Real-World case studies on transmission line fault location feasibility by using M-Class phasor measurement units

Abstract

Transmission line fault location is of paramount importance to speed up the power system restoration after outages. Among the existing fault location methods, the most widespread are those based on fundamental phasors, whose estimations must converge to the fault steady-state regime before the line circuit breakers open. Thereby, traditional fault locators usually consider phasor estimations obtained from protective relays or P-class Phasor Measurement Units, which present filtering latency times shorter than those of M-class Phasor Measurement Units. However, although it is commonly assumed that M-class phasor samples are not suitable for fault location applications due to their intrinsic filtering delay, studies on the feasibility of M-class data-based fault location applications are not yet available in the literature. Therefore, this work aims to investigate if M-class Phasor Measurement Units could be used in real fault location schemes, taking advantage of already deployed measurement systems. To do so, actual fault events occurred on the Brazilian power grid are analyzed, and the performance of four different phasor-based fault location algorithms are evaluated when phasor samples obtained from a traditional protective relay algorithm and from M-class Phasor Measurement Units are used as inputs. Unlike the preliminary expectations, the obtained results highlight evidences that M-class phasor measurements can be used in fault location applications, since they resulted in errors within the expected levels for phasor-based fault location methods.