Detection of Transformer Faults Using Frequency Response Analysis with Case Studies

2013 ◽  
pp. 456-486
Author(s):  
Nilanga Abeywickrama
Keyword(s):  
Frequency Response ◽  
Case Studies ◽  
Low Voltage ◽  
Short Circuit ◽  
Diagnostic Methods ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Mechanical Deformations ◽  
Mechanical Faults ◽  
Non Destructive

Power transformers encounter mechanical deformations and displacements that can originate from mechanical forces generated by electrical short-circuit faults, lapse during transportation or installation and material aging accompanied by weakened clamping force. These types of mechanical faults are usually hard to detect by other diagnostic methods. Frequency response analysis, better known as FRA, came about in 1960s (Lech & Tyminski 1966) as a byproduct of low voltage (LV) impulse test, and since then has thrived as an advanced non-destructive test for detecting mechanical faults of transformer windings by comparing two frequency responses one of which serves as the reference from the same transformer or a similar design. This chapter provides a background to the FRA, a brief description about frequency response measuring methods, the art of diagnosing mechanical faults by FRA, and some case studies showing typical faults that can be detected.

scholarly journals Frequency response analysis technique for induction motor short circuit faults detection

2020 ◽  
Vol 11 (3) ◽  
pp. 1653
Author(s):  
A. A. Alawady ◽  
M. F. M. Yousof ◽  
N. Azis ◽  
M. A. Talib
Keyword(s):  
Frequency Response ◽  
Induction Motor ◽  
Short Circuit ◽  
Diagnostic Methods ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Stator Windings ◽  
Analysis Technique ◽  
Three Phase ◽  
Internal Short Circuit

<p>The paper presents the description for diagnostic methods of induction motor's stator windings fault. The presented methods use Frequency Response Analysis (FRA) technique for detection of Winding Faults in Induction Motor . This method is previously reliable method for faults diagnosis and detection in many parts of transformers including transformer windings. In this paper, this method was used for motor windings faults detection. This paper presents the FRA response interpretation on internal short circuit (SC) fault at stator winding on three cases studies of different three-phase induction motors (TPIM), were analysed according to two status: healthy induction motor at normal winding status and same motor with windings shorted of main windings. A conclusion of this paper provides the interpretation of and validation the FRA response due to internal SC fault case by using NCEPRI algorithm, which is considered as one of certified statistical indicators. The proposed method in this paper had a useful result for detect and diagnosis of stator windings faults of TPIM. The applications of developed method can be used to detece the other machines types faults.</p>

scholarly journals Extended Use for the Frequency Response Analysis: Switching Impulse Voltage Based Preliminary Diagnosis of Potential Sources of Partial Discharges in Transformer

2020 ◽  
Vol 10 (22) ◽  
pp. 8283
Author(s):  
Kamalaselvan Arunachalam ◽  
Balasubramanian Madanmohan ◽  
Rajesh Rajamani ◽  
Natarajan Prabaharan ◽  
Hassan Haes Alhelou ◽  
...  
Keyword(s):  
Frequency Response ◽  
Low Voltage ◽  
Partial Discharges ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Potential Sources ◽  
Impulse Voltage ◽  
Before And After ◽  
Test Voltage ◽  
Low Capacitance

The Frequency Response Analysis approach (FRA) is useful in the fault diagnosis of transformers. However, its usefulness in diagnosing any potential sources of Partial Discharge (PD) in transformers has not been thoroughly investigated so far. In this work, the use of Impulse voltage-based FRA (IFRA) in diagnosing inter-turn shorts and potential sources of PD were investigated on a 315 kVA, 11 kV/433 V transformer. Inter-turn shorts and PD sources were emulated and the usefulness of IFRA in their diagnosis was investigated while using switching impulse voltage at different magnitude levels as the test signals. For emulating the inter-turn shorts and the PDs, special tappings were provided on one of the 11 kV windings through the low capacitance bushings. Low voltage impulse was successful in diagnosing the inter-turn shorts, but unsuccessful in identifying the sources of PDs. During the test condition, the test voltage was adjusted with the presence of artificially created PD sources. The frequency response of the transformer before and after the inception of PD was observed and analyzed in this article. The FRA results demonstrated that the switching impulse voltage based IFRA approach at moderate voltages could be useful in diagnosing the presence of the potential sources of PDs.

