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Advances in Power Electronics
Volume 2011 (2011), Article ID 912749, 7 pages
http://dx.doi.org/10.1155/2011/912749
Research Article

Design of Robust Current Controller for Two-Level 12-Pulse VSC-based STATCOM

1School of Electrical Engineering, VIT University, Vellore 632014, India
2Department of Electrical Engineering, Canara Engineering College, Mangalore 574219, India

Received 2 November 2010; Revised 22 March 2011; Accepted 6 April 2011

Academic Editor: Jose Pomilio

Copyright © 2011 M. Janaki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The static synchronous compensator (STATCOM) is a shunt connected voltage source converter (VSC) based FACTS controller using GTOs employed for reactive power control. A typical application of a STATCOM is for voltage regulation at the midpoint of a long transmission line for the enhancement of power transfer capability and/or reactive power control at the load centre. The PI controller-based reactive current controller can cause oscillatory instability in inductive mode of operation of STATCOM and can be overcome by the nonlinear feedback controller. The transient response of the STATCOM depends on the controller parameters selected. This paper presents a systematic method for controller parameter optimization based on genetic algorithm (GA). The performance of the designed controller is evaluated by transient simulation. It is observed that the STATCOM with optimized controller parameters shows excellent transient response for the step change in the reactive current reference. While the eigenvalue analysis and controller design are based on D-Q model, the transient simulation is based on both D-Q and 3-phase models of STATCOM (which considers switching action of VSC).