Control method, device and equipment for current loop of permanent magnet synchronous motor and storage medium

Abstract

The invention discloses a control method, device and equipment for a current loop of a permanent magnet synchronous motor and a storage medium, and relates to the technical field of electric vehicle driving motors, and the control method for the current loop of the permanent magnet synchronous motor comprises the steps: obtaining an input voltage; a current loop is controlled according to a target motor mathematical model and the input voltage, the target motor mathematical model is obtained by adjusting an initial model, and adjustment is based on the required torque, a rectangular axis open-loop transfer function and a zero-pole mutual elimination function. The initial model is constructed according to a target quadrature-axis voltage equation, a dynamic inductance parameter value, a locked-rotor test and a difference strategy, and the dynamic inductance parameter value and the target quadrature-axis voltage equation are at least calculated by three items of an initial quadrature-axis voltage equation, dynamic inductance, a quadrature-axis flux linkage equation and a back electromotive force-flux linkage relation. According to the invention, the control precision, efficiency and response speed of the permanent magnet synchronous motor are improved, and the robustness of the system is enhanced.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicle drive motors, and in particular to a control method, device, equipment and storage medium for a permanent magnet synchronous motor current loop. Background Art

[0002] Permanent magnet synchronous motors are widely used in electric vehicle drive motors due to their high efficiency and high performance. The torque control performance of the motor is directly related to the driving performance of the vehicle, and the accuracy and response speed of torque control are determined by the current loop control. Therefore, for electric vehicles, having a high-performance current loop control method is crucial to improving the performance of the vehicle.

[0003] In existing practices, the current loop control of permanent magnet synchronous motors mainly adopts two methods: feedforward voltage decoupling and feedback voltage decoupling. Feedforward decoupling improves the system response speed by compensating for motor parameter changes in advance, while feedback decoupling uses feedback current to decouple cross-coupling terms. These methods can improve the control performance of the motor to a certain extent, but they each have limitations.

[0004] Although feedforward decoupling can improve the system response speed, it is sensitive to changes in motor parameters. Once the motor parameters change, its accuracy is difficult to guarantee. Although feedback decoupling can be decoupled through feedback current, this method will cause delays in the system and affect the response speed. In addition, neither of these two methods solves the problem of strong coupling between the DQ axes (Direct Axis and Quadrature Axis, referred to as orthogonal axes), resulting in the inability to achieve complete decoupling, which affects the accuracy of control and the dynamic anti-interference ability of the system. Therefore, how to improve the control accuracy, response speed and robustness of the permanent magnet synchronous motor current loop has become an urgent problem to be solved.

[0005] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0006] The purpose of this application is to provide a control method, device, equipment and storage medium for a permanent magnet synchronous motor current loop, aiming to solve the technical problem of how to improve the control accuracy, response speed and robustness of the permanent magnet synchronous motor current loop.

[0007] To achieve the above object, the present application proposes a control method for a permanent magnet synchronous motor current loop, the method comprising:

[0008] Get the input voltage;

[0009] The current loop is controlled according to the target motor mathematical model and the input voltage. The target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function. The initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy. The dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship.

[0010] In one embodiment, the process of generating the dynamic inductance parameter value and the target orthogonal axis voltage equation includes:

[0011] The reference orthogonal axis voltage equation is calculated based on the initial orthogonal axis voltage equation, the dynamic inductance and the orthogonal axis flux equation;

[0012] Performing calibration test and curve fitting based on the reference orthogonal axis voltage equation to obtain a dynamic inductance parameter value;

[0013] The target orthogonal axis voltage equation is calculated based on the back electromotive force-flux linkage relationship, the difference strategy and the reference orthogonal axis voltage equation.

[0014] In one embodiment, the step of calculating the target orthogonal axis voltage equation according to the back electromotive force-flux linkage relationship, the difference strategy and the reference orthogonal axis voltage equation comprises:

[0015] Through the motor reverse drag test, the permanent magnet flux value at different temperatures is calculated by combining the back electromotive force-flux relationship and the difference strategy;

[0016] The permanent magnet flux linkage value and the corresponding temperature form a permanent magnet flux linkage value point set;

[0017] Performing curve fitting on the permanent magnet flux linkage value point set to obtain a permanent magnet flux linkage-temperature equation;

[0018] The target orthogonal axis voltage equation is calculated according to the permanent magnet flux linkage-temperature equation and the reference orthogonal axis voltage equation.

[0019] In one embodiment, the step of performing a calibration test and curve fitting based on the reference orthogonal axis voltage equation to obtain a dynamic inductance parameter value comprises:

[0020] Performing a calibration test under thermal steady state of the motor based on the reference orthogonal axis voltage equation to obtain calibration data;

[0021] The orthogonal axis flux-current equation is obtained by fitting according to the calibration data;

[0022] The partial derivative of the orthogonal axis flux-current equation is obtained to obtain the dynamic inductance parameter value.

[0023] In one embodiment, the target orthogonal axis voltage equation includes a direct axis voltage equation, and the construction process of the initial motor mathematical model includes:

[0024] The stator resistance of the motor in thermal steady state is calculated by a locked-rotor test in combination with the direct-axis voltage equation and the difference strategy;

[0025] An initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the stator resistance and the dynamic inductance parameter value.

[0026] In one embodiment, the process of constructing the mathematical model of the target motor includes:

[0027] Obtaining a current ramp function and a current loop proportional-integral parameter according to at least one of a required torque, a rectangular axis open-loop transfer function, and a zero-pole cancellation function;

[0028] Obtain the motor angular velocity, wave transmission delay, resolver signal sampling delay and rotor position angle;

[0029] The target angular velocity is calculated according to the motor angular velocity, the wave transmission delay and the resolver signal sampling delay;

[0030] Calculate a voltage vector angle according to the rotor position angle and the target angular velocity;

[0031] The initial motor mathematical model is adjusted according to the voltage vector angle, the current ramp function and the current loop proportional-integral parameter to obtain a target motor mathematical model.

[0032] In one embodiment, the step of obtaining the current ramp function and the current loop proportional-integral parameter according to at least one of the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation function comprises:

[0033] The given current value is calculated based on the required torque;

[0034] Calculating the module execution period and the pulse width modulation interruption period according to the given current value;

[0035] Designing a current ramp function according to the module execution cycle and the pulse width modulation interruption cycle;

[0036] The current loop proportional-integral parameters are calculated based on the orthogonal axis open-loop transfer function and the zero-pole cancellation function.

[0037] In addition, to achieve the above-mentioned purpose, the present application also proposes a control device for a current loop of a permanent magnet synchronous motor, the device comprising:

[0038] A data acquisition module, used for acquiring input voltage;

[0039] A control module is used to control the current loop according to a target motor mathematical model and the input voltage, wherein the target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function, and the initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy, and the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship.

[0040] In addition, to achieve the above-mentioned objectives, the present application also proposes a control device for a permanent magnet synchronous motor current loop, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the control method for the permanent magnet synchronous motor current loop as described above.

[0041] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by the processor, the steps of the control method of the permanent magnet synchronous motor current loop as described above are implemented.

[0042] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, it implements the steps of the control method of the permanent magnet synchronous motor current loop as described above.

