Research on parameter optimization for the energy management system of hybrid electric vehicle

The hybrid electric vehicle (HEV) has been widely studied recently due to its high potential in reduction of fuel consumption, exhaust emission, and noise. Because it is equipped with various power sources, an HEV requires an energy management system (EMS) to find out the sequence of optimal power splits at each instant of time that minimizes fuel consumption over a given driving schedule. The task in this paper is to design anenergy management strategy for the HEV developed by the industrial technology research institute (ITRI) of Taiwan. Due to the nonlinear nature and the uncertain parameters of the system model, a modified simplex method based energy management strategy is proposed for the HEV system. The modified simplex method was presented early in the 1965, which is originally developed for unconstrained deterministic optimization. Hence, a way to apply the modified simplex method for searching the optimal operating parameters of energy management strategy in real time is presented. The feasibility of the proposed method was verified by performing numerical simulation on the new European driving cycle.