Research On Internal Model Control Algorithm In600MW Supercritical Unit Feed Water Control System

Feedwater control system is the most important and complex control subsystem of supercritical once-through boiler, which is the core of the coordinated control and the steam temperature control, playing a very important role in the entire unit. Therefore, the quality of feedwater control system has very strict requirements. However, feedwater control system is interfered by both fuel and feedwater control factors in the control process, conventional control methods are difficult to meet the control requirements.Internal model control has the advantages of simple design, strong robustness, good regulating performance, can eliminate the unmeasurable disturbances on the system, suitable for the control of the large time delay system. Compared to conventional PID control, internal model control has only one adjustable parameter. Parameter adjustment has a clear relationship with control system robustness and dynamic properties. Introducing internal model control to the feedwater control system has very important significance in improving the system control quality.This paper discussed the basic theory of internal model control, the internal model algorithm of stable time-delay object, the PID control algorithm based on internal model control principle and the adaptive internal model control algorithm, fully analyzed the main loop working principle of a certain power plant#6supercritical unit feedwater control system, on this basis established the feed water control object transfer function by step response tests, and finally used the control algorithms to control the feed water system, verified the feasibility of the algorithms through simulation research.