A Truncated Fourier Based Analytical Model for SRMs with Higher Number of Rotor Poles

Switched reluctance motors (SRM) have been seen as a potential candidate for automotive, aerospace as well as domestic applications and High-Rotor pole SRM (HR-SRM) present a significant advancement in this area. This machine configuration offers most of the the benefits offered by conventional SRMs and has shown significant benefits in efficiency and torque quality. However, HR-SRM has a narrower inductance profile with a lower saliency ratio as compared to a conventional SRM with an identical stator. This can make it inherently challenging to directly adopt mathematical models and sensorless control approaches currently in use. This paper presents a time-efficient analytical model for the characterization of a 6/10 SRM using an inductance model utilizing truncated Fourier series as well as multi-order polynomial curve-fitting algorithm. The inductance model is extended to accurately predict back-EMF and electromagnetic torque response towards obtaining a comprehensive model for every operating point of the machine during dynamic operation. The effectiveness of the proposed concept has analyzed for a prototype machine and verified using Finite Element Analysis (FEA).