Power optimization for hybrid energy storage system of electric vehicle

Hybrid energy storage system of electric vehicles (EVs) has great potential to take full advantages of high power density with supercapacitor and high energy density with battery to improve the dynamic performance and energy efficiency of EVs. However, its energy management becomes much more complicated, in particular, the power distribution between super-capacitor and battery. This article proposes a power optimization method aimed to achieve the objective of minimum battery energy loss. A compound model for power optimization is first established, and a dynamic programming algorithm is used for optimal control. Simulation results show that with the proposed dynamic planning algorithm the battery current is reduced and the energy efficiency is improved, compared to traditional control strategy with logic threshold method.