An Analysis of Hybrid Electric Propulsion Systems for Transit Buses

The future of America’s truck and bus industry depends upon its ability to produce cost effective, high quality, environmentally sensitive, and safe vehicles. To spur innovation, agencies of the U.S. Government have partnered with industry for various heavy vehicle programs. The National Renewable Energy Laboratory (NREL) conducted heavy vehicle systems analysis for two such government/industry programs: the 21st Century Truck Program (21CT) and the U.S. Department of Energy (DOE) Advanced Heavy Vehicle Hybrid Propulsion System R & D Program (Heavy Hybrid Program). Systems analysis work on transit bus platforms for the 21CT Program and Heavy Hybrid Program is presented here. Simulation is conducted using NREL’s publicly available vehicle simulation tool, ADVISOR (ADvanced VehIcle SimulatOR), updated and modified for heavy vehicle analysis.