The Study Of Drum Level Control Based On Extension

Boiler drum water level control system is an important industry in the thermal control system, The water level object is a lag and no self-balance system.Its constant time is much bigger and its object model is not confirmable,So it is a difficult control system in the process of thermodynamic engineering.But he traditional control method such as PID controller work not effective. With studying of the intelligent control theory,it provides a new control method for the boiler water level automatic control.Extension theory has been employed to the research fields of artificial intelligent and its relevant sciences.The theory of extension set is a very important notion and the basic concept of extension control is imported. Then the paper discusses the structure,the theory and the design method of extension controller. For the characteristics of the boiler water level control system, select the error and bias differential of feature vectors, the establishment of correlation function, according to control requirements by measure mode, control mode and calculation to determine the controller output.Finally, by this method, objects are simulated whose system character variables are error and error differential. The experiment proves that the effect of water level extension controller is better and it is superior to the conventional PID controller at the area of anti-disturbance and rated load. Results of simulation show extension control is of good control performance,regulation, robust feature. It proved that the control scheme based on extension theory is feasible.