Application of Relay Based Closed Loop Evaluation and Controller Redesign Techniques to an Industrial Process

摘要

The success of the relay test to tune PI/PID controllers has motivated the development of new relay structures. For instance, it is possible to use a relay feedback structure to estimate the frequency at which a desired transfer function achieves a selected gain. The technique can be applied in a relay test for evaluating the gain and phase margins of a closed loop system and to sequentially redesign the controller to achieve desired specifications. The procedure is iterative and the new controller is computed after each relay test. In this paper it is presented the application of the technique to evaluate the closed loop and to redesign the controller of loops (Level and Temperature) in a Petrochemical Plant.