Fault-ride-through Strategies for Modular Multilevel Shipboard Storage System

In waterborne applications, the up-to-date objective is emissions reduction. The current effort to achieve this target is oriented towards a complete electrification of the maritime sector. The battery energy storage system plays a crucial role in this area, the reliability and the continuity of service of these battery systems are topics of remarkable interest. This paper deals with the failures in multilevel modular systems and the possible solutions to them. Every module is composed of a battery pack and a bidirectional DC-DC converter that regulates the electrical parameters of the battery pack. The effects of the fault of the power converter are investigated and fault-tolerant strategies in multilevel module structures are proposed. Several simulation results are presented to explore the control approach, for continuous power conversion with acceptable quality and output current levels, to be adopted after a fault event.