Management and control of short-term energy storage systems in electric ship

This paper proposes and studies a DC power system with SMES and ultracapacitor energy storage modules and their control system for an electric ship. The system allows the storage modules to primarily regulate the voltage of the ship DC switchboard against high fluctuation caused by any transient loads onboard. As such, the ship battery as prime mover only provides the average component of the total dynamic power, which can be far below the peak power supplied frequently to the load. This procedure would eventually lead to extending the lifespan of the battery and to the deferral of its costly replacement. The paper also covers comparison of the power system efficiency when connecting the energy storage modules. The dynamic results, obtained via real-time hardware-in-the-loop simulation and control implementation, have validated the concept, and helped to assess the design characteristics and system performance.