Improved power transformer winding fault detection using FRA diagnostics – part 2: radial deformation simulation

Abstract

Frequency response analysis (FRA) is proven to be a powerful tool to detect winding deformation within power transformers. Although the FRA test along with the equipment are well developed, interpretation of FRA signature is still a challenge and it needs skilled personnel to identify and quantify the fault type if exists as at this stage, there is no reliable standard code for FRA signature classification and quantification. As it is very hard to implement faults on physical transformer without damaging it, researchers investigated the impact of various mechanical winding deformations on the transformer FRA signature by randomly changing the value of particular electrical parameters of the transformer equivalent electrical circuit. None of them however, precisely investigated the correlation between physical fault level and the percentage change in each parameter. In this paper, the physical geometrical dimension of a singlephase transformer is simulated using 3D finite element analysis to emulate the real transformer operation. A physical radial deformation of different fault levels is simulated on both low voltage and high voltage windings. The impact of each fault level on the electrical parameters of the equivalent circuit is investigated and the correlation between the fault level and the percentage change in each parameter of the equivalent circuit is provided. This will facilitate precise fault simulation using transformer equivalent electrical circuit and ease the quantification analysis of FRA signature.

Detecting the location and severity of transformer winding deformation by a novel adaptive particle swarm optimization algorithm

“…In addition of improving the accuracy, phase function increases the convergence speed too. Even with all useful effects of the phase function, it is not often considered by researchers, for the sake of simplicity, increasing the convergence rate or evading a multiobjective problem . For simplifying the problem at first level, the number of considered frequency points decreased and only 1/10 of all frequency points are used at this level.…”

“…Even with all useful effects of the phase function, it is not often considered by researchers, for the sake of simplicity, increasing the convergence rate or evading a multiobjective problem. [14][15][16][17][18]22,24 For simplifying the problem at first level, the number of considered frequency points decreased and only 1/10 of all frequency points are used at this level. The second objective function computes the normalized Euclidean distance among the magnitude of the reference frequency points and the calculated FR points.…”

“…The physical geometrical dimension of a single‐phase transformer is simulated in Hashemnia et al and Hashemnia et al by utilizing the 3D finite element analysis to study the behavior of transformer. A method based on time domain terminal measurements of wave propagation along the winding is introduced in Alzekri and Gomez for determining the location of internal winding faults.…”

Failure Type Prediction Using Physical Indices and Data Features for Solenoid Valve

“…In general, methods of prognostic and diagnostics can be categorized into physics-based, data-driven, and hybrid approaches [3,4]. The physics-based method uses a specific physical model to represent the normal machine state and detects the potential failure types based on the deviations between the actual system and the physical model [5][6][7][8][9][10][11]. Hashemnia et al [5,6] used frequency response analysis diagnostics to improve the fault detection of power transformer winding.…”

Detection of power transformer bushing faults and oil degradation using frequency response analysis

“…While many researchers investigated the impact of various mechanical winding deformations such as axial displacement [17,18], buckling deformation [19][20][21], disk space variation [22] and short circuit turns [23] on the transformer FRA signature, no attention was given to the impact of transformer insulation aging and various bushings faults on the FRA signature [20,24,25]. In this paper, the geometric dimensions of a three-phase transformer including detailed transformer windings, insulation system and bushings are simulated using 3D finite element modelling (FEM) that allows the extraction of equivalent electrical circuit parameters of the transformer before and after applying a physical faults to the model.…”