A permanent magnet synchronous motor speed control method, system, device and storage medium

Abstract

The application discloses a permanent magnet synchronous motor speed control method, system, device and storage medium, which is applied to the technical field of control and has the method steps of establishing a kinematics equation of a permanent magnet synchronous motor; establishing an iteration learning-based sliding mode observer with predetermined time convergence according to the kinematics equation of the permanent magnet synchronous motor; establishing a permanent magnet synchronous motor speed controller with predetermined time convergence; compensating total disturbance observed by the sliding mode observer to the permanent magnet synchronous motor speed controller with predetermined time convergence; and performing speed control on the permanent magnet synchronous motor. The robustness and control precision of the permanent magnet synchronous motor system are further improved.

Description

Technical Field

[0001] This invention relates to the field of control technology, and in particular to a method, system, device and storage medium for speed control of a permanent magnet synchronous motor. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in electric vehicles, CNC machine tools, and robot servo control due to their advantages such as high power density, low energy loss, and high reliability. Therefore, achieving robust and high-precision speed control for PMSMs has become a research hotspot. Currently, methods to improve the speed control performance of PMSMs mainly include PMSM speed control, active disturbance rejection control, intelligent control, and model predictive control. Among these, PMSM speed control is widely used in PMSM speed control systems due to its robustness and simplicity. In practical PMSM drive systems, non-periodic disturbances such as load torque and parameter mismatch reduce the stability of the speed control system; periodic disturbances such as flux harmonics, inverter nonlinearity, current measurement errors, and cogging torque reduce the speed control accuracy.

[0003] Currently, the widely used strategy is to use disturbance observers to observe and compensate for the total disturbance of the system, such as Romberg observers, extended state observers, and sliding mode observers. However, traditional sliding mode observers have a slow convergence speed.

[0004] To overcome these shortcomings, this application proposes a speed control method, system, device, and storage medium for permanent magnet synchronous motors. Summary of the Invention

[0005] The purpose of this application is to provide a method, system, device, and storage medium for controlling the speed of a permanent magnet synchronous motor, in order to solve the aforementioned problems.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] This application provides a speed control method for a permanent magnet synchronous motor, including:

[0008] Establish the kinematic equations of the permanent magnet synchronous motor;

[0009] Based on the kinematic equations of the permanent magnet synchronous motor, a sliding mode observer based on iterative learning with predetermined convergence time is established;

[0010] A permanent magnet synchronous motor speed controller with a predetermined convergence time is established, and the total disturbance observed by the sliding mode observer is compensated to the permanent magnet synchronous motor speed controller with a predetermined convergence time to perform speed control of the permanent magnet synchronous motor.

[0011] Furthermore, the step of establishing the kinematic equations of the permanent magnet synchronous motor specifically includes the following steps:

[0012] Based on the influence of non-periodic disturbances on the permanent magnet synchronous motor system, the first kinematic equation is:

[0013]

[0014] Where j0, K t0 B0 and B0 are the nominal moment of inertia, electromagnetic torque, and coefficient of viscous friction, respectively; ΔJ = J - J0, ΔK t =K t -K t0 ΔB = B - B0 represents the mismatched moment of inertia, electromagnetic torque, and coefficient of viscous friction, respectively; ω m This refers to the rotational speed of the permanent magnet synchronous motor. i is the derivative of the speed of the permanent magnet synchronous motor. q T is the stator current along the q-axis. L This is the load torque;

[0015] Based on the influence of periodic disturbances on the permanent magnet synchronous motor system, the second kinematic equation is:

[0016]

[0017] Where T h Torque pulsation caused by periodic disturbances; T1, T2, T 6n and T cogi The numbers are 1, 2, 6n, and iN respectively. c The amplitudes of the second torque harmonic components; θ1, θ2 and θ 6n The phase angles θ for the 1st, 2nd, and 6nth order torque harmonic components, respectively. e N is the electrical angle of the permanent magnet synchronous motor. c It is the least common multiple between the number of tooth slots and the number of pole pairs in a permanent magnet synchronous motor;

[0018] The kinematic equations of the permanent magnet synchronous motor are:

[0019]

[0020] in Used as a q-axis current reference; It is the total disturbance that includes both aperiodic and periodic disturbances.

