Application of PMUs for high impedance fault detection of distribution network by considering effect of transformer vector group

This paper presents an algorithm for high impedance fault (HIF) detection by phasor measurement units (PMUs) that are basic elements in wide area monitoring and protection systems (WAMPS). This method uses output current phasors of PMU for detection of HIF. At first, change of current detects by summation of errors between sampled data and estimated samples that are obtained from output phasors of PMU,Then in order to certain that this change is HIF, 3rd harmonic phase of fault current is used to discriminate HIF from normal condition such as load increasing/decreasing. Effects of transformer vector group on 3r harmonic phase are also studied. Several cases are simulated in EMTP&MATLAB to evaluate accuracy of method.