Investigation of energy distribution and power split of hybrid energy storage systems in electric vehicles

In this paper, the model of the electric vehicles (EVs) with the hybrid energy storage system (HESS) consisting of battery and super-capacitor is proposed. Using the proposed model, the operation of the EV with HESS is simulated for various energy distributions of battery and super-capacitor (SC) energy storage system. The losses of the battery and super-capacitor, the travelled distance and the ratio of the SC power to the bus power are investigated and discussed. The study in this paper reveals the relationships between the losses of the battery and the super-capacitor, the energy distribution, the power allocation, the travelled distance and the load, and shows that the optimal ratio of the SC power to the bus power can be found to minimize the losses of the battery and the SC and maximize the travelled distance of the EV. Thus, this paper offers the valuable investigation for the optimal energy management and the maximum efficiency control of HESS.