A near-optimal power management strategy for rapid component sizing of power split hybrid vehicles with multiple operating modes

In the design of hybrid vehicles, it is important to identify proper component sizes. When the search space of the design problem is large, exhaustive power management strategy such as dynamic programming (DP) is too time-consuming to be feasible. Instead, a near-optimal method that is orders of magnitude faster than DP is needed. One such near-optimal method is developed and presented in this paper. This method is applied to design an input-split hybrid vehicle utilizing a single planetary gear (PG). There are 6 possible input split configurations, and each configuration has up to 4 modes [1]. Based on the analysis of the efficiency of powertrain components of the four modes, and the “Power-weighted Efficiency” (PE) concept, we show that the computation time for each sizing problem can be reduced by a factor of 10,000 compared with the dynamic-programming based approach.