Affiliations: [a] Department of Electrical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Correspondence:
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Corresponding author. Babak Mozaffari, Department of Electrical Engineering, Science and Research Branch,
Islamic Azad University, Tehran, Iran. Tel.: +989122776366; E-mail: mozafari@srbiau.ac.ir.
Abstract: In recent years, because of the regeneration and development of power systems many of their technical and economical characteristics have been changed in different sections of generation, transmission, distribution and consumption. This issue has great impact on transmission systems because of the increased demand and limitation in creation of new lines. System stability against disturbances of big signal is one of the important issues that have been under threat as a result of this issue. In such circumstances, FACTS devices have great impact on increase of control ability and power system stability. One of the most effective FACTS devices is generalized unified power flow controller (GUPFC). It can combine the capabilities of SSSC, STATCOM and TCPAR by control of different parameters of network and can be used as a multipurpose tool. In this essay, designing a neuro-fuzzy controller for GUPFC to improve transient stability has been investigated. For this purposed, a controllable compensator has been designed to increase transient stability margin and damp transient oscillation in such systems by use of lyapunov stability criterion. Since transient energy function of system is a suitable tool for investigating of stability issue, optimization of GUPFC energy function has been noticed in order to reach the highest margin of transient stability. This idea is the basis of producing required teaching information in ANFIS network and can be used as a GUPFC controller. In this essay, the impact of GUPFC on single machine system, infinite bus (SMIB) and 9-bus system (Anderson and Fouad, 1977) by use of supposed method has been studied. Moreover by simulation of other FACTS devices such as UPFC and IPFC, the priority of GUPFC has been shown and the comparison of its result has been proved.
Keywords: Generalized unified power flow controller (GUPFC), transient stability, lyapunov energy function, critical cleaning time (CCT), neuro-fuzzy control
