ABSTRACT
Electric vehicles (EV) used to be classified into two groups: the pure EV that was purely fed by batteries and propelled solely by an electric motor, and the hybrid EV (HEV) that was sourced by both batteries and liquid fuel and powered by both the engine and electric motor. When both batteries and gasoline/diesel fuel are the energy sources as well as both the engine and electric motor are the propulsion devices, they are termed the HEV or simply called the hybrid vehicle. With the introduction of some HEVs having the features of both the series hybrid and parallel hybrid, the basic configurations have been extended to three kinds-series, parallel, and series-parallel. A double-stator permanent-magnet (PM) brushless topology is proposed to tune the flux, but it needs a complicated mechanism to shift the spatial angle between two stators. It employs high-energy rare-earth PMs on both the inner rotor and the outer rotor.
