input real-time electrical parameters and temperature prediction values ​​of the permanent magnet synchronous motor, the real-time identification parameters of the permanent magnet synchronous motor are obtained, including the following S402-S404.

[0072] S402 performs temperature drift compensation based on the predicted temperature value and initialization parameters to obtain the motor identification parameters after temperature drift compensation.

[0073] The initialization parameters are the rated parameters of the motor at the factory. Initialization parameters may include initial resistance parameters, initial inductance parameters, and initial back electromotive force constant. Each initialization parameter corresponds one-to-one with the real-time identification parameters. Specifically, the initial resistance parameter is the real-time identification parameter before temperature drift compensation and error compensation processing; the initial back electromotive force constant is the back electromotive force parameter before temperature drift compensation and error compensation processing; and the initial inductance parameter is the inductance identification parameter before temperature drift compensation and error compensation processing.

[0074] It is understandable that changes in winding temperature will alter the stator winding resistance and direct-axis inductance of the permanent magnet synchronous motor. The parameter identification module can perform temperature drift compensation on the initialization parameters based on the temperature prediction value, correcting the changes in initial electrical parameters caused by winding temperature variations, and thus obtaining the motor identification parameters.

[0075] S404 performs error compensation processing based on motor identification parameters and real-time electrical parameters to obtain real-time identification parameters.

[0076] The real-time electrical parameters in this embodiment may include the real-time torque voltage, real-time torque current, and real-time excitation current of the permanent magnet synchronous motor. The parameter identification module can predict the torque voltage of the permanent magnet synchronous motor based on an improved extended Kalman filter algorithm, using the motor identification parameters obtained through software calculation, along with the real-time torque voltage and real-time excitation current. Then, the predicted torque voltage is compared with the real-time torque voltage, and the motor identification parameters are corrected based on the error between the two. This process is repeated multiple times to finally obtain real-time identification parameters that are closer to the true values.

[0077] In this embodiment, temperature drift compensation is first performed based on the predicted temperature value and initialization parameters to obtain the motor identification parameters after temperature drift compensation. Then, error compensation is performed based on the motor identification parameters and real-time electrical parameters to obtain the real-time identification parameters. This fully considers the influence of winding temperature changes on the resistance identification parameters, back electromotive force parameters, and inductance identification parameters, thereby improving the identification accuracy of the real-time identification parameters.

[0078] In some exemplary embodiments, S402 above may include the following S4022-S4024.

[0079] S4022, determine the temperature compensation value based on the predicted temperature value and the initial temperature value.

[0080] The initial temperature value is the winding temperature corresponding to the initialization parameters, typically 25℃. The parameter identification module can use the difference between the predicted temperature value and the initial temperature value as the temperature compensation value.

[0081] S4024: Based on the temperature compensation value, initial resistance parameter, initial inductance parameter, initial back EMF constant, and preset temperature drift coefficient, the motor identification parameters are obtained. Among these, the resistance identification parameter is positively correlated with the initial resistance parameter, the inductance identification parameter is positively correlated with the initial inductance parameter, and the back EMF parameter is positively correlated with the initial back EMF constant.

[0082] The preset temperature drift coefficients may include the copper resistance temperature drift coefficient, the back electromotive force temperature drift coefficient, and the inductance compensation coefficient. Among them, the copper resistance temperature drift coefficient can be used to correct the increase in stator resistance caused by winding heating, the back electromotive force temperature drift coefficient can be used to correct the demagnetization effect of permanent magnets caused by winding heating, and the inductance compensation coefficient can be used to correct the change in direct-axis inductance caused by the increase in winding temperature.

[0083] For example, the parameter identification module can calculate the motor identification parameters based on equation (1), according to the temperature compensation value, initial resistance parameter, initial inductance parameter, initial back electromotive force constant, and preset temperature drift coefficient.

