New adaptive sliding observer for sensorless control of surface permanent magnet synchronous motor

A new adaptive sliding observer is proposed for position and velocity sensorless controls of a surface permanent magnet synchronous motor. Stability of the proposed observer is guaranteed easily, because it is based on a linear model of the motor. Sliding mode is applied for the current estimation. Under the sliding node, the order of the observer's error equation is reduced. This makes the stability analysis easier so that robust position and velocity estimations might be achieved by the pole assignment. Experimental results show that the proposed method is very effective.