Optimized design of electric propulsion system for small crafts using the differential evolution algorithm

Abstract

Given the stricter environmental regulations and rising oil prices, means of transportation based on eco-friendly fuel are drawing increased attention. Electric propulsion systems (EPSs) have been applied to various means of transportation, including cars, and many studies have examined ships equipped with EPSs. Generally, because of the low energy density of the battery, EPS-equipped vehicles experience the disadvantages of limited operating time and distance compared to fossil fuel-based vehicles. In this study, we developed an algorithm that determines the optimal electric motor and battery specifications for the basic requirements of a small craft equipped with an EPS. Moreover, to control the stability of the craft, we developed an algorithm that optimally arranges EPS components, wherein the center of gravity is used as an object function. The differential evolution algorithm was used for optimization, and the effectiveness was verified by applying this algorithm to the actual design of a small craft. The proposed algorithm represents the research results for determining the basic EPS specifications for a small craft and deriving an optimal arrangement for these specifications. This algorithm is expected to be effectively applied to design a new electric propulsion ship or to convert an existing ship to an electric propulsion ship. © 2014 Korean Society for Precision Engineering.