Optimal Sizing of Li-Ion Capacitor for Off-Road Electric Vehicles

In hybrid energy storage systems (HESS) powered by battery (BAT) and lithium-capacitor (Li-CAP), sizing problems are crucial in optimizing system operation and reducing device costs. This study provides a novel hierarchical sizing technique based on mixed integer nonlinear programming and Pontryagin's minimum principle. With a multi-objective optimal problem, the algorithm allows for determining a series of feasible solutions satisfying given constraints. These constraints include nominal voltage of a source package, nominal current of a cell, and the maximum volume. The proposed algorithm's effectiveness is numerically validated.