Research On The Control System Of Gas Engine Cogeneration Unit

Gas engine cogeneration unit transforms and provides electric and heat energy on the spot. Its total efficiency of energy utilization is reach to 85%. On the situation of energy short, it is important to research gas engine cogeneration unit and its control system.The control system of gas engine cogeneration unit is a complex one with time-variable and nonlinear properties, in which contains a lots of transient and dynamic processes such as gas flow, combustion, reciprocating mechanical movement and electromagnetism transform. Based on analyzing the problems of the exiting control method and the running characters of the generattion unit, by combing nonlinear control and intelligent control theory, this dissertation aims at research and investigation thoroughly on power frequency control strategy, exciting control strategy, the interrelationship of power frequency and exciting control and its decoupling control strategy, the structure and control method of waste hot utilization system of the unit. Further more, these strategies and methods are tested through establishing experiment unit or simulation model.1. A model is studied for complicated multi-parameters engine generating unit. Firstly, the mechanism model is deduced base on the operating characteristics of natural gas engine and synchronous generator. Then, according to the limited test results, the relationship curves of input and output parameters are gained by artificial neural network calculating. Last, the parameters of mechanism model are adjusted according the relationship curves.2. The control method of power frequency is studied, of which the measured value of power frequency is as feedback, the current of load is as feedforward and throttle angle is adjusted by step motor. PID controller and fuzzy controller are designed and tested through experimental unit. The results indicate that PID controller and fuzzy controller can't get appropriate control precision for power frequency control. Then frequency control strategy combining feedforward and...