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

Abstract

The present application discloses a control method, device, equipment and storage medium for a permanent magnet synchronous motor current loop, and relates to the technical field of electric vehicle drive motors. The control method for the permanent magnet synchronous motor current loop includes: 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 an initial model, and the adjustment is based on the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function. The initial model is constructed based on the target orthogonal axis voltage equation, the dynamic inductance parameter value, the stall test and the difference strategy, wherein the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated from 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 present application improves the control accuracy, efficiency and response speed of the permanent magnet synchronous motor, and also enhances the robustness of the system.

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 current loop of a permanent magnet synchronous motor. Background Art

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

[0003] Current current loop control for permanent magnet synchronous motors primarily utilizes two methods: feedforward voltage decoupling and feedback voltage decoupling. Feedforward decoupling improves system response by proactively compensating for motor parameter changes, while feedback decoupling utilizes feedback current to decouple cross-coupling terms. While these methods can improve motor control performance to a certain extent, they each have limitations.

[0004] While feedforward decoupling can improve system response speed, it is sensitive to changes in motor parameters. Once these motor parameters change, its accuracy becomes difficult to guarantee. While feedback decoupling can achieve decoupling through feedback current, this method introduces delays in the system, impacting response speed. Furthermore, neither method effectively addresses the strong coupling between the Direct Axis and Quadrature Axis (DQ axes), making complete decoupling impossible. This impacts control accuracy and the system's dynamic anti-interference capability. Therefore, improving the control accuracy, response speed, and robustness of the permanent magnet synchronous motor current loop has become a pressing issue.

[0005] The above content is only used to assist in understanding the technical solution of this application and does not constitute an admission that the above content is prior art. Summary of the Invention

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

[0007] To achieve the above objectives, the present application proposes a method for controlling a current loop of a permanent magnet synchronous motor, 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 locked-rotor test and the difference strategy. The dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated based on 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, dynamic inductance and orthogonal axis flux equation;

[0012] Performing calibration tests 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 based on the back electromotive force-flux linkage relationship, the difference strategy, and the reference orthogonal axis voltage equation includes:

[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 values ​​and corresponding temperatures 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 based on 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 includes:

[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] Obtaining the orthogonal axis flux-current equation 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 process of constructing the initial motor mathematical model includes:

[0024] The stator resistance of the motor in thermal steady state is calculated by using the locked-rotor test and combining 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, an orthogonal axis open-loop transfer function, and a zero-pole cancellation function;

[0028] Obtain 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] Calculating 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 a module execution period and a 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 locked-rotor test, and the difference strategy, and the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated based on 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 purpose, the present application also proposes a control device for the current loop of a permanent magnet synchronous motor, which includes: a memory, a processor, and a computer program stored on the memory and runnable on the processor, and the computer program is configured to implement the steps of the control method of the current loop of the permanent magnet synchronous motor 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. 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] Obtaining an input voltage; controlling the current loop based on a target motor mathematical model and the input voltage. The target motor mathematical model is obtained by adjusting an initial motor mathematical model based on the required torque, an orthogonal axis open-loop transfer function, and a zero-pole cancellation function. The initial motor mathematical model is constructed based on a target orthogonal axis voltage equation, a dynamic inductance parameter value, a locked-rotor test, and a difference strategy. The dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated based on 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 motor input voltage using a voltage sensor. Accurate input voltage information provides basic data for current loop control, ensuring that the control strategy can be accurately adjusted based on the actual voltage. Next, the current loop is controlled using this input voltage and the adjusted target motor mathematical model. This model integrates factors such as the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation function, making the control strategy more adaptable to actual operating conditions and improving control accuracy and adaptability. Before constructing the target motor mathematical model, the control system constructs an initial motor mathematical model based on the target orthogonal voltage equation, dynamic inductance parameter values, locked-rotor tests, and an interpolation strategy. This model incorporates the motor's fundamental physical parameters and characteristics, providing a foundation for subsequent model adjustments, enabling the control strategy to be gradually optimized based on these fundamental motor characteristics. The dynamic inductance parameter values ​​and target orthogonal voltage equation are calculated based on the initial orthogonal voltage equation, dynamic inductance, orthogonal flux equation, and back-EMF-flux relationship. These precise calculations enable the control system to better understand and predict the motor's dynamic behavior, which is crucial for achieving precise current control and optimizing motor performance. Finally, the initial motor mathematical model is adjusted based on the required torque, orthogonal open-loop transfer function, and zero-pole cancellation function to obtain a more accurate target motor mathematical model. This adjustment process ensures that the model more accurately reflects the motor's performance under actual operating conditions, resulting in more precise and effective current loop control, improving the control accuracy, efficiency, and responsiveness of the permanent magnet synchronous motor, while also enhancing the system's robustness. 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

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

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

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

[0050] Figure 4 A schematic diagram of a permanent magnet flux temperature curve provided in Example 2 of the control method for the 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 the control device of the permanent magnet synchronous motor current loop 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 explained 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 merely used to explain the technical solutions of the present application and are not intended 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 (PMSMs) are widely used in electric vehicles due to their high efficiency and performance. Their torque control performance, which is determined by current loop control, directly impacts the vehicle's driving experience. Existing current loop control methods primarily include feedforward voltage decoupling and feedback voltage decoupling. The former improves response speed through pre-compensation but is sensitive to parameter changes, while the latter utilizes feedback current decoupling but introduces latency. Neither approach effectively addresses the strong coupling between the DQ axis, compromising control accuracy and system dynamic stability. Therefore, developing more advanced current loop control technologies is crucial for 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 target motor mathematical model 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 actual working conditions and improves the accuracy of control and motor performance.

