Experimental platform for permanent magnet synchronous motor control and control method

Abstract

The invention discloses an experimental platform control method for permanent magnet synchronous motor control, and a control mainboard in an experimental platform comprises a main controller, a speed sensor, a current sampling circuit and a motor driving circuit, the main controller performs integral sliding mode variable structure control, calculates control input, and inputs a required space vector pulse width modulation wave into a motor driving circuit according to the calculated space vector pulse width modulation wave; the speed sensor collects rotor speed and rotor position information of the permanent magnet synchronous motor; the current sampling circuit collects the three-phase current of the motor driving circuit; and the motor driving circuit converts the space vector pulse width modulation wave signal into a voltage signal, and controls the three-phase voltage of the permanent magnet synchronous motor so as to control the rotating speed of the permanent magnet synchronous motor. According to the invention, great help can be provided in education and teaching, the systematic and modular design is beneficial for students to understand the working principle of the permanent magnet synchronous motor, and the simple operation process is beneficial for the students to use the platform to carry out experiments and further understand the working process of a control algorithm.

Description

Technical Field

[0001] The invention belongs to the field of intelligent mechanical equipment and automatic control thereof, and relates to an experimental platform control method for controlling a permanent magnet synchronous motor. Background Art

[0002] The permanent magnet material industry and motor drive control technology are constantly developing. Permanent magnet synchronous motors have been widely used in many fields such as electric vehicles, hybrid vehicles, industrial automation, aerospace, renewable energy, rail transportation, etc. due to their advantages such as high efficiency, high power density, high torque / inertia ratio, good control performance, and high reliability. However, permanent magnet synchronous motors also face huge challenges due to many problems in the control process, such as parameter changes and uncertainties, nonlinearity and coupling problems, weak magnetic capability, complexity of control algorithms, real-time and computing resources, loss minimization, sensor dependence, and selection of optimization algorithms. Therefore, an experimental platform for control algorithm research is indispensable.

[0003] At present, there are many hardware platform solutions for permanent magnet synchronous motor control. The most widely used and mature one is that the main control chip controls the full-bridge inverter through an FD6288 chip to control the permanent magnet synchronous motor. However, these platforms have corresponding application scenarios, and it is difficult to find a control platform solution suitable for laboratory research on control algorithms. In addition, the cost of most solutions is very expensive, and the corresponding performance is also overflowing in scientific research. There is no simple process and supporting equipment for the verification process of the algorithm.

[0004] How to make the research process of permanent magnet synchronous motor control algorithm simpler and achieve rapid research of "conducting simulation experiments and then immediately conducting physical experiments" is an urgent issue in the current research process of motor control algorithm to improve research efficiency and reduce research pressure.

[0005] Therefore, in view of the above-mentioned defects existing in the current prior art, it is necessary to conduct research to build an experimental platform solution to solve the defects existing in the prior art. Summary of the invention

[0006] To solve the above problems, the technical solution of the present invention is an experimental platform for permanent magnet synchronous motor control, including a control mainboard and a load controller and a permanent magnet synchronous motor both connected to the control mainboard, wherein:

[0007] The control mainboard includes a main controller, a speed sensor, a current sampling circuit and a motor drive circuit, wherein the main controller performs integral sliding mode variable structure control, calculates control input, and inputs the required space vector pulse width modulation wave into the motor drive circuit according to the calculation; the speed sensor collects the rotor speed and rotor position information of the permanent magnet synchronous motor; the current sampling circuit collects the three-phase current of the motor drive circuit; the motor drive circuit converts the space vector pulse width modulation wave signal into a voltage signal, controls the three-phase voltage of the permanent magnet synchronous motor, and thus controls the speed of the permanent magnet synchronous motor.

[0008] Preferably, the main controller includes an STM32 single-chip microcomputer minimum system.

[0009] Preferably, the speed sensor comprises a TLE5012 chip, which adjusts the control of the permanent magnet synchronous motor through the feedback of the rotor position and outputs comparative data of the sensorless control of the permanent magnet synchronous motor.

[0010] Preferably, the current sampling circuit is a three-phase current acquisition circuit based on an on-chip operational amplifier in an STM32 single-chip microcomputer.

[0011] Preferably, the load controller comprises a tension controller, a magnetic powder brake and a tension detector, wherein the tension controller and the tension detector form a closed-loop tension control; the magnetic powder brake uses magnetic powder as a medium, and forms a magnetic powder chain to transmit torque when powered.