[0043] One or more technical solutions proposed in this application have at least the following technical effects:

[0044] Obtain input voltage; control the current loop according to the target motor mathematical model and the input voltage, the target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole mutual cancellation function, the initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy, the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship. The control system first accurately measures the input voltage of the motor through a voltage sensor, and the accurate information of the input voltage provides basic data for the current loop control, ensuring that the control strategy can be accurately adjusted based on the actual voltage. Then, the current loop is controlled using this input voltage and the adjusted target motor mathematical model, which integrates factors such as the required torque, the orthogonal axis open-loop transfer function and the zero-pole mutual cancellation function, so that the control strategy is more adapted to actual working conditions and improves the accuracy and adaptability of the control. Before constructing the target motor mathematical model, the control system will construct an initial motor mathematical model based on the target orthogonal axis voltage equation, dynamic inductance parameter value, stall test and difference strategy. This model contains the basic physical parameters and characteristics of the motor, providing a basis for subsequent model adjustment, so that the control strategy can be optimized step by step based on the basic motor characteristics. The calculation of the dynamic inductance parameter value and the target orthogonal axis voltage equation is based on the initial orthogonal axis voltage equation, dynamic inductance, orthogonal axis flux equation and back electromotive force-flux relationship. These precise calculations enable the control system to better understand and predict the dynamic behavior of the motor, which is crucial for achieving accurate current control and optimizing motor performance. Finally, the initial motor mathematical model will be adjusted according to the required torque, orthogonal axis open-loop transfer function and zero-pole cancellation function to obtain a more accurate target motor mathematical model. This adjustment process enables the model to more accurately reflect the performance of the motor under actual working conditions, thereby making the current loop control more accurate and effective, improving the control accuracy, efficiency and response speed of the permanent magnet synchronous motor, and also enhancing the robustness of the system. Through this series of steps, the motor control system can ensure that the motor can operate efficiently and stably under various operating conditions, while reducing energy loss and improving vehicle performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0047] Figure 1 A flow chart of a control method for a permanent magnet synchronous motor current loop according to a first embodiment of the present invention;

[0048] Figure 2 A schematic diagram of constructing a mathematical model of a target motor provided in Example 1 of the control method for a current loop of a permanent magnet synchronous motor of the present application;

[0049] Figure 3 A flow chart of a second embodiment of a method for controlling a current loop of a permanent magnet synchronous motor of the present application;

[0050] Figure 4 A schematic diagram of a permanent magnet flux temperature curve provided in Example 2 of the control method for a current loop of a permanent magnet synchronous motor of the present application;

[0051] Figure 5 This is a schematic diagram of the module structure of a control device for a current loop of a permanent magnet synchronous motor according to an embodiment of the present application;

[0052] Figure 6 Schematic diagram of the device structure of the hardware operating environment involved in the control method of the permanent magnet synchronous motor current loop in the embodiment of the present application.

[0053] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0054] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0055] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0056] Permanent magnet synchronous motors are widely used in electric vehicles due to their high efficiency and high performance. Their torque control performance directly affects the vehicle driving experience, and this performance is determined by the current loop control. Existing current loop control methods mainly include feedforward voltage decoupling and feedback voltage decoupling. The former improves the response speed through pre-compensation but is sensitive to parameter changes, while the latter uses feedback current decoupling but introduces delay. Both methods fail to effectively solve the problem of strong coupling between the DQ axes, affecting the control accuracy and system dynamic stability. Therefore, the development of more advanced current loop control technology is critical to improving the overall performance of electric vehicles.

[0057] The main solution of the embodiment of the present application is: the control system measures the motor input voltage through a voltage sensor to provide accurate data for current loop control. Based on these data and a mathematical model of the target motor that integrates the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function, the system performs current loop control. The target model is obtained by adjusting the initial model (constructed by the target orthogonal axis voltage equation, dynamic inductance parameter value, stall test and difference strategy), and these parameters are calculated based on the initial orthogonal axis voltage equation, dynamic inductance, orthogonal axis flux equation and back electromotive force-flux relationship. This process ensures that the control strategy can accurately adapt to the actual working conditions and improves the accuracy of control and motor performance.

[0058] It should be noted that the execution subject of the embodiment of the present application can be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a motor controller, a motor control system, etc. The following takes the motor control system as an example to illustrate this embodiment and the following embodiments.

[0059] Based on this, the present application embodiment provides a method for controlling a current loop of a permanent magnet synchronous motor, referring to Figure 1 , Figure 1 This is a flow chart of a first embodiment of a method for controlling a current loop of a permanent magnet synchronous motor according to the present invention.

[0060] In this embodiment, the control method of the permanent magnet synchronous motor current loop includes steps S10 to S20:

[0061] Step S10, obtaining input voltage;

[0062] It should be noted that the input voltage refers to the voltage supplied to the permanent magnet synchronous motor. This voltage is provided by the inverter part of the motor controller, which converts the direct current (DC) of the battery into the three-phase alternating current (AC) required by the motor. The input voltage is a key parameter in the motor control process because it directly affects the current and torque output of the motor.

[0063] It can be understood that, firstly, by connecting the voltage sensor to the power input terminal of the vehicle motor, the voltage value provided by the battery or power management system is directly measured. Secondly, the sensor converts the detected analog voltage signal into a digital signal so that the vehicle's motor control system can read and analyze it.

[0064] Step S20, controlling the current loop according to the target motor mathematical model and the input voltage, the target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function, the initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy, the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship.

[0065] It should be noted that the target motor mathematical model refers to the motor mathematical model adjusted according to the actual application requirements. This model takes into account the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function to more accurately predict and control the behavior of the motor. It is adjusted from the initial motor mathematical model. The purpose of the adjustment is to make the model closer to the performance of the actual motor under specific working conditions. The current loop refers to the control loop used to maintain the motor current at a set value in the motor control system. It usually includes a current sensor, a controller (such as a PI regulator) and an inverter. The purpose of the current loop is to quickly and accurately control the motor current to achieve precise motor control. The required torque refers to the torque value required to be generated by the motor according to the driving requirements of the electric vehicle or other application requirements. The orthogonal axis open-loop transfer function refers to a mathematical expression that describes the relationship between the input (such as voltage) and the output (such as current or speed) of the motor under open-loop conditions. For the direct axis (D axis) and the quadrature axis (Q axis), their respective open-loop transfer functions help design controllers to achieve precise control of motor performance. Zero-pole cancellation function refers to the process of simplifying the control algorithm by using the system's own characteristics (such as zeros and poles) in the design of motor control systems. Through zero-pole cancellation, the number of parameters of the PI controller can be reduced and the design of the control algorithm can be simplified. The initial motor mathematical model is a mathematical model built based on the basic physical principles and characteristics of the motor. It includes the basic equations of the motor, such as the voltage equation and the flux equation, which are used to describe the static and dynamic behaviors of the motor. The target orthogonal axis voltage equation refers to the equation obtained by adjusting the initial voltage equation according to the actual working conditions and control requirements of the motor. This equation takes into account factors such as dynamic inductance parameter values ​​and stall test results to more accurately describe the voltage behavior of the motor under actual working conditions. The dynamic inductance parameter value refers to the inductance value of the motor that changes under different working conditions. These values ​​are crucial for accurately controlling the motor current because they affect the electromagnetic characteristics of the motor. The stall test is a motor test method that applies resistance to the motor shaft to prevent it from rotating, and measures the voltage and current of the motor at different currents to determine certain parameters of the motor, such as the stator resistance. The difference strategy is a mathematical calculation method that calculates the changes in motor parameters by comparing measured values ​​under different conditions, such as the change of permanent magnet flux with temperature. The initial orthogonal axis voltage equation is a voltage equation established based on the basic electromagnetic relationship of the motor. It describes the relationship between the motor voltage and current, flux and other parameters when no additional factors (such as dynamic inductance changes) are considered. Dynamic inductance refers to the inductance of the motor that changes under different operating conditions (such as different currents and speeds). This is different from static inductance, which changes with the working state of the motor. The orthogonal axis flux equation describes the relationship between the flux on the direct and quadrature axes of the motor and the physical parameters of the motor (such as flux, inductance) and the working state (such as current) of the motor.The back-EMF-flux relationship describes the relationship between the motor back-EMF (the voltage generated when the motor operates as a generator) and the motor flux. This relationship is very important for calculating the motor flux and designing motor control strategies.

[0066] It can be understood that, first, the motor control system applies resistance to the motor shaft through a stall test to prevent it from rotating, and then gives the rated current and peak current respectively, records the D-axis voltage and current values ​​at a specific temperature (such as 65°C), and uses these data to calculate the stator resistance by the difference method; secondly, when the motor is in thermal steady state (temperature variation is within the range of ±10°), the control system scans the flux value of the current Map, gives different D-axis and Q-axis currents in steps, records the corresponding voltage and flux, and then fits the equations related to current and flux in Matlab, and calculates the dynamic inductance parameter value by taking partial derivatives; then, using these dynamic inductance parameter values ​​and the initial orthogonal axis voltage equation, combined with the orthogonal axis flux equation and the relationship between back electromotive force and flux, The control system calculates the target orthogonal axis voltage equation, which takes into account the time-varying nature of the motor parameters and can more accurately describe the voltage behavior of the motor under actual working conditions. Then, the control system adjusts the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation principle to form a target motor mathematical model, which can more accurately simulate the dynamic behavior of the motor. Finally, the control system uses this target motor mathematical model and input voltage to monitor the motor current and voltage in real time, adjust the inverter output voltage and frequency, and precisely control the current loop to ensure that the motor can respond quickly and accurately to external load changes and internal parameter fluctuations, and achieve precise control of the motor torque and speed, thereby improving the power performance and energy efficiency of the entire vehicle.

