Contribution to a detailed modeling and more reliable simulation of a ship's shaft machine

Abstract

In the following investigation the modeling of the complete electromechanical system of a doubly fed induction machine is discussed for power production/electric propulsion purposes, when being incorporated as a shaft generator into a ship's system. When the doubly fed induction machine serves as a power production machine, contributes to lower emission of CO2 and fuel saving since its capable of working at different speed (lower) than synchronous. This coincide with the enforcement with which the International Maritime Organization (IMO) and the EU demand reduction of Ship's emissions. The final goal within the frame of this paper is the development of a reliable mathematical model for the mechanical system which includes rotor dynamics and dynamics of tilting-pad journal bearings. The rotor dynamics are expressed in terms of complex variables for the planar coordinates. The total approach aspires to the development of a well established basis for studying the interactions between the electrical and mechanical subsystems and capable of expanding with more complicated models suitable for a reliable design or analysis of various types of faults.