Sensorless Control of Switched Reluctance Motor Based on Trapezoidal Inductance Profile

Switched Reluctance Motors (SRM) are known for their inherent fault tolerance and rugged design. However, the use of external position sensors compromises the reliability of the machine. A sensorless control method is proposed in this paper which tries to eliminate the need of an extensively computed magnetization characteristic, and utilize the variation of phase inductance with rotor position. The inductance profile is modeled by a simplified trapezoidal function whose coefficients can be easily determined, with minimal offline measurement. The method was implemented on a 50 V, 1 HP 4-Phase SRM. Experiments verified that the method is capable of characterizing the inductance variation and estimate the rotor position.