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

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

[0060] In this embodiment, the method for controlling the current loop of the permanent magnet synchronous motor 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] As you can see, first, by connecting a voltage sensor to the power input of the vehicle's motor, it directly measures the voltage value provided by the battery or power management system. Second, the sensor converts the detected analog voltage signal into a digital signal that can be read and analyzed by the vehicle's motor control system.

[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 locked-rotor test and the difference strategy, the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated based on 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 a motor mathematical model adjusted based on actual application requirements. This model takes into account the required torque, the orthogonal open-loop transfer function, and the zero-pole cancellation function to more accurately predict and control motor behavior. It is derived from the initial motor mathematical model and the purpose of the adjustment is to make the model more closely resemble the actual motor performance under specific operating conditions. The current loop refers to the control loop in the motor control system used to maintain the motor current at a set value. It typically 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 for precise motor control. The required torque refers to the torque required from the motor based on the driving requirements of the electric vehicle or other application requirements. The orthogonal open-loop transfer function is a mathematical expression that describes the relationship between the motor input (such as voltage) and output (such as current or speed) under open-loop conditions. The open-loop transfer functions of the direct (D) and quadrature (Q) axes help design controllers to achieve precise control of motor performance. The zero-pole cancellation function is a process used in motor control system design to simplify the control algorithm by leveraging the system's inherent characteristics (such as zeros and poles). This process reduces the number of parameters in the PI controller and simplifies the control algorithm design. The initial motor mathematical model is constructed based on the fundamental physical principles and characteristics of the motor. It includes basic motor equations, such as the voltage equation and the flux equation, and is used to describe the motor's static and dynamic behavior. The target orthogonal axis voltage equation is obtained by adjusting the initial voltage equation based on the motor's actual operating conditions and control requirements. This equation takes into account factors such as the dynamic inductance parameter value and locked-rotor test results to more accurately describe the motor's voltage behavior under actual operating conditions. The dynamic inductance parameter value refers to the change in the motor's inductance under different operating conditions. These values ​​are crucial for accurately controlling the motor's current because they affect the motor's electromagnetic characteristics. The locked-rotor test is a motor testing method that applies resistance to the motor shaft to prevent rotation while simultaneously measuring the motor's voltage and current at different currents to determine certain motor parameters, 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 in 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 voltage and current, flux and other parameters of the motor 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 (such as flux, inductance) and working state (such as current) of the motor.The back-EMF-flux relationship describes the relationship between the motor's back-EMF (the voltage generated when the motor operates as a generator) and the motor's flux. This relationship is very important for calculating the motor's 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 change 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 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 operating conditions. The control system then adjusts the initial motor mathematical model based on 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 the 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 quickly and accurately respond to external load changes and internal parameter fluctuations, thereby achieving precise control of the motor torque and speed, thereby improving the vehicle's power performance and energy efficiency.

[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 locked-rotor test and combining the direct axis voltage equation and the difference strategy to calculate the stator resistance of the motor in the thermal steady state; and constructing the initial motor mathematical model based on the target orthogonal axis voltage equation, the stator resistance and the dynamic inductance parameter value.