[0084]

[0085] in, Indicates the initial resistance parameters; This indicates the resistance identification parameters after temperature drift compensation; Indicates the temperature drift coefficient of copper resistance, for example, This represents the temperature drift coefficient of copper resistance, which can be 0.0039 / ℃. Indicates the temperature compensation value; Indicates the initial back electromotive force parameter; This represents the back electromotive force parameter after temperature drift compensation. This represents the temperature drift coefficient of the back electromotive force, which, for example, can be -0.0012 / ℃; Indicates the initial inductance parameters; This indicates the inductance identification parameters after temperature drift compensation; This represents the inductor saturation compensation function, reflecting the correlation between the direct-axis current (or magnetizing current) and winding temperature with the direct-axis inductance: an increase in the direct-axis current leads to... Decreasing the winding temperature will lead to... Increasing the value can improve the real-time measurement of the direct-axis current. and temperature forecast Input the inductor saturation compensation function to obtain the corresponding inductor compensation coefficient.

[0086] In this embodiment, by determining the temperature compensation value based on the predicted temperature value and the initial temperature value, and by performing temperature drift compensation processing on the initial resistance parameter, initial inductance parameter, and initial back electromotive force constant based on the temperature compensation value and the preset temperature drift coefficient, the parameter identification error caused by temperature change is basically eliminated, making the real-time identification parameters finally output by the parameter identification module more accurate, thereby improving the accuracy of the temperature prediction data and current control parameters obtained from the motor identification parameters.

[0087] In some exemplary embodiments, S404 above may include the following S4042-S4046.

[0088] S4042 obtains the torque voltage prediction value based on the motor identification parameters, real-time current and motor speed.

[0089] Real-time current can include real-time direct-axis current and real-time quadrature-axis current. The parameter identification module can obtain the torque voltage prediction value based on equation (2), according to the motor identification parameters, real-time current and motor speed.

[0090]

[0091] in, This represents the predicted torque-voltage value; Indicates the real-time quadrature-axis current; This indicates the motor speed.

[0092] S4044 obtains the error compensation value based on the predicted torque voltage and the real-time torque voltage.

[0093] The parameter identification module can use equation (3) to identify the real-time torque voltage. Torque voltage prediction value The difference is used as the error compensation value. .

[0094]

[0095] S4046: Obtain real-time identification parameters based on the error compensation value and the preset parameter identification model.

[0096] The preset parameter identification model aims to minimize the absolute value of the error compensation value. It can adjust the real-time identification parameters based on the error compensation value. For example, if the error compensation value is positive, the model increases the motor identification parameters to increase the predicted torque and voltage values, thus decreasing the error compensation value. If the error compensation value is negative, the model decreases the motor compensation parameters to decrease the predicted torque and voltage values, thereby reducing the absolute value of the error compensation value. The parameter identification model repeats steps S3042-S3046 multiple times until the error compensation value falls within a preset range, and then outputs the motor identification parameters at this point as the real-time identification parameters. The preset range can be an interval centered at 0.

[0097] In this embodiment, the torque voltage prediction value is obtained based on the motor identification parameters, real-time current and motor speed. The error compensation value is obtained based on the torque voltage prediction value and real-time torque voltage. The real-time identification parameters are obtained based on the error compensation value and the preset parameter identification model, thereby realizing the dynamic and accurate updating of the real-time identification parameters.

[0098] In some exemplary embodiments, such as Figure 5 As shown, based at least on the temperature prediction data, the current control parameters of the permanent magnet synchronous motor are output, including the following S502-S504.

[0099] S502, obtain torque current limiting parameters.

[0100] The torque current limiting parameters include the rated torque current, the preset temperature threshold, and the first limiting coefficient. The rated torque current is the maximum torque current specified at the motor's factory. For example, the preset temperature threshold can be between 110℃ and 140℃, such as 110℃, 120℃, 130℃, or 140℃. The first limiting coefficient represents the rate of change of the upper limit of the torque current. The torque current limiting parameters can be pre-stored in the control module.

[0101] S504: Based on the torque current limiting parameter and the temperature prediction value in the temperature prediction data, obtain the first current threshold. The first current threshold is negatively correlated with the temperature prediction value.

[0102] The current control parameters include a first current threshold, which can be used to represent the upper limit of the torque current of the permanent magnet synchronous motor.

