Sensorless control of switched reluctance motors using sliding mode observers

In this paper, a sliding mode observer is developed to estimate the rotor position and speed of switched reluctance motors based on inductance model of SRM. Simulation results show that the proposed observer estimates with high resolution the rotor position when the motor speed is above 20 RPM. To realize sensorless control for the whole speed range, a method to detect turn-on/turn-off instants at near zero speeds is suggested and simulated. A starting algorithm is also included. A combination of these algorithms results in a full speed range sensorless controller