• 제목/요약/키워드: Oil-filled transformer

검색결과 53건 처리시간 0.029초

식물성절연유의 가속열화에 따른 장기적 안정성 분석 (Research of Accelerated Aging According to Long-term Stability of Vegetable Oil)

  • 최순호;허창수
    • 전기학회논문지
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    • 제61권8호
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    • pp.1148-1152
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    • 2012
  • The vegetable-based insulating oils are substitutes for mineral oils in oil-filled transformer. The important properties of vegetable insulating oil is their higher flash/fire point and biodegradability than conventional mineral oils. The large oil-filled transformer eliminate the risk of explosion and fire should the transformer fail and oil ignite owing to high flash/fire point of vegetable insulating oil. In addition, higher biodegradability of vegetable insulating oils can let the oil spill damage reduced. In this experiment, the real oil-filled transformers using mineral oil and vegetable oil have accelerated aging. After working on the 100% accelerated aging experiment were conducted comparing the transformer. The hottest-spot temperature using thermal coefficients were calculated to determin the degree of accelerated aging. As a result, apply mineral oil transformer in accordance with the accelerated aging life come to an end. In contrast, vegetable insulating oils showed the opposite characteristics. Vegetable insulating oil compared to the mineral oil are found to be an long life. As a result, the vegetable oil has a long-term stability.

유입 변압기 진단을 위한 유중 열화 측정 센서의 개발 (Development of Deterioration Detecting Sensor in Oil for Diagnosis of Oil-Filled Transformers)

  • 민경래;윤용한;김영춘;김재철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 A
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    • pp.128-130
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    • 2000
  • This paper develops the deterioration detecting sensor in oil to monitor and diagnose oil-filled transformer more effectively. The on-line inspection of the oil-filled transformers used the temperature, the changes of the capacitance, the $tan{\delta}$ in oil. This sensor was designed based on the concentric cylindrical type so that it could be placed inside of the oil-filled transformer. And comparing to the existing system, it was proven to be appropriate. Establishment of the proposed sensor helps to build the confidence in monitoring of the oil-filled transformers.

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식물성 절연유의 유속과 BTA에 따른 유동대전 현상 연구 (Research of Flow Velocity and BTA According to the Streaming Electrification of Vegetable Insulating Oils)

  • 최순호;방정주;허창수
    • 한국전기전자재료학회논문지
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    • 제25권10호
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    • pp.791-797
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    • 2012
  • Mineral insulating oils are an important insulating materials in oil-filled transformer. However, the mineral oil is the cause of the environmental problem. The vegetable oils are substitutes for mineral oil because of its biodegradability characteristic. As large size and high rating of the transformer increases, the losses increase at a faster rate. So insulating oil is forced circulation in the oil-filled transformer by using oil pumps. The flow electrification occurs when insulating oil was forced to be circulated. To check the flow electrification, had conducted experiments varying factors. As a result, the streaming electrification could see the changes according to flow velocity, oil temperature and insulation materials.

유입전력용 변압기의 수명평가 기술 (Assessing the Life of the Oil-filled Transformer)

  • 박현주;남창현;윤여찬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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    • pp.498-499
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    • 2006
  • Oil-filled transformer technology has been around more than 100 years. The principle of operation in the same today as it has been for the previous decades. But all transformers have their life so it is important to know their useful life and the time for replacement. This paper will address this issue and provide the distribution transformer oil aging test results. Distribution transformer and laboratory specimens were externally heated to their respective maximum temperatures. Sample of oil and paper were removed at convenient intervals for testing. We believe that the results of this study will show the possibility of assessing the life of transformers.

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유입변압기 오일필터링에 따른 유전정접 변화사례 고찰 (Example study of the dissipation factor change according to the oil filtering in large oil-filled transformer)

  • 공태식;김희동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.2035_2036
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    • 2009
  • This paper is purpose to understand the dissipation factor properties of the oil-filled large transformer according to the oil filtering. In order to know the insulation characteristic change by insulating oil filtering, we carried out the insulation diagnostic test for the same transformer before oil filtering and after. The insulation diagnosis tests are consist of the megger, the polarization index, the AC current test, the dissipation factor test and the partial discharge test, Especially we took notice of dissipation factor change, we analyzed and made a comparison of the two cases test result.

