The Application And Research Of Robust Fuzzy Control In The Control Of Circulating Fluidized Bed Boiler

Recently, the combustion technology of Circulating Fluidized Bed (CFB) has been developed all over the world. The technology has been widely applied in boiler due its high efficiency, low environmental pollution and economy, known as 3E application technology. With the development of CFB application technology, the much higher request is bri ng up for the automation technology of CFB process.Although the circulating fluidized bed boiler has advanced well in the process, its combustion process has the characteristics, such as highly nonlinear, uncertainty, long time delay and serious multi-variable coupling and other complex. So far, the research on the combustion mechanism is immature, and there is no good model for real-time control of the process. As the most important parameter of the combustion control of CFB, the automation level of the bed temperature cannot be improved effectively. This paper takes the combustion system of CFB boiler as the research object and makes thorough research on the control of crystallization process.1) According to time-variable, uncertain and strong coupling characteristics, the control plan based on combing series decoupling and robust controller is proposed. The coupling strength of the combustion system is decreased with this scheme. On this basis, robust control method is designed and the stability and robust performance of the system are improved.2) According to the characteristics of combustion system, T-S fuzzy model is constructed. LMI-based H∞robust control method is used in T-S fuzzy model, and the effectiveness of this control scheme is studied from the simulation result. T-S fuzzy model is a fuzzy rule-based model and it is suitable for approximation of a large class of nonlinear system. T-S fuzzy model provide a suitable framework for modeling by decomposition of a nonlinear system into a collection of local linear models. Therefore, the dynamical model of the combustion system can be established effectively by using T-S fuzzy model. The state feedback H∞controller is designed by using linear matrix inequality (LMI) and all those have been studied by simulation. The simulation results show that the controller is very efficiently and the closed loop system has good adaptability and anti-interference ability. It has certain theoretical guidance for the design of practical combustion control system.