Combining Phasor Measurements to Monitor Cutset Angles

Power systems under stress can show large voltage angle differences between areas that can be monitored by wide area phasor measurements. One way to make this idea more specific is to choose a cutset of transmission lines that separates two power system areas and then define an angle difference across the cutset that is a suitable combination of the angle differences across lines of the cutset. We suggest that monitoring this cutset angle yields useful and specific information about power system stress.