A comparative study of vehicle drive performance and energy efficiency
In this paper, two types of increasingly more efficient and greener vehicles are analyzed and compared. These vehicles are: a proposed conceptual seriesparallel powertrain, the University of Technology, Sydney plug-in hybrid electric vehicle (UTS PREY); and, a conventional series-parallel hybrid electric vehicle with an internal combustion engine .. The UTS PREY requires only a single electric machine to function as an electric motor or generator in different time intervals controlled by a special energy management strategy. The UTS PREV uses two energy storage devices, the battery and the ultracapacitor, which can work together effectively to maintain the state of charge at a high level in order to improve the vehicle drive performance and energy efficiency. With the assistance of a novel automatic transmission, the UTS PREY can operate under multiple modes to suit the needs of various driving cycles including those in an emergency. A special power and energy management strategy was developed to control the power flows within the vehicle according to the desired operating mode. The overall structure ofUTS PREY, known as UTS PREY code are derived and implemented numerically in the MATLAB/SIMULINK environment for further analysis. Through simulations, the performance of the UTS PREY has been evaluated in terms of the fuel economy, all electric range (AER), electrical consumption and operation cost for low and high density traffic patterns drive cycles. The comparison between the performance and efficiency of the UTS PREY and those obtained results using existing powertrains are also presented. The obtained results demonstrate that the UTS PREY outperforms most existing powertrains and has great potential in applications to passenger cars for city and urban transportations.