Comparative Analysis on AC and DC Distribution Systems for Electric Propulsion Ship

Abstract

Decarbonization is an ongoing issue in the shipping industry, and electric propulsion systems are being proposed as alternative solutions to satisfy this requirement. To answer the fundamental questions of “Are electric propulsion systems the green solution?” and “Can DC distribution systems contribute to the decarbonization in shipping?”, this paper analyzed DC distribution system electrical characteristics, economic feasibility, and environmental evaluation for a full-scale AC-DC hybrid distribution electric propulsion system facility. By applying the actual ship’s operating profile as inputs, a DC distribution system with an active front end rectifier and a variable speed generator engine was proven to guarantee the same electric stability as the conventional AC distribution system. The life cycle assessment results achieved economic and life cycle environmental benefits of about 10% (8.9% for Case 1 and 12.4% for Case 2). These research findings offer meaningful insights into the DC distribution system to minimize fuel consumption and emissions toward cleaner shipping.