Research Of AC Electric Arc Furnace Control System

An electric arc furnace is the electric furnace that applies with the energy of electric arc. Electric steel accounts for31%of the total steel, and the process has been one of main methods in steelmaking field. However, Electric arc furnace is a multivariate, non-linear, coupling, time-varying, and deep it is difficult to keep the system running in all optimum status, such as electrode position, current/voltage of arc, length of arc, which blocks more develop of the technology of electric arc process control.This thesis descries the whole design method of electric arc furnace electrode control system in according with the requirement of the steelmaking process. The deep discussion and research have maken to the control strategy of electrode controller and put forward Adaptive PID control with feed-forward. It introduces the feed-forward control to reduce the inter-effect of three phase electrode. The control parameter can be calibrated by estimating the magnify-factor indirectly with the quantity of total actual inputting energy, as to the character of time-varying.This thesis sets forth the method of electric arc furnace control system in detail. Both PC (YANHUA Industrial Personal Computer) and Siemens S7-300PLC are described, Based on the design of the electrode position control algorithm, the realization method of control algorithm is proposed. The control software is designed with theS7-300series programming language produced by Siemens Company, including electrode’s position control unit. For the whole control system of AC electric arc furnace, the prospected effect has been obtained from the running in practice.