MODERN TECHNOLOGIES IN INCREASING THE EFFICIENCY OF PROPULSION SYSTEMS OF SEA VESSELS

Main development trends of modern ship power systems are analyzed. The purpose of the paper is the analysis of energy modes and the development of criteria for transitions between different modes of an integrated marine vessel`s power system, providing maximum efficiency in the use of fuel and motor resources of main engines of the vessel. It is proposed to identify, in addition to the shore-to-ship mode, four main operating modes in the presence of a synchronous machine on a propeller shaft and a converter that ensures an operation of this machine in both motor and generator modes. By dividing a load of the main engine into four levels – small, medium, nominal and large – an automatic system can accordingly control (or recommend in semiautomatic mode) the switching sequence of power equipment and actuating machines and mechanisms. Using the container ship Matilda Maersk as an example, it is shown when the ship moves at a low speed, the load of the main engine becomes so low that it can be provided by diesel generators of the ship's energy system ("Power-Take-Home" mode). This, on one hand, allows to save fuel, and on other hand increases the completeness of fuel oil consumption, since diesel generators operate at optimal load unlike the main engine, the load of which reaches only 10%. Similarly, in case of medium loading of the main engine, it is recommended to switch to the power supply of ship`s grid from the main engine with the shaft generator ("Power-Take-On" mode), and if it is necessary to obtain increased power of the propulsion system, the synchronous machine is switched to engine mode powered by diesel generators ("Power-Take-In" mode). In addition, the ability to quickly transitions between these and main modes in emergency cases increases a survivability and safety of the vessel. Based on the analysis, an algorithm for switching between modes is proposed, which can be implemented in Supervisory Control and Data Acquisition for ship's energy systems, in particular, on a physical simulator at the National University "Odessa Maritime Academy".