Hydraulic Servo-Control Analysis for Arc Furnace Electrode

An electric-arc furnace laboratory model was constructed and its characteristics under high temperature were studied. The response of the main hydraulic cylinder displacement with respect to step input was measured under high temperature conditions. The state equations of the system were set up by using bond graphs and its step response was computed. The computed results agree with the experimental results. The response of the main hydraulic cylinder controlled by a servo-valve along with a switching valve was also studied. Theoretical analysis and experiments indicate that if the appropriate closing voltage V_K2 of the switching valve is selected, the step response of system will have the performance of small overshoot and settling time, and the response will be close to an ideal step form. The product of settling time t_s and maximum overshoot M_P is minimum is used as an objective function to determine the optimum V_K2 which gives a satisfied step response.