火电厂球磨机制粉系统的自调整模糊控制

火电厂球磨机制粉系统是一个典型的3输入－3输出系统。其输入为再循环风门开度、热风门开度、给煤机转速，输出为磨入口负压、磨出口温度、磨前后差压。各变量之间存在严重耦合，利用PID控制很难达到理想效果。针对这些特点，提出了一种自调整模糊控制算法。该算法充分考虑了各变量之间的耦合关系，利用模型控制公式进行了有效解耦，并且可根据运行状况自动调整各变量的偏差及其变化率在算法中所占比重。对各种非正常工况采用不同控制方案，有效预防了正压跑粉、堵煤等各种故障的发生。仿真研究及现场实际应用表明，该算法运算简单，不涉及复杂的模糊控制规则，易于工程实现，用于实际电厂取得满意的控制效果。

THE SELF-TUNING FUZZY CONTROL ALGORITHM FOR BALL MILL PULVERIZING SYSTEM OF POWER PLANT

The ball mill pulverizer system is a topical MIMO system. The inputs are positions of recycle air valve, hot air valve and speed of coal feeder. The outputs are inlet pressure, outlet temperature and coal mass of the pulverizer. Because of the serious coupling among three outputs, perfect control result can hardly be gotten by ordinary PID controller. Against these characteristics, a new self tuning fuzzy control algorithm is introduced. In the algorithm, the coupling among the system variables has been taken into account in the fuzzy control formula, the coefficients of the deviation and its differential can be adjusted automatically. To prevent mill from failures such as coal powder leakage, coal blockage, different control rules are used at various abnormal situations. It is shown by simulation research and practical application that the fuzzy control formula in the algorithm is simple and easy to be used in real process control and perfect result can be gotten.