Design of wide-area power system damping controllers resilient to communication failures

Recent research has demonstrated that wide-area signals obtained using synchronized phasor measurements could be more effective than local signals in damping inter-area oscillations in large interconnected systems. To transmit wide-area signals for use in controls, communication systems are required. Communication systems are vulnerable to disruptions as a result of which the reliability of the power system could be jeopardized. In order to counteract communication failures, resiliency could be built in either the communication system or the physical system. In this paper an approach is developed to build resiliency in grid controls in the physical system. The resiliency is achieved by robustly designing a novel redundant two-input single-output (TISO) supplementary damping controller (SDC) associated with a static VAr compensator (SVC) that utilizes both a wide-area signal and a local signal to guarantee that the system is stabilized if the wide-area signal is lost. Numerical tests on the IEEE 50-generator test system have demonstrated that the proposed SDC is effective in stabilizing the system and improving grid control resiliency in response to communication failures.