Differentiation of High Impedance Faults from Other Distribution Network Events Using Microsynchrophasor Measurements

Abstract

High impedance faults (HIFs) are faults with currents of low magnitude which appear like a nonlinear load from the system’s perspective. Because this fault is an anomaly that the system might see as part of normal operations, it is important to differentiate it from actual normal distribution network events, such as capacitor and load switching. The development of the microsynchrophasor (µPMU), a device that provides current and voltage magnitudes and angles for distribution networks gives operators a different view during distribution level events. This paper aims to provide an interpretation of µPMU measurements to discern HIFs from other distribution network events. Simulations were focused on these events: high impedance faults, low impedance faults, and capacitor and load switching. It has been found that the HIF can be differentiated with the LIF using the current angle, this would not be enough to discern the HIF from capacitor switching events.