[0021] Furthermore, the step of establishing a sliding mode observer based on iterative learning that converges within a predetermined time according to the kinematic equations of the permanent magnet synchronous motor specifically includes the following steps:

[0022] The sliding mode observer based on iterative learning is designed as follows:

[0023]

[0024] in The observed motor speed; This is the error in velocity observation; denoted as the total observed perturbation; k represents the number of iterations. and The total perturbation observed The state variables at the kth and (k-1)th iterations; A sliding mode function that converges within a predetermined time. It is a forgetting factor, and η is the observer gain, and η < 0.

[0025] Furthermore, the sliding mode function that converges within the predetermined time specifically includes:

[0026] Define the first sliding surface that converges within a predetermined time as:

[0027]

[0028] Where T1>0 is the predetermined convergence time; α1 is an adjustable parameter, and 0<α1<1; It is a symbolic function;

[0029] Differentiating both sides of the first sliding surface expression that converges at the predetermined time, we obtain:

[0030]

[0031] in This represents the total disturbance observation error;

[0032] The first sliding mode convergence law with predetermined time convergence is defined as:

[0033]

[0034] in For switching item gain; It is a symbolic function;

[0035] Substituting the first sliding mode convergence law into the differentiated first sliding surface, we obtain the sliding mode function that converges within a predetermined time. Specifically:

[0036]

[0037] Furthermore, the step of establishing a permanent magnet synchronous motor speed controller that converges within a predetermined time, compensating the total disturbance observed by the sliding mode observer to the permanent magnet synchronous motor speed controller that converges within the predetermined time, and performing speed control of the permanent magnet synchronous motor specifically includes the following steps:

[0038] Define the second sliding surface that converges within a predetermined time as:

[0039]

[0040] in This refers to the motor speed error; The reference value is the motor speed; T2>0 is the predetermined convergence time; α2 is an adjustable parameter, and 0<α2<1; It is a symbolic function;

[0041] Differentiating both sides of the expression for the second sliding surface that converges at the predetermined time, we obtain:

[0042]

[0043] The second sliding mode convergence law with predetermined convergence time is defined as follows:

[0044]

[0045] Where μ>0 represents the switching term gain; It is a symbolic function;

[0046] Substituting the second sliding mode approach law into the differentiated second sliding mode surface, and compensating the total disturbance observed by the sliding mode observer into the predetermined time-converged permanent magnet synchronous motor speed control law, we obtain the predetermined time-converged permanent magnet synchronous motor speed control law:

[0047]

[0048] in

[0049] This application provides a speed control system for a permanent magnet synchronous motor, including:

[0050] Establishment Module: Establish the kinematic equations of the permanent magnet synchronous motor; based on the kinematic equations of the permanent magnet synchronous motor, establish a sliding mode observer based on iterative learning that converges within a predetermined time; establish a speed controller for the permanent magnet synchronous motor that converges within a predetermined time.

[0051] Control module: The total disturbance observed by the sliding mode observer is compensated to the permanent magnet synchronous motor speed controller that converges at the predetermined time to perform speed control of the permanent magnet synchronous motor.

[0052] This application provides an apparatus comprising a processor and a memory coupled to the processor, wherein the memory stores program instructions for implementing a speed control method for a permanent magnet synchronous motor; the processor is configured to execute the program instructions stored in the memory to implement a speed control method for a permanent magnet synchronous motor.

[0053] This application provides a storage medium storing processor-executable program instructions for executing a speed control method for a permanent magnet synchronous motor.

[0054] This application provides a speed control method, system, device, and storage medium for a permanent magnet synchronous motor, which has the following beneficial effects:

[0055] By applying iterative learning control theory to the design of a sliding mode observer, it is made possible to effectively observe periodic disturbances. Secondly, by designing a sliding surface and sliding mode reaching law with predetermined convergence time, a sliding mode function with predetermined convergence time is obtained. Under the action of the sliding mode function with predetermined convergence time, the proposed sliding mode observer can converge within a predetermined time, improving the convergence speed of the sliding mode observer. Simultaneously, by designing a sliding surface and sliding mode reaching law with predetermined convergence time, a sliding mode control law with predetermined convergence time is obtained. Under the action of the sliding mode control law with predetermined convergence time, the proposed sliding mode controller can converge within a predetermined time. This application further improves the robustness and control accuracy of permanent magnet synchronous motor systems, solving the problems of slow convergence speed and insufficient robustness of traditional sliding mode controllers and the inability of traditional sliding mode observers to effectively observe periodic disturbances. Attached Figure Description

[0056] Figure 1 This is a flowchart illustrating a speed control method for a permanent magnet synchronous motor according to Embodiment 1 of this application;

[0057] Figure 2 A schematic diagram showing the total disturbance observed by the conventional sliding mode observer in Embodiment 1 of this application and the Fourier analysis results in steady state;

[0058] Figure 3 A schematic diagram of the total disturbance observed by the sliding mode observer based on iterative learning and its Fourier analysis results in steady state, which converges at a predetermined time according to Embodiment 1 of this application.

