Aiming at the problems of traditional proportional integral（PI） controller

such as slow response speed

insufficient regulation ability and poor robustness

active disturbance rejection controller is used in direct drive permanent magnet synchronous motor（DPMSM） control.A new nonlinear control function with good continuity and smoothness around the origin is adopted in the active disturbance rejection controller to optimize the traditional nonlinear function.In addition

in order to improve the sensorless control performance of direct drive permanent magnet synchronous motor

the sliding mode observer is improved and the hyperbolic tangent function is used instead of the traditional symbol function to reduce system chattering.The simulation results show that when the motor starts without load

the maximum speed drop of the improved control system is reduced by 40 r/min

when sudden loading

and the recovery time is accelerated by 0.01 s compared with the traditional control system

which effectively improves the response speed of the control system and the ability of resisting load disturbance.