To date hybrid-electric vehicles (HEV) make use of high-power density ac propulsion systems to provide comparable performance with vehicles using internal combustion engine (ICE) technology. Electric motor, inverter, and associated control technology has made substantial progress during the past decade and it is not the limiting factor to either vehicle performance or the large-scale production of hybrid vehicles. The search for a compact, lightweight, and efficient energy storage system that is both affordable and has acceptable life cycle remains the major roadblock to large-scale production of HEVs.
DI NAPOLI, A., Crescimbini, F., Lidozzi, A., Solero, L., Pasquali, M., Puccetti, A., et al. (2004). Design and Testing of a Fuel-Cell Powered Propulsion System Supported by a Hybrid UC-Battery Storage. In SAE Technical Paper Series 2004-01-1303 [10.4271/2004-01-1303].