High-Power Electric Ship Propulsion Systems with Advanced Frequency Converters

Abstract

Abstract: Three types of frequency converter (FC) structures are considered as parts of high-power electric ship propulsion systems—multilevel FCs, cascade FCs, and FCs with an active rectifier. Algorithms for controlling the power keys of converters with the structures under consideration are described. Mathematical simulation models for the electric power systems of ships with electric propulsion based on the considered FC structures have been developed. Calculations are performed for the values of voltages and currents inherent in the buslines of the main switchboards of ship electric power systems. Voltage nonsinusoidality coefficient as a key electric-power quality index of the ship electricity supply network is calculated. Voltage oscillograms have been obtained for the marine-vessel electricity supply network onboard the ship in the course of sea trials. The results of calculations and experiments have been compared.