Abstract of doctoral thesis - Nikolaos Kintzios

In recent years ships have been electrified, including the propulsion system, replacing the conventional propulsion system, which was energy independent of the electric power system. 

The current trend is that in addition to some special purpose vessels (submarines, icebreakers and cable and pipeline vessels), Ro-Ro carriers, cruise ships, car ferries, LNG (liquefied natural gas tankers), and other vessels like yachts, to be studied for the implementation of a unified power system which will include both the main propulsion system and the conventional electric power system on a ship.

The complexity of these integrated systems increases, but the advantages are the mechanical simplification of some elements (e.g. significant reduction of propeller shafts length, or installation of AZIPOD thrusters, reduction of dimensions of funnels and air ducts with installation of generators on higher decks), its more economical operation in and low cruising speeds and the corresponding IMO emission regulations, making the respective ships more environmentally friendly.

Among the various design issues of the new electricity system is the diagnosis of failures both in the same electricity system and in its critical parts, such as generator motors, generators, propulsion engines, propellers, etc.

In the context of this doctoral dissertation an attempt will be made with experimental data, e.g. temperature / pressure measurements of diesel generator cylinders, angular accelerations on shafts, voltages and voltages of generators and motors, to identify in time points that need immediate maintenance / repair, such as propellers, cylinders, windings of the electric machines, especially going to the all-electric ship.

The holistic way of dealing with the problem beyond the measurements will include the development / utilization of methods for the analysis of the mechanical, thermodynamic and electrical behavior of the various components, such as generators, propulsion motors, etc., e.g. principal component analysis, recognition of patterns such as k-media, adaptive vector quantum (LVQ), fuzzy k-media, self-organizing maps (SOM) and hierarchical techniques. By using them, on the one hand, it will be possible for an item to be diagnosed in time with possible damage, and on the other hand, with statistical tools, the time period in which the corresponding item will be put out of safe operation.