Control strategies for an electric variable transmission based hybrid electric vehicle

This paper deals with the control strategies for an electric variable transmission (EVT) based hybrid electric vehicle (HEV). Rule-based and optimization-based control strategies are analyzed and developed. The simulation results show that the engine and battery have different missions in different strategies. DP strategy tends to deplete the battery in order to minimize the fuel consumption. The rule-based strategy tends to use battery as a buffer to make up the power differences between the engine and the vehicle requirements. Compared to DP strategy, the fuel consumption of the rule-based strategy is higher in urban cycles and will be reduced in highway cycles. Energetic macroscopic representation (EMR) is used in the global modeling and strategy simulation for the EVT based HEV, and a control scheme is deduced from EMR models using specific inversion rules.