High order sliding mode controller and observer for sensorless IPM sycnronous motor

In this paper, a robust sensorless control based on high order sliding mode technique (HOSM) for interior permanent magnet synchronous motor is presented. The proposed observer is designed by combining a super twisting algorithm and interconnection technique. The high order sliding mode observer is used to estimate the speed, the rotor position and the stator resistance. Furthermore, the proposed controller is based on the quasi-continuous sliding mode method. Here, this control is adapted to interconnected systems with bounded interconnection terms. This control allows to attenuate the effects of the chattering, to improve the robustness with respect to external disturbances and parameters uncertainties. Additionally, the maximum-torque per ampere (MTPA) strategy is applied to increase the efficiency of the controlled drive. The closed-loop system stability is ensured by using separation principle. Simulation results in the different speed range including very low speed confirm the effectiveness of the proposed method.