[0012] Preferably, the motor driving circuit includes a switching tube BSC070N10NS5.

[0013] Based on the above purpose, the present invention also provides a control method for an experimental platform for controlling a permanent magnet synchronous motor, based on the above-mentioned experimental platform for controlling a permanent magnet synchronous motor, comprising the following steps:

[0014] S10, the Hall sensor and the speed sensor obtain the high-speed and low-speed angular velocities of the motor;

[0015] S20, the main controller collects three-phase currents, calculates the q-axis current error, and controls the permanent magnet synchronous motor through the designed algorithm;

[0016] S30, updating the value of the sliding surface;

[0017] S40, updating the sliding mode control input.

[0018] Preferably, the simplified model of the permanent magnet synchronous motor in the control strategy id=0 and the dq rotating coordinate system in S20 is as follows:

[0019]

[0020] Among them, u d and uq are the d-axis and q-axis voltages, respectively, and R s is the resistance, i d and i q are the d-axis and q-axis currents, L d and L q are the d-axis and q-axis inductances, ω e is the angular velocity, ψ f is the rotor flux amplitude;

[0021] The electromagnetic torque equation of the motor is:

[0022]

[0023] where p n represents the number of magnetic pole pairs;

[0024] The mechanical motion equation of the motor is:

[0025]

[0026] Where J is the moment of inertia, B is the viscous friction coefficient, T L is the load torque;

[0027] The dynamic model of permanent magnet synchronous motor can be written as follows:

[0028]

[0029] Where K = 3p n ψ f / 2 is the torque constant;

[0030] In order to further realize the design of the main controller, the dynamic equation is rewritten as:

[0031]

[0032] Where i q * is the reference current of the q axis, which is used to achieve the desired control effect of the main controller, and D(t) is the lumped interference of the system, which is given by the following formula:

[0033]

[0034] The dynamic error model of the speed control system is defined as:

[0035]

[0036] Among them, e, is the error state variable and the first-order derivative, ω e * and are the reference speed and the first-order derivative.

[0037] Preferably, the sliding surface in S30 is designed as follows:

[0038]

[0039] Among them, σ, ρ, μ, θ, m 1 、m 2 、n 1 and n 2 They are all custom coefficient parameters. Their value ranges are as follows: σ>0, ρ>0, 0<μ<θ<2, μ=m 1 / n 1 ,θ=m 2 / n 2 , m 1 、m 2 、n 1 and n 2 are all positive odd numbers, s is the sliding surface;

[0040] In order to achieve faster convergence speed and reduce chattering, the design convergence rate is:

[0041]

[0042] Where a 1 、b 1 、p 1 ,q 1 , r and k are all custom coefficient parameters, and their value ranges are as follows: 1 >0,b 1 >0,0 <p 1 r<1,q 1 r>1,k>-T L / J-Bω e / J, J is the moment of inertia, B is the viscous friction coefficient, T L is the load torque, is the first-order derivative of the sliding surface.

[0043] Preferably, the sliding mode control input in S40 is designed as follows:

[0044]

[0045] Where u is the total control input, J is the moment of inertia, K = 3p n ψ f / 2 is the torque constant, p n represents the number of magnetic pole pairs, ψ f is the rotor flux amplitude, u eq and u s1 is the equivalent control and switching control component, defined as:

[0046]

[0047] Finally, the controller is designed as:

[0048]

[0049] Design of Lyapunov functions The derivative is

[0050]

[0051] The present invention has at least the following beneficial effects:

[0052] The present invention uses STM32G431 chip as the core to build the peripheral circuit of the hardware circuit board of the permanent magnet synchronous motor experimental platform, which is used to verify the effectiveness of various motor control algorithms. The construction of the platform is divided into two parts: hardware and software. The hardware includes a permanent magnet synchronous motor and a magnetic powder brake connector and a motor drive circuit. The connector is manufactured using 3D modeling and CNC technology. The motor drive uses a FD6288 chip to control 6 power MOS tubes to output VUW three-phase voltage, and integrates CH340\RS485 communication modules for communicating with the host computer and the load. At the same time, the MCU chip op amp is used to sample the three-phase current as control feedback. The software part uses the classic SVPWM modulation algorithm and combines SIMULINK to build the motor current loop and speed loop model and export the C language file to greatly facilitate the experiment of the control algorithm, and writes the MODBUS communication protocol to realize the communication between the driver board and the load and the host computer, and at the same time realizes the function of the motor Hall and speed sensor to obtain the motor rotor state for comparison with the non-sensing experimental results.

