scholarly journals Condition assessment of power transformers status based on moisture level using fuzzy logic techniques

2018 ◽  
Vol 9 (1) ◽  
pp. 17 ◽  
Author(s):  
Vezir Rexhepi ◽  
Petar Nakov
Keyword(s):  
Fuzzy Logic ◽  
Power System ◽  
Electrical Breakdown ◽  
Power Transformer ◽  
Condition Assessment ◽  
The State ◽  
Moisture Level ◽  
Power Transformers ◽  
Safe Operation ◽  
Fuzzy Logic Technique

Power transformers are one of the most expensive components; therefore the focus on their status and its continuous operation is the primary task. In the power systems, condition assessment of performance and reliability is based on the state of components, measurements, testing and maintenance as well as their diagnosis. Hence, condition assessment of power transformer parameters is the most important regarding their status and finding incipient failures. Among many factors, the most factors that affects the safe operation and life expentancy of the transformer is the moisture in oil. It is known that the low moisture oil in power transformers causes many problems including electrical breakdown, increase the amount of partial discharge, decreases the dielectric withstand strength and other phenomena. Thus, knowledge about the moisture concentration in a power transformer is significantly important for safe operation and lifespan. In this study, moisture level in oil is estimated and its status classification is proposed by using fuzzy logic techniques for the power transformer monitoring and condition assessment. Moreover, the goal of the study is to find methods and techniques for the condition assessment of power transformers status based on the state of moisture in oil using the fuzzy logic technique. These applied techniques increase the power system reliability, help to reduce incipient failures, and give the better maintenance plan using an algorithm based on logic rules. Also, by using the fuzzy logic techniques, it is easier to prevent failures which may have consequences not only for transformers but also for the power system as a whole.

Inter-turn fault stability enrichment and diagnostic analysis of power system network using wavelet transformation-based sample data control and fuzzy logic controller

2021 ◽  
pp. 014233122110070
Author(s):  
Arunesh Kumar Singh ◽  
Abhinav Saxena ◽  
Nathuni Roy ◽  
Umakanta Choudhury
Keyword(s):  
Fuzzy Logic ◽  
Power System ◽  
Wavelet Transformation ◽  
Fuzzy Logic Controller ◽  
Power Transformer ◽  
Harmonic Distortion ◽  
Inrush Current ◽  
Data Control ◽  
Sample Data ◽  
Z Transformation

In this paper, performance analysis of power system network is carried out by injecting the inter-turn fault at the power transformer. The injection of inter-turn fault generates the inrush current in the network. The power system network consists of transformer, current transformer, potential transformer, circuit breaker, isolator, resistance, inductance, loads, and generating source. The fault detection and termination related to inrush current has some drawbacks and limitations such as slow convergence rate, less stability and more distortion with the existing methods. These drawbacks motivate the researchers to overcome the drawbacks with new proposed methods using wavelet transformation with sample data control and fuzzy logic controller. The wavelet transformation is used to diagnose the fault type but contribute lesser for fault termination; due to that, sample data of different signals are collected at different frequencies. Further, the analysis of collected sample data is assessed by using Z-transformation and fuzzy logic controller for fault termination. The stability, total harmonic distortion and convergence rate of collected sample data among all three methods (wavelet transformation, Z-transformation and fuzzy logic controller) are compared for fault termination by using linear regression analysis. The complete performance of fault diagnosis along with fault termination has been analyzed on Simulink. It is observed that after fault injection at power transformer, fault recovers faster under fuzzy logic controller in comparison with Z-transformation followed by wavelet transformation due to higher stability, less total harmonic distortion and faster convergence.

