Sensorless Control of Switched Reluctance Motor Based on Current Waveform Detection

Abstract

This paper describes a sensorless control technique Based on current waveform detection for Switched Reluctance Motor (SRM) over full speed-range. For conventional sensorless method, the resistive drop and the back- EMF are always neglected, which may cause some errors in position determination and restrict the rotor speed-range. To overcome this problem, an improved current-slope-difference based approach is presented for sensorless starting and continuous low-speed sensorless operation. For medium and higher speeds, a current-gradient method is used for sensorless operation. Based on the proposed sensorless method, the position sensorless operation within the whole speed range of the SRM can be easily implemented. Finally, the experimental results demonstrate the validity of the hybrid sensorless approach in the full speed region.