PNNL

Abstract

Oscillation detectors based on root-mean-square (RMS) energy have been deployed by electric utilities and reliability coordinators. However, coordination among entities during oscillatory disturbances is currently limited, in part because there is no consistent approach for establishing detection thresholds. To address this shortcoming, an expression for a statistics-based detection threshold is derived. The threshold is expressed in terms of the detector's probability of false alarm, allowing the detector's statistical performance to be adjusted. Additionally, three options for calculating the threshold using synchrophasor measurements are proposed. Using field-measured data, the thresholds are shown to provide consistent detection of grid disturbances while maintaining a low probability of false alarm.