[0068] The direct-axis voltage equation is a mathematical expression that describes the relationship between the voltage on the direct axis (D-axis) of a permanent magnet synchronous motor and parameters such as current and flux linkage. This equation, typically based on the motor's electromagnetic induction law and circuit theory, is used to calculate the voltage response on the direct axis and is a key equation in motor control and analysis. A locked-rotor test is a motor testing method used to measure the electrical characteristics of a motor when it is unable to rotate. In this test, the motor shaft is fixed or subjected to sufficient resistance to prevent rotation. Then, varying currents are applied and the motor's voltage and current responses are measured. This data is used to determine motor parameters such as stator resistance and inductance. The interpolation strategy is a numerical calculation method that calculates parameter changes by comparing two or more measured values ​​under different conditions. In motor control, this method can be used to calculate changes in motor parameters (such as resistance) by measuring voltage at different currents and using these data points to estimate the parameter values. Motor thermal steady-state refers to the state in which the motor's internal temperature reaches a stable value after a period of continuous operation. In this state, the motor's temperature rise stabilizes, and the motor's thermal performance parameters (such as resistance) are relatively stable. This is crucial for accurately measuring motor parameters and designing control strategies. Stator resistance refers to the resistance of the motor's stator windings. This is a critical motor parameter that affects motor efficiency and thermal management. Understanding stator resistance is crucial for accurately calculating the motor's voltage and current response in motor control. The initial motor mathematical model is constructed based on the motor's fundamental physical principles and known parameters. This model includes the motor's voltage equation, flux equation, torque equation, and other equations, and is used to describe the motor's static and dynamic behavior. The initial model is the foundation of motor control, providing a theoretical basis for subsequent control strategy design and parameter adjustment. In practical 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 at thermal steady state (65°C) and convert the resistance voltage drop R s ·i d As feedforward compensation, to reduce the sensitivity of current loop decoupling. Based on the D-axis voltage equation, using the locked rotor test, i q =0 control, i d Given rated current i e and peak current i max , and record the D-axis voltage u when the temperature is 65℃ 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, a mathematical expression that describes the relationship between the voltage on the motor's direct axis and parameters such as current and flux linkage. Next, a locked-rotor test is performed, imposing resistance on the motor shaft to prevent rotation. At a thermal steady-state temperature of 65°C, the D-axis (direct-axis) voltage and current are recorded at both the rated and peak currents. Next, combining the direct-axis voltage equation with a difference strategy, the voltage values ​​measured at different currents are compared to calculate the motor's stator resistance at thermal steady-state. This resistance is a key parameter in motor control, impacting motor efficiency and thermal management. 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 values. This model forms the foundation for motor control algorithm development, describing the motor's static and dynamic behavior and providing a theoretical basis for subsequent control strategy design and parameter tuning. Through this detailed process, the motor control system can more accurately simulate and predict motor behavior, enabling more precise control.

[0074] As an example, the process of constructing the target motor mathematical model includes: obtaining a current ramp function and a current loop proportional-integral parameter based on 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 based on the motor angular velocity, the wave transmission delay, and the resolver signal sampling delay; calculating the voltage vector angle based on the rotor position angle and the target angular velocity; and adjusting the initial motor mathematical model based on the voltage vector angle, the current ramp function, and the current loop proportional-integral parameter to obtain the target motor mathematical model.

[0075] Required torque refers to the torque a motor needs to produce. This torque is determined based on the driving demands of an electric vehicle or other application requirements. In a motor control system, the required torque is one of the inputs to the current loop control algorithm, used to calculate the required current to produce the corresponding torque. The orthogonal open-loop transfer function describes the relationship between the motor's input (such as voltage) and output (such as current or speed) under open-loop conditions. For both the direct (D) and quadrature (Q) axes, these functions aid in controller design to achieve precise control of motor performance. The zero-pole cancellation function utilizes system characteristics (such as zeros and poles) to simplify the control algorithm in motor control system design. This zero-pole cancellation reduces the number of parameters in the PI controller and simplifies the control algorithm design. The current ramp function is a functional module that calculates the set current based on the required torque. It is typically placed within a longer task execution cycle (such as 1ms) to smoothly adjust the current command, reducing the current loop's regulation amplitude and torque ripple. 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 PI controller's response speed and stability to current deviations and need to be adjusted based on the motor's characteristics and control requirements. The motor angular velocity refers to the rotational speed of the motor rotor, typically measured in radians per second (rad / s). It is a critical parameter in motor control, affecting the motor's torque and speed control. Transmission delay refers to the time delay between the controller issuing a control signal and the inverter actually outputting the corresponding voltage. This delay affects the motor's response speed and control accuracy. Resolver signal sampling delay refers to the time delay between the controller sampling the resolver (resolver) signal and the controller sampling it. This delay is related to the software and hardware filtering parameters and the motor speed and requires calibration. The rotor position angle refers to the position of the motor rotor relative to the stator. This angle is crucial for vector-controlled motors because it determines the position of the rotor's magnetic field relative to the stator. The target angular velocity refers to the ideal angular velocity of the motor rotor, calculated based on the motor control system's control objectives. This angular velocity is the target the control system attempts to achieve and guides the actual operation of the motor. The voltage vector angle is the angle between the voltage vector applied to the motor and the motor's rotor magnetic field. This angle is crucial for torque and flux control in vector-controlled motors. The target motor mathematical model is a motor mathematical model adjusted to the actual application requirements. This model considers factors such as the required torque, the orthogonal open-loop transfer function, and the zero-pole cancellation function to more accurately predict and control motor behavior. It is derived from the initial motor mathematical model, adjusted to more closely match the performance of the actual motor under specific operating conditions.

[0076] By 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 effects between the DQ axis inductors and takes into account the time-varying nature of all motor parameters. The DQ axis current loops contain feedforward decoupling terms and cross-decoupling terms, respectively. Similarly, the motor is modeled based on precise voltage equations.

