Boosting system options for high efficiency Fuel Cell Electric Vehicles

Abstract

Mass-produced, off-the-shelf automotive air compressors cannot be directly used for boosting a fuel cell vehicle (FCV) application in the same way they are used in internal combustion engines, since requirements are different: a high pressure ratio with a low mass flow rate combined with a high efficiency requirement and compact size. From the established fuel cell types, the most promising for application in passenger cars or light commercial vehicle applications is the proton exchange membrane fuel cell (PEMFC), operating at around 80°C. In this case, an electric assisted turbocharger (E-turbocharger) and electric supercharger (single or two-stage) are more suitable than screw and scroll compressors. In order to determine which type of these boosting options is the most suitable for fuel cell vehicle (FCV) application and to assess their individual merits, a co-simulation between GT-SUITE and MATLAB/SIMULINK of FCV powertrains is realised to compare vehicles performances on the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) driving cycle. Results show that the vehicle equipped with an E-turbocharger has higher performances than vehicle equipped with a two-stage compressor in the aspects of electric system efficiency (+1.6%) and driving range (+3.7%) but, for the same maximal output power, the vehicle’s stack is 12.5% heavier and larger. Then, thanks to the turbine, the E-turbocharger leads to higher performances than the single stage compressor for the same stack size.