[0067] As an example, the target orthogonal axis voltage equation includes a direct axis voltage equation, and the process of constructing the initial motor mathematical model includes: performing a stall test and calculating the stator resistance of the motor in a thermal steady state by combining the direct axis voltage equation and a difference strategy; and constructing the initial motor mathematical model according to the target orthogonal axis voltage equation, the stator resistance and the dynamic inductance parameter value.

[0068] The direct-axis voltage equation refers to the mathematical expression that describes the relationship between the voltage and current, flux and other parameters on the direct axis (D axis) of a permanent magnet synchronous motor. This equation is usually based on the electromagnetic induction law and circuit theory of the motor, and is used to calculate the voltage response on the direct axis. It is one of the key equations in motor control and analysis. The stall test is a motor test method used to measure the electrical characteristics of the motor when it cannot rotate. In this test, the motor shaft is fixed or sufficient resistance is applied to prevent it from rotating. Then, by applying different currents, the voltage and current responses of the motor are measured. These data are used to determine the parameters of the motor, such as stator resistance and inductance. The difference strategy is a numerical calculation method that calculates the change of parameters by comparing two or more measured values ​​under different conditions. In motor control, this method can be used to calculate the change of motor parameters (such as resistance) by measuring the voltage at different currents and then using these data points to estimate the parameter value. The thermal steady state of the motor refers to the state in which the internal temperature of the motor reaches a stable value after the motor has been running continuously for a period of time. In this state, the temperature rise of the motor no longer changes, and the thermal performance parameters of the motor (such as resistance) are also relatively stable. This is very important for accurately measuring motor parameters and designing control strategies. Stator resistance refers to the resistance value of the motor stator winding. This is an important motor parameter that affects the efficiency and thermal management of the motor. In motor control, understanding the stator resistance is crucial for accurately calculating the voltage and current response of the motor. The initial motor mathematical model is a mathematical model built based on the basic physical principles and known parameters of the motor. This model includes the motor's voltage equation, flux equation, torque equation, etc., which are used to describe the static and dynamic behavior of the motor. The initial model is the basis of motor control. It provides a theoretical basis for subsequent control strategy design and parameter adjustment. In actual applications, the initial model may be adjusted and optimized based on experimental data and actual operating conditions to form a more accurate target motor mathematical model.

[0069] Calculate the stator resistance of the motor in thermal steady state (65°C) and convert the resistance voltage drop in thermal steady state R s ·i d As a feedforward compensation, to reduce the sensitivity of the current loop decoupling. Based on the D-axis voltage equation, using the locked-rotor test, i q =0 control, i d Given the rated current i e and the peak current i max , and record the D-axis voltage u at a temperature of 65°C e and u max , try to use the difference method to calculate the stator resistance:

[0070] u d =R s ·i d

[0071]

[0072] Among them, R s_65℃ is the stator resistance at a temperature of 65°C.

[0073] First, the motor control system uses the direct-axis voltage equation, which is a mathematical expression that describes the relationship between the voltage on the motor's direct axis and parameters such as current and flux. Then, by performing a stall test, resistance is applied to the motor shaft to prevent it from rotating, and the rated current and peak current are given at a thermal steady state of 65°C, and the D-axis (direct-axis) voltage and current values ​​are recorded at this time. Next, the direct-axis voltage equation and the difference strategy are combined to compare the voltage values ​​measured at different currents to calculate the stator resistance of the motor at thermal steady state. This resistance value is a key parameter in motor control and affects the efficiency and thermal management of the motor. Finally, the control system constructs an initial motor mathematical model based on the target orthogonal axis voltage equation, the newly calculated stator resistance, and the dynamic inductance parameter value. This model is the basis for the development of the motor control algorithm, which is used to describe the static and dynamic behavior of the motor and provides a theoretical basis for the subsequent control strategy design and parameter adjustment. Through this detailed step, the motor control system can more accurately simulate and predict the behavior of the motor, thereby achieving more precise control.

[0074] As an example, the construction process of the target motor mathematical model includes: obtaining a current ramp function and a current loop proportional-integral parameter according to at least one of the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation function; obtaining the motor angular velocity, the wave transmission delay, the resolver signal sampling delay, and the rotor position angle; calculating the target angular velocity according to the motor angular velocity, the wave transmission delay, and the resolver signal sampling delay; calculating the voltage vector angle according to the rotor position angle and the target angular velocity; adjusting the initial motor mathematical model according to the voltage vector angle, the current ramp function, and the current loop proportional-integral parameter to obtain the target motor mathematical model.

[0075] The demand torque refers to the torque that the motor needs to produce. This torque is determined according to the driving requirements of the electric vehicle or other application requirements. In the motor control system, the demand torque is one of the inputs of the current loop control algorithm and is used to calculate the required current value to generate the corresponding torque. The orthogonal axis open-loop transfer function describes the relationship between the input (such as voltage) and the output (such as current or speed) of the motor under open-loop conditions. For the direct axis (D axis) and the quadrature axis (Q axis), these functions help design controllers to achieve precise control of motor performance. The zero-pole cancellation function refers to the process of simplifying the control algorithm by using the system's own characteristics (such as zeros and poles) in the design of the motor control system. Through zero-pole cancellation, the number of parameters of the PI controller can be reduced and the design of the control algorithm can be simplified. The current ramp function refers to the functional module that calculates the given current based on the demand torque. It is usually placed in a longer task execution cycle (such as 1ms) to smoothly adjust the current command to reduce the adjustment amplitude of the current loop and reduce torque pulsation. The current loop proportional-integral parameters refer to the proportional (P) and integral (I) parameters in the current loop PI controller. These parameters determine the response speed and stability of the PI controller to the current deviation and need to be adjusted according to the characteristics and control requirements of the motor. The motor angular velocity refers to the rotation speed of the motor rotor, usually in radians per second (rad / s). It is an important parameter in motor control and affects the torque and speed control of the motor. The wave delay refers to the time delay from the controller sending the control signal to the inverter actually outputting the corresponding voltage in motor control. This delay will affect the response speed and control accuracy of the motor. The resolver signal sampling delay refers to the time delay when the resolver (resolver) signal is sampled by the controller. This delay is related to the software and hardware filtering parameters and the motor speed, and needs to be obtained through calibration. The rotor position angle refers to the position angle of the motor rotor relative to the stator. This angle is very important for vector control motors because it determines the position of the motor rotor magnetic field relative to the stator. The target angular velocity refers to the ideal angular velocity of the motor rotor calculated according to the control target of the motor control system. This angular velocity is the target that the control system tries to achieve and is used to guide the actual operation of the motor. The voltage vector angle refers to the angle between the voltage vector applied to the motor and the motor rotor magnetic field. This angle is very important for the torque and flux control of the vector-controlled motor. The target motor mathematical model refers to the motor mathematical model adjusted according to the actual application requirements. This model takes into account factors such as the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation function to more accurately predict and control the behavior of the motor. It is obtained by adjusting the initial motor mathematical model. The purpose of the adjustment is to make the model closer to the performance of the actual motor under specific working conditions.

[0076] From the above u d 、u q Voltage equation, permanent magnet flux linkage Dynamic inductance L dd , L dq , L qd , L qq , stator resistance R s_65℃ Design a current loop structure. This current loop completely decouples the inductive effect between the DQ axis inductances, taking into account the time-varying nature of all motor parameters. The DQ axis current loop contains feedforward decoupling terms and cross decoupling terms, respectively. Similarly, the motor is modeled based on the precise voltage equation.