scholarly journals Frequency Response Analysis Technique of Short Circuit Faults Detection in Photovoltaic Single-Phase Inverter Experimental Study

2021 ◽  
Vol 23 (4) ◽  
pp. 337-343
Author(s):  
Ouadfel Ghania ◽  
Houassine Hamza ◽  
Gacemi Abderzak ◽  
Bensaid Samir
Keyword(s):  
Frequency Response ◽  
Fault Location ◽  
Single Phase ◽  
Short Circuit ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Phase Inverter ◽  
Efficient Detection ◽  
Healthy State ◽  
Single Phase Inverter

The work proposed in this paper concerns the study of short circuit faults in a single-phase inverter dedicated to a photovoltaic application by applying the frequency response analysis (FRA) technique on this IGBT-based inverter controlled by a 18F2550 microcontroller, a prototype inverter was designed in the laboratory to be able to apply off-line short-circuit faults using an LRC meter. The FRA technique is based on the comparison of amplitude-frequency and phase-frequency signatures of healthy cases and fault situations. The experimental results also led to the conclusion that frequency response analysis can be used as an effective tool to detect faults in power electronic devices. This method allows for efficient detection and classification of faults with ease of implementation. For fault location, the fault branch is determined according to its position relative to its healthy state.

scholarly journals Application of Frequency Response Analysis Technique to Detect Transformer Tap Changer Faults

2021 ◽  
Vol 11 (7) ◽  
pp. 3128
Author(s):  
Salem Mgammal Al-Ameri ◽  
Abdulaziz Almutairi ◽  
Muhammad Saufi Kamarudin ◽  
Mohd Fairouz Mohd Yousof ◽  
Ahmed Abu-Siada ◽  
...  
Keyword(s):  
Frequency Response ◽  
Low Voltage ◽  
Experimental Testing ◽  
Equivalent Circuit Model ◽  
Distribution Networks ◽  
Diagnostic Tools ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Electrical Transmission ◽  
Tap Changer

Power transformers are located in the electrical transmission and distribution networks where different voltage levels are needed. The turn ratio of the low voltage and high voltage windings is mechanically controlled by an on-load tap changer or de-energized tap changer. As the tap changer is the transformer’s only moving part, it is highly susceptible to mechanical failure and aging degradation. While some diagnostic tools have been used to determine the mechanical condition of tap changer contacts, not much attention was given to use the frequency response analysis to diagnose the transformer’s tap changers’ mechanical integrity. This paper is taking one step forward into maturing the application of the frequency response analysis (FRA) technique to detect transformer tap changer faults. In this regard, two common tap changer faults are created, and experimental testing for four FRA test configurations is conducted. For a better understanding of the tap changer fault mechanism, an electrical equivalent circuit model is proposed and designed using Simulink. The simulation and implementation of the equivalent circuits using MATLAB\R2018a.

scholarly journals Interpretation of Frequency Response Analysis for Fault Detection in Power Transformers

2021 ◽  
Vol 11 (7) ◽  
pp. 2923
Author(s):  
Salem Mgammal Al-Ameri ◽  
Muhammad Saufi Kamarudin ◽  
Mohd Fairouz Mohd Yousof ◽  
Ali A. Salem ◽  
A. Abu Siada ◽  
...  
Keyword(s):  
Frequency Response ◽  
High Frequency ◽  
Short Circuit ◽  
International Standards ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Three Phase ◽  
One Step ◽  
Interpretation Process

Frequency response analysis (FRA) is a method of monitoring a power transformer’s mechanical integrity. However, identifying the type of fault and its severity by comparing measured responses is still challenging and mostly relies on personnel expertise. This paper is taking one step forward to standardize the FRA interpretation process by proposing guidelines based on various international standards and FRA case studies. In this study, the FRA signature is divided into three regions: low-, mid- and high-frequency regions. The deviation from the fingerprint signature for various faults is classified into small, large, and no variations, based on the calculation of the correlation coefficient. The proposed guidelines are developed based on the frequency regions, and the level of variation is represented using a simple arrow method to simplify the interpretation process. A case study is conducted on a three-phase 11/0.433 kV, 500 kVA distribution transformer with a short circuit winding fault to validate the proposed guidelines.

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