Abstract:A new inductorless control method based on a new integral differential sliding mode controller and a new slid- ing mode observer is proposed to address the problems ofexcessiveovershoot of the speed loop proportional-integral con- trol(PI)and high-frequency jitter of the conventional sliding mode observer(SMO)in permanent magnet synchronous motors.The method replaces the PI controller with a new differential-integral sliding mode controller,uses continuous function instead of switching function to reduce jitter,designs the sliding mode observer with exponential convergence law and estimates the counter-electromotive force,and designs the adaptive law according to the counter-electromotive force to avoid the use of low-pas filter to obtain more accurate rotor position.Finally,the model is built by MATLAB/ Simulink,and the results show that the method has the characteristics ofjitter reduction,no overshoot,and accurate ro- tor position estimation,and the maximum error of speed is reduced from 18 to 2.5 r/min,and the error of rotor position is reduced from 0.048 to 0.021 rad.