Fault Detection and Faulted Line Identification in Active Distribution Networks Using Synchrophasors-Based Real-Time State Estimation

Abstract

Abstract-We intend to prove that PMU-based state estimation processes for active distribution networks exhibit unique time determinism and refresh rate that make them suitable to satisfy the time-critical requirements of protections as well as the accuracy requirements dictated by faulted line identification. In this respect, we propose a real-time fault detection and faulted line identification functionality obtained by computing parallel synchrophasor-based state estimators. Each state estimator is characterized by a different and augmented topology in order to include a floating fault bus. The selection of the state estimator providing the correct solution is done by a metric that computes the sum of the weighted measurement residuals. The proposed process scheme is validated by means of a real-time simulation platform in which an existing active distribution network is simulated together with a PMU-based monitoring system. The proposed process is shown to be suitable for active and passive networks, with solid-earthed and unearthed neutral, for low and high impedance faults of any kind (symmetric and asymmetric) occurring at different locations.

A Review of Fault Diagnosing Methods in Power Transmission Systems

“…Although fault intrusion is beyond human control, it is essentially important to accurately detect, classify and locate the fault location. Fault detection, classification and location finding methods in power transmission systems have been extensively studied [1][2][3][4][5][6]. Efforts are under way develop an intelligent protection system that is able to detect, classify and locate faults accurately.…”

Iterative-Interpolated DFT for Synchrophasor Estimation: A Single Algorithm for P- and M-Class Compliant PMUs

“…and protection functionalities of situational awareness systems does not need to equip every measurement point with two different devices. From a measurement reliability perspective, the performance of fault management systems using PMU data to tune or back-up existing protection schemes, are not degraded by the presence of interharmonic tones [6]. In this respect, [4] proposes a hybrid P+M-class PMU design based on tunable trigger thresholds to switch between two different frequency-tracking filters.…”

Architecture and experimental validation of a low-latency phasor data concentrator

“…Depending on the supplied applications (see [14] for a complete review of the latency requirements of various WAMC applications), this parameter can vary between few hundreds of milliseconds (e.g., hard real-time applications like synchrophasor-based fault management systems [15]), to few tens of seconds (e.g., soft real-time applications like voltage control [16]). …”

“…The electrical network is composed of 7 electrical substations connected through 15 cabled and overhead lines (see Fig. 5) and has been equipped with 15 PMUs that monitor the current flows and nodal voltages (the number of PMUs installed in each substation is proportional to the number of power lines being monitored).…”

“…Then, it compares the timing performances of the aforementioned logics in terms of reliability, determinism and reduction of the overall latencies, by validating them in two real PMU deployments that adopt different telecom infrastructures. The first one is based on optical fiber links that transmit synchrophasor data measured by 15 PMUs installed in the sub-transmission network of the city of Lausanne, Switzerland. The second one adopts a 4G LTE wireless infrastructure to support the data streaming of 10 PMUs installed in a distribution network supplying the city of Huissen, in the Netherlands.…”