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유입식 변압기의 열화시간에 따른 절연 열화특성 및 선형회귀법을 이용한 상관관계 분석 (Analysis for Insulating Degradation Characteristics with Aging Time for Oil-filled Transformers and/or Correlation between using Linear Regression Method)

  • 이승민
    • 전기학회논문지
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    • 제59권4호
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    • pp.693-699
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    • 2010
  • General transformer's life is known as paper insulation' life. If a transformer is degraded by these aging factors, it is known that electrical, mechanical and chemical characteristics for transformer's oil-paper are changed. When the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. The paper breakdown is accompanied by an increase in the content of furanic compounds within the dielectric liquid. In this paper it is aimed at analysis on correlation between aging characteristics for insulating diagnosis of thermally aged paper. For investigating the accelerated aging process of oil-paper samples accelerating aging cell was manufactured for estimating variation of paper insulation during 500 hours at $140^{\circ}C$ temperature. To derive the results, it was performed analysis such as tensile strength(TS), depolymerization(DP), dielectric strength(DS), relative permittivity, water content(WC) and furan compound(FC) for aged paper. Also for analyzing correlation between insulating degradation characteristics, we used linear regression method. As as results of linear regression analysis, there was a close correlation between TS and DP. WC, FC. But dielectric strength was a weak correlation with aging time.

변압기 절연재료 분석과 내부점검 결과와의 상관성 연구 (Review on the Relationship of Dissolved Gas Analysis and Internal Inspection of Transformer)

  • 박현주;남창현;정년호
    • 전기학회논문지
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    • 제59권10호
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    • pp.1869-1873
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    • 2010
  • For reliable operation of oil-filled electrical equipment, monitoring and maintenance of insulating oil is essential. Dissolved gas analysis(DGA) is widely used for monitoring faults in high voltage electrical equipment in service. Therefore, oil analysis should be monitored regularly during its service life. KEPCO has investigated thousands of dissolved gas analysis data since 1985, and conducted studies on the relationship of gas in oil analysis and internal inspection results of transformer. As the results, KEPCO revised criteria for transformer diagnosis and has applied it since 2008. Almost of 100 cases of internal inspection results since 2001 have been investigated. This paper presents the correlation of the fault-identifying gases with faults found in actual transformers and how should we approach to internal inspection of transformer by dissolved gas analysis.

DGA Interpretation of Oil Filled Transformer Condition Diagnosis

  • Alghamdi, Ali Saeed;Muhamad, Nor Asiah;Suleiman, Abubakar A.
    • Transactions on Electrical and Electronic Materials
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    • 제13권5호
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    • pp.229-232
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    • 2012
  • DGA is one of the most recent techniques developed to diagnose the fault condition on oil filled insulation transformers. There are more than 6 known different methods of DGA fault interpretation technique and so there is the likelihood that they may vary in their interpretations. A series of combined interpretation methods that can determine the power transformer condition faults in one assessment is therefore needed. This paper presents a computer program- based system developed to combine four DGA assessment techniques; Rogers Ratio Method, IEC Basic Ratio Method, Duval Triangle method and Key Gas Method. An easy to use Graphic User Interface was designed to give a visual display of the four techniques. The result shows that this assessment method can increase the accuracy of DGA methods by up to 20% and the no prediction result had been reduced down to 0%.

Gas Detector for Hydrogen Dissolved in Transformer Oil

  • Seo Ho-Joon;Hwang Kyu-Hyun;Rhie Dong-Hee
    • KIEE International Transactions on Electrophysics and Applications
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    • 제5C권2호
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    • pp.72-75
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    • 2005
  • In oil-filled equipment such as transformers, partial discharge or local overheating will precede a final shutdown. Accompanied with such problems is a decomposition of insulating material into gases, which are dissolved into the transformer oil. The gases dissolved in oil can be separated with some membranes based on the differences in permeability of membranes to different gases. This paper discuss the permeability characteristics of several membranes for separation hydrogen gas in oil. With result of this paper, it may become possible to detect fault-related gases from transformer oil and predict incipient failures in the

유중가스 분석법과 지능형 확률모델을 이용한 유입변압기 고장진단 (Fault Diagnosis of Oil-filled Power Transformer using DGA and Intelligent Probability Model)

  • 임재윤;이대종;지평식
    • 전기학회논문지P
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    • 제65권3호
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    • pp.188-193
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    • 2016
  • It has been proven that the dissolved gas analysis (DGA) is the most effective and convenient method to diagnose the transformers. The DGA is a simple, inexpensive, and non intrusive technique. Among the various diagnosis methods, IEC 60599 has been widely used in transformer in service. But this method cannot offer accurate diagnosis for all the faults. This paper proposes a fault diagnosis method of oil-filled power transformers using DGA and Intelligent Probability Model. To demonstrate the validity of the proposed method, experiment is performed and its results are illustrated.