Coupling thermodynamics modeling and analysis of a free piston linear generator range-extender for HEVs

This paper proposes a concept of free piston linear generator (FPLG) range-extender for the application of hybrid electric vehicles (HEVs). The coupling thermodynamics model of the FPLG range-extender is developed mathematically. Its stable operation characteristics are analyzed accordingly. In addition, the effects of the variations of the key operational parameters on the effective output power and overall efficiency are investigated. The simulation results verify that the designed FPLG range-extender can provide 15kW effective charging power with the overall efficiency of 38.2%, and the peak power can even reach as high as 47.5kW. It is a promising alternative range-extender of the HEVs that can dramatically enhance the battery life.