Short-circuit current calculations of a harbor electrical distribution system with shore power connection

Abstract

Shore power connection, a practice whereby shore-side electrical power is provided to vessels at berth in a port, is set to play a major role in shaping the future energy requirements of the commercial shipping industry. Short circuit level compatibility of systems is a problem when a ship power system is connected to a shore electrical distribution system. A method that is able to evaluate the shore-side and ship-side impedances and determine the prospective short circuit current level is essential. This paper aims at presenting a methodology for calculating the short circuit current in the shore power connection system. Two analysis models: IEC std. 61363-1 and IEC std. 60909-0 combined with IEC std. 60909-0 are developed and used in this paper for short circuit current analysis. Performance of the proposed method is validated by short circuit current calculation results gathered from several visiting ship scenarios in a practical shore power connection system. The proposed method can provide engineers with useful information about the prospective magnitude of short circuit currents, as well as on the effect of shore supply on ship power system, to assist them in ensuring short circuit level compatibility and allowing the selection and setting of protective devices.