[0059] Figure 4 This is a schematic diagram of the motor speed and its steady-state Fourier analysis results for the conventional sliding mode control strategy in Embodiment 1 of this application;

[0060] Figure 5 This is a schematic diagram of the motor speed and its steady-state Fourier analysis results for a sliding mode control strategy based on iterative learning that converges within a predetermined time according to Embodiment 1 of this application.

[0061] Figure 6 This is a schematic diagram of the structure of a permanent magnet synchronous motor speed control system according to Embodiment 2 of this application;

[0062] Figure 7 This is a schematic diagram of a simulation model of a speed control system for a permanent magnet synchronous motor according to Embodiment 2 of this application;

[0063] Figure 8 This is a schematic diagram of the device structure in Embodiment 3 of this application;

[0064] Figure 9 This is a schematic diagram of the storage medium structure of Embodiment 4 of this application. Detailed Implementation

[0065] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0066] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0067] Example 1

[0068] Please see Figure 1 This is a flowchart illustrating a speed control method for a permanent magnet synchronous motor according to Embodiment 1 of this application; the steps include:

[0069] S1: Establish the kinematic equations of the permanent magnet synchronous motor.

[0070] In this embodiment, the initial kinematic equations of the permanent magnet synchronous motor are as follows:

[0071]

[0072] Where ω m Motor speed, J is the moment of inertia, T e Where B is the electromagnetic torque, B is the coefficient of viscous friction, and T is the electromagnetic torque. L This represents the load torque.

[0073] For a surface-mounted permanent magnet synchronous motor, the electromagnetic torque equation can be expressed as:

[0074]

[0075] Where i d and i q The stator currents L and L are the d-axis and q-axis currents, respectively. d =L qThe stator inductances along the d-axis and q-axis are respectively, ψ f For rotor flux linkage, n p K is the number of magnetic pole pairs. t is the electromagnetic torque constant.

[0076] The main non-periodic disturbances in permanent magnet synchronous motor (PMSM) systems are load torque and parameter mismatch. In actual PMSM drive systems, the moment of inertia, electromagnetic torque constant, and viscous friction coefficient change with temperature and operating environment, leading to a mismatch between actual and nominal parameters. Considering the impact of non-periodic disturbances on system performance, the kinematic equations of the PMSM can be expressed as:

[0077]

[0078] Among them, J0, K t0 B0 and B0 are the nominal moment of inertia, electromagnetic torque, and coefficient of viscous friction, respectively; ΔJ = J - J0, ΔK t =K t -K t0 ΔB = B - B0 represents the mismatched moment of inertia, electromagnetic torque, and coefficient of viscous friction, respectively.

[0079] The periodic disturbances in a permanent magnet synchronous motor (PMSM) system mainly include flux harmonics, inverter nonlinearity, current measurement errors, and cogging torque. Flux harmonics and inverter nonlinearity cause periodic torque pulsations of orders 6 and 6, current measurement errors cause 1st and 2nd order periodic torque pulsations, and cogging torque causes torque pulsations with frequencies related to the number of cogging teeth and pole pairs. Considering the impact of periodic disturbances on system performance, the kinematic equations of the PMSM can be expressed as:

[0080]

[0081]

[0082] Where T h Torque pulsation caused by periodic disturbances; T1, T2, T 6n and T cogi The numbers are 1, 2, 6n, and iN respectively. c The amplitudes of the second torque harmonic components; θ1, θ2 and θ 6n The phase angles θ for the 1st, 2nd, and 6nth order torque harmonic components, respectively. e For the electrical angle of a permanent magnet synchronous motor, N c It is the least common multiple between the number of tooth slots and the number of pole pairs in a permanent magnet synchronous motor.

[0083] Furthermore, the kinematic equations of the permanent magnet synchronous motor can ultimately be expressed as:

[0084]

[0085] The total system disturbance is characterized by both sexual and periodic disturbances.

