A Propulsion System Design Methodology Based on Overall Efficiency Optimization for Electrically-Powered Vessels

Abstract

Boats have historically been an important mean of transportation, both for passengers and cargo, mainly in water-rich countries. Today, the electrification of transportation includes fluvial navigation, but energy efficiency remains a key issue. Energy consumption, in electrically powered vessels, is strongly influenced by several technical systems (e.g. hydrodynamics, battery, propulsion, etc.). While advances in some of those main systems are found in the literature, this research work focuses on the design and optimization of the “propulsion system (PS)” (Motor–Transmission–Propeller). By implementing an electric motor, the interaction of the mechanical components can be analyzed to find the optimal variables that will govern the performance of the vessel and that allow the optimal Motor–Transmission–Propeller combination. This manuscript presents the development of a multivariable optimization methodology to maximize the overall efficiency of a propulsion system and, therefore, the autonomy of an electrically powered river vessel. The methodology starts with the analysis of the physical variables that define the performance of the propulsion unit components, and establish an optimality problem and an exhaustive search model that considers all possible values of the key design parameters. A case study is presented for the design of an electrically powered river boat, for the transport of people, within the framework of the ENERGETICA 2030 project. This methodology enabled the choice of the PS’s components, while optimizing the energy consumption.