[0103] Torque current threshold Identification parameters related to winding temperature T and resistance and back electromotive force parameters The following constraints exist:

[0104]

[0105] in, Indicates the winding temperature limit; and Indicates weight, This indicates that the temperature margin is converted into the current margin. This represents the thermal resistance scaling factor. , Indicates ambient temperature. Indicates resistance temperature drift constraint; Indicates the torque coefficient. This indicates that the thermal constraint is mapped to the quadrature-axis current (or torque current). As an example, It can be 0.85. It can be 0.15. Therefore, the torque current threshold can be adjusted based on real-time identified parameters and temperature prediction values.

[0106] To simplify the computational complexity, the control module can obtain the first current threshold based on equation (5), according to the torque current limiting parameter and the temperature prediction value in the temperature prediction data.

[0107]

[0108] in, Indicates the first current threshold; Indicates the rated torque and current; Indicates the first limiting coefficient; This indicates the preset temperature threshold.

[0109] In this embodiment, by obtaining the torque current limiting parameter and dynamically adjusting the first current threshold based on the torque current limiting parameter and the temperature prediction value in the temperature prediction data, the first current threshold is reduced when the temperature prediction value exceeds the preset temperature threshold, which can avoid the problem of motor winding insulation failure due to motor overheating.

[0110] In some exemplary embodiments, the current control parameters of the permanent magnet synchronous motor are output based at least on temperature prediction data, and S506 is also included.

[0111] S506, based on the temperature change rate in the temperature prediction data, obtain the second current threshold; the second current threshold has an exponential relationship with the temperature change rate.

[0112] The current control parameters also include a second current threshold, which, along with the first current threshold, represents the upper limit of the torque current of the permanent magnet synchronous motor.

[0113] For example, the control module may obtain the second current threshold based on Equation (6) and the rate of temperature change in the temperature prediction data.

[0114]

[0115] in, Indicates the second current threshold; This represents the torque current threshold, and its value may be... or ; This represents the second limiting factor, as an example. The value can be 0.5, or any other suitable value; This represents the rate of temperature change.

[0116] The triggering conditions for S506 and S502 are different. S506 is executed only when the temperature change rate is greater than a preset change rate threshold. As an example, the preset change rate threshold can be 2℃ / s, or other suitable values. This embodiment does not impose any restrictions on this.

[0117] In this embodiment, when the rate of temperature change exceeds a preset threshold, a second current threshold is obtained based on the temperature change rate in the temperature prediction data. This allows for pre-derating of the torque current threshold, suppressing thermal inertia overshoot and preventing excessive instantaneous temperature rise in the windings due to response delay after temperature exceedance, thus avoiding damage to the permanent magnet synchronous motor. Compared to a consistently linear derating method, this application can shorten the response delay from 480ms to 120ms, significantly reducing temperature rise overshoot events and improving the stability and safety of the permanent magnet synchronous motor.

[0118] In some exemplary embodiments, the current control parameters of the permanent magnet synchronous motor are output based at least on temperature prediction data, and S508 is also included.

[0119] S508 obtains the third current threshold based on inductance identification parameters, back EMF parameters, bus voltage, and motor speed.

[0120] The current control parameters also include a third current threshold, which is used to represent the upper limit of the excitation current of the permanent magnet synchronous motor.

[0121] For example, the control module can identify parameters based on equation (7). Back electromotive force parameters Bus voltage and motor speed Obtain the third current threshold .

[0122]

[0123] In this embodiment, by obtaining the third current threshold based on the inductance identification parameters and back electromotive force parameters after temperature drift compensation, the risk of demagnetization of the permanent magnet synchronous motor can be reduced.

[0124] In some exemplary embodiments, such as Figure 6 As shown, based on real-time electrical parameters, resistance identification parameters, and inductance identification parameters, the temperature prediction data of the stator winding of the permanent magnet synchronous motor is obtained, including the following S602-S604.

[0125] S602 obtains at least one of copper loss power, iron loss power, and convective heat dissipation power based on real-time electrical parameters, resistance identification parameters, and inductance identification parameters.

