Relative Gain Array Application for Typical Chemical Process

This article analyzes solutions to the following two problems using relative gain array. The first challenge is to select pairs of controlled and manipulated variables of the control system for a nonlinear control object for various operating points. The second task is to define object control degrees of freedom considering interactions between process variables. The solution of the tasks set is considered using the example of the first stage of separation of the oil treatment unit for transport, which includes two separators and five valves. As a result of the relative gain array calculation square matrices of different dimensions with various relative gain were received. The analysis of these matrices was based on fundamental definition of the relative gain. As a consequence of this research, a method is proposed for assessing the possibility of decoupling the technological process from the point of view of choosing the structure of the control system, taking into account the analysis of the degrees of freedom, and assessing the stability of the selected pairs of variables for various operating points of the nonlinear control object.