New "D-state-observer" based sensorless vector control for permanent magnet synchronous motors

This paper proposes a new sensorless vector control method that can be applied to both of salient-pole and non-salient-pole permanent magnet synchronous motors (PMSM). The proposed method estimates phase of rotor flux by newly developed flux state-observer for sensorless vector controls of PMSM, which is referred to as "D-state-observer". The D-state-observer has the following attractive features: 1) it requires no additional steady-state condition to the motor mathematical model; 2) its order is the minimum second; 3) a single observer gain is simply constant over wide operating range, and easily designed; 4) it utilizes motor parameters in a very simple manner; and 5) its structure is very simple and it can be realized at very low computing load. Usefulness of the proposed method is examined and confirmed through extensive experiments.