A position sensorless control strategy based on sliding mode observer (SMO) and adaptive back-stepping sliding mode controller is proposed for the speed estimation of double linear flux switching permanent magnet (DLFSPM) motor in order to solve the problem that the sensor is easily disturbed. First, the mathematical model of the DLFSPM motor is established and the sliding mode control system is built. Aiming at the problems of high-frequency chattering and poor observation accuracy of the traditional SMO, a new piecewise function to replace the symbolic function in the traditional SMO, which improves the approaching speed of sliding mode and reduces the high-frequency chattering caused by the switch. At the same time, the phase-locked loop technology is used to estimate the position and speed of the motor to improve the accuracy of estimated position. Then, the adaptive back-stepping sliding mode controller is proposed to further reduce chattering and improve anti-interference ability of system. Finally, the dynamic performance of the system under the condition of speed mutation and load mutation is simulated. The simulation results show that the the proposed strategy can accurately identify the position and speed of the motor under different working conditions, and has good dynamic performance, which proves the feasibility and effectiveness of the proposed control strategy.

Position Sensorless， sliding mode observer， adaptive back-stepping， double linear flux switching permanent magnet motor.