A robust sliding mode observer for permanent magnet synchronous motor drives

This paper presents a sliding mode observer to estimate the position and speed of a permanent magnet synchronous motor (PMSM). The observer error under parameters´ detuning is analysed. Simulation results showed that the observer is robust to the parameter uncertainties. An adaptive gain scheduling is used to increase the observer speed of convergence. A phase-compensation is introduced to minimize the unwanted phase lag introduced by the observer low pass filter. The observer lowest speed is 0.5 rad/s.