Research Of The Electrode Lifting Hydraulic System Of Electric Arc Furnace

Modern electric arc furnace develops in the direction of increasingly large, ultra-high-powerfully. The stability and reliability, speed and control precision of electrode take-off and landing system which is one of the key control institutions of electric arc furnace is very important for shorting the melting time, reducing energy consumption, controlling cost and achieving optimal power factor. Therefore, research of control method of electric arc furnace is concentrated in the electrode regulation system.Nowadays, although there are many kinds of automatic adjustment devices, due to the advantages of fast response, high gain, frequency bandwidth, large proportion of the torque (or force) weight, compared with the other electrode regulation system, the hydraulic servo control system has shown more and more unique advantages, especially in large electric arc furnace. So, it is very important to make research of the electrode lifting hydraulic system of electric arc furnace.On the basis of the research of status and development of the electro-hydraulic proportional servo system and its power institution, a system is used which is made up of the three-way valve and nonsymmetrical plunger cylinder and which can meet the requirement of the site condition. The bond graph model of the electrode hydraulic lifting system of electric arc furnace is built with the method of power bond graph and we can get the mathematical model-state equation from the bond graph. Because the state equation of the hydraulic system is nonlinear, the Simulink module of Matlab cannot be used and the solution is to programming in MATLAB environment. Because of the introduction of PID control and fuzzy adaptive PID control, the dynamic response of the system is corrected. The results show that both controllers can make the system has better responsiveness and higher steady-state, and fuzzy adaptive PID controller is superior to the ordinary PID controller.