High-Voltage Shore Connection Systems: Grounding Resistance Selection and Short-Circuit Currents Evaluation

Cold ironing represents an effective solution to remove air-polluting emissions from ports. The high voltage shore connection (HVSC) system is the key enabling facility that allows providing power from the shore-side electrical system to the ship. The design of the shore connection needs a comprehensive assessment of the fault currents in different operating scenarios. International standards require the neutral point of the shore connection transformer to be equipped with a neutral grounding resistor. Its value has to be defined to guarantee the safety and protection of equipment and personnel in the case of single phase-to-ground faults. Moreover, three-phase short circuits need to be considered to size equipment and protection devices. A crucial role is played by the frequency converter control system, required to adapt the mains frequency to the frequency of the ship. In this work, a complete electromagnetic dynamic model of the HVSC has been developed, including a frequency converter, a shore-side transformer, connection medium voltage (MV) cables, and a power system of the ship, to analyze in detail the behavior of the system in the case of single phase-to-ground fault and three-phase short circuit, taking into account relevant standards and best practices.