[0126] For example, parameters can be identified based on resistance according to equation (8). With real-time torque current in real-time electrical parameters Real-time excitation current Obtain copper loss power .

[0127]

[0128] Based on equation (9), the inductance identification parameters can be determined. Motor speed in real-time electrical parameters and real-time excitation current and the preset iron loss coefficient and To obtain the iron loss power.

[0129]

[0130] Where B represents magnetic flux density, a parameter that can be identified through inductance. and real-time excitation current Calculated using nonlinear curve interpolation; This indicates hysteresis loss during washing. This represents the eddy current loss coefficient.

[0131] Based on equation (10), the convective heat dissipation power can be obtained according to the preset heat dissipation coefficient and the collected winding temperature and ambient temperature.

[0132]

[0133] in, Indicates convective heat dissipation power; Indicates the convective heat transfer coefficient; Indicates the heat dissipation surface area; The collected winding temperature can be obtained through a sensor or by resistance measurement. The ambient temperature can be derived by working backwards from the thermal conductivity model of the motor housing. The specific derivation process is as follows:

[0134] The shell thermal network equation can be constructed based on the copper loss power, iron loss power, convective heat dissipation power, shell equivalent thermal resistance, and shell equivalent heat capacity. The shell temperature prediction value can be obtained by solving the shell thermal network equation. When the thermal steady-state condition is met (for example, the shell temperature fluctuation is less than 0.1℃ / s for 5 consecutive days), the ambient temperature can be calculated by equation (11).

[0135]

[0136] in, This indicates the casing temperature, which is between the winding temperature and the ambient temperature. This represents the equivalent thermal resistance of the shell as determined experimentally. This represents the heat capacity compensation coefficient.

[0137] S604 obtains temperature prediction data based on at least one of copper loss power, iron loss power, and convective heat dissipation power.

[0138] The heat network equation can be constructed and solved based on at least one of the copper loss power, iron loss power, and convective heat dissipation power to obtain temperature prediction data. The heat network equation reflects the correlation between at least one of the copper loss power, iron loss power, and convective heat dissipation power and the rate of temperature change, as well as the temperature itself.

[0139] For example, this application can construct a winding thermal network equation including copper loss power, iron loss power and convective heat dissipation power, as shown in equation (12).

[0140]

[0141] in, The equivalent heat capacity of the casing can be obtained by fitting the casing temperature rise rate with the motor input power.

[0142] In this embodiment, by constructing and solving the winding thermal network equation, which includes copper loss power, iron loss power, and convective heat dissipation power, the temperature change rate and temperature prediction value are obtained. The thermal capacity and the spatial distribution differences of copper loss, iron loss, and heat dissipation path are taken into account. Furthermore, the copper loss power and iron loss power are updated in real time with the identification parameters, so that the error range of the temperature prediction data calculated based on the winding thermal network equation is within ±2.7℃. This improves the accuracy of the temperature prediction data, reduces the false trigger rate of overheat protection, and thus reduces the performance loss caused by premature derating of the motor.

[0143] In some exemplary embodiments, such as Figure 7 As shown, a control method for a permanent magnet synchronous motor is provided, including the following steps S702-S714. This method can be applied to applications such as... Figure 1Taking the control device shown as an example, the refresh rates of the parameter identification module, temperature prediction module, and control module are synchronized with the refresh rate of the FOC system.

[0144] S702, the parameter identification module performs temperature drift compensation processing on the initialization parameters based on the temperature prediction value output by the temperature prediction module and the preset temperature drift coefficient, and obtains the motor identification parameters after temperature drift compensation.

[0145] S704, the parameter identification module performs error compensation processing based on the motor identification parameters and real-time electrical parameters, obtains the resistance identification parameters, inductance identification parameters and back EMF parameters, outputs the resistance identification parameters and inductance parameters to the temperature prediction module, and outputs the back EMF parameters to the control module.

[0146] The S706 temperature prediction module calculates copper loss power based on resistance identification parameters, real-time torque current, and real-time excitation current; calculates iron loss power based on inductance identification parameters, motor speed, real-time excitation current, and preset iron loss coefficient; and calculates convective heat dissipation power based on preset heat dissipation coefficient, collected winding temperature, and ambient temperature.

