Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357016
Xiaoming Ren, Qin Zhou
The paper introduced the work principle of the 10/350μs impulse current generation and analyzed the feature of the crowbar trigger circuit. Crowbar trigger circuit with 10/350μs impulse current and follow current of voltage switching type surge protective device (SPD) has been researched using EMTP simulation. In order to simulate voltage switching type SPD, the equivalent impedance of the sample and the acting time of crowbar can be obtained from test. The simulation showed that follow current trend of positive and negative polarity were almost the same under impulse of 10/ 350μs impulse current. With the same synchronous trigger angle, the initial part of follow current of SPD can be influenced due to the different polarity of impulse current.
{"title":"Simulation studies of power frequency continuous current under 10/ 350µs impulse current tests","authors":"Xiaoming Ren, Qin Zhou","doi":"10.1109/ICHVE.2012.6357016","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357016","url":null,"abstract":"The paper introduced the work principle of the 10/350μs impulse current generation and analyzed the feature of the crowbar trigger circuit. Crowbar trigger circuit with 10/350μs impulse current and follow current of voltage switching type surge protective device (SPD) has been researched using EMTP simulation. In order to simulate voltage switching type SPD, the equivalent impedance of the sample and the acting time of crowbar can be obtained from test. The simulation showed that follow current trend of positive and negative polarity were almost the same under impulse of 10/ 350μs impulse current. With the same synchronous trigger angle, the initial part of follow current of SPD can be influenced due to the different polarity of impulse current.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"2009 1","pages":"141-144"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78667028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357063
P. Tuethong, P. Yutthagowith, A. Kunakorn, S. Potivejkul
This paper presents internal failure analysis of transformer windings based on the characteristic of winding impedance in the frequency domain. Two winding samples are selected to test. The simple equivalent circuit of the transformer winding is investigated and proposed. The two windings under test have 76 turns with different length. An iron core is either inserted or not inserted inside a winding in the test to investigate the effect of the iron core. Turn to turn short circuit on the windings is considered as internal failure in this paper. The simulated turn to turn short on the model is carried out in the experiment to observe impedance characteristic in the frequency domain. A number and position of short turns are varied to observe characteristics of impedances The impedance of the models of the transformer windings are measured by a spectrum analyzer in a wide frequency range upto 2 MHz. From the test results, it is investigated that a resonance frequency of the transformer model is depended on a number and position of short turns. From the investigation, it has high possibility that the characteristic can be used for analysis of internal failures occurring in a transformer.
{"title":"Internal failure analysis of transformer windings","authors":"P. Tuethong, P. Yutthagowith, A. Kunakorn, S. Potivejkul","doi":"10.1109/ICHVE.2012.6357063","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357063","url":null,"abstract":"This paper presents internal failure analysis of transformer windings based on the characteristic of winding impedance in the frequency domain. Two winding samples are selected to test. The simple equivalent circuit of the transformer winding is investigated and proposed. The two windings under test have 76 turns with different length. An iron core is either inserted or not inserted inside a winding in the test to investigate the effect of the iron core. Turn to turn short circuit on the windings is considered as internal failure in this paper. The simulated turn to turn short on the model is carried out in the experiment to observe impedance characteristic in the frequency domain. A number and position of short turns are varied to observe characteristics of impedances The impedance of the models of the transformer windings are measured by a spectrum analyzer in a wide frequency range upto 2 MHz. From the test results, it is investigated that a resonance frequency of the transformer model is depended on a number and position of short turns. From the investigation, it has high possibility that the characteristic can be used for analysis of internal failures occurring in a transformer.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"13 1","pages":"100-104"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79151131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357153
M. Cao, Kunnan Cao, Bo Wu, Min Tan
Condition monitoring and management system (CMMS) for power transmission and distribution equipments is an important part of smart grid. This paper addresses issues relating to the techniques of CMMS and its application in Yunnan Power Grid. After introducing the basic concepts and essential characters of Intelligent CMMS, many technological challenging issues of it are discussed. And engineering research and application cases in Yunnan Power Grid for develop a fully perceptive smart are also introduced in detail, including the Data Supervise System (DSS), some original methods for faults diagnosis or disaster warning, and the research project about intelligent monitoring and full lifecycle management for power transmission and distribution equipments based on internet of things. Those are helpful to improve the reliability of power grid devices and ensure the safety of Yunnan Power Grid.
