A new rotor position detection method using bifilar windings and resonant circuit in SRM drive

This paper presents a new method for indirect sensing of rotor position in a switched reluctance motor using bifilar windings in a resonant circuit. The detection method stems from the fact that the changes in sine wave magnitude produced in a RLC resonant circuit by motor variable phase inductance can be used to detect the rotor position. The proposed method is applicable at standstill as well as the running mode. The use of bifilar windings for rotor position detection makes the control circuit to be completely isolated from main winding and the power transistors. It also results in simple hardware which minimizes the cost of drive circuitry. The proposed method was implemented on a 3-phase 6/4 SRM with bifilar windings and the experimental results demonstrated the accuracy and function ability of this method.