A New Self-Commissioning Technique for Sensorless Synchronous Reluctance Motor Drives

A new approach is proposed to enable the self-commissioning on back-EMF based sensorless synchronous reluctance motor drives, providing an inexpensive mean to improve the performance and control robustness. The proposed approach is based on the injection of suitable current signals and on adjusting the estimated value of the rotor angular position in order minimize the ripple generated on a signal produced by a phase locked loop speed estimator. Exploiting such a technique look-up tables can be off-line built which can be used to on-line correct the estimated rotor angular position according to actual d,q stator currents. The proposed approach does not need additional current or voltage sensors, nor motor design modifications and can be also exploited to compensate the effects of the variation of the stator resistance with the temperature.