Research on Energy Management Strategy for Electric Vehicles with Hybrid Battery/Capacitor Energy Storage System

The combined use of supercapacitors and power batteries as energy sources in electric vehicle energy storage devices is expected to reduce the peak current, thereby extending the cycle life of the power battery. In view of electric vehicles with hybrid energy storage system(HESS) composed of supercapacitor(SC) and power battery, an adaptive on-line energy management strategy based on Pontryagin's Minimum Principle(PMP) is proposed. The state of energy of the supercapacitor is used as the state variable and the Hamilton function is established based on PMP, then the covariate variable is adjusted online to optimize the effectiveness of energy management. The simulation verification has been carried out on different driving schedules. The results show that the proposed adaptive on-line PMP-control strategy can reduce the peak power and energy loss of the battery, to ensure safe and efficient operation of the electric vehicles.