[0077] First, the control system determines the required torque by receiving instructions from the vehicle control unit, and then calculates the current ramp function, i.e., the slope of the current over time, and the proportional-integral parameters of the current loop, based on the orthogonal axis open-loop transfer function, which is a mathematical model that describes the input-output relationship of the motor when there is no feedback, and the zero-pole cancellation function, which is a process that uses the system's own characteristics to simplify the control algorithm. These parameters determine the response speed and stability of the PI controller to the current deviation. Secondly, the system obtains the real-time angular velocity of the motor by sampling the data of the motor angular velocity sensor at high speed, and measures the time difference between the inverter sending the PWM signal and the motor actually receiving the voltage, i.e., the wave delay, and the time difference between the resolver signal being sampled by the controller, i.e., the resolver signal sampling delay. These delay data are very critical for correcting the timing of the control signal. Then, the system combines the motor angular velocity, wave delay, and resolver signal sampling delay, and calculates the target angular velocity through an algorithm. This is the ideal angular velocity that the motor should achieve, which is used to guide the actual operation of the motor. Next, the system calculates the voltage vector angle, that is, the angle between the voltage vector and the rotor magnetic field, through the vector control algorithm based on the rotor position angle and the target angular velocity. This is critical for controlling the torque and flux of the motor. Finally, the system adjusts the initial motor mathematical model based on the voltage vector angle, current ramp function, and current loop proportional-integral parameters. This model is built based on the basic physical principles of the motor. Through these adjustments, a more accurate target motor mathematical model can be obtained. This model can more accurately simulate the actual behavior of the motor, thereby achieving precise control of the motor and improving the power performance and energy efficiency of the vehicle. Through this series of precise calculations and adjustments, the motor control system can ensure that the motor can operate efficiently and stably under various working conditions, while reducing energy loss and improving vehicle performance.

[0078] Please refer to Figure 2 , Figure 2 A schematic diagram of constructing a mathematical model of a target motor provided in Example 1 of a control method for a current loop of a permanent magnet synchronous motor of the present application is provided, and the diagram includes three main parts: a current controller, a wave generation delay-resolver signal sampling delay module, and a motor model.

[0079] In the current controller part, feedforward decoupling and cross decoupling of the static inductance and dynamic inductance of the DQ axis are performed, and the decoupling terms all take into account the time-varying nature of all motor parameters. First, the proportional gain (k pd =K c *L dd and k pq =K c *L qq ) for a given d-axis and q-axis current reference value ( and ) and the actual current (i d and i q ) to amplify the error between them to quickly respond to current deviations. The error signal is then accumulated by an integrator (1 / s) to eliminate the steady-state error. The controller also contains a feedforward term (k pdq1 and k pqd1 ), these feedforward terms are obtained by multiplying the angular velocity (ω e ) to compensate for the current change caused by the motor rotation. In addition, the controller also takes into account the cross-coupling term (k pdq and k pqd ) to further improve the control performance.

[0080] The wave delay-resolver signal sampling delay module simulates the transmission and processing delay of the signal in the control system, including the wave delay (τ r ) and resolver signal sampling delay (τ c These delays are compensated by the voltage vector angle (ω e +φ f ) to ensure that the control signal is synchronized with the actual state of the motor.

[0081] Loop delay compensation design: There are wave delay and resolver signal sampling delay in the control loop. According to the analysis of current sampling and vector voltage action principle, in the single sampling and single update wave mode, the wave delay t c Generally 1.5T PWM , the sampling delay of the resolver signal is related to the software and hardware filtering parameters, that is, it is related to the motor speed and can be obtained through calibration. d =i e ,i q =0, adjust the sampling delay time of the resolver signal. When the actual torque of the motor is equal to the friction torque at this speed, record the sampling delay time t of the resolver signal at this time. r The system delay is compensated according to the wave transmission delay and the resolver signal sampling delay. The specific compensation method is to compensate the voltage vector angle:

[0082] θ e =θ0+ω e *(t c +tr )

[0083] Among them, θ e is the compensated voltage vector angle, and θ0 is the rotor position angle collected by the resolver.

[0084] The motor model is based in part on the physical properties of the motor, such as the stator resistance (R s )、Inductance(L d and L q ) and back EMF To simulate the dynamic response of the motor. The differential equations in the motor model ( and ) describes the change of current with time, while the voltage equation (u′ d and u′ q ) describes the relationship between the motor terminal voltage, current and flux.

[0085] The entire system is constantly adjusted through the feedback loop to ensure that the motor runs precisely according to the required torque. At the same time, the system also takes into account the time-varying nature of motor parameters, such as dynamic inductance, and the effect of temperature on permanent magnet flux linkage, thereby achieving high-performance current loop control. Through this series of detailed steps, the motor control system can achieve efficient and precise control of the motor, optimizing the driving performance and energy efficiency of electric vehicles.

[0086] As an example, the step of obtaining the current ramp function and the current loop proportional-integral parameters according to at least one of the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function includes: calculating a given current value according to the required torque; calculating a module execution cycle and a pulse width modulation interruption cycle according to the given current value; designing the current ramp function according to the module execution cycle and the pulse width modulation interruption cycle; and calculating the current loop proportional-integral parameters according to the orthogonal axis open-loop transfer function and the zero-pole cancellation function.

[0087] The given current value refers to the current value that the motor needs to generate at a specific moment, calculated by the motor control system based on the required torque. This value is the target of the current loop control algorithm and is used to guide the current regulation of the motor to meet the torque requirement. The module execution cycle refers to the execution cycle of the current calculation given current function module. In this embodiment, this cycle is usually set to 1 millisecond (ms), which means that the calculation and update of the current given value are performed every 1 millisecond. This cycle determines the frequency of the current given value update. The pulse width modulation interrupt cycle refers to the cycle of the current loop module executing the PWM (pulse width modulation) signal update. In this embodiment, this cycle is usually set to 100 microseconds (us), which means that the current loop control algorithm updates the PWM signal every 100 microseconds to adjust the current of the motor. This cycle determines the response speed of the current loop control.

[0088] Given current ramp design: The function module that calculates the given current according to the required torque is usually placed in the 1ms task execution cycle, while the feedback current and current loop module are placed in the 100us PWM (pulse width modulation) interrupt cycle. As a result, the given current can be gradually transferred from the previous 1ms cycle command current to the current required command current within 10 current loop execution cycles, thereby reducing the current loop single adjustment amplitude and thus reducing medium and high speed torque pulsation.

[0089]

[0090] Among them, T pwm Refers to the execution cycle of the current loop module. is a given current, T Idqmap_task is the execution cycle of the current calculation given the current function module.

[0091] First, the control system calculates the required torque according to the driving requirements of the electric vehicle, and then uses this torque value to determine the given current value that the motor needs to generate. This is the target current of the current loop control algorithm, which is used to ensure that the motor can generate the required torque. Secondly, the control system determines the execution cycle of the current calculation module according to the given current value, which is usually 1 millisecond, and the interrupt cycle of PWM (pulse width modulation), which is usually 100 microseconds. These two cycles determine the update frequency of the current control algorithm and the adjustment frequency of the PWM signal. Then, the control system designs the current ramp function according to these cycles. This function is used to smoothly adjust the current command within the module execution cycle to reduce the adjustment amplitude of the current loop, reduce torque pulsation, and improve the smoothness and stability of motor control. Finally, the control system calculates the proportional-integral parameters of the current loop according to the orthogonal axis open-loop transfer function and the zero-pole mutual cancellation function. These parameters determine the response speed and stability of the PI controller to the current deviation, which is crucial to achieving accurate current control and ensuring that the motor can respond quickly and accurately to changes in torque demand. Through this series of precise calculations and adjustments, the motor control system can ensure that the motor can operate efficiently and stably under various working conditions.

