Dynamic Feasibility Assessment of Ship-to-Grid Interconnection by DC-Link

The concept of ship-to-grid has been explored in recent years, which allows electric ships to supply a part of power demand in the terrestrial electric grid during normal operations or extreme conditions under disruptive events. While this could potentially enhance the resiliency of the power grid during extreme events, interconnected ship-to-grid may pose certain threats to the special equipment on the shipboard power system. To better evaluate the dynamic feasibility of ship-to-grid interconnection, this paper investigates the use of a DC-link for safely integrating a medium voltage AC (MVAC) ship to the grid. To evaluate the effectiveness of the DC-link for ship-to-grid connection, different disturbances are simulated in the shoreline grid, and their impacts on the shipboard power system are analyzed. The proposed strategy has been verified by a case study on a 4-zone shipboard power system and various shoreline grids with different characteristics. The dynamic simulations are conducted with the PSS@E and PSS@NETOMAC software.