Detection, classification, and location of faults on grid‐connected and islanded AC microgrid

Abstract

Summary A new spectral energy differential protection scheme using sparse Fourier kernel fast time‐frequency transform is proposed for the detection, classification, and location of faults either on the grid‐connected or islanded AC microgrid. Initially, the three‐phase average and differential components of the current samples measured on either side of the distribution line are processed through an alteration detection filter, which identifies the fault incipient and consequently registers an alteration index for the particular phase, which identifies the fault. The spectral energy of the differential current components are than computed to classify the type of the fault under a number of intrinsic operating conditions like the meshed and radial architectures and grid‐connected or islanded mode of operation and varying fault distance ratios. Extensive numerical experimentation illustrates satisfactory results for all the cases investigated in this paper, which include detection, classification, and location of faults on the microgrid.

Voltage‐based protection of microgrids using decision tree algorithms

“…In, V dyn‐k is not a fixed value (as used in the CUSUM algorithm) and can change with the signal amplitude. The value of V dyn ‐ k is obtained by recursive discrete Fourier transform (DFT) for the last cycle of each phase voltage.…”

“…In the last decade, the use of renewable energy resources such as wind, photovoltaic, and geothermal has sharply increased in the electricity production. Such energy sources are embedded in conventional electrical networks and are better known as distributed energy resources (DERs) . With increasing penetration of DERs in power system networks, their management and control would be a difficult and complex task.…”

“…Such energy sources are embedded in conventional electrical networks and are better known as distributed energy resources (DERs). 1 With increasing penetration of DERs in power system networks, their management and control would be a difficult and complex task. Therefore, the networks with large-scale penetration of DERs are operated as a microgrid.…”

Microgrid protection using iterative filtering

“…Several protection schemes have been proposed in the literature to deal with the aforementioned issues, such as impedance‐based protection, distance protection, traveling wave‐based protection, adaptive protection with central processing unit, and differential protection schemes. Impedance and traveling wave‐based schemes are unsuitable for microgrids with shorter distribution lines.…”

“…List of symbols and abbreviations: CB, circuit breaker; DG, distributed generation; ELM, empirical mode decomposition; PLL, phase-locked loop; PWM, pulse width modulation; R, relay; T, transformer; VT, voltage transformer. Several protection schemes have been proposed in the literature to deal with the aforementioned issues, such as impedance-based protection, 2,3 distance protection, 4 traveling wave-based protection, 5,6 adaptive protection with central processing unit, [7][8][9][10][11] and differential protection schemes [12][13][14][15] . Impedance and traveling wave-based schemes are unsuitable for microgrids with shorter distribution lines.…”