Comparison of short-circuit current in AC and DC shipboard electrical power distribution systems: A case study of 17,500 DWT tanker vessel

The current ability of power electronic devices increases the possibility to change the shipboard electrical power distribution system from widely-used alternating current (AC) to direct current (DC) systems. DC distribution systems has been known to offer higher power efficiency compared with AC distribution systems. However, the decision to move the shipboard electrical power distribution systems to DC systems requires more information in technical aspects aside of power efficiency. In this study, the investigation to compare short-circuit current between AC and DC distribution systems in non-electric propulsion vessel is conducted. The investigation is performed for electrical power distribution system of 17,500 DWT tanker vessel. Short-circuit current profile for both systems are obtained from simulation in computer software. The results indicate that the DC shipboard electrical power distribution systems has lower short-circuit current than the AC system for the same vessel.