An Investigation on the Effect of Drivetrain Hybridization in a Transit Bus, Series Configuration

To achieve higher fuel economy and lower emissions hybridization of conventional vehicles seems to be an effective solution and an important step. In this paper, after a short introduction about the hybrid electric vehicles a brief design of series electric vehicles is introduced. Then one of the Iran-Khodro city buses named O457 is chosen 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 value 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.