Speed Control System Design Of AC Permanent Magnet Synchronous Motor

With the development of high performance permanent magnetic materials,power electronics,digital controller,AC permanent magnet synchronous motor developed rapidly,and has been widely applied in petroleum,electric vehicles,ship lift,robot and other fields,occupies an important position in modern industry,so the design of servo control system with excellent performance is an important part to promote the further development of the permanent magnet synchronous motor.For the design and research of permanent magnet synchronous motor’s speed control system,according to the working principle and mathematical model,the motor’s simulink model is built,and starting motor directly without control is simulated,the simulation results show that the motor is instable and likely to lose step.Working principle of the key component of control system--inverter,is analyzed.Method for controlling inverter using PWM is described.The difference between SPWM and SVPWM is compared,and the principle of SVPWM be emphasized,then the simulink model of SVPWM is bulit by m language.On this basis,this paper analyzes the realization method of space vector pulse width modulation technology on MC9S12XS128,and gives the programming template based on C language;Finally,the whole simulation model of current and speed double closed loop AC permanent magnet synchronous motor speed control system is built,For problem of the step response’s large overshoot,and long time of eliminating static error with traditional PID control in speed loop,integral separate and variable speed integrating PID controller is designed,whose control performance is better than the traditional PID controller.Although overshoot is still large in low speed,but the time of eliminate static error is shortened significantly,which make the system meeting the condition of using model prediction control method.In order to further improve the speed control performance,a kind of improved modelpredictive control method is proposed,which could applied to the nonlinear object,The simulation results show that the control performance of the designed MPC-PID cascade controller,is superior to the traditional PID controller and integral separate and variable speed integrating PID controller,reduces the overshoot and the setting time,which proves the validity of this method.