Modelling of diesel electric propulsion

Diesel Electric Propulsion (DEP), in which the ship propeller is driven by electric motors and diesel-generator sets that provide the energy necessary to cover the demand in mechanical and electrical loads of a ship, is gaining ground in marine applications. This paper deals with alternative ways of modelling of DEP electrical and mechanical components in MATLAB/Simulink® and simulations that are carried out for an offshore supply vessel. Firstly, a comprehensive model for the diesel-generator set of the DEP, which includes the diesel engines and synchronous generators, is developed. Different types of short-circuits are imposed at the terminals of the generator in order to assess the transient response of the diesel engine-generator set, and to identify if any dangerous operations conditions arise. Furthermore, the development of a detailed model for the overall DEP that includes variable speed drives and propulsion motors has been implemented. Scenarios that correspond to realistic ship operating conditions have been simulated.