The impact of load sharing on multi-drive propulsion drive system efficiency

Abstract

This article investigates the efficiency of a propulsion motor drive system due to load sharing. Two 2250HP-rated induction motor drives controlled via indirect field oriented control are simulated. Load sharing with different configurations is studied to analyze the impact of individual drive loads on the multi-drive system efficiency. Motor losses, Inverter losses and propeller losses are accounted for in efficiency calculations. For each load torque shared, the individual drive efficiency is calculated to determine which load sharing scheme provides maximum system efficiency. The approach for load sharing and system efficiency maximization is applicable to ship propulsion motor drives for maximum efficiency beyond rated load torques, and to other multi-drive systems.