Simulation Study of a Transit Bus Equipped with an Ultracapacitor-Based Hybrid System

Abstract

Due to the significant share of Internal Combustion Engines (ICE) in global energy demand, primarily through the transportation sector, great efforts are invested in research for solutions that will increase the fuel economy of ICE-powered vehicles. Several directions, most prominently that of Hydraulic Hybrid Technology, are considered for achieving pronounced powertrain efficiency breakthroughs on heavy vehicles in the near and mid-term. However, even simpler hybrid solutions, such as those employing an ultracapacitor-based energy accumulator, may provide significant fuel economy improvements at diminished implementation costs. In this paper, considerations regarding the use of such a system are laid out. A data acquisition on a transit bus circulating on Belgrade’s transportation system has been performed in order to evaluate the real driving cycle and obtain the powertrain parameters necessary for calibrating a high-fidelity AMESim model of the vehicle. Initial study shows that considerable fuel consumption reduction in excess of 15% could be achieved by implementing a regenerative hybrid system employing an ultracapacitor-based accumulator.