Calculation of short-circuit currents in shore power connection systems

Shore power connection that is a practice whereby shore-side electrical power is provided to vessels when a ship is 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 the system 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, including 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, which will assist them in ensuring short-circuit level compatibility and allowing the selection and setting of protective devices.