Condition assessment of power transformers based on multi-attributes using fuzzy logic

2017 ◽  
Vol 11 (8) ◽  
pp. 983-990 ◽  
Author(s):  
Chilaka Ranga ◽  
Ashwani Kumar Chandel ◽  
Rajeevan Chandel
Keyword(s):  
Fuzzy Logic ◽  
Condition Assessment ◽  
Power Transformers

scholarly journals A Fuzzy Logic Model for Power Transformer Faults’ Severity Determination Based on Gas Level, Gas Rate, and Dissolved Gas Analysis Interpretation

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1009 ◽  
Author(s):  
Rahman Azis Prasojo ◽  
Harry Gumilang ◽  
Suwarno ◽  
Nur Ulfa Maulidevi ◽  
Bambang Anggoro Soedjarno
Keyword(s):  
Fuzzy Logic ◽  
Power Transformer ◽  
Local Population ◽  
Gas Analysis ◽  
Power Transformers ◽  
Support Vector ◽  
Dissolved Gas ◽  
New Approach ◽  
Dissolved Gas Analysis ◽  
Novel Approach

In determining the severity of power transformer faults, several approaches have been previously proposed; however, most published studies do not accommodate gas level, gas rate, and Dissolved Gas Analysis (DGA) interpretation in a single approach. To increase the reliability of the faults’ severity assessment of power transformers, a novel approach in the form of fuzzy logic has been proposed as a new solution to determine faults’ severity using the combination of gas level, gas rate, and DGA interpretation from the Duval Pentagon Method (DPM). A four-level typical concentration and rate were established based on the local population. To simplify the assessment of hundreds of power transformer data, a Support Vector Machine (SVM)-based DPM with high agreements to the graphical DPM has been developed. The proposed approach has been implemented to 448 power transformers and further implementation was done to evaluate faults’ severity of power transformers from historical DGA data. This new approach yields in high agreement with the previous methods, but with better sensitivity due to the incorporation of gas level, gas rate, and DGA interpretation results in one approach.

Review of Condition Assessment for Power Transformer

2014 ◽  
Vol 681 ◽  
pp. 160-163
Author(s):  
Jin Jiao Kong ◽  
Feng Wang ◽  
Yong Liang Li ◽  
Xu Tao Wu ◽  
Jian Gang Bi
Keyword(s):  
Power System ◽  
Power Transformer ◽  
Condition Assessment ◽  
Condition Based Maintenance ◽  
Future Directions ◽  
Research Status ◽  
Existing Problems ◽  
Assessment Research

Transformer is one of the most important equipment in power system, and accurate condition assessment for transformer is the key for condition based maintenance (CBM). So the study of condition assessment is particularly important. In this paper, the function, role and steps of condition assessment, research status, existing problems and future directions are analyzed and summarized. And this paper can be a reference for transformer’s condition assessment.

scholarly journals Analyzing Ferroresonance Phenomena in Power Transformers Including Zinc Oxide Arrester and Neutral Resistance Effect

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Hamid Radmanesh ◽  
Fathi Seyed Hamid
Keyword(s):  
Zinc Oxide ◽  
Power System ◽  
Power Transformer ◽  
Periodic Oscillation ◽  
Power Transformers ◽  
System Configuration ◽  
Fundamental Resonance ◽  
Short Period ◽  
Simulation Results ◽  
Nonlinear Resistance

This paper studies the effect of zinc oxide arrester (ZnO) and neutral earth resistance on controlling nonconventional oscillations of the unloaded power transformer. At first, ferroresonance overvoltage in the power system including ZnO is investigated. It is shown this nonlinear resistance can limit the ferroresonance oscillations but it cannot successfully control these phenomena. Because of the temperature dissipation of ZnO, it can withstand against overvoltage in a short period and after that ferroresonance causes ZnO failure. By applying neutral earth resistance to the system configuration, mitigating ferroresonance has been increased and chaotic overvoltage has been changed to the smoother behavior such as fundamental resonance and periodic oscillation. The simulation results show that connecting the neutral resistance exhibits a great mitigating effect on nonlinear overvoltage.

scholarly journals Evaluation of Geomagnetic Induced Current on 275 kV Power Transformer for a Reliable and Sustainable Power System Operation in Malaysia

2020 ◽  
Vol 12 (21) ◽  
pp. 9225
Author(s):  
Anis Adiba Zawawi ◽  
Nur Fadilah Ab Aziz ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Halimatun Hashim ◽  
Zmnako Mohammed
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Power Transformer ◽  
Power Transformers ◽  
Half Cycle ◽  
Induced Current ◽  
System Operation ◽  
Power System Operation ◽  
Voltage Instability ◽  
The Impact