[0053] The present invention provides a simple solution for the physical experiment of permanent magnet synchronous motor control algorithm in scientific research. After designing the algorithm, build the algorithm circuit through SIMULINK and then export it as a C language file. Transplant this file into the algorithm module of the experimental platform, and then carry out the physical experiment of the control algorithm. During the experiment, the matching CNC load can complete the control experiment more accurately. At the same time, looking forward to the future. The platform can also provide great help in education and teaching. Its systematic and modular design is conducive to students' understanding of the working principle of permanent magnet synchronous motor. The simple operation process is conducive to students using the platform to conduct experiments and further understand the working process of the control algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of the structure of an experimental platform for controlling a permanent magnet synchronous motor according to an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of the main controller circuit of the experimental platform for controlling the permanent magnet synchronous motor according to an embodiment of the present invention;

[0056] Figure 3 A schematic diagram of a speed sensor circuit of an experimental platform for controlling a permanent magnet synchronous motor according to an embodiment of the present invention;

[0057] Figure 4 This is a schematic diagram of a current sampling circuit of an experimental platform for controlling a permanent magnet synchronous motor according to an embodiment of the present invention;

[0058] Figure 5 A schematic diagram of a motor drive circuit of an experimental platform for controlling a permanent magnet synchronous motor according to an embodiment of the present invention;

[0059] Figure 6 This is an experimental flow chart of an experimental platform for controlling a permanent magnet synchronous motor according to an embodiment of the present invention;

[0060] Figure 7 This is a simulation speed result diagram of an experimental platform for controlling a permanent magnet synchronous motor according to an embodiment of the present invention;

[0061] Figure 8 This is a diagram of actual experimental results of the experimental platform control method for controlling a permanent magnet synchronous motor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0063] On the contrary, the present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention as defined by the claims. Further, in order to make the public have a better understanding of the present invention, some specific details are described in detail in the detailed description of the present invention below. Those skilled in the art can fully understand the present invention without the description of these details.

[0064] The technical solution of the present invention is an experimental platform for controlling a permanent magnet synchronous motor, comprising a control mainboard 10, a load controller and a permanent magnet synchronous motor 30 both connected to the control mainboard 10, wherein:

[0065] The control motherboard 10 includes a main controller, a speed sensor, a current sampling circuit and a motor drive circuit, wherein the main controller performs integral sliding mode variable structure control, calculates control input, and inputs the required space vector pulse width modulation wave into the motor drive circuit according to the calculation; the speed sensor collects the rotor speed and rotor position information of the permanent magnet synchronous motor; the current sampling circuit collects the three-phase current of the motor drive circuit; the motor drive circuit converts the space vector pulse width modulation wave signal into a voltage signal, controls the three-phase voltage of the permanent magnet synchronous motor 30, and thus controls the speed of the permanent magnet synchronous motor 30.

[0066] See also Figure 2 , which is the schematic diagram of the main controller circuit. The main controller includes the minimum system of STM32 microcontroller.

[0067] See also Figure 3 , is the schematic diagram of the speed sensor circuit. The speed sensor includes a TLE5012 chip, which adjusts the control of the permanent magnet synchronous motor through the feedback of the rotor position and outputs the comparison data of the permanent magnet synchronous motor's sensorless control.

[0068] See also Figure 4 , is the schematic diagram of the current sampling circuit. The current sampling circuit is a three-phase current acquisition circuit based on the on-chip operational amplifier in the STM32 microcontroller.

[0069] The load controller includes a tension controller 21, a magnetic powder brake 22 and a tension detector. The tension controller 21 and the tension detector form a closed-loop tension control. The magnetic powder brake 22 uses magnetic powder as a medium and forms a magnetic powder chain to transmit torque when powered.

[0070] See also Figure 5 , is the schematic diagram of the motor drive circuit, the motor drive circuit includes a switch tube BSC070N10NS5.