{"title":"Intelligent condition monitoring and management for power transmission and distribution equipments in Yunnan Power Grid","authors":"M. Cao, Kunnan Cao, Bo Wu, Min Tan","doi":"10.1109/ICHVE.2012.6357153","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357153","url":null,"abstract":"Condition monitoring and management system (CMMS) for power transmission and distribution equipments is an important part of smart grid. This paper addresses issues relating to the techniques of CMMS and its application in Yunnan Power Grid. After introducing the basic concepts and essential characters of Intelligent CMMS, many technological challenging issues of it are discussed. And engineering research and application cases in Yunnan Power Grid for develop a fully perceptive smart are also introduced in detail, including the Data Supervise System (DSS), some original methods for faults diagnosis or disaster warning, and the research project about intelligent monitoring and full lifecycle management for power transmission and distribution equipments based on internet of things. Those are helpful to improve the reliability of power grid devices and ensure the safety of Yunnan Power Grid.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"64 1","pages":"8-11"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80695411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357104
J. Han, Wubin Qiu, Wei Wang, Hongwei Cao, De-heng Yao
Insulating vegetable oils are environment-friendly and fire-resistant liquid dielectrics. This paper presented a new type of high fire resistance transformer filled with insulating camellia oil. The main physical, chemical and electrical properties of insulating camellia oil were measured and compared with those parameters of mineral oil. A new type of sealing camellia oil filled transformer was designed. The performances of camellia oil filled transformer were tested. The test results indicated good insulation performances of camellia oil filled transformer. The temperature rise of an ordinary transformer which was filled successively with insulating camellia oil and mineral oil were tested. The results showed that the temperature rise of insulating camellia oil filled transformer is slightly higher than that of mineral oil immersed transformer, suggesting that the oil gallery structure should be improved and the heat resistant grade of insulation paper should be enhanced.
{"title":"Application of insulating camellia oil in high fire resistance transformer","authors":"J. Han, Wubin Qiu, Wei Wang, Hongwei Cao, De-heng Yao","doi":"10.1109/ICHVE.2012.6357104","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357104","url":null,"abstract":"Insulating vegetable oils are environment-friendly and fire-resistant liquid dielectrics. This paper presented a new type of high fire resistance transformer filled with insulating camellia oil. The main physical, chemical and electrical properties of insulating camellia oil were measured and compared with those parameters of mineral oil. A new type of sealing camellia oil filled transformer was designed. The performances of camellia oil filled transformer were tested. The test results indicated good insulation performances of camellia oil filled transformer. The temperature rise of an ordinary transformer which was filled successively with insulating camellia oil and mineral oil were tested. The results showed that the temperature rise of insulating camellia oil filled transformer is slightly higher than that of mineral oil immersed transformer, suggesting that the oil gallery structure should be improved and the heat resistant grade of insulation paper should be enhanced.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"2673 1","pages":"655-658"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75260681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357145
Ming-jie Tang, Min Lei, Hao Xu, Y. Lu, Xu Wei, Peng Wu, Guanjun Zhang
Based on the platform designed for thermal aging test of oil-paper insulation system, the problem of thermal aging of solid insulation used in the oil-paper insulation of power equipment has been studied. The method of Frequency Domain Spectrum (FDS) has been applied to obtain frequency domain dielectric response properties of oil immersed paper insulation, and an unscrambling method according to Universal Relaxation Law (URL) has been proposed and the characteristic frequency parameter fp used to describe dielectric response properties of oil immersed paper insulation has been extracted from FDS data. It shows that the proposed unscrambling method and the characteristic frequency parameter fp are effective in aging condition assessment of oil-paper insulation.
{"title":"Frequency domain characteristics and insulation condition evaluation of power transformer oil-paper insulation","authors":"Ming-jie Tang, Min Lei, Hao Xu, Y. Lu, Xu Wei, Peng Wu, Guanjun Zhang","doi":"10.1109/ICHVE.2012.6357145","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357145","url":null,"abstract":"Based on the platform designed for thermal aging test of oil-paper insulation system, the problem of thermal aging of solid insulation used in the oil-paper insulation of power equipment has been studied. The method of Frequency Domain Spectrum (FDS) has been applied to obtain frequency domain dielectric response properties of oil immersed paper insulation, and an unscrambling method according to Universal Relaxation Law (URL) has been proposed and the characteristic frequency parameter fp used to describe dielectric response properties of oil immersed paper insulation has been extracted from FDS data. It shows that the proposed unscrambling method and the characteristic frequency parameter fp are effective in aging condition assessment of oil-paper insulation.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"299 1","pages":"443-446"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74180145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357079
G. Haddad, R. Gupta, K. Wong
Polymeric insulators are widely used in electrical power system in particular transmission and distribution lines. Silicon rubber is a high performance polymeric material with superior insulation property and physical properties such as light weight. This paper presents the effects of ultra violet radiation and heat on the aging of silicon rubber and estimates the lifetime of insulators made of this material based on chemical bounds percentage at different exposure times. Experimental works were performed on samples collected from a 22KV silicone rubber insulator. The specimens were subjected to accelerated aging cycles using an Accelerated Weathering Tester (QUV) at 50°C and UVA exposure of 340nm at the irradiation intensity of 0.68W/m2 for up to 3000 hours. A series of tests were conducted on the samples using instruments that measure different aspects of aging. The degradation was examined using a Scanning Electron Microscope (SEM) and a Fourier Transforms Infrared Spectroscopy (ATR-FTIR). In addition, the color change of the specimens was measured by CHROMA Meter (CR-300). In this paper, we show that the remaining service life of the insulators can be estimated using the chemical measurements and color factors by making comparisons between new, aged and totally damaged specimens. The 3D scatterplot for the obtained data show a clear trend and timeline on how a new specimen degrades over time and eventually leads to complete failure. This information provided by the 3D scatterplot could be used to estimate the remaining life of silicone rubber insulators.
