Sizing of energy storage system for a battery operated short endurance marine vessel /

Abstract

Conventional marine vessels are operated by either diesel or diesel-electric propulsion which results in the production of harmful emissions that affect the lives inhabiting near the harbor. By employing the Battery-operated Electric Propulsion (BEP) system, harmful emissions released by marine vessels will be reduced to zero. In this study, a harbor tugboat with 30 tonne weight carrying capacity, maneuvering at 9 knot speed is considered for the sizing of BEP. The effective power demanded by the marine vessel when operating at rated speed with full weight is calculated from the hydrostatic and speed power analysis, and the designing of a suitable propeller is discussed. The power train is presented with the calculation of power rating for each component of BEP. Battery count and its total weight are evaluated with different types of Li-ion batteries which are commercially used in electric vehicles and a suitable one is identified for BEP application. Sizing of the supercapacitor for DC link and battery buffer is presented. For the short endurance operation of a marine vessel, the weight of the battery based energy storage system (ESS) is compared with the conventional diesel-electric generator.