Dual Battery System for Commercial Plug-In Hybrid Electric Vehicles

Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for EV mode range. The dual ESS allows the best utilization of battery technologies for both high power density and high energy density. In this paper, we have conducted vehicle level study and modeling to quantify the benefit of bi-directional DC-DC converter in dual battery systems for commercial heavy duty vehicles. The goal of this study is to increase the overall efficiency and fuel economy of PHEV. The simulation results show that PHEV with two sets of battery packs and a DC-DC converter has better performance and higher overall efficiency over the conventional PHEV.