[0086] S2: Based on the kinematic equations of the permanent magnet synchronous motor, establish a sliding mode observer based on iterative learning that converges within a predetermined time.

[0087] In this embodiment, in order to solve the problems of slow convergence speed and inability to observe periodic disturbances in traditional sliding mode observers, this application establishes a sliding mode observer based on iterative learning with predetermined time convergence, based on predetermined time control theory and iterative learning control theory, to estimate and compensate for non-periodic and periodic disturbances in permanent magnet synchronous motor systems.

[0088] The design of a sliding mode observer based on iterative learning with predetermined convergence time is as follows:

[0089]

[0090] in To observe the motor speed, For velocity observation error, Let k be the total observed perturbation, and k be the number of iterations. and The total perturbation observed The state variables at the kth and (k-1)th iterations, For a sliding mode function that converges within a predetermined time, η is the forgetting factor, and η<0 is the observer gain.

[0091] In order to obtain a sliding mode function that converges within a predetermined time. Define the first sliding surface that converges within a predetermined time as:

[0092]

[0093] Where T1>0 is the predetermined convergence time; α1 is an adjustable parameter, and 0<α1<1;

[0094]

[0095] Differentiating both sides of the first sliding surface expression that converges at the predetermined time, we obtain:

[0096]

[0097] in This represents the total disturbance observation error.

[0098] The first sliding mode convergence law with predetermined time convergence is defined as:

[0099]

[0100] in For switching item gain; It is a symbolic function.

[0101] Substituting the first sliding mode convergence law into the differentiated first sliding surface, we obtain the sliding mode function that converges within a predetermined time. Specifically:

[0102]

[0103] It is understood that the time-convergent sliding mode observer established in this application applies iterative learning control theory to the sliding mode observer, enabling it to effectively observe periodic disturbances. Secondly, the time-convergent sliding mode function is obtained through the first time-convergent sliding mode surface and the first sliding mode reaching law. Sliding mode function that converges within a predetermined time Under the influence of this, the sliding mode observer can converge within a predetermined time, thus improving the convergence speed of the sliding mode observer.

[0104] Specifically, the convergence time of the iterative learning-based sliding mode observer with a predetermined convergence time is 2T1, and the predetermined convergence time can be proved by the following method:

[0105] Define a positive semidefinite Lyapunov function The derivative of V1 can then be derived as follows:

[0106]

[0107] Clearly, V1 converges slowest when the equality condition of the above inequality holds. In this case, the derivative equation of V1 can be expressed as:

[0108]

[0109] Furthermore, by using the derivative equation of V1, the expression for the convergence time of V1 is obtained as follows:

[0110]

[0111] Where V 1,0 Let V1 be the initial value.

[0112] Initial value V 1,0 As the threshold of infinity approaches infinity, the convergence time t1 reaches its maximum, and the maximum convergence time is... Represented as:

[0113]

[0114] Lyapunov function We get: When V1→0, Therefore, the first sliding surface converges within the predetermined time. It is able to converge within the predetermined time T1.

[0115] When the iteratively learned sliding mode observer, which converges within the predetermined time, reaches the first sliding surface, Substitution To the sliding surface By taking the expression and differentiating both sides, we get:

[0116]

[0117] Similarly, define a positive semi-definite Lyapunov function. The derivative of V2 can then be derived as:

[0118]

[0119] The derivative equation of V2 can be rewritten as:

[0120]

[0121] Furthermore, the expression for the convergence time of V2 can be obtained from the derivative equation of V2 as follows:

[0122]

[0123] Where V 2,0 Let V2 be the initial value.

[0124] Initial value V 2,0 As the threshold approaches infinity, the convergence time t2 reaches its maximum, and the maximum convergence time is... Represented as:

[0125]

[0126] Lyapunov function We get: When V2→0, Therefore, the speed estimation error The permanent magnet synchronous motor system reaches the sliding surface If the iterative learning-based sliding mode observer can converge within the predetermined time T1, then the total convergence time of the convergent sliding mode observer within the predetermined time is 2T1.

[0127] S3: Establish a permanent magnet synchronous motor speed controller that converges within a predetermined time, and compensate the total disturbance observed by the sliding mode observer to the permanent magnet synchronous motor speed controller that converges within the predetermined time to perform speed control of the permanent magnet synchronous motor.

