Research On Control Method Of Electric Arc Furnace Electrodes

In this thesis,based on a large number of related literatures,the development process,research status and future development trend of electric arc furnace and its electrode control methods are summarized.Three-phase AC arc furnace system is a complex multivariable system with strong coupling,time-varying parameters,serious random interference and other characteristics,which make the system difficult to maintain the best running state.Based on the arc mathematical model of the three-phase arc furnace and the output model of the power supply system,the whole control scheme of the electrode regulating system is researched here combined with the requirements of the EAF steelmaking process to the electrode controller.The control strategy of electrode lift is discussed,and an self-adaptive PID controller with feedforward loop is designed.And this restrain interference among three electrodes.In order to avoid the problem of continuous temperature measurement,the method of energy input accumulation is used to indirectly estimate the time-varying degree of the system parameters,And through online correction for PID controller parameters to compensate for changes in system parameters,so that the control system can operate in the best condition.This thesis set the semi-physical simulation platform of intelligent arc furnace as background and design a control scheme of electrode regulation.The hardware control system is designed by Siemens S7-300PLC.The software platform is based on STEP7 programming software and WinCC configuration software.The motor control method proposed in this thesis has been implemented in the laboratory platform and basically achieved the anticipated results.