Ship With Virtual Test Technology Of Gas Turbine Propulsion System Research

Because of its advantages such as various assemblage forms and outstanding economy,Combined power plant has been the main development trend of large war ship power plant ofthe countries in the world in the future. The combined power plant, in particular, COGAGhas many advantages: such as short startup and loading time, high power density, smalllow-frequency noise, etc. Because of the above advantages, COGAG is increasingly favoredby the navy around the world, and therefore it’s essential to have a thorough study of itsperformance.This paper analyzed the main disposition form of COGAG propulsion system, one’s owncharacteristic and the application in marine propulsion system, and designed the COGAGlaboratory bench preliminarily.The power generation module is modeled and simulated withMATLAB/Simulink simulation tools in the dissertation. The mathematical model andsimulation model of the whole COGAG propulsion system are built up with block method,and the entire sysem contains gas turbine model, fuzzy self-tuning PID model, sss clutchmodel, gear box model, GOGAG controller model, propeller model, hull model, etc. Then,we made use of the models to simulate the prime motor’s dynamic performance and thecourse of combination, breakaway and switching of two motors in the same type. We got thechange rule of the two gas turbine’s rotational speed, torsion and the middle part’sdisplacement of the clutch on the end of the gas turbine which merged in or relieved undervarious operational modes and carried on preliminary research on the control scheme andcontrol parameter of COGAG power plant.The key of the establishment of gas turbine simulation model is the treatment to thecharacteristics of gas turbine’s components. In order to grasp the characteristics of gasturbine’s components, although Robbins WH, Dugan JF and other predecessors havesummarized level-superposition method, element-cascade method and the extrapolationmethod based on similarity law which is applied widely in recent years, the results calculatedby these methods are still far from the requirements of their practical application. So far, thetrue characteristics of its components still need to get through the experimental data. Acomputer software was designed for the calculation of characteristic data by automationtechnology. We combine least-square and neural-network method to fit characteristic curve,and get a more overall accurate result than a single fitting method. The governor is theimportant control components of COGAG propulsion system. In this paper, the governorcontrols the speed by fuzzy self-tuning PID method. This approach can automatically modify, adjust and improve the fuzzy control rules, which reproduce the actual operation experienceof the gas turbine. At last,we achieve the desired effect of controling the COGAG propulsionsystem,which is highly nonlinear, large time delay and time-varying complex system,.