[0128] In this embodiment, in order to solve the problem of slow convergence speed of traditional sliding mode controllers, this application establishes a sliding mode controller with predetermined time convergence based on predetermined time control theory, so that the permanent magnet synchronous motor system can converge within a predetermined time.

[0129] First, define the second sliding surface that converges within a predetermined time as:

[0130]

[0131] in This refers to the motor speed error; The reference value is the motor speed; T2>0 is the predetermined convergence time; α2 is an adjustable parameter, and 0<α2<1; It is a symbolic function.

[0132] Differentiating both sides of the expression for the second sliding surface that converges at the predetermined time, we obtain:

[0133]

[0134] The second sliding mode convergence law with predetermined convergence time is defined as follows:

[0135]

[0136] Where μ>0 represents the switching term gain; It is a symbolic function.

[0137] Substituting the second sliding mode approach law into the differentiated second sliding mode surface, and then using the total disturbance observed by the sliding mode observer... The compensation is applied to the permanent magnet synchronous motor speed control law that converges within the predetermined time, resulting in a permanent magnet synchronous motor speed control law that converges within the predetermined time.

[0138]

[0139] in

[0140] It can be understood that the sliding mode controller with predetermined convergence time obtains a sliding mode control law with predetermined convergence time by designing a second sliding surface and a second sliding mode convergence law. Under the action of the sliding mode control law with predetermined convergence time, the proposed sliding mode controller can converge within a predetermined time, thus improving the convergence speed of the sliding mode observer. Specifically, the convergence time of the sliding mode controller with predetermined convergence time is 2T², and the method for proving the predetermined convergence time is the same as that for the sliding mode observer based on iterative learning with predetermined convergence time.

[0141] Please see Figure 2 and Figure 3The figures are schematic diagrams of the total disturbance observed by the traditional sliding mode observer and the Fourier analysis results of the iterative learning-based sliding mode observer that converges within a predetermined time, respectively, in Embodiment 1 of this application.

[0142] With motor speed reference as Under the condition of a sudden increase of 3 N·m external load torque at 5 seconds, it can be seen that both sliding mode observers can effectively observe the non-periodic 3 N·m external load torque disturbance. However, the convergence time of the traditional sliding mode observer is 1.52 seconds, while the convergence time of the proposed time-converged sliding mode observer based on iterative learning is only 0.077 seconds, which is much faster than the traditional sliding mode observer. In addition, the steady-state Fourier analysis results show that the amplitude of each harmonic in the total disturbance observed by the traditional sliding mode observer is very small, with a total harmonic disturbance (THD) of only 0.02%, which cannot effectively observe periodic disturbances. In contrast, the amplitude of each harmonic in the total disturbance observed by the proposed time-converged sliding mode observer based on iterative learning is larger, with a total harmonic disturbance (THD) of 6.10%, which can effectively observe periodic disturbances.

[0143] Please see Figure 4 and Figure 5 The figures are schematic diagrams showing the motor speed and the Fourier analysis results in steady state of the traditional sliding mode control strategy and the iterative learning-based sliding mode control strategy with predetermined convergence time, respectively, in Embodiment 1 of this application.

[0144] With motor speed reference as Under the condition of a sudden increase of 3 N·m of external load torque at 5 seconds, it can be seen that the speed drop using the traditional sliding mode control strategy is 6.21 rpm, while the speed drop using the proposed time-converged sliding mode control strategy based on iterative learning is only 0.25 rpm. Therefore, the robustness of the time-converged sliding mode control strategy based on iterative learning is far superior to that of the traditional sliding mode control strategy. Furthermore, from the steady-state motor speed and its Fourier analysis results, it can be seen that the steady-state speed fluctuation amplitude using the traditional sliding mode control strategy is 0.094 rpm, and the amplitudes of its harmonics are relatively large, with a total harmonic disturbance (THD) of 0.04%. Conversely, the steady-state speed fluctuation amplitude using the proposed time-converged sliding mode control strategy based on iterative learning is only 0.011 rpm, and the amplitudes of its harmonics are relatively small, with a total harmonic disturbance (THD) of less than 0.01%, which is much smaller than that of the traditional sliding mode control strategy. Therefore, the proposed sliding mode control strategy with predetermined convergence time based on iterative learning can effectively improve the speed control accuracy of the system.

