| Since the 21 st century, the rapid development of economy promotes the demand of power consumption. In order to ease the tension of power consumption, a large number of super-critical units and ultra super-critical units are building across the country. Boiler is one of the most important parts of super-critical units and ultra super-critical units, but it's low efficiency is the main reason for the high coal consumption, which also increases the boiler's toxic wastes during the flue gas emission, such as nitrogen oxides, sulfur oxide and so on. It threats the people's living environment and health potentially.At present, most thermal power plants of our country are still using the classical PID control system widely, but as the generating of unit's capacity and the application of intelligent control theory, the intelligent control system will be the general trend of the coal-fired power units.This paper studies the application of fuzzy control in coal-fired power units based on one 600 MW unit control system. Firstly, this paper investigated the object characteristics of three subsystems of the combustion system and presents the corresponding research status. The paper expounded the principle of fuzzy control theory,and established the corresponding control strategy,then proposed a variable universe fuzzy self-tuning PID controller combined with the variable domain control theory and fuzzy self-tuning PID controller. Secondly, the paper established different fuzzy rules tables according to the mathematical models of each subsystem built on the step response experiments under different working conditions. The control effect is verified in simulation software. Finally in order to avoid the original scale factor potential“distortion” problem, the paper optimized the control strategy by turning the scaling factors online using particle swarm algorithm in M file, by the counting fitness function J.Simulation experiments using Matlab verify the feasibility of the control strategy. |
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