[0077] First, the control system receives commands from the vehicle control unit to determine the required torque. It then calculates the current ramp function (the slope of the current over time) and the proportional-integral parameters of the current loop based on the orthogonal open-loop transfer function (a mathematical model that describes the relationship between the motor's input and output when there is no feedback) and the zero-pole cancellation function (a process that leverages the system's inherent characteristics to simplify the control algorithm). These parameters determine the PI controller's response speed and stability to current deviations. Second, the system obtains the motor's real-time angular velocity by sampling data from the motor's angular velocity sensor at high speed. The system also measures the time difference between the inverter issuing the PWM signal and the motor actually receiving the voltage (called the transmission delay) and the time difference between the resolver signal being sampled by the controller (called the resolver signal sampling delay). These delays are critical for correcting the timing of control signals. The system then combines the motor's angular velocity, the transmission delay, and the resolver signal sampling delay to calculate the target angular velocity through an algorithm. This is the ideal angular velocity the motor should achieve, which guides actual motor operation. Next, based on the rotor position angle and target angular velocity, the system uses a vector control algorithm to calculate the voltage vector angle—the angle between the voltage vector and the rotor magnetic field—which is critical for controlling the motor's torque and flux. 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 constructed based on the fundamental physical principles of the motor. These adjustments yield a more accurate target motor mathematical model that more accurately simulates the motor's actual behavior, enabling precise control of the motor and improving the vehicle's overall power performance and energy efficiency. Through this series of precise calculations and adjustments, the motor control system ensures efficient and stable operation of the motor under various operating conditions, while reducing energy loss and enhancing vehicle performance.

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

[0079] In the current controller part, the feedforward decoupling and cross decoupling of the static inductance and dynamic inductance of the DQ axis are carried out, 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 includes a feedforward term (k pdq1 and k pqd1 ), these feedforward terms are multiplied by 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 signal transmission and processing delay 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 make corrections 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 filter parameters, that is, it is related to the motor speed and can be obtained through calibration. At different speeds, given i 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 of the resolver signal t r The system delay is compensated based on 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 characteristics 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 continuously adjusts through a feedback loop to ensure the motor operates precisely according to the required torque. It also accounts for the time-varying nature of motor parameters, such as dynamic inductance, and the effect of temperature on permanent magnet flux linkage, enabling high-performance current loop control. Through this detailed series of steps, the motor control system achieves efficient and precise control of the motor, optimizing the drivability 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 the module execution cycle and the 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 motor current. This cycle determines the response speed of the current loop control.

[0088] Design of a set current ramp: The functional module that calculates the set current based on the required torque is typically placed within the 1ms task execution cycle, while the feedback current and current loop modules are placed within the 100us PWM (pulse width modulation) interrupt cycle. This allows the set current to gradually transition from the previous 1ms cycle's command current to the current demanded current within 10 current loop execution cycles, thereby reducing the current loop's single adjustment amplitude and thus lowering torque ripple at medium and high speeds.

[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 function module given the current.

[0091] First, the control system calculates the required torque based on the electric vehicle's driving demands. This torque value is then used to determine the required current value for the motor. This serves as the target current for the current loop control algorithm, ensuring the motor can produce the required torque. Second, based on the required current value, the control system determines the execution cycle of the current calculation module, typically 1 millisecond, and the PWM (pulse width modulation) interrupt cycle, typically 100 microseconds. These two cycles determine the update frequency of the current control algorithm and the adjustment frequency of the PWM signal. The control system then designs a current ramp function based on these cycles. This function smoothly adjusts the current command within the module execution cycle, reducing the current loop's regulation amplitude, lowering torque ripple, and improving the smoothness and stability of motor control. Finally, the control system calculates the proportional-integral parameters of the current loop based on the orthogonal open-loop transfer function and the zero-pole cancellation function. These parameters determine the response speed and stability of the PI controller to current deviations and are crucial for achieving precise current control, ensuring that the motor can quickly and accurately respond to changes in torque demand. Through this series of precise calculations and adjustments, the motor control system ensures efficient and stable motor operation under various operating 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] This embodiment provides a method for controlling a current loop of a permanent magnet synchronous motor. The method comprises obtaining an input voltage and controlling the current loop based on a target motor mathematical model and the input voltage. The target motor mathematical model is obtained by adjusting an initial motor mathematical model based on the required torque, an orthogonal axis open-loop transfer function, and a zero-pole cancellation function. The initial motor mathematical model is constructed based on a target orthogonal axis voltage equation, a dynamic inductance parameter value, a locked-rotor test, and a difference strategy. The dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated based on 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 motor input voltage using a voltage sensor. Accurate input voltage information provides basic data for current loop control, ensuring that the control strategy can be accurately adjusted based on the actual voltage. The current loop is then controlled using this input voltage and the adjusted target motor mathematical model. This model integrates factors such as the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation function, making the control strategy more adaptable to actual operating conditions and improving control accuracy and adaptability. Before constructing the target motor mathematical model, the control system constructs an initial motor mathematical model based on the target orthogonal voltage equation, dynamic inductance parameter values, locked-rotor tests, and an interpolation strategy. This model incorporates the motor's fundamental physical parameters and characteristics, providing a foundation for subsequent model adjustments, enabling the control strategy to be gradually optimized based on these fundamental motor characteristics. The dynamic inductance parameter values ​​and target orthogonal voltage equation are calculated based on the initial orthogonal voltage equation, dynamic inductance, orthogonal flux equation, and back-EMF-flux relationship. These precise calculations enable the control system to better understand and predict the motor's dynamic behavior, which is crucial for achieving precise current control and optimizing motor performance. Finally, the initial motor mathematical model is adjusted based on the required torque, orthogonal open-loop transfer function, and zero-pole cancellation function to obtain a more accurate target motor mathematical model. This adjustment process ensures that the model more accurately reflects the motor's performance under actual operating conditions, resulting in more precise and effective current loop control, improving the control accuracy, efficiency, and responsiveness of the permanent magnet synchronous motor, while also enhancing the system's robustness. 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 embodiment 1 can be referred to the above introduction and will not be described in detail later. Figure 3 , Figure 3This is a flow chart of a second embodiment of the control method for the current loop of a permanent magnet synchronous motor of the present application. Before step S10, the control method for the current loop of a permanent magnet synchronous motor further includes steps S01 to S03:

[0108] Step S01, calculating a reference orthogonal axis voltage equation based on 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's direct axis (D axis) and quadrature axis (Q axis) voltage and parameters such as motor current and magnetic flux, based on the basic electromagnetic theory and control theory of the motor. This equation usually includes the motor's electromagnetic induction, circuit theory, and the motor's physical characteristics, such as resistance, inductance, and back electromotive force. In this embodiment, this equation is the basis for constructing a mathematical model of the motor, which is used for subsequent control strategy design and parameter adjustment. Dynamic inductance refers to the inductance value of the motor that changes under different operating conditions (such as different currents and speeds). Unlike static inductance, dynamic inductance changes with the motor's operating state. This change is crucial for accurately controlling the motor current and achieving precise 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 operating 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 of the motor (such as flux, inductance) and the operating state (such as current). The flux is a measure of the strength of the motor's magnetic field. For permanent magnet synchronous motors, 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 and combined with the dynamic inductance and 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] As you can understand, the control system begins with the initial orthogonal voltage equations, which are based on the basic electromagnetic theory of electric motors and describe the relationship between the voltage on the direct (D-axis) and quadrature (Q-axis) motors and parameters such as current and flux. The control system then incorporates the value of the dynamic inductance into its calculations. Dynamic inductance refers to the changing inductance of the motor under different operating conditions. This value is obtained through experiments and calibration and reflects the electromagnetic characteristics of the motor at different currents and speeds. The control system then considers the orthogonal flux equation, which describes the relationship between the motor flux and its physical parameters and operating conditions. Flux is a measure of the motor's magnetic field strength and is crucial for controlling the motor's torque and speed. Finally, combining the initial orthogonal voltage equation, the dynamic inductance, and the orthogonal flux equation, the control system calculates the reference orthogonal voltage equation. This equation takes into account the actual operating conditions and dynamic characteristics of the motor, providing a more accurate voltage control reference for motor control. This enables the motor control system to more precisely control the motor's voltage and current, achieving precise control of the motor's torque and speed, thereby improving vehicle performance and energy efficiency.

[0111] The initial orthogonal axis voltage equation is:

[0112]

[0113] Among them, u d 、u q is the voltage of D and Q axis, i d 、i q are the D and Q axis currents, 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 magnetic 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 magnet flux.

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

[0122]

[0123] Step S02, performing a 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 calibration tests refer to a series of tests performed during actual motor operation, the purpose of which is to determine the key parameters used in the motor control algorithm. The calibration tests mentioned in this embodiment particularly refer to experiments used to obtain dynamic inductance parameter values. 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 theoretical models to calibrate and optimize the control algorithm. Curve fitting is a mathematical method used to determine 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 a motor that vary under different operating conditions. These values ​​are not fixed but change with the motor's operating state (such as current, temperature, and speed). Dynamic inductance parameter values ​​are crucial for precise motor control because they affect the motor's electromagnetic characteristics and response. In this embodiment, dynamic inductance parameter values ​​are obtained through calibration testing and curve fitting. These values ​​are used to construct and adjust the motor's mathematical model to achieve more precise motor control.

[0125] It can be understood that first, the control system uses the reference orthogonal axis voltage equation, a voltage equation derived from the motor's basic electromagnetic characteristics and theoretical model, as the theoretical basis for the calibration test. Then, calibration tests are conducted on actual motors, measuring the motor's voltage and current at different operating points (e.g., different current and speed conditions) to collect data. This data reflects the dynamic characteristics of the motor during actual operation, including changes in dynamic inductance. Next, curve fitting is performed using this experimental data, and by selecting the most appropriate function model to approximate the experimental data, the relationship between dynamic inductance and parameters such as current and speed is determined. Ultimately, using the equations derived from the curve fitting, the control system can accurately calculate the dynamic inductance parameter values ​​under different operating conditions. These parameter values ​​are crucial for achieving precise motor control because they directly affect the motor's electromagnetic characteristics and response speed. This enables the motor control system to more accurately predict and respond to the motor's behavior, improving control accuracy and efficiency.

[0126] As an example, the step of performing calibration tests 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 the thermal steady state of the motor to obtain calibration data; fitting the orthogonal axis flux-current equation according to the calibration data; and taking the partial derivative of the orthogonal axis flux-current equation to obtain a dynamic inductance parameter value.