[0071] The control method of the experimental platform for permanent magnet synchronous motor control is based on the above-mentioned experimental platform for permanent magnet synchronous motor control, and comprises the following steps:

[0072] S10, the Hall sensor and the speed sensor obtain the high-speed and low-speed angular velocities of the motor;

[0073] S20, the main controller collects three-phase currents, calculates the q-axis current error, and controls the permanent magnet synchronous motor through the designed algorithm;

[0074] S30, updating the value of the sliding surface;

[0075] S40, updating the sliding mode control input.

[0076] The simplified model of the permanent magnet synchronous motor in S20 under the control strategy id=0 and the dq rotating coordinate system is as follows:

[0077]

[0078] Among them, u d and u q are the d-axis and q-axis voltages, respectively, and R s is the resistance, i d and i q are the d-axis and q-axis currents, L d and L q are the d-axis and q-axis inductances, ω eis the angular velocity, ψ f is the rotor flux amplitude;

[0079] The electromagnetic torque equation of the motor is:

[0080]

[0081] where p n represents the number of magnetic pole pairs;

[0082] The mechanical motion equation of the motor is:

[0083]

[0084] Where J is the moment of inertia, B is the viscous friction coefficient, T L is the load torque;

[0085] The dynamic model of permanent magnet synchronous motor can be written as follows:

[0086]

[0087] Where K = 3p n ψ f / 2 is the torque constant;

[0088] In order to further realize the design of the main controller, the dynamic equation is rewritten as:

[0089]

[0090] Where i q * is the reference current of the q axis, which is used to achieve the desired control effect of the main controller, and D(t) is the lumped interference of the system, which is given by the following formula:

[0091]

[0092] The dynamic error model of the speed control system is defined as:

[0093]

[0094] Among them, e, is the error state variable and the first-order derivative, ω e * and are the reference speed and the first-order derivative.

[0095] The sliding surface design of S30 is:

[0096] s=e+∫ 0 t σsig μ (e)+ρsig θ(e)dt

[0097] Among them, σ, ρ, μ, θ, m 1 、m 2 、n 1 and n 2 They are all custom coefficient parameters. Their value ranges are as follows: σ>0, ρ>0, 0<μ<θ<2, μ=m 1 / n 1 ,θ=m 2 / n 2 , m 1 、m 2 、n 1 and n 2 are all positive odd numbers, s is the sliding surface;

[0098] In order to achieve faster convergence speed and reduce chattering, the design convergence rate is:

[0099]

[0100] Where a 1 、b 1 、p 1 ,q 1 , r and k are all custom coefficient parameters, and their value ranges are as follows: 1 >0,b 1 >0,0 <p 1 r<1,q 1 r>1,k>-T L / J-Bω e / J, J is the moment of inertia, B is the viscous friction coefficient, T L is the load torque, is the first-order derivative of the sliding surface.

[0101] The sliding mode control input in S40 is designed as:

[0102]

[0103] Where u is the total control input, J is the moment of inertia, K = 3p n ψ f / 2 is the torque constant, p n represents the number of magnetic pole pairs, ψ f is the rotor flux amplitude, u eq and u sw is the equivalent control and switching control component, defined as:

[0104]

[0105] Finally, the controller is designed as:

[0106]

[0107] Design of Lyapunov functions The derivative is

[0108]

[0109] Step 1: Stability analysis at arrival stage:

[0110]

[0111] No matter what s is, ks+D(t)≥0, then:

[0112]

[0113] By Lyapunov function V 1 The negative definiteness of the derivative shows that the system will reach the sliding surface s = 0 from the state origin in a finite time. In addition, the system will reach the sliding surface in a fixed time, and the required time T 1 for:

[0114]

[0115] The convergence time constant is

[0116] Step 2: Sliding mode stability analysis:

[0117] When the system state reaches the sliding surface, that is, s = 0, substituting into the sliding surface, we can get:

[0118] e=-∫ 0 t σsig μ (e)+σsig θ (e)dt

[0119] Taking the derivative of both sides:

[0120]

[0121] It is easy to conclude that under any given initial conditions, the state of the system will converge to the sliding mode surface within a fixed bounded time, and the upper bound of the stable time can be expressed as:

[0122]

[0123] The permanent magnet synchronous motor control system converges to zero from any initial condition in a finite time, thus achieving fixed convergence of the closed-loop control system.

