| This work proposes 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-Prong method. Rules are developed for increasing Multi-Prong method's observability and dependability. These rules are applied to simulated signals, but also to real noisy measurements.; When the Central Control Unit detects an oscillatory interarea mode with low or negative damping ratio, say less than 1 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.; Rules for operating the SVC controls in the damping enhancement mode and for the application of the Multi-Prony algorithm on detecting the onset of the oscillations are proposed and tested in a two-area power system and in large scale simulation example.; The controller is shown to be effective on a validated western American large-scale power system model of the August 10, 1996 blackout event. |
