Development of a Vehicle Control System for a Fuel Cell Hybrid Bus

A vehicle control system basing on instantaneous energy optimization and series regenerative braking strategy was successfully developed for a fuel cell hybrid bus. The control system includes a vehicle control unit and other warning and measure systems. The control algorithm contains several blocks: start/stop, motor mode switch, diagnose and energy management. The movement of vehicle is divided into two parts: A) no braking process and B) braking process. An instantaneous equivalent hydrogen consumption optimization strategy was applied in process A. And in process B the braking energy was recovered partly so that the vehicle longitudinal dynamics would not be greatly affected. As a result, the fuel economy is improved from 9.6kg/100km to 7.9kg/100km in “China typical city bus cycle”.