聚合物绝缘子广泛应用于电力系统，特别是输配电线路中。硅橡胶是一种高性能高分子材料，具有优异的绝缘性能和重量轻等物理性能。本文介绍了紫外线辐射和热对硅橡胶老化的影响，并根据不同暴露时间下硅橡胶绝缘子的化学界百分比估算了其寿命。对22KV硅橡胶绝缘子的样品进行了实验研究。采用加速老化仪(QUV)，在50°C、340nm UVA照射强度为0.68W/m2、持续3000小时的条件下进行加速老化试验。使用仪器对样品进行了一系列测试，以测量老化的不同方面。利用扫描电子显微镜(SEM)和傅里叶变换红外光谱(ATR-FTIR)对降解进行了研究。并用CHROMA Meter (CR-300)测定样品的颜色变化。在本文中，我们表明，通过比较新的，老化的和完全损坏的样品，可以使用化学测量和颜色因子来估计绝缘子的剩余使用寿命。所获得数据的3D散点图显示了一个清晰的趋势和时间线，关于一个新的试样如何随着时间的推移而退化，最终导致完全失效。三维散点图提供的信息可用于估计硅橡胶绝缘子的剩余寿命。
{"title":"Study of surface degradation of HTV silicone rubber under thermal and ultraviolet exposures","authors":"G. Haddad, R. Gupta, K. Wong","doi":"10.1109/ICHVE.2012.6357079","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357079","url":null,"abstract":"Polymeric insulators are widely used in electrical power system in particular transmission and distribution lines. Silicon rubber is a high performance polymeric material with superior insulation property and physical properties such as light weight. This paper presents the effects of ultra violet radiation and heat on the aging of silicon rubber and estimates the lifetime of insulators made of this material based on chemical bounds percentage at different exposure times. Experimental works were performed on samples collected from a 22KV silicone rubber insulator. The specimens were subjected to accelerated aging cycles using an Accelerated Weathering Tester (QUV) at 50°C and UVA exposure of 340nm at the irradiation intensity of 0.68W/m2 for up to 3000 hours. A series of tests were conducted on the samples using instruments that measure different aspects of aging. The degradation was examined using a Scanning Electron Microscope (SEM) and a Fourier Transforms Infrared Spectroscopy (ATR-FTIR). In addition, the color change of the specimens was measured by CHROMA Meter (CR-300). In this paper, we show that the remaining service life of the insulators can be estimated using the chemical measurements and color factors by making comparisons between new, aged and totally damaged specimens. The 3D scatterplot for the obtained data show a clear trend and timeline on how a new specimen degrades over time and eventually leads to complete failure. This information provided by the 3D scatterplot could be used to estimate the remaining life of silicone rubber insulators.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"267 1","pages":"241-245"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76316817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357154
G. Chen, Junwei Zhao
A new model based on space charge dynamics under very high dc electric field has been proposed to explain thickness dependent dielectric breakdown. Space charge phenomenon under high electric field has been studied for several decades thanks to the development of new charge mapping techniques. Overwhelming evidences show that the charge packet can be formed in the material under high electric field. The formation and dynamics of the charge packet will result in local electric field enhancement that has a direct impact on breakdown. It has been found that the key factors leading to the formation of charge packet are negative differential mobility and low trapping coefficient. Take these factors into the space charge based model, our simulation results clearly show that the breakdown is dependent on the sample thickness. Through the simulation, it has been noticed that the electrical breakdown field reduction depends on several parameters such as the onset of critical electric field when breakdown occurs. By varying the ramp rate of dc applied voltage, simulation has also shown that the breakdown strength increases with the voltage ramp rate.