[0092] D-axis system open loop transfer function:

[0093]

[0094] Zero-pole cancellation principle:

[0095] (k pd +k pqd1 )s+k id +j*k pqd *ω e =K c [R s +s*(L dd +Ldq )+jω e L q ]

[0096] Calculate the D-axis PI parameters:

[0097] k Pd =K c *L dd

[0098] k id =K c *R s

[0099] k pqd =K c *L q

[0100] k pqd1 =K c *L dq

[0101] Similarly, Q-axis PI parameters:

[0102] k pq =K c *L qq

[0103] k iq =K c *R s

[0104] k pdq =K c *L d

[0105] k pdq1 =K c *L qd

[0106] The present embodiment provides a control method for a permanent magnet synchronous motor current loop, obtaining an input voltage; controlling the current loop according to a target motor mathematical model and the input voltage, wherein the target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function, and the zero-pole mutual cancellation function, and the initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test, and the difference strategy, and the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation, and the back electromotive force-flux relationship. The control system first accurately measures the input voltage of the motor through a voltage sensor, and the accurate information of the input voltage provides basic data for the current loop control, ensuring that the control strategy can be accurately adjusted based on the actual voltage. Then, the current loop is controlled using this input voltage and the adjusted target motor mathematical model, which integrates factors such as the required torque, the orthogonal axis open-loop transfer function, and the zero-pole mutual cancellation function, so that the control strategy is more adapted to actual working conditions and improves the accuracy and adaptability of the control. Before constructing the target motor mathematical model, the control system will construct an initial motor mathematical model based on the target orthogonal axis voltage equation, dynamic inductance parameter value, stall test and difference strategy. This model contains the basic physical parameters and characteristics of the motor, providing a basis for subsequent model adjustment, so that the control strategy can be optimized step by step based on the basic motor characteristics. The calculation of the dynamic inductance parameter value and the target orthogonal axis voltage equation is based on the initial orthogonal axis voltage equation, dynamic inductance, orthogonal axis flux equation and back electromotive force-flux relationship. These precise calculations enable the control system to better understand and predict the dynamic behavior of the motor, which is crucial for achieving accurate current control and optimizing motor performance. Finally, the initial motor mathematical model will be adjusted according to the required torque, orthogonal axis open-loop transfer function and zero-pole cancellation function to obtain a more accurate target motor mathematical model. This adjustment process enables the model to more accurately reflect the performance of the motor under actual working conditions, thereby making the current loop control more accurate and effective, improving the control accuracy, efficiency and response speed of the permanent magnet synchronous motor, and also enhancing the robustness of the system. Through this series of steps, the motor control system can ensure that the motor can operate efficiently and stably under various operating conditions, while reducing energy loss and improving vehicle performance.

[0107] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can refer to the above introduction, and will not be repeated later. Figure 3 , Figure 3This is a flow chart of the second embodiment of the control method of the permanent magnet synchronous motor current loop of the present application. Before step S10, the control method of the permanent magnet synchronous motor current loop also includes steps S01 to S03:

[0108] Step S01, calculating a reference orthogonal axis voltage equation according to an initial orthogonal axis voltage equation, a dynamic inductance, and an orthogonal axis flux equation;

[0109] It should be noted that the initial orthogonal axis voltage equation refers to a mathematical expression that describes the relationship between the motor direct axis (D axis) and quadrature axis (Q axis) voltage and the motor current, magnetic flux and other parameters based on the basic electromagnetic theory and control theory of the motor. This equation usually includes the electromagnetic induction of the motor, circuit theory and the physical properties of the motor, such as resistance, inductance and back electromotive force. In this embodiment, this equation is the basis for constructing a mathematical model of the motor for subsequent control strategy design and parameter adjustment. Dynamic inductance refers to the inductance value of the motor that changes under different working conditions (such as different currents and speeds). Unlike static inductance, dynamic inductance changes with the working state of the motor. This change is crucial for accurately controlling the motor current and achieving accurate motor control. In this embodiment, the dynamic inductance parameter value is obtained through experiments and calibration, and is used to describe the electromagnetic characteristics of the motor under different working conditions. The orthogonal axis flux equation describes the relationship between the flux on the direct and quadrature axes of the motor and the physical parameters (such as flux, inductance) and working state (such as current) of the motor. The flux is a measure of the magnetic field strength of the motor. For a permanent magnet synchronous motor, the flux is directly related to the torque generation and control of the motor. In this embodiment, the orthogonal axis flux equation is used to calculate the flux of the motor, which is very important for the precise control and performance optimization of the motor. The reference orthogonal axis voltage equation refers to the voltage equation used in actual control, which is calculated based on the initial orthogonal axis voltage equation in combination with the dynamic inductance and the orthogonal axis flux equation. This equation takes into account the actual working conditions and dynamic characteristics of the motor, and provides a more accurate voltage control reference, so that the motor control system can more accurately control the voltage and current of the motor, thereby achieving precise control of the motor torque and speed. In this embodiment, the reference orthogonal axis voltage equation is a key part of the motor control algorithm, which directly affects the performance and efficiency of the motor.

[0110] It can be understood that, first, the control system starts with the initial orthogonal axis voltage equation, which is an equation established based on the basic electromagnetic theory of the motor, describing the relationship between the voltage and current, flux and other parameters of the motor on the direct axis (D axis) and the quadrature axis (Q axis). Then, the control system incorporates the value of dynamic inductance into the calculation. Dynamic inductance refers to the inductance value that changes under different working conditions of the motor. This value is obtained through experiments and calibration, and reflects the electromagnetic characteristics of the motor under different currents and speeds. Next, the control system also considers the orthogonal axis flux equation, which describes the relationship between the motor flux and the physical parameters and working state of the motor. The flux is a measure of the strength of the motor magnetic field and is crucial for controlling the torque and speed of the motor. Finally, combining the initial orthogonal axis voltage equation, dynamic inductance and orthogonal axis flux equation, the control system calculates the reference orthogonal axis voltage equation. This equation takes into account the actual working conditions and dynamic characteristics of the motor, and provides a more accurate voltage control reference for motor control, so that the motor control system can more accurately control the voltage and current of the motor, and achieve accurate control of the motor torque and speed, thereby improving the performance and energy efficiency of the vehicle.

[0111] The initial orthogonal axis voltage equation is:

[0112]

[0113] Among them, u d 、u q is the voltage of D and Q axes, i d 、i q is the D and Q axis current, is the magnetic flux of D and Q axes, R s is the stator resistance, ω e is the angular velocity of the motor.

[0114] with i d 、i q and Related, Depends on temperature, i.e. with i d 、i q Related, that is Therefore, the derivative of flux with respect to current can be solved by partial derivative:

[0115]

[0116] Define dynamic inductance:

[0117]

[0118] Combined with the magnetic flux equation:

[0119]

[0120] in, is the permanent magnetic flux.

[0121] Thus, the reference orthogonal axis voltage equation is further obtained:

[0122]

[0123] Step S02, performing calibration test and curve fitting based on the reference orthogonal axis voltage equation to obtain a dynamic inductance parameter value;

[0124] It should be noted that the calibration test refers to a series of tests performed in actual motor operation, the purpose of which is to determine the key parameters used in the motor control algorithm. The calibration test mentioned in this embodiment refers in particular to an experiment used to obtain the dynamic inductance parameter value. These tests may include measuring the voltage and current of the motor at different currents and speeds in order to accurately capture the dynamic behavior of the motor. Through these measurements, the control system can determine the performance of the motor in actual operation and compare these performances with the theoretical model to calibrate and optimize the control algorithm. Curve fitting is a mathematical method for determining the best fit curve for a set of data points. In the field of motor control, curve fitting is often used to analyze data collected in calibration tests to determine the relationship between motor parameters (such as dynamic inductance) and motor operating conditions (such as current, speed). By using mathematical models (such as polynomials, exponentials or logarithmic functions) to approximate data points, the control system can obtain an accurate equation that describes the dynamic characteristics of the motor. In this embodiment, curve fitting is used to extract dynamic inductance parameter values ​​from calibration test data. Dynamic inductance parameter values ​​refer to the inductance values ​​of the motor that change under different working conditions. These values ​​are not fixed, but change with the working state of the motor (such as current, temperature and speed). Dynamic inductance parameter values ​​are crucial for precise control of the motor because they affect the electromagnetic characteristics and response of the motor. In this embodiment, the dynamic inductance parameter values ​​are obtained through calibration tests and curve fitting, and these values ​​are used to build and adjust the mathematical model of the motor to achieve more precise motor control.

[0125] It can be understood that, first, the control system uses the reference orthogonal axis voltage equation, which is a voltage equation obtained based on the basic electromagnetic characteristics and theoretical model of the motor, as the theoretical basis for the calibration test. Then, the calibration test is performed on the actual motor, that is, the voltage and current of the motor are measured at different working points (such as different current and speed conditions) to collect data. These data reflect the dynamic characteristics of the motor in actual operation, including the change of dynamic inductance. Next, these experimental data are used for curve fitting, and the relationship between dynamic inductance and parameters such as current and speed is determined by selecting the most appropriate function model to approximate the experimental data. Finally, through the equations obtained by curve fitting, the control system can accurately calculate the dynamic inductance parameter values ​​under different working conditions. These parameter values ​​are crucial to achieve accurate motor control because they directly affect the electromagnetic characteristics and response speed of the motor, so that the motor control system can more accurately predict and respond to the behavior of the motor, and improve the accuracy and efficiency of control.