[0124] The permanent magnet synchronous motor control experimental platform is composed of a control mainboard 10, a permanent magnet synchronous motor 30 and a load controller, and is connected to a host computer 40 and an external power supply 50 when in use.

[0125] The DC-DC, main controller, three-phase inverter bridge circuit, encoder and other circuits are integrated into a 10cm*10cm control motherboard 10, and communication is established through the motherboard to achieve connection between the motor 30, load, tension controller 21 and PC end.

[0126] Permanent magnet synchronous motor 30 and load controller: Through the bracket and connector designed by us, the motor and load equipment are stably connected together, so that the running status of the motor with no load and with load can be effectively observed.

[0127] Experimental interface: This experimental interface is designed based on vofa software, which can display important data of motor operation such as motor bus voltage, angular velocity, speed, id and iq, and can also adjust parameters such as iqref and speed.

[0128] The tension controller 21 receives the signal transmitted by the tension detector, and after internal PID calculation processing, adjusts the actuator to automatically control the winding / unwinding tension of the material. It can control the two magnetic powder brakes 22 for braking at the same time, and can arbitrarily adjust the size of the load applied.

[0129] Figure 6 The experimental flow chart of the experimental platform of the present invention is shown. The designed program is divided into five modules: ADC data sampling, sampling data processing, SVPWM generation, host computer communication, and Modbus communication. The ADC data sampling module will sample the three-phase current signal and the rotor angle signal. The sampling data processing module will perform Clark change and Park change on the three currents sampled to obtain the required α, β, d, and q axis currents, and combine the rotor position information obtained by sampling to calculate U_α and U_β. The SVPWM module converts the obtained U_α and U_β into pulse width modulation waves of the three-phase channel. The host computer 40 communication module transmits the data collected during the operation of the motor and the data generated in the intermediate calculation process to the host computer 40 through the serial port, and the host computer 40 can send data to modify the parameters in the motor control process. The Modbus communication module sends the value of the load size required for the test motor to the load controller, and reads the current load state and size from the load controller.

[0130] The execution flow is as follows:

[0131] (1) Start with initializing each hardware component, configuring the I / O ports, MCU clock, serial port, and motor control algorithm of each hardware component, and assigning the initialization values ​​of the parameters required for motor operation.

[0132] (2) ADC sampling starts and the rotor position is collected. The rotor position is differentiated to obtain speed information, and the rotor speed is mean filtered and the rotor speed parameters are updated in real time.

[0133] (3) When the host computer communication starts, all parameters of the current state are packaged and the data is sent to the host computer through the serial port. The host computer unpacks the received data and prints it in the data window in the form of a broken line. If the host computer sends data, the MCU will enter the serial port data read callback function interrupt, read the data sent by the host computer and update the parameters.

[0134] (4) If the MCU controls the state of the load controller, the MCU will send control data to the load controller to change the parameters and state of the load controller.

[0135] (5) The ADC interrupt frequency is 10kHz. Each interrupt will update the sampled value of the motor's three-phase current, perform motor algorithm calculations, update the loading value of the three-phase PWM timer, and package some of the acquired motor parameter data.

[0136] (6) Check whether a key is pressed. If a key is pressed, the PWM signal output is turned on and the motor starts running. If no key is pressed, the ADC sampling is returned to proceed in sequence.

[0137] Figure 7 and Figure 8 The simulation and physical experiment of the above control algorithm show the following phenomena: at 0 seconds, the motor rotor speed starts to accelerate from zero, reaches 500 rpm at 3.1 seconds, and successfully switches to PI control mode, remaining stable at 500 rpm. Then, at 6 seconds, the rotor speed continues to accelerate, reaches 600 rpm and stabilizes again.

[0138] Such experimental results show the good performance of the motor control system. Through the integral sliding mode speed loop control, fast and stable rotor speed regulation can be achieved, allowing the motor to run at the expected speed.

[0139] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An experimental platform for permanent magnet synchronous motor control, characterized in that: It includes a control mainboard, a load controller and a permanent magnet synchronous motor both connected to the control mainboard, wherein: The control mainboard includes a main controller, a speed sensor, a current sampling circuit and a motor drive circuit, wherein the main controller performs integral sliding mode variable structure control, calculates control input, and inputs the required space vector pulse width modulation wave into the motor drive circuit according to the calculation; the speed sensor collects the rotor speed and rotor position information of the permanent magnet synchronous motor; the current sampling circuit collects the three-phase current of the motor drive circuit; the motor drive circuit converts the space vector pulse width modulation wave signal into a voltage signal, controls the three-phase voltage of the permanent magnet synchronous motor, and thus controls the speed of the permanent magnet synchronous motor.

