System Design and Energy Management for Li-ion Battery, Seawater Battery and Fuel Cell Hybrid Energy Storage System

This paper focuses on the system design and control methods of the hybrid energy storage systems. The parameters of three different power supplies are designed based on the dive length and the cascade utilization requirement of material and energy flow. Based on the analysis of the energy system demand and the characteristics of the batteries, two electrical architectures are proposed and the DC bus voltage floating structure is selected for further investigation. A closed-loop control strategy is presented to control the current of seawater batteries and fuel cells to satisfy both the Li-ion battery pack's current and the load demands. Simulation and HIL test results show that the combined operation of primary batteries and Li-ion battery pack can ensure a fast dynamic response.