Research On Control System Of Smelting Electric Furnance Based On Molten Bath Power

Smelting electric furnace is the main equipment of ferroalloy producing.The quality of the product and the enterprise's economic efficiency mainly depend on the controlling of it.There is much significance and value for the studying of the controlling strategy and automation technological reform of it.This dissertation is on the background of the smelting electric furnace.By means of studing the develepment trency of the process technology of it,and comprehensive analysis of technology of energy saving and consumption reduction about it,on the basis of mastering and developping the advanced technology of the special equipments,design the control system of it,dicuss and study the appliance of ralative controller on the smelting electric furnace control.First of all,research analysis at home and abroad are collected and studied.On the basis of application background,the system framework is designed and function are described.Secondly,because it is a complicated object with serious non-linearity,time changing,strong couple.According to disadvantage which use the current as control variable now,the low-frequency power is applied to the control system based on comprehensive analysis to production process and optimizing to advanced technology in china and abroad.The difficulty of three phrases power unbalance is solved owing to the difference of busbar impedance.The high accracy roil coil is used to sample busbar current and intelligence control controller is adapted too which ensure the reality of three phrases molten bath power.Then,the control system which consisits of PC and PLC is desigined according to the features of production process of smelting electric furnace.The WINCC software is used to design super-visory programmme which has a friendly human machine interface and design application montior and achieve the functions of data-manag,data-display,alarm and monitor.The PLC simens S7-300 is used to collect data and control production process and process parameters.Finally,adjusting the electrode is the core of control system of smelting electric furnace,but it is difficult to get good control purpose by the tradional PID controller owing to feature of non-linearity,time changing of smelting electric furnace.In order to improving the control effectiveness and accury of the control system.Fuzzy-PID control algorithm is used,and acoording to the principles of fuzzy contol and the features of PLC,the dissertation presents amethod of realizing FUZZY-PID control based on the PLC,and sugggests a design and program of the FUZZY-PID controller based on Siments S7-300 PLC.