A Position Sensorless Control of Switched Reluctance Motors

Abstract

Switched reluctance motor (SRM) is an attractive candidate for many industrial and domestic applications such as electric vehicles and home appliances. Rotor position detection is of significant importance for SRM control. However, external position sensors like absolute encoders and magnetic sensors reduce the reliability of SRM drive system in hash environments and increase the cost. Therefore, position sensorless control becomes a promising technique for SRM. In this thesis, a new position sensorless control method for SRM is proposed to estimate rotor position and speed. Sliding mode observer is adopted at high speed and pulse injection method is adopted at low speed. Both of the two methods are adopted with a motion model based on the third order phase locked loop to improve the dynamic tracking performance. The analysis method of the proposed position sensorless method is also presented. Both simulation and experiment results are presented to verify the proposed sensorless control method. The simulation results show that the proposed method can precisely estimate rotor position and speed with short response time. Experimental results further demonstrate the reliability and effectiveness of the proposed positon sensorless control method.