Optimal operation of the power-split hybrid electric vehicle powertrain

A discussion on how to manage the hybrid electric vehicle powertrain is dealt with in this paper. An approach to analyse the optimal operation of a power-split hybrid electric vehicle is suggested on the basis of multi-objective optimization. A quasi-static powertrain model is developed and an entire space of operational choices is explored in order to find an attainable set of the optimal operation candidate group. Using this concept, two types of simulation are developed: the first simulation is based on the minimization of the equivalent fuel consumption and the latter simulation uses dynamic optimization. By analysing and comparing the results, choosing a single optimal operation point by minimizing the equivalent fuel consumption was found to give almost as high an energy efficiency as the theoretical maximum performance obtained by optimal control simulation. The results did not show a noticeable difference except in the case of high-power load conditions. From this analysis, a threshold is also proposed for vehicle operation in the pure electric vehicle mode.