[0127] Calibration data refers to a series of measurement values ​​collected during a calibration test. These data 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 measurement values ​​of parameters such as voltage, current, and flux obtained by performing a calibration test with reference to the orthogonal axis voltage equation under thermal steady-state conditions, that is, when the motor temperature reaches a stable state. These data are crucial 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 changes in 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, namely the orthogonal axis flux-current equation, using curve fitting technology. This equation is crucial 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 the range of ±10°), the flux value of the scanning current Map is given by the step size i d 、i q , record u d 、u q, calculate φ under 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, after the motor reaches thermal steady-state (i.e., a state where the motor temperature is stable and no longer fluctuates), the control system performs a calibration test based on a reference orthogonal voltage equation. By measuring motor parameters such as voltage, current, and flux at different operating points, a set of calibration data is collected; these data reflect the electromagnetic characteristics of the motor during actual operation. Then, using this calibration data, the control system uses curve fitting techniques to determine the mathematical relationship between the orthogonal flux and current, namely the orthogonal flux-current equation. This equation accurately describes how the flux changes with current. Finally, by taking the partial derivatives of the orthogonal flux-current equation, the control system calculates the dynamic inductance parameters. These parameters represent the rate at which the motor inductance changes with current and are crucial for achieving precise motor control and optimizing motor performance, as they directly affect the motor's response speed and efficiency. Through this detailed series of steps, the control system obtains 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 relationship is a mathematical expression that describes the relationship between the motor's back EMF (Electromotive Force, EMF) and flux. Back EMF is the voltage generated in a circuit due to changes in magnetic flux when the motor rotates, while flux is a measure of the motor's magnetic field and is related to magnetic flux and area. In permanent magnet synchronous motors, the relationship between back EMF and flux can be used to estimate the motor's back EMF, which is then used in control algorithms to achieve precise current and torque control. The interpolation strategy is a numerical calculation method used to calculate parameter changes by comparing measured values ​​under different conditions. In motor control, this method can be used to calculate changes in motor parameters (such as flux) 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, the interpolation strategy provides an effective means of estimating changes in motor parameters. The target orthogonal axis voltage equation is the voltage equation obtained by adjusting the initial orthogonal axis voltage equation based on the actual operating 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 and flux changes, to more accurately describe the voltage behavior of the motor under actual operating 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] As can be understood, the control system first measures the motor's back-EMF and flux data under different operating conditions and uses the back-EMF-flux relationship to determine the motor's back-EMF value at a specific flux. This is because back-EMF is a key parameter in motor control and directly affects the accuracy of the current loop control. Secondly, the system uses a difference strategy to compare the back-EMF data under different operating conditions to calculate the change in flux. This more accurately captures the characteristics of flux variation with operating conditions and provides more accurate parameters for the motor model. Then, using these measured and calculated data, combined with a reference orthogonal voltage equation, the control system adjusts and optimizes the equation to obtain a target orthogonal voltage equation that better matches actual operating conditions. This enables the motor control algorithm to more accurately predict and control the motor's voltage and current, thereby achieving more refined motor torque and speed control, improving motor efficiency and overall vehicle performance. Finally, through these steps, the motor control system achieves efficient and precise control of the motor, optimizing the drivability 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 combining the back electromotive force-flux relationship and the difference strategy to calculate the permanent magnet flux values ​​at different temperatures; 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 a 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] A motor reverse-drag test is a test method in which the motor is not operated as a drive, but is instead rotated by an external force (such as a dynamometer) to simulate generator operation. During this test, the motor's input is disconnected, and the motor's output (i.e., back EMF) is measured. This test is used to obtain back EMF data at different temperatures and speeds, which is crucial for understanding the motor's electromagnetic characteristics. The permanent magnet flux linkage value is a measure of the flux linkage generated by the permanent magnets in a permanent magnet synchronous motor. Flux linkage is a measure of the motor's magnetic field and is directly related to the motor's back EMF and torque generation. The permanent magnet flux linkage value varies with temperature, making understanding its variations at different temperatures crucial for precise motor control. A permanent magnet flux linkage value point set is a collection of permanent magnet flux linkage values ​​and corresponding temperatures obtained through reverse-drag testing at different temperatures. This point set contains multiple data sets, each corresponding to a specific temperature and the permanent magnet flux linkage value measured at that temperature. These data points are used in subsequent curve fitting to determine the mathematical model for the temperature variation of the permanent magnet flux linkage. The permanent magnet flux-temperature equation is a mathematical equation obtained by curve fitting based on a set of permanent magnet flux value points. This equation describes how the permanent magnet flux value changes with temperature and is key to understanding and predicting motor performance at different temperatures. Through this equation, the permanent magnet flux value at any given temperature can be calculated, which is crucial for 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 as 20℃, whenever the temperature reaches the step length value, stop running, disconnect the controller and the motor three-phase line, use the dynamometer to reverse drag (let the motor run in generator mode), 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 electromotive force, 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 the permanent magnet flux at different temperatures.

