Optimal Energy Management and Storage Sizing for Electric Vehicles With Dual Storage

Battery degradation reduces the performance and lifetime of electric vehicles (EVs). Using energy storage devices with different characteristics alongside the battery can minimize degradation while satisfying driving demands. However, this introduces the additional complexities of sizing multiple storage devices and controlling them in real time. In this brief, we first provide a computationally tractable method to manage power-sharing between dual energy storages using approximate linear programming (ALP), an approximation of infinite horizon dynamic programming (DP). We formulate a procedure to determine the optimal sizes of the two storages based on the solution to the energy management problem to account for the tradeoff between vehicle range, storage size, and weight. We validate our approaches on a numerical case study. Numerical results show that our controller shares power efficiently between the storages, and our sizing procedure provides a design with minimal cost.