[0147] S708, the temperature prediction module solves the heat network equation based on the copper loss power, iron loss power and convective heat dissipation power to obtain the temperature prediction value and temperature change rate, and outputs the temperature prediction value to the parameter identification module, and outputs the temperature prediction value and temperature change rate to the control module.

[0148] S710, the control module calculates the first current threshold based on the predicted temperature value, the rated torque current value, the preset temperature threshold and the first limiting coefficient, and calculates the second current threshold based on the temperature change rate, the first current threshold and the second limiting coefficient when the temperature change rate is greater than the preset change rate threshold, and outputs the first current threshold or the second current threshold to the FOC system.

[0149] S712, the control module calculates the third current threshold based on the inductance identification parameters, back EMF parameters, bus voltage and motor speed, and outputs the third current threshold to the FOC system.

[0150] S714, if the torque current threshold (first current threshold and / or second current threshold) calculated by the control module is continuously lower than the preset current threshold within a preset time period, a model calibration request is sent to the temperature prediction module so that the temperature prediction module can perform a self-test.

[0151] As an example, the preset time period can be 30 seconds, and the preset current threshold can be 80% of the rated torque current.

[0152] In this embodiment, real-time identification parameters of the permanent magnet synchronous motor (PMSM) are obtained based on the input real-time electrical parameters and temperature prediction values. Furthermore, temperature prediction data for the stator windings of the PMSM is obtained based on the real-time electrical parameters, resistance identification parameters, and inductance identification parameters. Software algorithms are used to monitor the winding temperature, eliminating the need for hardware structures such as temperature sensors and reducing the manufacturing cost of the PMSM. Moreover, the motor parameter identification and winding temperature prediction form a bidirectional closed-loop control. On one hand, real-time identification parameters are obtained based on the real-time electrical parameters and temperature prediction values, fully considering the changes in real-time identification parameters caused by temperature rise, thus improving parameter identification accuracy. On the other hand, the temperature prediction values ​​are corrected based on the real-time identification parameters, further improving the accuracy of the temperature prediction data. Because the accuracy of temperature prediction data is improved, the first, second, and third current thresholds for the permanent magnet synchronous motor (PMSM) obtained from this data are also more accurate. This enables dynamic and precise control of the upper limit of the torque current of the PMSM based on the first or second current threshold, and dynamic and precise control of the upper limit of the excitation current based on the third current threshold. This avoids motor failures caused by overheating, such as winding insulation failure and permanent demagnetization of the permanent magnets, and also reduces performance losses caused by premature derating of the motor. Furthermore, by using both temperature prediction values ​​and the rate of temperature change as dual references, the torque current of the PMSM can be predictively drated in advance, reducing the response delay time of the control device.

[0153] Based on the above method, when applied to an air conditioning compressor, the error of the obtained resistance identification parameters can be less than or equal to 3%, the error of the back electromotive force parameters can be less than or equal to 0.05%, and the current loop bandwidth of the field-oriented control system is increased by 15%, the response time is shortened to 1.2 ms, and the error range of the temperature prediction value is within ±2.7℃. In the method without temperature drift compensation for the initialization parameters, the error range of the resistance identification parameters is 8%-12%, the error of the back electromotive force parameters is 0.12%, and the response time of the field-oriented control system is 1.5 ms. It can be seen that compared with the method without temperature drift compensation for the initialization parameters, this application can significantly improve the parameter identification accuracy and the accuracy of temperature prediction.

