Research On Fuzzy Predictive Control In Digital Fused Quartz Furnace

Fused quartz furnace is an industrial furnace which used for melting andpurifying quartz. Currently there are many problems in fused quartz industry such aslow efficiency, energy consumption, poor product quality, serious pollution to theenvironment and so on. The main reason for these problems is that the equipment offused quartz furnace is relatively backward and the automation level is low. Theymainly manifest in temperature control, power supply structure, and the degree ofdigitization in fused quartz furnace. Therefore, the research work in the digital controlsystem of fused quartz furnace has important theoretical and practical significance.The AC fused quartz furnace play a leading role in the fused quartz industry. Butits inherent disadvantages can’t be ignored such as high power consumption, noise,lining ablation fast, strong interference, high electrode consumption and so on. On thecontrary the DC fused quartz furnace overcomes these shortcomings, and receives themajority attention of the researchers. So our research is based on the DC fused quartzfurnace.Because the DC power supply in the fused quartz furnace has large energyconsumption and bad control effect, a new DC power supply is designed. The three-phase five-limb double reverse-star rectifier power supply take this method thatputting AC voltage regulator on the transformer primary side and rectifier circuit ofdouble star in reverse on the secondary side. Some experiments show that the powersupply has stable output voltage, low loss, improves the conversion efficiency andpower factor, and reduces the harmonic pollution.The fused quartz furnace itself is a complicated control object with large timedelay, time-varying and nonlinear characteristics, so this paper identifies thetemperature model through fuzzy neural system modeling. Then we take the fuzzypredictive functional control theory which using the T-S fuzzy model as the predictivemodel to control the quartz furnace temperature, and the control theory is derived in detail. Taking MATLAB as a development platform to study and simulation, the resultsshow that it has small overshoot, less adjusting time, greater robustness and anti-interference ability. The fuzzy predictive functional control can meet the requirementsof the fused quartz furnace system.According to the requirement of the produce process of the digital fused quartzfurnace, a powerful and stable system is built. The system is composed of two layersof computer control structure, which host computer fulfils the function of control,management and alarm, and basic automation fulfils the control of I/O points andsome important equipment states. The actual production running shows that the systemhas good stability, adaptability, achieves the ideal control effect, and promotes thedevelopment of the digitalization and automation of the fused quartz furnace system.