Shipboard DC systems, a Critical Overview: Challenges in Primary Distribution, Power Electronics-based Protection, and Power Scalability

This article gives an overview of challenges in primary distribution, protections and power scalability for shipboard DC systems. Given that DC technology is in development, several aspects of shipboard systems have not yet been sufficiently devised to ensure the protection and efficiency demanded. Several issues in DC systems arise from the lack of complete relevant standardisation from different regulation bodies. Unipolar and bipolar bus architectures have application-specific advantages that are discussed and compared. The placement of power electronics in DC systems creates opportunities for switchboard design, and this article compares the centralised and distributed approaches. Likewise, protection architectures for shipboard DC systems have challenges. Breaker-based protection utilises slow fuses, mechanical circuit breakers, and solid-state circuit breakers. In addition, power electronics-based protection embeds the protective circuit in the power converters, but its development lags. This paper compares the state of the art technologies, reviewing their main features. Finally, the power requirement of various applications and the low production rate of vessels force the designers to utilise commercial off-the-shelf converters to scale up power. The misuse of such converters, the modular topologies and power electronics building blocks are exposed highlighting challenges and opportunities towards the mass adoption of DC systems onboard maritime vessels.Transport Engineering and LogisticsShip Design, Production and Operation