[0126] As an example, the step of performing a calibration test and curve fitting based on the reference orthogonal axis voltage equation to obtain a dynamic inductance parameter value includes: performing a calibration test based on the reference orthogonal axis voltage equation under thermal steady state of the motor to obtain calibration data; fitting the orthogonal axis flux-current equation according to the calibration data; and obtaining a partial derivative of the orthogonal axis flux-current equation to obtain a dynamic inductance parameter value.

[0127] Calibration data refers to a series of measured values ​​collected in the calibration test, which are used to determine the actual performance parameters of the motor. In the steps mentioned in this embodiment, the calibration data specifically refers to the measured values ​​of voltage, current, flux and other parameters obtained by the calibration test with reference to the orthogonal axis voltage equation under the thermal steady state of the motor, that is, when the temperature of the motor reaches a stable state. These data are essential for calibrating the motor model and verifying the accuracy of the theoretical equation. The orthogonal axis flux-current equation refers to a mathematical equation that describes the relationship between the orthogonal axis flux and current of the motor. This equation is based on the electromagnetic theory of the motor and reflects how the flux of the motor changes with the change of current under specific conditions. In this embodiment, the large amount of data obtained through the calibration test can be used to determine the specific mathematical relationship between the orthogonal axis flux and current, that is, the orthogonal axis flux-current equation, using curve fitting technology. This equation is essential for understanding and predicting the electromagnetic behavior of the motor.

[0128] Based on the initial orthogonal axis voltage equation and orthogonal axis flux equation, the dynamic inductance parameter value is obtained by calibration. When the motor is in thermal steady state (temperature change is within ±10°), the flux value of the scanning current Map is: given by step size i d 、i q , record u d 、u q, calculate φ for different current combinations d ,φ q :

[0129] u d =R s ·i d -ω e φ q

[0130] u q =R s ·i q +ω e φ d

[0131] Fitting φ in Matlab using calibration data d with i d 、i q Equation and φ q with i d 、i q Equation, φ d to i d 、i q Find the partial derivative and calculate L dd , L dq ,φ q to i d 、i q Find the partial derivative and calculate L qd , L qq .

[0132] First, when the motor reaches thermal steady state, that is, the motor temperature is stable and no longer changes, the control system performs a calibration test based on the reference orthogonal axis voltage equation. By measuring the motor parameters such as voltage, current and flux at different working points, a set of calibration data is collected; these data reflect the electromagnetic characteristics of the motor in actual operation. Then, using these calibration data, the control system determines the mathematical relationship between the orthogonal axis flux and current through curve fitting technology, that is, the orthogonal axis flux-current equation, which can accurately describe how the flux changes with current. Finally, by taking the partial derivative of the orthogonal axis flux-current equation, the control system calculates the dynamic inductance parameter values, which represent the rate at which the motor inductance changes with current, and are crucial to achieving accurate motor control and optimizing motor performance, because they directly affect the motor's response speed and efficiency. Through this series of detailed steps, the control system can obtain accurate dynamic inductance parameter values, thereby improving the accuracy and efficiency of motor control.

[0133] Step S03, calculating and obtaining a target orthogonal axis voltage equation according to a back electromotive force-flux linkage relationship, a difference strategy and the reference orthogonal axis voltage equation.

[0134] It should be noted that the back-EMF-flux linkage relationship refers to a mathematical expression that describes the relationship between the back-EMF (Electromotive Force, EMF) and the flux linkage of the motor. Back-EMF is the voltage generated in the circuit due to the change in magnetic flux when the motor rotates, while flux linkage is a measure of the motor's magnetic field, which is related to the magnetic flux and area. In permanent magnet synchronous motors, the relationship between back-EMF and flux linkage can be used to estimate the back-EMF of the motor, which is then used in the control algorithm to achieve accurate current and torque control. The difference strategy is a numerical calculation method used to calculate the change of parameters by comparing the measured values ​​under different conditions. In motor control, this method can be used to calculate the change of motor parameters (such as flux linkage) with temperature or other variables. Specifically, by measuring the back-EMF under different conditions and then using these data points to estimate the change in flux linkage, the difference strategy provides an effective means of estimating the change of motor parameters. The target orthogonal axis voltage equation refers to the voltage equation obtained by adjusting the initial orthogonal axis voltage equation according to the actual working conditions and control requirements of the motor. This equation takes into account the dynamic characteristics and actual operating parameters of the motor, such as dynamic inductance, flux change, etc., to more accurately describe the voltage behavior of the motor under actual working conditions. The target orthogonal axis voltage equation is a key part of the motor control algorithm, which directly affects the control performance and efficiency of the motor.

[0135] It can be understood that, first, the control system uses the back-EMF-flux relationship to determine the back-EMF value of the motor under a specific flux by measuring the back-EMF and flux data of the motor under different working conditions. This is because the back-EMF is a key parameter in motor control and is directly related to the accuracy of the current loop control. Secondly, the system adopts a difference strategy to calculate the change in flux by comparing the back-EMF data under different working conditions. This can more accurately capture the characteristics of flux changes with working conditions and provide more accurate parameters for the motor model. Then, using these measured and calculated data, combined with the reference orthogonal axis voltage equation, the control system adjusts and optimizes the equation to obtain a target orthogonal axis voltage equation that is more in line with actual working conditions. The effect of this is that the motor control algorithm can more accurately predict and control the voltage and current of the motor, thereby achieving more refined motor torque and speed control, and improving the efficiency of the motor and the performance of the vehicle. Finally, through these steps, the motor control system can achieve efficient and precise control of the motor, optimizing the driving performance and energy efficiency of electric vehicles.

[0136] As an example, the step of calculating the target orthogonal axis voltage equation based on the back electromotive force-flux relationship, the difference strategy and the reference orthogonal axis voltage equation includes: performing a motor reverse drag test, and calculating the permanent magnet flux values ​​at different temperatures in combination with the back electromotive force-flux relationship and the difference strategy; forming a permanent magnet flux value point set with the permanent magnet flux values ​​and the corresponding temperatures; performing curve fitting on the permanent magnet flux value point set to obtain the permanent magnet flux-temperature equation; and calculating the target orthogonal axis voltage equation based on the permanent magnet flux-temperature equation and the reference orthogonal axis voltage equation.

[0137] The motor reverse drag test is a test method in which the motor is not operated as a driver, but is driven to rotate by an external force (such as a dynamometer) to simulate the working state of a generator. In this test, the input of the motor is disconnected, and the output of the motor (i.e., back EMF) is measured. This test is used to obtain the back EMF data of the motor at different temperatures and speeds, which is essential for understanding the electromagnetic characteristics of the motor. The permanent magnet flux linkage value refers to the measurement of the flux linkage generated by the permanent magnet in the permanent magnet synchronous motor. The flux linkage is a measure of the motor's magnetic field. For permanent magnet synchronous motors, it is directly related to the motor's back EMF and torque generation. The permanent magnet flux linkage value changes with temperature, so understanding its changes at different temperatures is very important for precise control of the motor. The permanent magnet flux linkage value point set refers to the set of permanent magnet flux linkage values ​​and corresponding temperatures obtained by reverse drag tests at different temperatures. This point set contains multiple sets of data, each of which corresponds to a specific temperature and the permanent magnet flux linkage value measured at that temperature. These data points are used for subsequent curve fitting to determine the mathematical model of the permanent magnet flux linkage changing with temperature. The permanent magnet flux-temperature equation is a mathematical equation obtained by curve fitting based on the permanent magnet flux value point set. This equation describes how the permanent magnet flux value changes with temperature and is the key to understanding and predicting the performance of the motor at different temperatures. Through this equation, the permanent magnet flux value at any given temperature can be calculated, which is crucial for the precise control and performance optimization of the motor.

