Research On Dual Sliding Mode Control System Of Sensor-Less Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor is used in every aspect of daily life because of its advartages of high efficiency,fast response speed and low energy consumption.At the same time as a multi-variable,nonlinear,strong coupling electromechanical system,the control system also put forward higher requirements.Accurate rotor position acquisition by sensor cr encoder is the control premise of most permanent magnet synchronous motors,but the complexity of the application environment brings a severe test to the reliability of the sensor In order to avoid affecting the performance of control system due to sensor faults,it is very important to study sensorless control technology to improve the stability of contrcol system.In this paper,the working principle and mathematical model of permanent magnet synchroncus motor are briefly summarized,the space vector control system of speed current double closed-loop motor based on PI controller is described and formula is deduced,the motor control system is built on Simulink and simulation analysis is carried out.Sliding mode variable structure control can make the control system insensitive to external disturbance when the state variable reaches the sliding mode surface,and it can restrain the parameter change caused by disturbance due to its discontinuity.The traditional sliding mode observer is designed to replace the motor rotor position and speed sensor observaticn,the design of linear sliding mode plane and exponential reaching law instead of PI contioller to do the double closed loop speed regulation system of speed controller.the sliding mode observer and combir ing sliding mode controller,to achieve double sliding mode control of sersorless permanent magnet synchronous motor.In view of the traditional controller by external disturbances of large amount of overshoot and adjustment time is long,etc,this paper designed the nonsingular terminal sliding mode surface quickly,and on the basis of system state space position and the sliding mode surface spatial location relationship automatically adjust the adaptive factor,combined with the power function of the system state variables to construct new reaching law;Aiming at the inherent chattering problem in sliding mode control and the low detection accuracy in traditional sliding mode control,an adaptive sliding mode observer based on phase-locked loop was designed to observe the rotor Angle combining with tanh(x)saturation function.The Lyapunov function was constructed and the simulation model was built in Simulink for comparison and verification.The results show that the improved method is feasible and has better stability.Finally,a hardware experimental platform was built to verify the proposed method,and the correctness of the proposed method was verified by analyzing the experimental results.