High-Frequency-Injection-Assisted “Active-Flux”-Based Sensorless Vector Control of Reluctance Synchronous Motors, With Experiments From Zero Speed

This paper presents a hybrid motion sensorless control of an axially laminated anisotropic reluctance synchronous machine (RSM). The zero- and low-speed sensorless method is a saliency-based high-frequency signal injection technique that uses the motor itself as a resolver. The second method is based on a state observer incorporating the “active-flux” concept used to deliver RSM rotor position and speed information for medium- and high-speed range. Even if both methods perform successfully in separate speed regions, estimation of the two algorithms is combined as a sensor fusion to improve the performance at zero and very low speeds. Experimental results validate the proposed control strategies.