Intelligent Energy Management in Hybrid Electric Vehicles

Energy management in vehicles is an important issue because it can significantly influence the performances of the vehicles. Improving energy management in vehicles can deliver important benefits such as reducing fuel consumption, decreasing emission, lower running cost, reducing noise pollution, and improving driving performance and ease of use. According to Mainins (Manins, 2000), each year more then 50 million new cars are produced in the world. However, usually only 30% to 40% of the energy produced by the engine is used to drive a car. The large energy waste of around 60% is the result of having an engine powerful enough to cope with the maximum power demand despite the fact that such power is required for only a vary small percentage of vehicles’ operating time. In addition, vehicle emissions are a source of greenhouse gas pollution emitting 70% to 90% of urban air pollution (SOE, 2006). Fuel economy benchmarks and emission regulations have encouraged vehicle manufactures and researchers to investigate new technologies to enhance fuel economy and minimise emissions. The energy efficiency of vehicles can be improved by enhancing the efficiency of the vehicle. Implementing energy management strategies in classical vehicles does not fully deliver the expected benefits. Hybrid electric vehicles, on the other hand, offer a platform that can accommodate advanced energy management strategies giving rise to full realization of the stated benefits. Intelligent energy management methods can observe and learn driver behavior, environmental and vehicle conditions, and intelligently control the operation of the hybrid electric vehicle. A Hybrid Electric Vehicle (HEV) takes advantage of an Internal Combustion Engine (ICE) and an Electric Motor (EM) to deliver fuel consumption and exhaust emission reduction. An EM is powered by on-board battery packs to drive the vehicle. From the consumers overall perspective, the HEV is essentially the same as a Conventional Vehicle (CV). Moreover, HEVs are refuelled in the same way as a CV. A HEV has the advantage over a pure Electric Vehicle (EV) in both travelling range and convenience, as there is no need to recharge the battery through a power point for long hours. Importantly, a HEV has the potential to improve fuel economy by almost 50%, while also possessing all the advantages and flexibility of a CV (Ehsani et al,. 2005). Hence, HEVs solve the problems of EVs whilst minimising the shortcoming of CVs providing the benefits of both electric and conventional 8