Research On Modeling And Cloud Model Speed Control Of Marine Diesel-Engine Generator

As regard to the modern marine power system,the most common method to generate power is to use diesel-engine generator system.With the increasing tonnage of marine ships and the higher power load,therefore,the requirement of stability of marine power system becomes more strict.The speed control performance of marine diesel-engine generator is directly responsible for the stability of power system.In the thesis,marine diesel-engine generator as the research object,focusing on the mathematical modeling to marine diesel-engine generator speed control system and intelligent control algorithm based on cloud model The thesis mainly completed the following work.Firstly,this thesis analyzes the structure and working principle of marine diesel-engine generator system,including diesel engine,speed control system,excitation system,synchronous generator and load,and the mathematical model of marine diesel-engine generator system is established.Simultaneously,the typical marine speed controller UG-25+ is modeled and simulated.The cloud model has the ability to combine the ambiguity and randomness of the uncertain artificial intelligence to conplete the uncertainty conversion between qualitative and quantitative.In this thesis,in view of the complexity,time-varying and nonlinearity of marine diesel-engine generator,it is designed and simulated that the cloud model speed controller based on uncertainty reasoning ability of cloud model control rules to marine diesel-engine generator.Compared with fuzzy control,the results show that cloud model and fuzzy control can realize the speed control to diesel-engine generator,but the cloud model is superior to the fuzzy control in the overshoot performance index.In addition,taking into account the current marine speed regulators mostly use conventional PID control method,the cloud model PID speed controller combining the cloud model with the conventional PID is designed,which improves the adaptive ability of the controller.The simulation results show that the cloud model PID control algorithm has better robustness and dynamic performance.Finally,considering the fault of the actuator and the diesel engine itself,the speed control simulation experiment is carried out under the control of cloud model PID controller designed in this thesis.The result shows that the controller has the capability of fault tolerance to some degree.