Power Accounting for Ship Electric Propulsion

Coarse and accurate power accounting methods for ship electric propulsion are observed and compared. For the purpose of analysis, the propulsion system has been separated into two units, namely the ship load and the motor drive. In the load model, variation of such factors like static and dynamic hull resistance and efficiency is explored while the supply characteristics, drive loading, propeller speed, and transmission where included to the factors responsible for the drive power consumption. A case study of the pro-ecological BalticSWATH vessel is described where the brake power dependence on the vessel velocity is estimated within the broad efficiency variation range at different methods of electrical drive organisation and control.