[0138] Given the rated torque, the motor is continuously running, and the motor temperature gradually rises from T0 to T max , take the temperature step length of 20℃, whenever the temperature reaches the step length value, stop running, disconnect the controller and the three-phase line of the motor, use the dynamometer to reverse drag (let the motor run in generator mode) the motor under test, and record the back electromotive force E at the rated speed E_Speed ​​of the motor. e_speed and the back electromotive force E at the peak speed Max_Speed max_speed .

[0139] According to the relationship table between back electromotive force and magnetic flux:

[0140]

[0141] φ is the permanent magnet flux, E peak is the peak value of the motor back EMF, p is the number of motor pole pairs, and n is the motor speed.

[0142] Use the difference method to calculate the permanent magnet flux size at different temperatures:

[0143]

[0144] Among them, φ f_Tstep is the size of permanent magnet flux at different temperatures.

[0145] First, through the motor reverse drag test, the motor is driven to rotate by an external force when it is not powered, and the back electromotive force generated by the motor at different temperatures is measured. Then, the permanent magnet flux value at these temperatures is calculated using the back electromotive force-flux relationship and the difference strategy (the back electromotive force was used before, and it must be converted to flux before fitting). This step is to obtain the actual data of the flux change with temperature. Next, these measured permanent magnet flux values ​​are combined with their corresponding temperature values ​​to form a permanent magnet flux value point set. This point set contains multiple data points, each of which represents a specific temperature and corresponding flux value. Then, these point sets are analyzed using curve fitting technology to obtain a mathematical model that describes the change of permanent magnet flux with temperature, namely the permanent magnet flux-temperature equation, which can accurately predict the flux value of the motor at different temperatures. Finally, the target orthogonal axis voltage equation is calculated by combining the permanent magnet flux-temperature equation and the reference orthogonal axis voltage equation. This equation takes into account the influence of flux changes with temperature, and provides a more accurate voltage control reference for motor control, so that the motor control system can more accurately control the voltage and current of the motor, realize precise control of the motor torque and speed, and improve the performance of the motor and the energy efficiency of the whole vehicle. Through this series of detailed steps, the motor control system can achieve efficient and precise control of the motor, and optimize the driving performance and energy efficiency of electric vehicles.

[0146] Please refer to Figure 4 , Figure 4A schematic diagram of a permanent magnet flux temperature curve provided for the second embodiment of the control method for the current loop of a permanent magnet synchronous motor of the present application, wherein the horizontal axis in the figure represents temperature (T), and the vertical axis represents permanent magnet flux (Fai or φ), and the points in the figure represent the permanent magnet flux values ​​obtained by experimental measurement at different temperatures. The curve is obtained by curve fitting based on these measurement data, which describes the trend that the permanent magnet flux decreases with increasing temperature. This relationship is crucial for motor control because the change in permanent magnet flux affects the electromagnetic performance and control accuracy of the motor. In this embodiment, the permanent magnet flux is measured at different temperatures through a motor reverse drag test, and then the data points are calculated using a difference strategy. Then, the curve fitting is performed on these data points to obtain a permanent magnet flux-temperature equation, which can accurately predict the flux value of the motor at different temperatures. Through this equation, the motor control system can adjust the control strategy in real time to compensate for the influence of temperature changes on the flux, thereby achieving more accurate motor control and improving the performance and energy efficiency of the vehicle.

[0147] The permanent magnet flux-temperature equation obtained by fitting is:

[0148] φ f =p1*T 2 +p2*T+p3

[0149] Among them, p1=0.000001023, p2=-0.0006109, p3=0.585.

[0150] Since p1 is small, the p1 term can be ignored relative to the base value 0.585Wb (magnetic flux dimension). Therefore, the differential of permanent magnet magnetic flux with respect to temperature is:

[0151]

[0152] The voltage equation can be updated as follows:

[0153]

[0154] This embodiment calculates the reference orthogonal axis voltage equation based on the initial orthogonal axis voltage equation, dynamic inductance and orthogonal axis flux equation; performs calibration test and curve fitting based on the reference orthogonal axis voltage equation to obtain the dynamic inductance parameter value; calculates the target orthogonal axis voltage equation based on the back electromotive force-flux relationship, the difference strategy and the reference orthogonal axis voltage equation. The control system first calculates the reference orthogonal axis voltage equation based on the initial orthogonal axis voltage equation, the dynamic inductance and the orthogonal axis flux equation. This step is to establish a preliminary voltage control model by combining the basic electromagnetic characteristics and working state of the motor, providing a theoretical basis for current control, so that the control system can perform preliminary current control according to the actual working conditions of the motor. Then, based on this reference orthogonal axis voltage equation, calibration test and curve fitting are performed to obtain the dynamic inductance parameter value. This process involves collecting voltage and current data under different working conditions on the actual motor, and accurately determining the relationship between dynamic inductance and current, temperature and other parameters through curve fitting technology, providing more accurate motor model parameters, making the current loop control more accurate and adaptable, and improving the accuracy of control. Finally, the target orthogonal axis voltage equation is calculated based on the back electromotive force-flux relationship, the difference strategy, and the reference orthogonal axis voltage equation. This step uses the relationship between the motor's back electromotive force and flux, as well as the data on the change of flux with temperature, to adjust the reference voltage equation and obtain a target voltage equation that is more in line with actual working conditions, so that the motor control system can more accurately predict and control the motor's voltage and current, improve the control accuracy and system efficiency, and optimize the driving performance and energy efficiency of electric vehicles. Through this series of steps, the motor control system can achieve efficient and precise control of the motor, improving the performance and energy efficiency of the entire vehicle.

[0155] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the control method of the permanent magnet synchronous motor current loop of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0156] The present application also provides a control device for a permanent magnet synchronous motor current loop, please refer to Figure 5 , the control device of the permanent magnet synchronous motor current loop comprises:

[0157] A data acquisition module 10 is used to acquire an input voltage;

[0158] The control module 20 is used to control the current loop according to the target motor mathematical model and the input voltage, the target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function, the initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy, the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship.

[0159] In one embodiment, the control module 20 is also used to calculate a reference orthogonal axis voltage equation based on the initial orthogonal axis voltage equation, the dynamic inductance and the orthogonal axis flux equation; perform calibration tests and curve fitting based on the reference orthogonal axis voltage equation to obtain a dynamic inductance parameter value; and calculate a target orthogonal axis voltage equation based on a back electromotive force-flux relationship, a difference strategy and the reference orthogonal axis voltage equation.

[0160] In one embodiment, the control module 20 is further used to calculate the permanent magnet flux linkage values ​​at different temperatures through a motor reverse drag test in combination with a back electromotive force-flux linkage relationship and a difference strategy; the permanent magnet flux linkage values ​​and corresponding temperatures form a permanent magnet flux linkage value point set; curve fitting is performed on the permanent magnet flux linkage value point set to obtain a permanent magnet flux linkage-temperature equation; and a target orthogonal axis voltage equation is calculated based on the permanent magnet flux linkage-temperature equation and the reference orthogonal axis voltage equation.

[0161] In one embodiment, the control module 20 is also used to perform a calibration test under the thermal steady state of the motor based on the reference orthogonal axis voltage equation to obtain calibration data; fit the orthogonal axis flux-current equation according to the calibration data; and calculate the partial derivative of the orthogonal axis flux-current equation to obtain a dynamic inductance parameter value.

[0162] In one embodiment, the control module 20 is also used to calculate the stator resistance of the motor in thermal steady state through a stall test in combination with the direct-axis voltage equation and the difference strategy; and to construct an initial motor mathematical model according to the target direct-axis voltage equation, the stator resistance and the dynamic inductance parameter value.

[0163] In one embodiment, the control module 20 is further used to obtain a current ramp function and a current loop proportional-integral parameter according to at least one of a required torque, an orthogonal axis open-loop transfer function, and a zero-pole cancellation function; obtain a motor angular velocity, a wave transmission delay, a resolver signal sampling delay, and a rotor position angle; calculate a target angular velocity according to the motor angular velocity, the wave transmission delay, and the resolver signal sampling delay; calculate a voltage vector angle according to the rotor position angle and the target angular velocity; and adjust the initial motor mathematical model according to the voltage vector angle, the current ramp function, and the current loop proportional-integral parameter to obtain a target motor mathematical model.

