Self-sensing methods extended to four phase switched reluctance machines

This paper presents novel high-frequency signal injection-based self-sensing methods for four-phase switched reluctance machines. The methods cover full magnetic operating range of the drive including saturation and show compensation methods to improve the rotor position estimation under saturation. The effects of magnetic saturation on machine saliencies are studied and modified carrier signal injection methods are developed to mitigate the effect of saturation on rotor position estimation. Simulation and experimental results are presented to demonstrate the effectives of the proposed method for continuous rotor position estimation at low speeds.