A review of pivotal energy management strategies for extended range electric vehicles

To address the urgent environmental challenges of transportation related air pollution and energy shortage, hybrid electric vehicles (HEV) and battery electric vehicles (BEV) with potential for higher energy efficiency are gaining in popularity and gradually replacing those conventional vehicles. Extended range electric vehicle (EREV) is a subset of these new energy vehicles aiming to gain benefits of both HEVs and BEVs and provide a solution to reducing tailpipe emissions whilst providing satisfactory driving-range compared with tradition internal combustion engine (ICE) vehicle counterparts. This paper systematically introduces the current developments of EREV in terms of the powertrain structure, energy management and vehicle performance, while the two key focus areas of auxiliary power unit (APU) charging control and (hybrid) energy storage system ((H)ESS) power management. A case analysis on a typical EREV is presented to study the application potential. Comprehensive comparisons of popular APU control strategies and different energy storage dispositions are shared, several existing issues are also discussed in this paper. Furthermore, a general manufacturing cost analysis for different types of vehicles is presented, and the outlook of EREV for future research is presented.