A Near-Optimal Power Management Strategy for Rapid Component Sizing of Multimode Power Split Hybrid Vehicles

In the design of hybrid vehicles, it is important to identify proper component sizes along with the optimal control. When the design search space is large, exhaustive optimal control strategies, such as dynamic programming (DP) is too time consuming to be used. 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 identify the optimal powertrain parameters of all power-split hybrid configurations utilizing a single planetary gear. There are 12 possible configurations, six input and output splits, and each configuration has up to four modes. Based on the analysis of the efficiency of powertrain components of the four modes, and the power-weighted efficiency concept, we show that the computation time can be reduced by a factor of 10 000 without consequential performance compromise, compared with the DP approach. The optimal design of each configuration is analyzed and presented.