Energy management strategy for Diesel hybrid electric vehicle

This paper focuses on hybrid energy management for a Diesel hybrid electric vehicle (HEV). The paper presents an adaptation of the equivalent consumption minimization strategy (ECMS) dedicated to the Diesel HEV control issues. The purpose of this paper is to introduce an additional degree of freedom into the ECMS that allows to modify the optimization tradeoffs from the pure fuel economy case to the pure NOx limitation case. The influence of this weighting parameter is evaluated for several engine configurations. The main contribution of this paper is to provide tools and methods to deal with the Diesel HEV control task. This paper applies a methodology based on SiL and HiL simulations in order to understand the system performance according to the powertrain configurations and also to tune the proposed energy management strategy. The simulation results are confirmed by experiments performed on hybrid-hardware in the loop (Hy-HiL) test bench. These results demonstrate the ability of the proposed strategy to reduce the NOx emissions while maintaining a reasonable fuel consumption. This result is mostly due to the ability of the modified ECMS to operate the Diesel engine within its LTC region where the NOx emissions are very low.