Model predictive control of a power-split Hybrid Electric Vehicle with combined battery and ultracapacitor energy storage

In this paper, merits of using an ultracapacitor in combination with a battery in a power-split Hybrid Electric Vehicle (HEV) is analyzed. For this, an online optimization-based model predictive controller (MPC) is designed and a closed-loop model of the system is developed. Based on the definition of C-rate parameter which indicates the discharge intensity of the battery, a number of simulations over standard driving cycles are performed. Closed-loop simulations on a detailed model of the HEV show that adding the ultracapacitor to the ESS unit can reduce intensity of battery discharge, as indicated by the C-rate, noticeably.