Sensorless Synchronous Reluctance Motor Drives: A Sensitivity Analysis Framework and Design to Achieve Stator Resistance Immunity

The paper presents a generic framework for analysis of stator resistance variation in the stability of position observers. The adverse impact of the resistance error on the active flux based sensorless control is studied. A new technique, Adaptive Projection vector for Position error estimation (APP), is proposed to have inherent immunity to resistance errors; in addition, a resistance adaption is devised for accurate estimation of stator flux and torque. The observers are subjected to stability analysis. The instability of active flux control and the merits of the proposed technique are experimentally demonstrated on a 1 kW synchronous reluctance machine test bench.