Postmortem analysis of power grid blackouts - The role of measurement systems

Promptly following any blackout, an investigation is conducted to determine the who, what, where, when, why, and how. At the heart of the postmortem investigation is the detailed sequence of events. The sequence of events is based on vast amounts of data collected from multiple points in the system from myriad data collection instruments, some devoted to the purpose of supporting system disturbance postmortem analysis, others providing useful additional context or filling in missing gaps. The more that the investigators know about their available sources of data, and the inherent limitations of each, the better (and quicker) will be the analysis. This is especially important when a large blackout has occurred, wherein there is pressure to find answers quickly, but because of the size and complexity of the event, a deliberate and methodical investigation is necessary. This paper discusses the role that system monitoring plays in supporting the investigation of large-scale system disruptions and blackouts