Analytical Solution for Energy Management of Parallel Hybrid Electric Vehicles

Abstract

An analytical method is proposed to solve the optimization problem of energy management for a parallel hybrid electric vehicle. This method is based on Pontryagin’s Maximum Principle (PMP) for a class of Hybrid Dynamic Systems (HDS). Therefore, the analytical models are used, which are an approximation of the reference models. A numerical method based on the reference models is also used in order to validate the analytical solution by comparing their results. In this paper, two types of optimization variables are considered: continuous and discrete. The first type is the power split between the Internal Combustion Engine (ICE) and the Electric Machine (EM). The second one is the transmission ratio, which includes the ICE On/Off decision. The results show that the analytical and the numerical solutions are almost the same. In addition, the analytical approach requires less computing time and requires less memory space than the numerical method.