A Study on LQG/LTR Control for Damping Inter-Area Oscillations in Power Systems

• Published in: IEEE transactions on control systems technology Vol. 15; no. 1; pp. 151 - 160
• Main Authors: Zolotas, A.C., Chaudhuri, B., Jaimoukha, I.M., Korba, P.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-01-2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Centralized control; Computer science; control theory; systems; Control system synthesis; Control systems; Control theory. Systems; Damping; Disturbances; Electrical engineering. Electrical power engineering; Electrical power engineering; Exact sciences and technology; Filtering theory; Flexible ac transmission systems (FACTS) devices; Gaussian; inter-area oscillations; Linear quadratic; linear-quadratic Gaussian; loop transfer recovery; Oscillations; Power networks and lines; Power system control; Power system faults; Power systems; reduced order systems; Robust control; Robustness; Signal design; Signal measurement; transmission zeros; LQG control; Thyristor; Control synthesis; Frequency domain method; Transmission zero; Robust control; Flexible ac transmission systems (FACTS) devices; Machine design; Time domain method; Electrical network; Non linear model; linear-quadratic Gaussian; inter-area oscillations; Robustness; Reduced order systems; power systems; Loop transfer recovery; Capacitor; Minimum phase; transmission zeros
• ISSN: 1063-6536; 1558-0865
• DOI: 10.1109/TCST.2006.883232

This brief presents results on a robust linear quadratic Gaussian (LQG) damping control scheme for improving the inter-area mode oscillations of power systems. A technique is also proposed to guarantee minimum-phase/well-damped transmission zeros by appropriately "squaring" the design plant, for the purposes of efficient robust recovery. A 7th-order multiple-input single-output (MISO) centralized controller is designed for a 16-machine, 5-area power system (138th order) reinforced with a thyristor-controlled series capacitor (TCSC) to improve the damping of the critical inter-area modes by employing appropriate global signal measurements. Loop transfer recovery (LTR) is then applied to reinforce controller robustness in the case of faults and unknown disturbances. The performance of the designed system is assessed in the frequency domain and via appropriate time-domain simulations based upon the nonlinear model under a variety of scenaria