Energy Storage Analysis of a Fuel Cell Hybrid Vehicle with Constant Force Acceleration Profile

Batteries commonly cater to the power flows and load leveling in hybrid fuel cell vehicles especially during startup and acceleration. Power provided by the energy storage unit (ESU) need not be constant but can be variable according to the instantaneous power and energy requirement of the vehicle. This paper investigates the design methodology for a combined ultracapacitor and a battery ESU. The acceleration profile of a constant tractive force will be considered compared to constant power. The required masses of the storage elements with the various battery and ultracapacitor characteristics for both the constant force and constant torque cases are discussed.