Design of an output feedback variable structure series vectorial compensator to enhance dynamic stability

This paper presents an output feedback based Variable Structure Controller (VSC) is described for a series vectorial compensator (SVeC) in order to enhance the dynamic stability of electric power system. The input to the VSC is speed deviation and it is employed to design the switching surface of the proposed VSC. SVeC is a new series Flexible AC Transmission System (FACTS) device and this can regulate the line reactance by vary the duty ratio of PWM switches. The main aim is to check the effectiveness of the SVeC with VSC to enhance the stability in unique system. For this cause, proposed a novel SVeC current injection model incorporated in the test system. The mathematical model of VSC sliding controller gain proposed. The test system is derived using Heffron-Phillips model. The dynamic stability of the system with this proposed Variable Structure SVeC is analysed through eigenvalues and nonlinear time domain simulations for a unique system at nominal load. The performance of the proposed system is compared with SVeC with Feedback control, with PSS control and without control. From the results, it is concluded that the dynamic stability of the system is enhanced with proposed Variable Structure Feedback based SVeC controller compared with other methods.