Abstract:

The wide speed ratio range and continuously variable ratio characteristics of continuously variable transmission (CVT) can effectively improve the energy economy of electric vehicles (EVs). However, the relatively low mechanical efficiency and high hydraulic loss limit its application in EVs. Therefore, an electric CVT configuration based on an electric oil pump (EOP) is proposed, and a dynamic model of the EV equipped with CVT is constructed and verified through bench tests. Subsequently, the model is used to study the factors affecting the energy economy of EVs in driving cycles. The simulation results indicate that a reasonable selection of speed ratio range can reduce power loss and improve energy consumption economy, an optimized speed ratio matching strategy can effectively improve electric drive efficiency, and adopting EOP to supply oil can decrease hydraulic loss. The analysis results provide a perfect reference for further exploring the energy-saving potential of EVs equipped with CVT.