SVC compensation on a real-time wide-area control for mitigating small-signal instability in large electric power systems

This paper proposes an SVC compensation strategy on a real-time centralized controller for addressing small-signal instability related events in large electric power systems. The proposed system is meant to be a safety net type control strategy that will detect and mitigate small-signal stability phenomena as they emerge in the system. Specifically, it will use wide-area monitoring schemes to identify the emergence of growing or undamped oscillations related to interarea and/or local modes. The damping levels of the associated interarea and local oscillatory modes will be estimated by analyzing predefined sets of signals using Multi- Prony´s method with increased observability and dependability. When the central control unit detects an oscillatory mode with low or negative damping ratio, say less than one percent, the controller will initiate strategically located static VAR compensator (SVC) devices, initially working in voltage regulation mode, into a full interarea active power damping operation for correcting the damping level of the problematic mode. This centralized wide-area controller is shown to be effective on a validated western American large- scale power system model of the August 10, 1996 blackout event.