Synchrophasor monitoring of single line outages via area angle and susceptance

Synchrophasor monitoring of angles around the area has been used to track the area stress caused by the single outage. We applied the idea of the area angle which is a combination of synchrophasor measurements of voltage angles around the border of the area to measure the severity of the single line outages inside 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.