[0145] First, through the motor back-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 back electromotive force-flux relationship and the difference strategy are used to calculate the permanent magnet flux value at these temperatures (previously, the back electromotive force was used, which needs to be converted into flux before fitting). This step is to obtain actual data on the change of flux 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 point representing 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. This equation can accurately predict the flux value of the motor at different temperatures. Finally, the target orthogonal voltage equation is calculated by combining this permanent magnet flux-temperature equation with the reference orthogonal voltage equation. This equation accounts for the temperature-dependent effects of flux variation and provides a more accurate voltage control reference for motor control. This enables the motor control system to more precisely control the motor's voltage and current, achieving precise control of motor torque and speed, improving motor performance and overall vehicle energy efficiency. Through this series of detailed steps, the motor control system achieves efficient and precise control of the motor, optimizing the drivability and energy efficiency of electric vehicles.

[0146] Please refer to Figure 4 , Figure 4A schematic diagram of a permanent magnet flux temperature curve is provided for the second embodiment of the control method for the current loop of a permanent magnet synchronous motor of the present application. The horizontal axis in the figure represents temperature (T), and the vertical axis represents permanent magnet flux (Fai or φ). 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. It 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 these data points are calculated using a difference strategy. Then, these data points are curve fitted to obtain a permanent magnet flux-temperature equation. This equation 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 impact of temperature changes on the flux, thereby achieving more precise motor control and improving the performance and energy efficiency of the entire 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 a reference orthogonal voltage equation based on the initial orthogonal voltage equation, dynamic inductance, and orthogonal flux equation. Calibration tests and curve fitting are performed based on the reference orthogonal voltage equation to obtain the dynamic inductance parameter value. The target orthogonal voltage equation is calculated based on the back-electromotive force-flux relationship, a difference strategy, and the reference orthogonal voltage equation. The control system first calculates the reference orthogonal voltage equation based on the initial orthogonal voltage equation, dynamic inductance, and orthogonal flux equation. This step establishes a preliminary voltage control model by combining the motor's basic electromagnetic characteristics and operating conditions, providing a theoretical basis for current control and enabling the control system to perform preliminary current control based on the motor's actual operating conditions. Next, calibration tests and curve fitting are performed based on this reference orthogonal voltage equation to obtain the dynamic inductance parameter value. This process involves collecting voltage and current data from an actual motor under different operating conditions. Curve fitting techniques are used to accurately determine the relationship between dynamic inductance and parameters such as current and temperature. This provides more accurate motor model parameters, making current loop control more precise and adaptable, and improving control accuracy. Finally, the target orthogonal voltage equation is calculated based on the back-EMF-flux relationship, the difference strategy, and the reference orthogonal voltage equation. This step uses the relationship between the motor's back-EMF and flux, as well as data on how flux varies with temperature, to adjust the reference voltage equation, resulting in a target voltage equation that better matches actual operating conditions. This enables the motor control system to more accurately predict and control the motor's voltage and current, improving control accuracy and system efficiency, and optimizing the electric vehicle's driving performance and energy efficiency. Through this series of steps, the motor control system achieves efficient and precise control of the motor, enhancing 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 scope of protection of the present application.

[0156] This application also provides a control device for the current loop of a permanent magnet synchronous motor. Figure 5 , the control device of the permanent magnet synchronous motor current loop includes:

[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, 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 locked-rotor test and the difference strategy, and the dynamic inductance parameter value and the target orthogonal axis voltage equation are calculated based on 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 further 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 the back electromotive force-flux relationship, the 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 values ​​at different temperatures through a motor reverse drag test, combined with a back electromotive force-flux relationship and a difference strategy; the permanent magnet flux values ​​and corresponding temperatures are combined into a permanent magnet flux value point set; curve fitting is performed on the permanent magnet flux value point set to obtain a permanent magnet flux-temperature equation; and a target orthogonal axis voltage equation is calculated based on the permanent magnet flux-temperature equation and the reference orthogonal axis voltage equation.

[0161] In one embodiment, the control module 20 is further 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 further used to calculate the stator resistance of the motor in the thermal steady state through a locked-rotor test in combination with the direct-axis voltage equation and the difference strategy; and to construct an initial motor mathematical model based on the target orthogonal-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 based on at least one of the required torque, the orthogonal axis open-loop transfer function, and the zero-pole cancellation function; obtain the motor angular velocity, the wave transmission delay, the resolver signal sampling delay, and the rotor position angle; calculate the target angular velocity based on the motor angular velocity, the wave transmission delay, and the resolver signal sampling delay; calculate the voltage vector angle based on the rotor position angle and the target angular velocity; and adjust the initial motor mathematical model based on 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 further 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 a 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 for the permanent magnet synchronous motor current loop provided in this application utilizes the control method for the permanent magnet synchronous motor current loop in the above-mentioned embodiment, 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 control device for the permanent magnet synchronous motor current loop provided in this application are the same as the beneficial effects of the control method for the permanent magnet synchronous motor current loop provided in the above-mentioned embodiment. The other technical features of the control device for the permanent magnet synchronous motor current loop are the same as those disclosed in the above-mentioned embodiment method, and are not further described here.

