Abstract
Restrictions imposed by environmental organizations on vehicle designers and manufacturers have forced them to convey their researches and productions towards less pollutant and fewer fuel consuming vehicles. This growing need to improve fuel economy and emissions in the world transportation sector and has spurred urban transit bus operators to pioneer the adoption of alternate fuels and new drive system technologies. One of the most promising technologies to receive attention is hybrid electric drive, which consists of two or more energy sources that supply energy to electric traction motors that in turn drive the wheels. HEVs are mostly grouped in two different configurations: series and parallel.
In this paper, after a short introduction about the hybrid electric vehicles a brief design of series electric vehicles is introduced. In this study, it is focused on hybridization of the Iran- Khodro company´s O457 transit bus to change to a series hybrid electric bus. After choosing the proper hybrid components the bus performance is investigated to assure whether it can satisfy the required performance or not. Then the conventional O457 and its series configurations for two different control strategies are defined and evaluated using the ADvanced VehIcle SimulatOR, ADVISOR.
Simulations are carried out in a combined urban drive cycle because of the lack of a real drive cycle for Tehran city. The fuel consumption and the amount of produced emissions are compared together for three mentioned cases. The validity of simulation has been proved by the close conformity between the values of fuel consumption of the conventional vehicle reported by the company to what has been achieved from the simulation. It is observed that compared to the conventional vehicle, a reduction in fuel consumption about 32% in the maximum SOC control strategy and about 27% in the thermostat control strategy are possible to achieve. In addition, simulation results indicate that air pollution caused by vehicle engine can be greatly reduced through hybridization using each of the mentioned control strategies.
Keywords:Hybrid Electric Vehicle, Emission, Drivetrain, Simulation.