Sensorless rotor position analysis using resonant method for switched reluctance motor

An attempt is being made to develop a sensitive, simple, robust, low-cost sensing method for the positioning of a rotor in a doubly salient motor. The authors describe an experimental modeling of the stator phase with regard to the frequency and amplitude of a sinusoidal carrier and a method based on the principle of inductance measurement in the unenergized phase. A series resonant circuit R L(θ) C is used: L(θ) is the phase inductance varying with the rotor position. The resonant circuit is supplied by a high-frequency sinusoidal current generator. A synchronous demodulation technique, based on the extraction of the maximal amplitude, gives a voltage signal. This component is a direct measure of the angle linked to the phase inductance. The advantages of this method are its simplicity, low cost, and robustness. It amplitudes the phenomenon of inductance variation, thereby enhancing the accuracy in the measurement of the position angles