Signal-injection assisted full-order observer with parameter adaptation for synchronous reluctance motor drives

A back-EMF-based position observer for motion-sensorless synchronous reluctance motor (SyRM) drives is augmented with parameter-adaptation laws for improved low, medium, and high speed operation. The augmented observer is experimentally evaluated using a 6.7-kW SyRM drive under various speeds and load conditions. The analysis and experimental results indicate that the stator-resistance adaptation should be enabled only at low speeds, the d-axis inductance adaptation should be enabled only at medium and high speeds near no load, and the q-axis inductance adaptation should be enabled only at high speeds under high load.