SYMMETRICAL FAULT DETECTION DURING POWER SWING CONDITION WITH SINGLE ENDED MEASUREMENTS

Examples of symmetric fault detection during power sing condition with single ended current measurements are described. In one example, measurements corresponding to each phase of one of a three-phase electric current or voltage are received. The measurements are obtained using measurement equipment associated with a terminal of a power transmission line of the power transmission system. Based on the measurements, phasor magnitudes for a plurality of samples in each measurement window is determined. Thereafter a detrended phasor value is calculated for each current phasor magnitude by detrending the phasor magnitudes calculated for the plurality of samples. Based on the detrended phasor value, a value of a fault indicator is estimated. The fault indicator may then be used for detecting occurrence of a symmetric fault in the power transmission line monitored with the measurement.