Switched reluctance motors: small motors of the next generation for automobiles?

This paper presents the development in switched reluctance motors (SRM) for applications in automotive small motor drives. As the automobile industry searches for advanced small motors with low cost, high reliability, low acoustic noise, long life cycle, variable speed capability, integrated protection functions and high efficiency, SRMs present an alternative choice. SRMs possess several desired qualities for automotive small motors including high power density, high torque per ampere, simple stator and rotor structures, high reliability and high efficiency. The author has conducted research into SRM drives for automobile applications by proposing a systematic SRM design methodology based on empirical formulas, finite element analysis and analytical modeling, and by developing a C-dump-converter-based, 250 W, 3-phase, 12 V, 6/4 pole SRM drive. The performance characteristics of the developed SRM drive were evaluated based on tests of the drive with an automobile fan load. Through the research results, it was concluded that while SRMs possess many desirable features, they are not yet ready for mass production as a replacement for DC motors in automobiles.