Injectionless Full Range Speed Sensorless Control for Synchronous Reluctance Motors based on PWM Current Ripple

This paper deals with a rotor position estimator algorithm for anisotropic motors based on current ripple, and no additional voltage injections are requested. The current trace in the αβ reference frame is fitted on the implicit ellipse equation by using the least square algorithm, and no parameters are requested for the estimator tuning. A modified modulation scheme is implemented to guarantee a suitable current ripple in all operating conditions. The estimated position is smoothen and adjusted by using a quadrature-PLL, exploiting the obtained sine and cosine components of the rotor position. Simulation results with a synchronous reluctance motor were carried out to prove the effectiveness and the accuracy of the proposed injectionless sensorless algorithm.