Synchrophasor monitoring of single line outages via area angle and susceptance

The area angle is a scalar measure of power system area stress that responds to line outages within the area and is a combination of synchrophasor measurements of voltage angles around the border of the area. Both idealized and practical examples are given to show that the variation of the area angle for single line outages can be approximately related to changes in the overall susceptance of the area and the line outage severity.Comment: adjusted version accepted at North American Power Symposium (NAPS), Pullman WA USA, September 201

Monitoring voltage collapse margin by measuring the area voltage across several transmission lines with synchrophasors

We consider the fast monitoring of voltage collapse margin using synchrophasor measurements at both ends of transmission lines that transfer power from two generators to two loads. This shows a way to extend the monitoring of a radial transmission line to multiple transmission lines. The synchrophasor voltages are combined into a single complex voltage difference across an area containing the transmission lines that can be monitored in the same way as a single transmission line. We identify ideal conditions under which this reduction to the single line case perfectly preserves the margin to voltage collapse, and give an example that shows that the error under practical non-ideal conditions is reasonably small.Comment: IEEE Power and Energy Society General Meeting, July 201

Models, metrics, and their formulas for typical electric power system resilience events

We define Poisson process models for outage and restore processes in power system resilience events in terms of their rates. These outage and restore processes easily yield the performance curves that track the evolution of resilience events, and their area, nadir and duration are standard resilience metrics. We derive explicit and intuitive formulas for these metrics for mean performance curves in terms of the model parameters; these parameters can be estimated from utility data. This clarifies the calculation of metrics of typical resilience events, and shows what they depend on. We give examples of the metric formulas using a typical model of transmission system outages with lognormal rate restoration, and also for constant rate and exponential rate restorations. We give similarly nice formulas for the area metric for empirical power system data