The rotor speed and position sensorless control of switched reluctance motor using the adaptive observer

The speed control of a SRM (switched reluctance motor) needs the accurate position and speed data of the rotor. This information is provided by a shaft encoder or a resolver. In some cases, high temperature, dust, and EMI may cause difficulties in maintaining the satisfactory position detection performance. The elimination of the position and speed sensor has gained wide attention. In this paper a new algorithm for the estimation of the rotor position and speed is proposed for the SRM drives. A nonlinear adaptive observer on the basis of the adaptive control theory is used to estimate the rotor speed and position. The stability of the adaptive observer is proved by the Lyapunov stability theorem. The adaptive observer estimates the rotor speed and position using the phase current and the estimated current. This algorithm was implemented with a DSP (digital signal processor) TMS320C31. Experimental results prove that the observer is able to estimate the speed and position.