Feasibility of a Regenerative Braking System for a School Bus

Objective The goal of this thesis is to determine the feasibility of a regenerative braking system (RBS) on a school bus and to subsequently develop and test a prototype system. Motivation It is proposed that a regenerative braking system be utilized on a school bus to improve fuel efficiency and reduce exposure of children to diesel particulates. The primary benefit of a RBS is a decrease in the amount of fuel used to drive the bus. The advantage of using less fuel is a decline in emissions. Previous studies conducted at Clarkson University have shown the level of exposure to tailpipe emissions that is experienced by children on a school bus. [1] The characteristic stages of driving a vehicle to its destination combine to create the vehicle's mission. First the car is started and then accelerated to speed. Acceleration of a vehicle is an extremely inefficient process; when a vehicle is accelerated, a large amount of fuel is consumed to increase the speed of the vehicle. After acceleration, the vehicle may stop and go through red lights, or idle in city traffic, but eventually it comes to a halt at its destination. The braking process of a vehicle is the most wasteful task, from an energy perspective. When a vehicle decelerates, all the kinetic energy that has been built up through acceleration is lost to heat, in a matter of seconds through friction. This cycle of starting and stopping is magnified by a school bus, whose average number of stops is much higher than that of a typical car driving down the road.