[0154] Combination Figure 2 and Figure 8 As shown, Figure 8The control timing process of the parameter identification module, temperature prediction module, and control module is provided. During the 0~50ms time period, the permanent magnet synchronous motor is suddenly loaded. The parameter identification module outputs the initialization parameters, and the temperature prediction module predicts the temperature to be 80℃. At this time, the upper limit of torque current is not derated. At 50ms, the temperature prediction module predicts that the temperature has changed. At this time, the temperature rise rate is 1.5℃ / s. The parameter identification module starts to compensate for the temperature drift of the initialization parameters. The control module performs smooth and gradual derated in advance based on equation (5). At 100ms, the motor has a heat dissipation failure. The temperature prediction module predicts the temperature to be 110℃. The parameter identification module performs temperature drift compensation for the initialization parameters. At this time, the control module still performs smooth and gradual derated based on equation (5). At 150ms, the temperature prediction module predicted a temperature change rate of 4.2℃ / s. The real-time identification parameter identified by the parameter identification module increased by 15% compared to the initial parameter. The control module aggressively reduced the derating in advance based on equation (6) to avoid problems such as winding insulation failure and permanent magnet demagnetization due to motor overheating. At 200ms, the temperature prediction module predicted a temperature of 145℃, which exceeded the safety threshold, and the permanent magnet synchronous motor was shut down. It can be seen that the parameter identification module, temperature identification module and control module have short response delays to sudden events such as sudden load increase and heat dissipation failure, and can complete the derating more quickly, reducing the risk of winding insulation failure and permanent magnet demagnetization due to motor overheating.

[0155] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially as indicated in the figures, these steps are not necessarily executed in the order shown in the figures. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0156] Based on the same inventive concept, this application also provides a control device for a permanent magnet synchronous motor to implement the control method of the permanent magnet synchronous motor described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the control device for a permanent magnet synchronous motor provided below can be found in the limitations of the control method for the permanent magnet synchronous motor described above, and will not be repeated here.

[0157] In one embodiment, based on the same inventive concept, such as Figure 1 As shown, this application also provides a control device for a permanent magnet synchronous motor, including a parameter identification module 102, a temperature prediction module 104, and a control module 106.

[0158] The parameter identification module 102 is connected to the temperature prediction module 104. The parameter identification module 102 is used to output the real-time identification parameters of the permanent magnet synchronous motor based on the real-time electrical parameters of the input permanent magnet synchronous motor and the temperature prediction value output by the temperature prediction data. The real-time identification parameters include resistance identification parameters, back electromotive force parameters and inductance identification parameters.

[0159] The temperature prediction module 104 is used to output temperature prediction data of the stator winding of the permanent magnet synchronous motor based on the input real-time electrical parameters, resistance identification parameters and inductance identification parameters; the temperature prediction data includes at least the temperature prediction value.

[0160] The control module 106 is connected to the temperature prediction module 104 and the parameter identification module 102 respectively. The control module 106 is used to output the current control parameters of the permanent magnet synchronous motor based at least on the temperature prediction data.

[0161] In this embodiment, bidirectional data transmission occurs between the temperature prediction module 104 and the parameter identification module 102. The parameter identification module 102 obtains real-time identification parameters based on the real-time electrical parameters of the permanent magnet synchronous motor and the temperature prediction value, fully considering the changes in the real-time identification parameters of the motor caused by temperature rise, thus improving the accuracy of parameter identification. The temperature prediction module 104 can correct the temperature prediction value based on the real-time identification parameters, further improving the accuracy of the temperature prediction data. In addition, due to the improved accuracy of the temperature prediction data, the current control parameters of the permanent magnet synchronous motor obtained by the control module 106 based on the temperature prediction data are also more accurate. The current control parameters are output to the FOC system, which limits the torque current of the permanent magnet synchronous motor based on these current control parameters. This avoids problems such as motor winding insulation failure and permanent demagnetization of the permanent magnet due to motor overheating, and also reduces performance loss caused by premature derating of the motor.

[0162] In one embodiment, the parameter identification module is further configured to perform temperature drift compensation processing based on the temperature prediction value and initialization parameters to obtain the motor identification parameters after temperature drift compensation; and to perform error compensation processing based on the motor identification parameters and real-time electrical parameters to obtain the real-time identification parameters.

