Component size and gear ratio optimization in PHEV powertrain

A PHEV powertrain using gears instead of transmission is discussed in this paper. Because a transmission or planetary gear ratio is usually given, there is no need to consider gear ratio in component sizing process. In this case, however, gear ratios are not given. These ratios are a critical factor for fuel economy. So component sizing optimization is conducted including gear ratios. An energy management strategy is suggested based on optimization result and evaluated by forward vehicle simulation.