Determination of the radius of robust stability of the automatic pressure control system in the stabilization column of a catalytic reforming unit

Abstract

It is proposed to take into account the influence of uncontrolled disturbances on the regulation of pressure in the stabilization column of a catalytic reforming unit by changing the coefficients of the denominator polynomial of the transfer function of the automatic pressure control system based on robust stability methods. To describe the problem in a general form, a general view of the polynomial of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer is obtained. The purpose of the study is to determine the maximum range of change in the coefficients of the polynomial of the denominator of the transfer function of an automatic pressure control system in the stabilization column of a catalytic reformer, at which robust stability is maintained. Methods - methods of robust stability, automatic control theory. A family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of a catalytic reformer with squared uncertainty parameters is considered.The problem of determining the area of robust stability of a family of polynomials is reduced to determining the areas of stability of four edge polynomials and the intersection of all areas to determine the area of robust stability of the family. In general, the problem of determining the robust stability of each edge polynomial is described. To determine the area of robust stability of the family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer, three polynomials, including the nominal one, are specified. Based on the general description of the problem, the radius of stability of each edge polynomial is determined using a graphical criterion and the construction of a Tsypkin-Polyak hodograph. Results - based on the intersection of the stability regions of four rib polynomials, the robust stability region of the family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer with a stability radius of 1.5 was determined. Conclusion - this result can be used in the development of an automatic pressure control system in the stabilization column of the catalytic reformer and the choice of regulator settings.