[0166] The present application provides a control device for a permanent magnet synchronous motor current loop, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed 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), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 6 The control device for the permanent magnet synchronous motor current loop shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0168] like Figure 6 As shown, the control device for the permanent magnet synchronous motor current loop may include a processing device 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes based on programs stored in a read-only memory (ROM) 1002 or programs loaded from a storage device 1003 into a random access memory (RAM) 1004. RAM 1004 also stores various programs and data required for the operation of the control device for the permanent magnet synchronous motor current loop. Processing device 1001, ROM 1002, and RAM 1004 are interconnected via 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: an input device 1007 including, for example, a touch screen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the control device for 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 for the permanent magnet synchronous motor current loop with various systems, it should be understood that not all of the illustrated systems are required to be implemented or present. More or fewer systems may alternatively be implemented or present.

[0169] In particular, according to the embodiments disclosed in the present application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program comprising 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 via 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 for the permanent magnet synchronous motor current loop provided in this application utilizes the control method for the permanent magnet synchronous motor current loop in the above-described embodiment, 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 control device for the permanent magnet synchronous motor current loop provided in this application are the same as the beneficial effects of the control method for the permanent magnet synchronous motor current loop provided in the above-described embodiment. Other technical features of the control device for the permanent magnet synchronous motor current loop are the same as those disclosed in the method in the above-described embodiment, and are not further described here.

[0171] It should be understood that the various parts disclosed in this application can be implemented using 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 description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0173] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, a computer program) stored thereon, wherein the computer-readable program instructions are 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 this 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 thereof. 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 thereof. In this embodiment, the computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction 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 thereof.

[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 above-mentioned computer-readable storage medium carries one or more programs. When the above-mentioned 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 locked-rotor 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 stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In cases involving 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., through the Internet using an Internet service provider).

[0178] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of 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 box can also occur in a different order than that marked in the accompanying drawings. For example, two 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 box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0179] The modules described in the embodiments of the present application may be implemented in software or hardware, wherein the name of a module does not necessarily limit the unit itself.

[0180] The computer-readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described method for controlling the current loop of a permanent magnet synchronous motor. This computer-readable storage medium can address the technical problem of improving the control accuracy, response speed, and robustness of the current loop of a permanent magnet synchronous motor. Compared to the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the method for controlling the current loop of a permanent magnet synchronous motor provided in the above-described embodiment, and are not further elaborated here.

[0181] The present application also provides a computer program product, comprising a computer program, which implements the steps of the above-mentioned method for controlling the current loop of the permanent magnet synchronous motor when executed by a processor.

[0182] The computer program product provided in this application can solve the technical problem of improving the control accuracy, response speed, and robustness of the current loop of a permanent magnet synchronous motor. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the control method of the current loop of a permanent magnet synchronous motor provided in the above-mentioned embodiment, and are not further described here.

[0183] The above description is only part of the embodiments of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application 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; 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 an initial motor mathematical model according to a required torque, an orthogonal axis open-loop transfer function, and a zero-pole cancellation function, wherein the initial motor mathematical model is constructed according to a target orthogonal axis voltage equation, a dynamic inductance parameter value, a locked-rotor test, and a difference strategy, wherein the locked-rotor test is used to measure stator resistance, and the difference strategy is a mathematical calculation method that calculates changes in motor parameters by comparing measured values ​​under different conditions; The process of generating 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, dynamic inductance and orthogonal axis flux equation; Performing calibration tests 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.

2. The method according to claim 1, wherein 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 includes: 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 values ​​and corresponding temperatures 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 based on the permanent magnet flux linkage-temperature equation and the reference orthogonal axis voltage equation.

3. The method according to claim 1, wherein 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 under thermal steady state of the motor based on the reference orthogonal axis voltage equation to obtain calibration data; Obtaining the orthogonal axis flux-current equation 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.

4. The method according to claim 1, wherein 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 using the locked-rotor test and combining 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.

5. The method according to claim 1, wherein The process of constructing the mathematical model of the target motor includes: The current ramp function and the current loop proportional-integral parameters are obtained according to the required torque, the orthogonal axis open-loop transfer function and the zero-pole cancellation function; Obtain 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; Calculating 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.

6. The method according to claim 5, wherein The step of obtaining the current ramp function and the current loop proportional-integral parameter according to 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 a module execution period and a 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.

7. 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 for 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 an initial motor mathematical model according to a required torque, an orthogonal axis open-loop transfer function, and a zero-pole cancellation function, wherein the initial motor mathematical model is constructed according to a target orthogonal axis voltage equation, a dynamic inductance parameter value, a locked-rotor test, and a difference strategy, wherein the locked-rotor test is used to measure stator resistance, and the difference strategy is a mathematical calculation method that calculates changes in motor parameters by comparing measured values ​​under different conditions; The control module is further 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.

8. A control device for a current loop of a permanent magnet synchronous motor, characterized in that: The device includes: 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 6.

9. 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 method for controlling the current loop of a permanent magnet synchronous motor according to any one of claims 1 to 6 are implemented.

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