Design of Physics-based EMF Observer for sensorless control of PM synchronous machines

Design of Physics-based EMF Observer for 3-phase surface mounted permanent magnet synchronous machine (SMPMSM) using a physics-based back electromotive force (EMF) observer is presented. The mathematical modeling, stability, and transient analysis of the observer are developed and described in details. The sensorless operation of a 0.2 (kW) SMPMSM is verified numerically and experimentally for medium low and low speeds at different operational contingencies. The results show that despite of the increased noise level and temperature rise due to an over loading condition at low speeds, the speed control and rotor position estimator show great performances.