Application of SSSC and IPFC for Stability Enhancement for SMIB and MMIB using FUZZY Logic Controller

Abstract

In this dissertation, a static synchronous series compensator (SSSC) and Internal Power Flow Controller (IPFC) independently are used to improve small signal stability in a series compensated transmission system. SSSC is applied for both Single Machine Infinite Bus (SMIB) system and IPFC is applied for Multi Machine Infinite Bus (MMIB) system to enhance power oscillations such as power angle, stator terminal voltage. Further enhancement can be achieved by using MAMDANI based FUZZY Logic Controller (FLC). Complete stability analyses, including voltage, small perturbation and transient stability        studies, and the associated models and controls of a SSSC and IPFC with 7 rules Mandeni based FLC are studied in this work. It   is shown that the SSSC and IPFC improve the synchronizing power coefficient for SMIB and MMIB and further ensures increased damping of small signal oscillations. It is also shown through detailed simulations that the SSSC and IPFC independently is a competitive device against series power-flow controllers and it might be a better option for similar purposes where space and costs are at premium. Hence, a full comparative evaluation of this controller with respect to controllers used mainly for oscillation control in transmission corridors, namely, SSSC, IPFC is also presented. The results obtained show that the SSSC and IPFC have better oscillation damping characteristics with FLC than conventional PI controller, hence making these types of controllers a competitive alternative against existing series flexible ac transmission sys(FACTS)controllers for dynamic series compensation of transmission lines.