The Main Steam Temperature Control Strategy Research In The 300MW Drum Boiler Unit

Followed the requirement of society and economy,electric power industry needs to improve efficiency and reduce pollution, so the related power ministry introduced some improvement measures, such as enhancing capacity and parameters of the power generating units. along with the control parameter increasing, the control index is also increasing. In order to meet the improving target of the thermal power plant, it is the main steam temperature of boiler in 300MW unit that were optimized in the paper.This paper briefly introduces the research background, the main steam temperature control problems and research status, in order to make the main steam temperature changes within a certain range, there are many ways to make improvements, such as the leading signal selection, optimal control algorithm, the object model and so on, at last, this paper adapts the research on the optimal control algorithm to improve the control effect of the traditional method. After determining the direction of improving control strategy, the paper analyzes researched boiler on this subject and the relevant main steam temperature system, the dynamic characteristics of controlled object, so people can get an understanding of the process of the main steam temperature system and the related influence, and the paper will use the sprayed water amount to control the main steam temperature. Then introduces the conventional control system of main steam temperature:the PID control system with the differential signal and cascade PID control system. Considering the main steam temperature is a big-lag,imprecise model time-varying nonlinear object, only the PID control system of power plant achieve good dynamic performance in a certain range, and the fuzzy PID controller can meet this situation, the paper decides to combine fuzzy control technology and cascade system, The secondary regulator adopts P controller. the main regulator adopts the fuzzy adaptive PID controller, of which the scale factor is adjusted online by another auxiliary fuzzy controller, adjusting the three parameters of PID controller according to the variation of the output, so as to own the control effect of on-line self adjustment.In the MATLAB/Simulink simulation platform, comparing the performance of cascade PID control system and the improvement scheme, the improved project has improved anti interference and robustness ability greatly, which has improved the dynamic ability of the main steam control system, but it is delay the time that the output achieve the define data.