Fictitious Flux Observer for Sensorless Control of Synchronous Reluctance Motors Considering Magnetic Cross -Coupling Effects

This paper extends the previously proposed position and speed estimator for synchronous reluctance motors which is based on the fictitious flux concept by taking into consideration the magnetic cross-coupling effects. Definition of the fictitious flux has been modified to include also the cross-coupling flux, and a new expression for the motor model is introduced. A globally stable flux observer is then derived, along with the rotor position and speed estimator by a vector phase-locked loop. Theoretical results are verified by simulation carried out under various operating conditions to confirm stability and performance of the sensorless drive using the proposed estimator.