[0163] In one embodiment, the parameter identification module is further configured to determine a temperature compensation value based on the predicted temperature value and the initial temperature value; and to obtain motor identification parameters based on the temperature compensation value, the initial resistance parameter, the initial inductance parameter, the initial back electromotive force constant, and the preset temperature drift coefficient; wherein, the resistance identification parameter in the motor identification parameters is positively correlated with the initial resistance parameter, the inductance identification parameter is positively correlated with the initial inductance parameter, and the back electromotive force parameter is positively correlated with the initial back electromotive force constant.

[0164] In one embodiment, the parameter identification module is further configured to obtain a torque voltage prediction value based on the motor identification parameters, real-time current, and motor speed; obtain an error compensation value based on the torque voltage prediction value and real-time torque voltage; and obtain real-time identification parameters based on the error compensation value and a preset parameter identification model.

[0165] In one embodiment, the control module is further configured to obtain torque current limiting parameters; obtain a first current threshold based on the torque current limiting parameters and the temperature prediction value in the temperature prediction data; the first current threshold is negatively correlated with the temperature prediction value.

[0166] In one embodiment, the control module is further configured to obtain a second current threshold based on the temperature change rate in the temperature prediction data; the second current threshold is exponentially related to the temperature change rate.

[0167] In one embodiment, the control module is further configured to obtain a third current threshold based on inductance identification parameters, back electromotive force parameters, bus voltage, and motor speed.

[0168] In one embodiment, the temperature prediction module is further configured to obtain the copper loss power based on the resistance identification parameters and the real-time torque current and real-time excitation current in the real-time electrical parameters; and / or,

[0169] Based on the inductance identification parameters, the motor speed and real-time excitation current in the real-time electrical parameters, and the preset iron loss coefficient, the iron loss power is obtained; and / or,

[0170] Based on the preset heat dissipation coefficient and the collected winding temperature and ambient temperature, the convective heat dissipation power is obtained;

[0171] Temperature prediction data is obtained based on at least one of copper loss power, iron loss power, and convective heat dissipation power.

[0172] In one embodiment, this application also provides a motor control system, which includes a permanent magnet synchronous motor and a control device for the permanent magnet synchronous motor provided in any of the above embodiments. This motor control system can be used in fields such as smart home appliances (e.g., air conditioners), new energy vehicles, and industrial frequency converters.

[0173] In one exemplary embodiment, a motor controller is provided, which may be a server, and its internal structure diagram may be as follows. Figure 9 As shown, the motor controller includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database stores electrical parameters and identification parameters. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a control method for a permanent magnet synchronous motor.

[0174] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the motor controller to which the present application is applied. A specific motor controller may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0175] In one exemplary embodiment, a motor controller is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the control method for a permanent magnet synchronous motor provided in any of the above embodiments.

[0176] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the control method for a permanent magnet synchronous motor provided in any of the above embodiments.

[0177] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the control method for a permanent magnet synchronous motor provided in any of the above embodiments.

[0178] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0179] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0180] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0181] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control method for a permanent magnet synchronous motor, characterized in that, include: Based on the input real-time electrical parameters and temperature prediction values ​​of the permanent magnet synchronous motor, the real-time identification parameters of the permanent magnet synchronous motor are obtained. The real-time identification parameters include resistance identification parameters, back electromotive force parameters, and inductance identification parameters; Based on the real-time electrical parameters, the resistance identification parameters, and the inductance identification parameters, the temperature prediction data of the stator winding of the permanent magnet synchronous motor is obtained. The temperature prediction data includes at least the temperature prediction value; Based at least on the temperature prediction data, output the current control parameters of the permanent magnet synchronous motor.

2. The method according to claim 1, characterized in that, Based on the input real-time electrical parameters and predicted temperature values ​​of the permanent magnet synchronous motor, the real-time identification parameters of the permanent magnet synchronous motor are obtained, including: Temperature drift compensation is performed based on the predicted temperature value and initialization parameters to obtain the motor identification parameters after temperature drift compensation. Error compensation processing is performed based on the motor identification parameters and the real-time electrical parameters to obtain the real-time identification parameters.