2. The experimental platform for permanent magnet synchronous motor control according to claim 1 is characterized in that: The main controller includes an STM32 single-chip microcomputer minimum system.

3. The experimental platform for permanent magnet synchronous motor control according to claim 1 is characterized in that: The speed sensor includes a TLE5012 chip, which adjusts the control of the permanent magnet synchronous motor through the feedback of the rotor position and outputs comparative data of the sensorless control of the permanent magnet synchronous motor.

4. The experimental platform for permanent magnet synchronous motor control according to claim 1 is characterized in that: The current sampling circuit is a three-phase current acquisition circuit based on the on-chip operational amplifier in the STM32 single-chip microcomputer.

5. The experimental platform for permanent magnet synchronous motor control according to claim 1 is characterized in that: The load controller comprises a tension controller, a magnetic powder brake and a tension detector, wherein the tension controller and the tension detector form a closed-loop tension control; the magnetic powder brake uses magnetic powder as a medium and forms a magnetic powder chain to transmit torque when powered on.

6. The experimental platform for permanent magnet synchronous motor control according to claim 1 is characterized in that: The motor driving circuit includes a switch tube BSC070N10NS5.

7. A control method for an experimental platform of a permanent magnet synchronous motor control, characterized in that: An experimental platform for controlling a permanent magnet synchronous motor according to any one of claims 1 to 6 comprises the following steps: S10, the Hall sensor and the speed sensor obtain the high-speed and low-speed angular velocities of the motor; S20, the main controller collects three-phase currents, calculates the q-axis current error, and controls the permanent magnet synchronous motor through the designed algorithm; S30, updating the value of the sliding surface; S40, updating the sliding mode control input.

8. The control method according to claim 7, characterized in that: The simplified model of the permanent magnet synchronous motor in the control strategy id=0 and the dq rotating coordinate system in S20 is as follows: Among them, u d and u $ are the d-axis and q-axis voltages, respectively, and R " is the resistance, i d and i $ are the d-axis and q-axis currents, L d and L $ are the d-axis and q-axis inductances, ω e is the angular velocity, ψ ％ is the rotor flux amplitude; The electromagnetic torque equation of the motor is: where p n represents the number of magnetic pole pairs; The mechanical motion equation of the motor is: Where J is the moment of inertia, B is the viscous friction coefficient, T L is the load torque; The dynamic model of permanent magnet synchronous motor can be written as follows: Where K = 3p n ψ ％ / 2 is the torque constant; In order to further realize the design of the main controller, the dynamic equation is rewritten as: Where i $ * is the reference current of the q axis, which is used to achieve the desired control effect of the main controller, and D(t) is the lumped interference of the system, which is given by the following formula: The dynamic error model of the speed control system is defined as: Among them, e, is the error state variable and the first-order derivative, ω e * and are the reference speed and the first-order derivative.

9. The method according to claim 1, characterized in that: The sliding surface in S30 is designed as follows: Among them, σ, ρ, μ, θ, m1, m2, n1 and n2 are all custom coefficient parameters. Their value ranges are as follows: σ>0, ρ>0, 0<μ<θ<2, μ=m1 / n1, θ=m2 / n2, m1, m2, n1 and n2 are all positive odd numbers, and s is the sliding surface; In order to achieve faster convergence speed and reduce chattering, the design convergence rate is: Where a1, b1, p1, q1, r and k are all custom coefficient parameters, and their value ranges are as follows: a1>0, b1>0, 0 <p1r<1,q1r> 1,k>-T L / J-Bω e / J, J is the moment of inertia, B is the viscous friction coefficient, T L is the load torque, is the first-order derivative of the sliding surface.

10. The method according to claim 9, characterized in that The sliding mode control input in S40 is designed as: Where u is the total control input, J is the moment of inertia, K = 3p n ψ ％ / 2 is the torque constant, p n represents the number of magnetic pole pairs, ψ ％ is the rotor flux amplitude, u e$ and u "1 is the equivalent control and switching control component, defined as: Finally, the controller is designed as: Design of Lyapunov functions The derivative is

Images