The Research On Unit Coordinated Control System

The object of boiler-turbine units is to successfully assure the process of energy transition and energy current balance.The whole process of energy transition is a complicated process with compound input and output which is associated and coupled. The main priority of coordinated control method based on boiler following turbine is that the control system has rapid load response,the shortcoming is that the steam pressure of the control system fluctuates greatly.According to the character of coordinated control system(CCS)based on boiler following turbine,the fuzzy control strategy and the conventional PID control are introduced in CCS for meeting electricity net load instruction demand and ensuring the stabilization of boiler-turbine units.A conclusion was drawn in the paper that the nonlinear feature of the boiler is the main reason to lead the variable parameter of the unit by analyzing the dynamic characteristic of the boiler-turbine unit in detail;introducing the characteristics of all kinds of running manners of CCS;presented the principles of one-way decoupling and given the principles of two stage changeable universe fuzzy controller and self-tuning fuzzy PID controller in detail in this paper.Because the coordinated control system for boiler-turbine unit is a complicated multi-variable control plant,and it has some characters such as nonlinear,parameters time varying and large delay.So the control strategy of conventional coordinated control system is far from responding to the request of the electric network.One-way decoupling research was done after analyzing the dynamic characters of CCS.Based on the fuzzy control theory,a two stage changeable universe fuzzy controller and self-tuning fuzzy PID controller were presented.Intelligent power feed-forward controller is used in the boiler sides to overcome the energy problems in dynamic and static process so as to make the practical main steam pressure equal to the set value. These controllers were used in CCS.And a lot of simulation experiments were done to the CCS.From the simulation experiments we can get the results:the control method in this paper has good control quality.The research to fuzzy control and multi-variables control system has certain theory meaning and project using value.