Research On Modeling And Fuzzy Control To Marine Power System

The marine power system is one of the most important parts to the ship, with the development direction of the ships continually to large scale and automation, which also becomes more and more complicated. The running quality of the marine power system has directly relationship with the safety of ships navigation and seamen’s lives; therefore, higher requests to control quality and running stability of the system are put forward. The marine power system is an independent and complicated system, which has many properties, such as time variation, nonlinearity, strong coupling and so on. It is difficult to establish the mathematics model of the power system for the reasons what has been said above. The traditional control methods generally applied in the system, which has precisely mathematics model; these control methods are now difficult to fulfill the daily higher requirements of the marine power system. Based on these reasons, it needs to design a more advanced control method to improve the control performance of the power system.Firstly, the thesis establishes the mathematics model, simulation model based on Simulink software; and on this basis, taking coordination control simulation tests on marine power system, which is under the control method of PID. The results show that the performance indexes of the marine power system basically satisfy the requirements to the <RULES AND REGULATIONS FOR THE CONSTRUCTION AND CLASSICATION OF SEA-GOING STEEL SHIPS>; but the overshoot is a little larger and the time fluctuation is a little longer during the adjustment process.Secondly, in this thesis, by reading quantity of papers in the fields of marine power system control; by combining the merits of both of the PID and Fuzzy control, proposing a new Fuzzy-PID controller which can meet the performance requirements of marine power system. Establishing Fuzzy-PID controller of speed governing and excitation control separately, aiming at the speed governing and excitation system.Lastly, replacing the PID controller in the simulation model of marine power system, which is by using the Fuzzy-PID controller what has been established above; and making comparative analysis on the simulation results of two controllers. The analysis results show that the performance indexes of the marine power system satisfy the requirements to the <RULES AND REGULATIONS FOR THE CONSTRUCTION AND CLASSICATION OF SEA-GOING STEEL SHIPS>, which is under the control of Fuzzy-PID controller; in the speed governing aspect, the effect of Fuzzy-PID controller is better than the effect of PID controller; in the excitation aspect, there are merits and demerits of both of controllers; comparing with PID controller, the Fuzzy-PID controller has smaller overshoot and shorter time fluctuation during the adjustment process. The results what have been said above give expression to the feature of Fuzzy control that has strong robustness, which achieving the research objective.The Fuzzy-PID control strategy, which is proposed in this thesis, is a new try to the control method of marine power system; and obtaining good control effect, having wide development and application prospect.