[0145] In summary, Embodiment 1 of this application applies iterative learning control theory to the design of a sliding mode observer, enabling it to effectively observe periodic disturbances. Secondly, by designing a sliding mode surface and a sliding mode reaching law with predetermined convergence time, a sliding mode function with predetermined convergence time is obtained. Under the action of this sliding mode function, the proposed sliding mode observer can converge within a predetermined time, improving the convergence speed of the sliding mode observer. Simultaneously, by designing a sliding mode surface and a sliding mode reaching law with predetermined convergence time, a sliding mode control law with predetermined convergence time is obtained. Under the action of this sliding mode control law, the proposed sliding mode controller can converge within a predetermined time, further improving the robustness and control accuracy of the permanent magnet synchronous motor system.

[0146] Example 2

[0147] Please see Figure 6 This is a schematic diagram of the structure of a permanent magnet synchronous motor speed control system according to Embodiment 2 of this application; the specific content includes:

[0148] Establishment Module: Establish the kinematic equations of the permanent magnet synchronous motor; based on the kinematic equations of the permanent magnet synchronous motor, establish a sliding mode observer based on iterative learning that converges within a predetermined time; establish a speed controller for the permanent magnet synchronous motor that converges within a predetermined time.

[0149] Control module: The total disturbance observed by the sliding mode observer is compensated to the permanent magnet synchronous motor speed controller that converges at the predetermined time to perform speed control of the permanent magnet synchronous motor.

[0150] Please see Figure 7 This is a schematic diagram of the simulation model structure of a permanent magnet synchronous motor speed control system according to Embodiment 2 of this application. In the established simulation model, the speed loop controller adopts the proposed sliding mode control strategy based on iterative learning with predetermined convergence time, and the current loop controller adopts a PI controller. First, the speed reference of the permanent magnet synchronous motor is given as... Using an encoder to collect the electrical angle θ of the motor e and rotational speed ω m Electrical angle θ e Used for coordinate transformation, rotational speed ω m The iterative learning-based sliding mode observer, used for convergence at a predetermined time, obtains the observations of the total perturbation. The q-axis reference current is obtained by the sliding mode control law with a predetermined time. Then, the three-phase current i of the motor is obtained using a current sensor. a i b and i c Then, the actual currents i along the d-axis and q-axis of the motor are obtained through coordinate transformation. d and i q Used for current loop control to obtain the voltage u on the d-axis and q-axis.d and u q Furthermore, the inverter's switching signal state vector S is obtained through coordinate transformation and SVPWM pulse modulation method. abc Finally, the inverter outputs three-phase current to drive the permanent magnet synchronous motor.

[0151] Example 3

[0152] Please see Figure 8 This is a schematic diagram of the device structure in Embodiment 3 of this application. The device 50 includes a processor 51 and a memory 52 coupled to the processor 51.

[0153] The memory 52 stores program instructions for implementing the above-described method for controlling the speed of a permanent magnet synchronous motor.

[0154] The processor 51 is used to execute program instructions stored in the memory 52 to implement a speed control of a permanent magnet synchronous motor.

[0155] The processor 51 can also be referred to as a CPU (Central Processing Unit).

[0156] Processor 51 may be an integrated circuit chip with signal processing capabilities. Processor 51 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor may be a microprocessor or any conventional processor.

[0157] Example 4

[0158] Please see Figure 9 This is a schematic diagram of the storage medium in Embodiment 4 of this application. The storage medium in this embodiment stores a program file 61 capable of implementing all the above methods. This program file 61 can be stored in the storage medium in the form of a software product, including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, or devices such as computers, servers, mobile phones, and tablets.

[0159] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0160] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0161] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

[0162] Of course, the present invention may have many other embodiments. Based on this embodiment, other embodiments obtained by those skilled in the art without any creative effort are all within the scope of protection of the present invention.

