Author(s)

Abdlmnam Abdlrahem¹, Parimal Saraf¹, Karthikeyan Balasubramaniam¹, Ramtain Hadidi¹, Alireza Karimi², Elham Makram¹

¹Department of Electrical and Computer Engineering, Clemson University, Clemson, USA.
²Laboratoired'Automatique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.

This paper presents the design of a robust fixed-order H_∞ controller to damp out the inter-area oscillations and to enhance the stability of the power system. The proposed H_∞ approach is based on shaping the open-loop transfer function in the Nyquist diagram through minimizing the quadratic error between the actual and the desired open loop transfer functions in the frequency domain under linear constraints that guarantee robustness and stability. The proposed approach is robust with respect to multi-model uncertainty closed-loop sensitivity functions in the Nyquist diagram through the constraints on their infinity norm. The H_∞ constraints are linearized with the help of a desired open-loop transfer function. The controller is designed using the convex optimization techniques in which the difference between the open-loop transfer function and the desired one is minimized. The two-area four-machine test system is selected to evaluate the performance of the designed controller under different load conditions as well as different levels of wind penetrations.

H_∞, Multi-Machine Power System, Nyquist Diagram, Robust Control, Wind Penetrations, SVC

Abdlrahem, A. , Saraf, P. , Balasubramaniam, K. , Hadidi, R. , Karimi, A. and Makram, E. (2016) Design of a Fixed-Order Robust Controller to Damp Inter-Area Oscillations in Power Systems. Journal of Power and Energy Engineering, 4, 61-70. doi: 10.4236/jpee.2016.43006.