Development Of Combined Marine Generator Set Test System

Marine generator set is the heart of a ship, its stability and reliability is critical to the ship.Therefore, strict test to marine generator set has very vital significance.In this thesis, both theoretical research and program design-implementation are used.First, the contents and principles of marine generator set test are analyzed in depth from atheoretical perspective. Eight indicators of frequency and voltage are summarized, and thenproblems of active power allocation which is determined by frequency characteristics andreactive power allocation which is determined by voltage characteristics are discussed. At last,a kind of power quality evaluation indicator system is put forward. Combined withtechnology indicators provided by the shipyard, we put up with a scheme named CombinedMarine Generator Set Test System. PLC technology, touch screen technology, SCADAtechnology, database technology and fieldbus technology are adopted to implement thisscheme, which make marine generator set test automatic, intelligent and informationalized.Combined Marine Generator Set Test System can get the performance of marine generator setall-round, which have independent and combined mode, to meet different test requirements.Test capacity is span with good flexibility and high equipment utilization rate.After analyzing lots of material, a kind of pneumatic liquid rheostat is designedcombined with previous experience. It has good characteristics; water level fluctuation issmall with good stablity. According to the characteristics of the pneumatic liquid rheostat,subsection control method is adopted, which combined continuous control and fuzzy controltogether, and dead zone is set with hysteresis. All these methods make the system have smallovershoot, high precision and less number of switching. The actuators are protected greatly,and the current adjustment error is under0.3%. To meet the needs of more equipments andmore master stations, Industrial Ethernet and Modbus TCP/IP are used to replace RS-485andModbus RTU, which makes the communication speed from19.2Kbps up to100Mbps, andgreatly improves the real-time performance of network. Remote monitoring response speed isin millisecond level. At the same time, network load is calculated according to related theories,and several methods of reducing network load are put forward. This proves the high real-timeperformance theoretically. The system can regulate currents and record datas automaticly. When improving variousperformance indicators, it greatly reduces the labor intensity of workers, and has theadvantages of high efficiency and energy saving, which can help the shipyard upgrading itsindustry.