Research On Active Disturbance Rejection Control And Dead-time Compensation Method For AC Servo System

Modern AC servo control system should first have a fast command response capability.And should also ensure strong anti-jamming characteristics.However,the traditional PID controller has a simple structure and cannot guarantee the overall robustness of the servo.So it is difficult to meet the requirement of quickly suppressing the disturbance.An autodisturbance rejection control method based on dead-zone compensation is studied to suppress the internal and external disturbances in the working process of PMSM and compensate the voltage error caused by the dead-time.The main research contents of this paper are arranged as follows:The types and characteristics of the interference are analyzed in the AC servo system.Then the similarities and differences between PID and ADRC are compared.While explaining the advantages of the auto-disturbance control,the influence of the PWM deadtime in the inverter is studied.Then the o frame of the speed-loop first-order autodisturbance rejection control with dead-zone compensation is designed.The optimization performance of the command transition process is analyzed.An observer of disturbance extended state applied to the speed loop overall scheme of the AC servo system is proposed.The feed forward mechanism is analyzed and designed to reduce the response time of the motor feedback speed.The controller’s disturbance suppression effect is verified in speed loop simulation model.The dead-band effect of the current loop in AC servo is studied.Then voltage compensation algorithm is used to compensate the current waveform distortion caused by PWM dead zone.In order to improve the accuracy of voltage compensation,a stator current polarity detection method is designed and implemented to eliminate the interference caused by high-frequency noise.And the compensation method is simulated.The servo drive system experiment platform is set up.Then anti-disturbance experiments and dead-zone compensation experiments are performed on the servo driver developed by the laboratory team.Experimental results show that the disturbance control method designed by the paper observes the disturbance accurately.The ADRC controller has better disturbance rejection than the PID controller.And the dead-zone compensation algorithm can improve the sine of the current signal.