Claims

1. A speed control method for a permanent magnet synchronous motor, characterized in that, include: Establish the kinematic equations of the permanent magnet synchronous motor; Based on the kinematic equations of the permanent magnet synchronous motor, a sliding mode observer based on iterative learning with predetermined convergence time is established; Establish a permanent magnet synchronous motor speed controller that converges within a predetermined time, and compensate the total disturbance observed by the sliding mode observer to the permanent magnet synchronous motor speed controller that converges within the predetermined time to perform speed control of the permanent magnet synchronous motor. The kinematic equations of the permanent magnet synchronous motor are: in for Shaft current reference; The total disturbance includes both aperiodic and periodic disturbances. , , These are the nominal moment of inertia, electromagnetic torque, and coefficient of viscous friction, respectively. These represent the mismatched moment of inertia and coefficient of viscous friction, respectively. This refers to the speed of the permanent magnet synchronous motor. This is the derivative of the speed of the permanent magnet synchronous motor. for Stator current of the shaft; For load torque, Torque pulsation caused by periodic disturbances; The step of establishing a permanent magnet synchronous motor speed controller that converges within a predetermined time, and compensating the total disturbance observed by the sliding mode observer to the permanent magnet synchronous motor speed controller that converges within the predetermined time, for speed control of the permanent magnet synchronous motor, specifically includes the following steps: Define the second sliding surface that converges within a predetermined time as: in This refers to the motor speed error; For motor speed reference; The predetermined convergence time; It is an adjustable parameter, and ; It is a symbolic function; Differentiating both sides of the expression for the second sliding surface that converges at the predetermined time, we obtain: The second sliding mode convergence law with predetermined convergence time is defined as follows: in For the gain of the switching item; It is a symbolic function; Substituting the second sliding mode approach law into the differentiated second sliding mode surface, and compensating the total disturbance observed by the sliding mode observer into the predetermined time-converged permanent magnet synchronous motor speed control law, we obtain the predetermined time-converged permanent magnet synchronous motor speed control law: in The total perturbation observed The state variable at the k-th iteration.

2. The speed control method for a permanent magnet synchronous motor according to claim 1, characterized in that, The steps for establishing the kinematic equations of the permanent magnet synchronous motor specifically include the following steps: Based on the influence of non-periodic disturbances on the permanent magnet synchronous motor system, the first kinematic equation is: in This represents the mismatched electromagnetic torque. Based on the influence of periodic disturbances on the permanent magnet synchronous motor system, the second kinematic equation is: in , , and 1 time, 2 times, respectively Subsequent The amplitude of the second torque harmonic component; , and They were 1 time, 2 times and respectively Phase angle of the second torque harmonic component; The electrical angle of the permanent magnet synchronous motor; It is the least common multiple between the number of tooth slots and the number of pole pairs in a permanent magnet synchronous motor.

3. The speed control method for a permanent magnet synchronous motor according to claim 2, characterized in that, The step of establishing a sliding mode observer based on iterative learning that converges within a predetermined time according to the kinematic equations of the permanent magnet synchronous motor specifically includes the following steps: The sliding mode observer based on iterative learning is designed as follows: in The observed motor speed; This is the error in velocity observation; denoted as the total observed perturbation; k represents the number of iterations. and The total perturbation observed The state variables at the kth and (k-1)th iterations; A sliding mode function that converges within a predetermined time. It is a forgetting factor, and ; For observer gain, and .

4. The speed control method for a permanent magnet synchronous motor according to claim 3, characterized in that, The sliding mode function that converges within the predetermined time specifically includes: Define the first sliding surface that converges within a predetermined time as: in The predetermined convergence time; It is an adjustable parameter, and ; It is a symbolic function; Differentiating both sides of the first sliding surface expression that converges at the predetermined time, we obtain: in This represents the total disturbance observation error; The first sliding mode convergence law with predetermined time convergence is defined as: in For the gain of the switching item; It is a symbolic function; Substituting the first sliding mode convergence law into the differentiated first sliding surface, we obtain the sliding mode function that converges within a predetermined time. Specifically: 。 5. A system for a speed control method for a permanent magnet synchronous motor according to claim 1, characterized in that, include: Establish module: Establish the kinematic equations of the permanent magnet synchronous motor; Based on the kinematic equations of the permanent magnet synchronous motor, a sliding mode observer based on iterative learning with predetermined convergence time is established; Establish a speed controller for a permanent magnet synchronous motor that converges within a predetermined time. Control module: The total disturbance observed by the sliding mode observer is compensated to the permanent magnet synchronous motor speed controller that converges at the predetermined time to perform speed control of the permanent magnet synchronous motor.

6. A computer device, characterized in that, The device includes a processor and a memory coupled to the processor, wherein the memory stores program instructions for implementing a speed control method for a permanent magnet synchronous motor according to any one of claims 1-4; the processor is used to execute the program instructions stored in the memory to implement a speed control method for a permanent magnet synchronous motor.

7. A computer-readable storage medium, characterized in that, The device stores processor-executable program instructions for performing a speed control method for a permanent magnet synchronous motor as described in any one of claims 1-4.

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