Coal-fired Boiler Fuzzy Pid Control Algorithm With Application

The character of modern industrial production is having many operational variables,coupling, uncertainty, nonlinear, big delay and so on. Traditional PID control has can notmeet the demand. So, we must adopt advanced control algorithms.In fuzzy control systems, if fuzzy means and fuzzy decision means have been chosen,the core question of control lies in fuzzy control rules. In fact, the fuzzy control rules arebased on the experience and information of operators and experts. However, it is difficulty toobtain perfect fuzzy control rules in some complicated industries process, so that fuzzycontrol rules are absence or roughness, and the control effects will be infected, if theparameters of control objects are changed. From some means, fuzzy control rules are good ornot will directly affect capability and character of the control systems. So to optimize thefuzzy rules of control systems is very important for improving the system capability andcharacterFuzzy control algorithm with adjustable gene, dynamic matrix control algorithm andfuzzy PID control algorithm were used in this paper. Thereinto, in fuzzy control algorithmwith adjustable gene, adopt the idea of dynamic control and bring forward the idea ofchanging domain. In dynamic matrix control algorithm, a new method of error-correction wasbrought forward. In fuzzy PID control algorithm, the idea of fuzzy rule switch in referencewas used.The leading content at this paper are outlined as follows:1.To introduce the background, meaning and the development of fuzzy control, thesignificance of optimizing fuzzy control rules in fuzzy control system.2.To analyze the effect to fuzzy control systems performance which is stemmed from thequantification factor, to optimize the fuzzy control rules by adjusting the quantification factor,so performance of the control systems will be improved through adjusting the quantificationfactor. Based on the fuzzy algorithm with adjustment factor we design an new fuzzycontroller with dynamic state and variable domain. The software MATLAB is used tosimulate the algorithm.3.On the basis of bias-flow analysis and its countermeasures, a control scheme is givenfor the three fuzzy controller to be built by three pipes absolute temperature-difference as theinput, the openness the valve as the controlled object. After realizing this control scheme.the problem of bias-flow has be resolved perfectly. Now coked pipes are burned once a year, but no coking occurs. We use this control scheme from beginning to now for six years. Thereis no need to change the heating-pipes at all. A new design method of fuzzy controller withdynamic state and variable domain presented in this paper can resolve the bias-flow problemin other fluid distribution control system.