An Effective Method Based on Time Reversal and Optimization Techniques for Locating Faults on Power Grids

Abstract

Electromagnetic time reversal (EMTR) has recently emerged as a promising technique applied for locating faults in power networks. It directly transposes the idea of focusing energy back to its source introduced in original time-reversal (TR) methods. Accordingly, we present in this paper, FasTR, a method based on the tenets of TR, that estimates the fault location by employing optimization based algorithms for fetching the highest peak amplitude with maximum coherence in space and time. However, it uses an alternative approach for executing the cumbersome TR postprocessing, thanks to a simplified analytical model capable of evaluating the voltage (or current) at any position and any instant of the tested network resulting from the back-injection of the recorded time-revered signals. FasTR is shown to accurately locate a fault in a complex network with just a basic knowledge of its topology in no more than a couple tens of seconds. More importantly is its ability to locate multiple faults in non-homogeneous networks. The performance of the proposed method is validated by numerical simulations as well as an experimental setup by making reference to a reduced-scale coaxial cable network where real faults are hardware-emulated.

A review of time reversal-based methods applied to fault location in power networks

“…A similar effort to accelerate the backward-propagation process led to the so-called FasTR method Kafal et al (2021a).…”

“…Different types of full-scale experiments, including field experiments and pilot tests, have been performed worldwide in the past years, with particular attention to assessing the fault location performance of the EMTR method in real power-system environments. So far, three experimental studies have been reported in the literature Wang et al (2018a), Wang et al (2020b), Kafal et al (2021a). Note that a series of reduced-scale experiments in laboratory environments were also conducted during the same period, providing a preliminary validation of some of the foregoing EMTR fault location metrics [e.g., Razzaghi et al (2013a), He et al (2018)].…”

Pilot Tests of FasTR Method for Locating Transient Faults in Medium Voltage Underground Power Networks

“…Thanks to the TR invariance of the transmission-line equations and the inherent spatial focusing property of the TR invariant system, FasTR has emerged as a promising technique for detecting and locating faults in power systems [19]. With a limited knowledge of the tested network and a moderate need for computing resources, FasTR follows a similar analogy to EMTR based methods but uses a different post-processing approach for locating the fault.…”

“…Within the same context, a recent proposal for fault location in power grids is FasTR [19], a method also inspired from the idea of TR focusing. Thanks to a simplified analytical model that computes the voltage (or the current) at any position and any instant of the network under test (NUT), FasTR gets rid of the ponderous simulation stage endured by EMTR [19].…”

“…Within the same context, a recent proposal for fault location in power grids is FasTR [19], a method also inspired from the idea of TR focusing. Thanks to a simplified analytical model that computes the voltage (or the current) at any position and any instant of the network under test (NUT), FasTR gets rid of the ponderous simulation stage endured by EMTR [19]. It has proven an ability of locating faults from their emitted transient signals recorded with precision from probes placed at distant locations of the tested network, by virtue to an accurate shared time synchronization system.…”