Optimisation of switched reluctance motors for hybrid electric vehicles

A switched reluctance motor (SRM) is well suited to the electric propulsion of a hybrid electric vehicle (HEV), due to its simple and rugged construction, low cost, and ability to operate over a wide speed range at constant power. This paper presents the design optimisation of SRMs for HEV applications, by using a combination of 2D electromagnetic finite element (FE) analysis, experience from previous designs, 3D correction factors, simple lumped-parameter thermal models, and computer search techniques. A prototype SRM was built and fully tested. The experimental results validate the design methodology. Based on the optimal lamination profile of the prototype, five motors were constructed for two HEVs: two for a parallel HEV and three for a series HEV. The two cars have demonstrated excellent performance with the optimised SRMs.