3. The method according to claim 2, characterized in that, The initialization parameters include: initial resistance parameters, initial inductance parameters, and initial back electromotive force constant; the process of performing temperature drift compensation based on the predicted temperature value and the initialization parameters to obtain motor identification parameters includes: The temperature compensation value is determined based on the predicted temperature value and the initial temperature value; The motor identification parameters are obtained based on the temperature compensation value, the initial resistance parameter, the initial inductance parameter, the initial back electromotive force constant, and the preset temperature drift coefficient; wherein, the resistance identification parameter is positively correlated with the initial resistance parameter, the inductance identification parameter is positively correlated with the initial inductance parameter, and the back electromotive force parameter is positively correlated with the initial back electromotive force constant.

4. The method according to claim 2, characterized in that, The real-time electrical parameters include at least real-time torque voltage, real-time current, and motor speed; Error compensation processing is performed based on the motor identification parameters and the real-time electrical parameters to obtain the real-time identification parameters, including: Based on the motor identification parameters, the real-time current, and the motor speed, the torque voltage prediction value is obtained; Based on the predicted torque voltage and the real-time torque voltage, an error compensation value is obtained; The real-time identification parameters are obtained based on the error compensation value and the preset parameter identification model.

5. The method according to any one of claims 1-4, characterized in that, The current control parameters include at least a first current threshold; the step of outputting the current control parameters of the permanent magnet synchronous motor based at least on the temperature prediction data includes: Obtain torque current limiting parameters; The first current threshold is obtained based on the torque current limiting parameter and the temperature prediction value in the temperature prediction data; the first current threshold is negatively correlated with the temperature prediction value.

6. The method according to claim 5, characterized in that, The current control parameters also include a second current threshold, wherein the second current threshold and the first current threshold are used to represent the upper limit of the torque current of the permanent magnet synchronous motor. The step of outputting current control parameters for the permanent magnet synchronous motor based at least on the temperature prediction data further includes: The second current threshold is obtained based on the temperature change rate in the temperature prediction data; The second current threshold is exponentially related to the rate of temperature change.

7. The method according to claim 5, characterized in that, The real-time electrical parameters include at least the bus voltage and the motor speed; The current control parameters also include a third current threshold, which is used to represent the upper limit of the excitation current of the permanent magnet synchronous motor. The method further includes: The third current threshold is obtained based on the inductance identification parameters, the back electromotive force parameters, the bus voltage, and the motor speed.

8. The method according to any one of claims 1-4, characterized in that, The step of obtaining temperature prediction data for the stator winding of the permanent magnet synchronous motor based on the real-time electrical parameters, the resistance identification parameters, and the inductance identification parameters includes: Based on the resistance identification parameters and the real-time torque current and real-time excitation current in the real-time electrical parameters, the copper loss power is obtained; and / or, Based on the inductance identification parameters, the motor speed and real-time excitation current in the real-time electrical parameters, and the preset iron loss coefficient, the iron loss power is obtained; and / or, Based on the preset heat dissipation coefficient and the collected winding temperature and ambient temperature, the convective heat dissipation power is obtained; The temperature prediction data is obtained based on at least one of the copper loss power, the iron loss power, and the convective heat dissipation power.

9. A control device for a permanent magnet synchronous motor, characterized in that, include: Temperature prediction module, parameter identification module, and control module; The parameter identification module is connected to the temperature prediction module. The parameter identification module is used to output the real-time identification parameters of the permanent magnet synchronous motor based on the real-time electrical parameters of the input permanent magnet synchronous motor and the temperature prediction value output by the temperature prediction data. The real-time identification parameters include resistance identification parameters, back electromotive force parameters and inductance identification parameters. The temperature prediction module is used to output temperature prediction data of the stator winding of the permanent magnet synchronous motor based on the input real-time electrical parameters, the resistance identification parameters, and the inductance identification parameters; the temperature prediction data includes at least the temperature prediction value. The control module is connected to the temperature prediction module and the parameter identification module respectively. The control module is used to output the current control parameters of the permanent magnet synchronous motor based at least on the temperature prediction data.

10. A motor control system, characterized in that, It includes a permanent magnet synchronous motor and a control device for the permanent magnet synchronous motor as described in claim 9.

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