New approach for high-performance PMSM drives without rotational position sensors

A new approach to the position sensor elimination of permanent magnet synchronous motor (PMSM) drives is presented in this paper. With the help of the modern drive technique, the actual rotor position as well as the machine speed can be estimated accurately even in the transient state using the "electrical steady-state" operation concepts. Due to the angle-modification scheme with error-tracking function, the sensorless drive system has robustness to parameter variations. As well as giving a detailed explanation of the new algorithm, the paper presents a wide range of experimental results, demonstrating the feasibility of the proposed method under full operating conditions in the /spl plusmn/50/spl sim//spl plusmn/2000 [RPM] speed range and 0/spl sim/1 per unit (p.u.) load conditions.