[0164] In one embodiment, the control module 20 is also used to calculate a given current value based on the required torque; calculate the module execution cycle and the pulse width modulation interruption cycle based on the given current value; design the current ramp function based on the module execution cycle and the pulse width modulation interruption cycle; and calculate the current loop proportional-integral parameters based on the orthogonal axis open-loop transfer function and the zero-pole cancellation function.

[0165] The control device of the permanent magnet synchronous motor current loop provided by the present application adopts the control method of the permanent magnet synchronous motor current loop in the above-mentioned embodiment, which can solve the technical problem of how to improve the control accuracy, response speed and robustness of the permanent magnet synchronous motor current loop. Compared with the prior art, the beneficial effects of the control device of the permanent magnet synchronous motor current loop provided by the present application are the same as the beneficial effects of the control method of the permanent magnet synchronous motor current loop provided by the above-mentioned embodiment, and other technical features in the control device of the permanent magnet synchronous motor current loop are the same as the features disclosed in the above-mentioned embodiment method, which will not be repeated here.

[0166] The present application provides a control device for a permanent magnet synchronous motor current loop, the control device for a permanent magnet synchronous motor current loop comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the control method for the permanent magnet synchronous motor current loop in the above-mentioned embodiment one.

[0167] Reference below Figure 6, which shows a schematic diagram of the structure of a control device for a permanent magnet synchronous motor current loop suitable for implementing an embodiment of the present application. The control device for the permanent magnet synchronous motor current loop in the embodiment of the present application may include but is not limited to mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 6 The control device of the permanent magnet synchronous motor current loop shown is only an example and should not bring any limitation to the function and scope of use of the embodiments of the present application.

[0168] like Figure 6 As shown, the control device of the permanent magnet synchronous motor current loop may include a processing device 1001 (such as a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. Various programs and data required for the operation of the control device of the permanent magnet synchronous motor current loop are also stored in the RAM1004. The processing device 1001, the ROM1002 and the RAM1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 1003 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 1009. The communication device 1009 can allow the control device of the permanent magnet synchronous motor current loop to communicate with other devices wirelessly or by wire to exchange data. Although the figure shows a control device of the permanent magnet synchronous motor current loop with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be implemented or have alternatively.

[0169] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0170] The control device of the permanent magnet synchronous motor current loop provided by the present application adopts the control method of the permanent magnet synchronous motor current loop in the above-mentioned embodiment, which can solve the technical problem of how to improve the control accuracy, response speed and robustness of the permanent magnet synchronous motor current loop. Compared with the prior art, the beneficial effects of the control device of the permanent magnet synchronous motor current loop provided by the present application are the same as the beneficial effects of the control method of the permanent magnet synchronous motor current loop provided by the above-mentioned embodiment, and other technical features in the control device of the permanent magnet synchronous motor current loop are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0171] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0172] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0173] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, the computer-readable program instructions being used to execute the control method for the permanent magnet synchronous motor current loop in the above-mentioned embodiment.

[0174] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0175] The computer-readable storage medium may be included in the control device of the permanent magnet synchronous motor current loop; or may exist independently without being assembled into the control device of the permanent magnet synchronous motor current loop.

[0176] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by the control device of the permanent magnet synchronous motor current loop, the control device of the permanent magnet synchronous motor current loop: obtains the input voltage; controls the current loop according to the target motor mathematical model and the input voltage, the target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function, the initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy, the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship.

[0177] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0178] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0179] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0180] The readable storage medium provided in the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned control method of the permanent magnet synchronous motor current loop, and can solve the technical problem of how to improve the control accuracy, response speed, and robustness of the permanent magnet synchronous motor current loop. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in the present application are the same as the beneficial effects of the control method of the permanent magnet synchronous motor current loop provided in the above-mentioned embodiment, and will not be repeated here.

[0181] The present application also provides a computer program product, including a computer program, which implements the steps of the control method of the permanent magnet synchronous motor current loop as described above when the computer program is executed by a processor.

[0182] The computer program product provided by the present application can solve the technical problem of how to improve the control accuracy, response speed and robustness of the permanent magnet synchronous motor current loop. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as the beneficial effects of the control method of the permanent magnet synchronous motor current loop provided by the above embodiment, which will not be repeated here.

[0183] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for controlling a current loop of a permanent magnet synchronous motor, characterized in that: The method comprises: Get the input voltage; The current loop is controlled according to the target motor mathematical model and the input voltage. The target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function. The initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy. The dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship.

2. The method according to claim 1, characterized in that The generation process of the dynamic inductance parameter value and the target orthogonal axis voltage equation includes: The reference orthogonal axis voltage equation is calculated based on the initial orthogonal axis voltage equation, the dynamic inductance and the orthogonal axis flux equation; Performing calibration test and curve fitting based on the reference orthogonal axis voltage equation to obtain a dynamic inductance parameter value; The target orthogonal axis voltage equation is calculated based on the back electromotive force-flux linkage relationship, the difference strategy and the reference orthogonal axis voltage equation.

3. The method according to claim 2, characterized in that The step of calculating the target orthogonal axis voltage equation according to the back electromotive force-flux linkage relationship, the difference strategy and the reference orthogonal axis voltage equation comprises: Through the motor reverse drag test, the permanent magnet flux value at different temperatures is calculated by combining the back electromotive force-flux relationship and the difference strategy; The permanent magnet flux linkage value and the corresponding temperature form a permanent magnet flux linkage value point set; Performing curve fitting on the permanent magnet flux linkage value point set to obtain a permanent magnet flux linkage-temperature equation; The target orthogonal axis voltage equation is calculated according to the permanent magnet flux linkage-temperature equation and the reference orthogonal axis voltage equation.

4. The method according to claim 2, characterized in that The step of performing calibration test and curve fitting based on the reference orthogonal axis voltage equation to obtain a dynamic inductance parameter value comprises: Performing a calibration test under thermal steady state of the motor based on the reference orthogonal axis voltage equation to obtain calibration data; The orthogonal axis flux-current equation is obtained by fitting according to the calibration data; The partial derivative of the orthogonal axis flux-current equation is obtained to obtain the dynamic inductance parameter value.

5. The method according to claim 1, characterized in that The target orthogonal axis voltage equation includes a direct axis voltage equation, and the construction process of the initial motor mathematical model includes: The stator resistance of the motor in thermal steady state is calculated by a locked-rotor test in combination with the direct-axis voltage equation and the difference strategy; An initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the stator resistance and the dynamic inductance parameter value.

6. The method according to claim 1, characterized in that The process of constructing the mathematical model of the target motor includes: Obtaining a current ramp function and a current loop proportional-integral parameter according to at least one of a required torque, a rectangular axis open-loop transfer function, and a zero-pole cancellation function; Obtain the motor angular velocity, wave transmission delay, resolver signal sampling delay and rotor position angle; The target angular velocity is calculated according to the motor angular velocity, the wave transmission delay and the resolver signal sampling delay; Calculate a voltage vector angle according to the rotor position angle and the target angular velocity; The initial motor mathematical model is adjusted according to the voltage vector angle, the current ramp function and the current loop proportional-integral parameter to obtain a target motor mathematical model.

7. The method according to claim 6, characterized in that The step of obtaining the current ramp function and the current loop proportional-integral parameter according to at least one of the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation function comprises: The given current value is calculated based on the required torque; Calculating the module execution period and the pulse width modulation interruption period according to the given current value; Designing a current ramp function according to the module execution cycle and the pulse width modulation interruption cycle; The current loop proportional-integral parameters are calculated based on the orthogonal axis open-loop transfer function and the zero-pole cancellation function.

8. A control device for a current loop of a permanent magnet synchronous motor, characterized in that: The device comprises: A data acquisition module, used for acquiring input voltage; A control module is used to control the current loop according to a target motor mathematical model and the input voltage, wherein the target motor mathematical model is obtained by adjusting the initial motor mathematical model according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function, and the initial motor mathematical model is constructed according to the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy, and the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated according to at least three of the initial orthogonal axis voltage equation, the dynamic inductance, the orthogonal axis flux equation and the back electromotive force-flux relationship.

9. A control device for a permanent magnet synchronous motor current loop, characterized in that: The device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the method for controlling a current loop of a permanent magnet synchronous motor according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the control method of the permanent magnet synchronous motor current loop as described in any one of claims 1 to 7 are implemented.

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