Characteristic analysis of electro-slag remelting system model and multi-loop PID control

The cooperative control of both electrode remelting rate and position was applied in order to obtain optimal electro-slag remelting metallurgy effect and improve melting production efficiency. The nonlinear dynamic model of electro-slag remelting process was linearized. And the linearization model was analyzed including its stability, coupling property and variable matching strategy. The multi-loop PID controllers with cascade PID controllers were applied to the linearization model based on matching strategy. The dynamic performance was analyzed to electro-slag remelting control system. Study results show that linearization model of electro-slag remelting process have characteristic of stability and weakly-coupled property. Multi-loop PDD control system can realize stable control both electrode melting rate and electrode position. The control system has faster dynamic response and better anti-interference capability.