An Optimal Robust Controller Design for Automatic Voltage Regulator System Using Coefficient Diagram Method

摘要

Design of a robust controller for any control system is of paramount importance in the field of control system design. Despite parameter variations, the controller has to generate signals to enable satisfactory performance of the system. One of the recent developments of the robust controller design methods is the coefficient diagram method (CDM), which is an algebraic approach, wherein the characteristic polynomial along with the controller is simultaneously obtained from the design. A graph on semilog axis, known as coefficient diagram, is a single tool used to analyze the key features of the system performance namely speed of response, stability and robustness. Although controller design using CDM has been used in many control applications, the method needs to be explored in the field of power system control problems. One of the crucial systems is the automatic voltage regulator (AVR) system. In this paper, a controller based on CDM has been designed for an AVR system and its robustness is analyzed in the presence of parameter variations. Also, the functioning of the system with conventional PID controller is contrasted with the performance of CDM-based controller. The results of the CDM-based controller are found to be better as compared to the former.