Characterization of advanced drive system for hybrid electric vehicles

The electric drive is a key component in a plug-in hybrid electric vehicle (PHEV). The ideal tendency is to use the electric machine over the entire torque/speed range. This paper presents the characterization of the electrical drive suitable for a recently proposed PHEV powertrain, and the design optimization of the electric machine. The newly proposed PHEV powertrain has only one electric machine functioning as either a motor or generator at a time, an energy storage unit consisting of battery and super-capacitor banks for fast charging/discharging during regenerative braking and fast acceleration/deceleration, and a transmission line consisting of two power split devices and a gearbox. The electric machine must be designed for frequent start/stop, fast acceleration/deceleration, high torque and power densities, and high efficiency at all speeds. The drive system was modeled and characterized by using MATLAB/SIMULINK and PSAT, while the machine design was conducted through electromagnetic field analysis by using ANSYS. The design optimization was carried out for four different electric machines, including a double salient permanent magnet (DSPM) machine, a hybrid excitation DSPM (HEDSPM) machine, and two flux-switching permanent magnet (FSPM) machines of two different pole arrangements. The results show that the 6/7 pole FSPM machine has the best performance.