An Examination of Mutual Influences between High-Voltage Shore-Connected Ships and Port Earthing Systems during Phase-to-Ground Faults

High-voltage shore connection (HVSC) is a technical solution to supply ships at berth in an economic way while reducing air pollution in city ports. When multiple megawatt-HVSC installations are to be exercised, electric power has to be delivered to the port from a primary high-voltage (HV) line at voltages higher than 100 kV. In this case, large earth fault currents can arise on the HV side, flowing through the port earthing system and the bonded ship hulls. Due to these faults, possible dangerous voltage gradients in sea water around the bonded ship hulls may occur. This phenomenon is pointed out and investigated in this paper to identify possible safety issues in some given scenarios.