Research On Vector Control System Of Permanent Magnet Synchronous Motor Based On Fuzzy Sliding Mode Variable Structure

Permanent magnet synchronous motor (PMSM) has been widely used in many fields, such as robots, CNC machine tools, aerospace and so on due to its simple structure, small size and high power density. However, there exists system parameters variation and load disturbance in application,therefore,it is necessary to study the advanced control algorithm of PMSM servo system to meet the control requirements of the system. Sliding mode variable structure control can overcome these problems caused by the uncertainty of the system,which is insensitive to parameters variation and load disturbance. Naturally,it is practical significance to study the application of sliding mode variable structure in permanent magnet synchronous motor control system.Firstly, the mathematical model of permanent magnet synchronous motor has been analyzed in a brief way. The rotor flux linkage oriented control is established based on is =0, and the control scheme for permanent magnet synchronous motor servo system is established based on space vector pulse width modulation (SVPWM).Secondly, variable structure control theory is introduced and the main problem that affects the practical application of variable structure control is chattering. Then, the exponential approach law is applied to deal with chattering to improve the quality of the sliding movement stage. Furthermore, in order to further weaken the chattering of the system,real-time adjustment coefficient of the variable structure control switch to control the amount of saturated function by fuzzy control,design a fuzzy controller to adjust the sliding mode variable structure speed loop, improve the adaptive ability of the system. The simulation model of PMSM is built in Matlab/Simulink, the simulation results show that compared with the traditional PI control method, the fuzzy sliding mode variable structure PMSM vector control system has better robustness and anti-interference ability.Based on the theoretical analysis and research of the control system, taking STM32F103ZET6 as the control core, the hardware circuit and software circuit of PMSM servo system are designed. The hardware part mainly includes the peripheral circuit of STM32 control unit, power drive circuit and detection circuit, and so on,the software part mainly includes the whole structure of the control chip software,the SVPWM generation,the speed loop control and so on. Through the system test platform for experimental analysis, the experimental results show that the overshoot of the motor is very small under the variable structure control mode, and it has good robustness in normal operation.