Transducerless position and velocity estimation in induction andsalient AC machines

摘要

This paper presents a viable transducerless rotor position andvelocity estimation scheme for PWM inverter driven induction,synchronous, and reluctance machines with the capability of providingrobust and accurate dynamic estimation independent of operating point,including zero and very high speeds, light and heavy loading. Theinjection of a balanced 3 phase high frequency signal (500 to 2 kHz)generated by the inverter, followed by appropriate signal demodulationand processing combined with a closed-loop observer, enable the trackingof rotor magnetic saliencies from the machine terminals. Although rotormagnetic saliency is inherent within reluctance machines, and mostsynchronous machines, saliency in the induction machine is introducedvia a modulation of the rotor slot leakage with minimal detrimentaleffects on the machine performance. Experimental verification for theinduction machine is included