A novel steedy-state optimization (SSO) of internal combustion engine (ICE) strategy is proposed to maximize the efficiency of the overall powertrain for hybrid electric vehicles,in which the ICE efficiency,the effciencies of the electric motor (EM) and the energy storage device are all explicitly taken into account.In addition,a novel idle optimization of ICE strategy is implemented to obtain the optimal idle operating point of the ICE and corresponding optimal parking generation power of the EM using the view of the novel SSO of ICE strategy.Simulations results show that potential fuel economy improvement is achieved relative to the conventional one which only optimized the ICE efficiency by the novel SSO of ICE strategy,and fuel consumption per voltage increment decreases a lot during the parking charge by the novel idle optimization of ICE strategy.