Geomagnetic induced current (GIC) occurs as a direct consequence of abnormal space weather which starts from the sun and may flow into a power system network through neutral grounding connections. The flow of GIC through grounded neutral power transformer has been a major concern to researchers since it can potentially affect power system equipment. Most of the previous research was focused on high and mid latitude countries only. However, it has been proven that the GIC is not only limited to high and mid latitudes, but also extends to power systems at lower geographic latitudes. This paper aims to investigate the impacts of GIC on selected 275 kV subpower system networks in Peninsular Malaysia, which is among the low latitude countries. Its impact in terms of magnitude and duration is also assessed together with the use of neutral earthing resistor (NER) as a potential blocking component to reduce the impact of GIC on the Malaysian power system network. Results demonstrated that when GIC exists in the power system, power transformers undergo half-cycle saturation that may lead to a reactive power loss and power system voltage instability. In this case, the power transformer can only withstand a maximum GIC value of 7 A, and beyond this value, if prolonged, may lead to voltage instability. It turned out that GIC magnitude had more impact compared to duration. However, long duration with high magnitude of GIC is the most hazardous to power transformers and could potentially cause major faults in the power system network. As part of mitigation, NER with a value of 315.10 Ω can be used to limit the GIC current flow and thus provide protection to the power system network. Clearly, the issue of GIC undoubtedly affects the reliability, security and sustainability of power system operation, especially networks with highly critical load and capacity and, therefore, thorough studies are required to assess and mitigate this issue.

scholarly journals Study on the increase in power supply reliability for the consumers of electricity

2021 ◽  
Vol 939 (1) ◽  
pp. 012011
Author(s):  
A Rakhmatov
Keyword(s):  
Water Management ◽  
Chemical Composition ◽  
Power Supply ◽  
Power Transformer ◽  
The State ◽  
Transformer Oil ◽  
Power Transformers ◽  
Degree Of Damage ◽  
Physical And Chemical ◽  
Supply Systems

Abstract The issues of increasing the reliability of power transformers used in power supply systems for agriculture and water management were discussed in this article.The degree of damage to the insulation of power transformers by the physical and chemical composition of the transformer oil and insulation of other parts was also investigated, materials on the assessment of the state of insulation by the degree of damage to the insulation of individual units of the power transformer were presented.

scholarly journals IOT Based Fault Detection and Protection of Power Transformer in the Smart Grid

2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Muhammad Kashif Sattar ◽  
Muhammad Waseem ◽  
Saqib Fayyaz ◽  
Riffat Kalsoom ◽  
Hafiz Ashiq Hussain ◽  
...  
Keyword(s):  
Fault Detection ◽  
Smart Grid ◽  
Power System ◽  
Power Transformer ◽  
Optimal Operation ◽  
Protection System ◽  
Power Transformers ◽  
Practical Implementation ◽  
Operating Condition ◽  
Current Voltage

This paper presents a novel Arduino-based fault detection and protection system for power transformers. Power transformers are an integral component of the power system infrastructure. Power transformers are present in such a significant number in the power architecture that any alteration in its operation effects the whole power system. The optimal operation of the transformer depends upon its operating condition; for this reason, its monitoring and protection are very important. Currently, power transformers employ differential relays to ensure optimal operation, but differential relays are unable to ascertain conditions such as overloading and intra turn faults. In this paper, Arduino was used to monitor transformer operation instead of differential relays and generate tripping or alert signals based on sensed values. Arduino autonomously sensed the current, voltage, and temperature values of the power transformer round the clock and handled any fault by comparing preset values of these parameters. In addition, the differential relay functionality of fault detection was implemented in the Arduino environment. Whenever a fault occurred, Arduino sent the fault signal to a Wi-Fi module, which was then displayed in the Blynk app. The practical implementation of this proposed system was tested, and its operation was found to be effective in fault detection.

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