{"title":"Space charge and thickness dependent dc electrical breakdown of solid dielectrics","authors":"G. Chen, Junwei Zhao","doi":"10.1109/ICHVE.2012.6357154","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357154","url":null,"abstract":"A new model based on space charge dynamics under very high dc electric field has been proposed to explain thickness dependent dielectric breakdown. Space charge phenomenon under high electric field has been studied for several decades thanks to the development of new charge mapping techniques. Overwhelming evidences show that the charge packet can be formed in the material under high electric field. The formation and dynamics of the charge packet will result in local electric field enhancement that has a direct impact on breakdown. It has been found that the key factors leading to the formation of charge packet are negative differential mobility and low trapping coefficient. Take these factors into the space charge based model, our simulation results clearly show that the breakdown is dependent on the sample thickness. Through the simulation, it has been noticed that the electrical breakdown field reduction depends on several parameters such as the onset of critical electric field when breakdown occurs. By varying the ramp rate of dc applied voltage, simulation has also shown that the breakdown strength increases with the voltage ramp rate.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"120 1","pages":"12-15"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78173239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357097
D. A. K. Pham, T. M. T. Pham, V. Ho, H. Borsi, E. Gockenbach
The lumped transformer equivalent circuit has been recently adapted based on duality principle and verified for the purposes of transient analysis with reasonable accuracy and frequency response analysis. However such circuit is developed and validated for balanced and unbalanced three-phase excitation. On the other hand, several diagnostic tests such as Frequency Response Analysis (FRA), ratio, short-circuit impedance measurements etc. are performed only under single-phase excitation in open- and short-circuit conditions. Therefore, there is a requirement to develop an equivalent circuit for power transformers under single-phase excitation to analyse relevant tests, which has not been completely investigated until now. The required equivalent circuit should in general include all windings of three phases as suggested by several recent publications since the influence from other non-tested windings to the tested phase winding was confirmed. The paper's main contribution is to introduce a duality-principle-based lumped equivalent circuit for a three-phase two-winding transformer under single-phase excitation at low frequencies for the purpose of impedance and frequency response analyses. More importantly, a method for determining internal, i.e. per-phase, parameters of the circuit based on impedance tests is also proposed. Results show that, thanks to frequency-dependent functions of the parameters and their connection in the circuit, inter-phase effect and quantitative interpretation of several first parallel- and series resonances in frequency response of winding impedances in transformer bulk are now possible. Furthermore, these physical parameters can be useful as input for machine-learning algorithms to diagnose transformer failures.
{"title":"Duality-based lumped transformer equivalent circuit at low frequencies under single-phase excitation","authors":"D. A. K. Pham, T. M. T. Pham, V. Ho, H. Borsi, E. Gockenbach","doi":"10.1109/ICHVE.2012.6357097","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357097","url":null,"abstract":"The lumped transformer equivalent circuit has been recently adapted based on duality principle and verified for the purposes of transient analysis with reasonable accuracy and frequency response analysis. However such circuit is developed and validated for balanced and unbalanced three-phase excitation. On the other hand, several diagnostic tests such as Frequency Response Analysis (FRA), ratio, short-circuit impedance measurements etc. are performed only under single-phase excitation in open- and short-circuit conditions. Therefore, there is a requirement to develop an equivalent circuit for power transformers under single-phase excitation to analyse relevant tests, which has not been completely investigated until now. The required equivalent circuit should in general include all windings of three phases as suggested by several recent publications since the influence from other non-tested windings to the tested phase winding was confirmed. The paper's main contribution is to introduce a duality-principle-based lumped equivalent circuit for a three-phase two-winding transformer under single-phase excitation at low frequencies for the purpose of impedance and frequency response analyses. More importantly, a method for determining internal, i.e. per-phase, parameters of the circuit based on impedance tests is also proposed. Results show that, thanks to frequency-dependent functions of the parameters and their connection in the circuit, inter-phase effect and quantitative interpretation of several first parallel- and series resonances in frequency response of winding impedances in transformer bulk are now possible. Furthermore, these physical parameters can be useful as input for machine-learning algorithms to diagnose transformer failures.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"1 1","pages":"600-603"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82342231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357135
Chao Guo, R. Liao, Lijun Yang, Ke Wang, Chaoliang Qi
The accelerated thermal aging test with controlled air was performed at 170°C for 216 hours, using the oil-paper insulation samples which were composed of BIOTEMP oil, NOMEX paper and pressboard. Some aging indicators including degree of polymerization of pressboard, dielectric strength of oil, acid value of oil, furfural concentration of oil, and water content, etc, were measured and recorded during the aging process. The variation of the parameters against the aging time, the correlation among these parameters and reasons for them are analyzed systematically. The results show that: with the increase of aging time, the breakdown voltage of oil decreases gradually, the acid value of oil increases, the moisture content of oil and paper first increase and then decrease but the moisture content of pressboard fluctuates; the logarithm of the furfural has a good linear relationship with the DP.
{"title":"Thermal aging properties of BIOTEMP oil with controlled air","authors":"Chao Guo, R. Liao, Lijun Yang, Ke Wang, Chaoliang Qi","doi":"10.1109/ICHVE.2012.6357135","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357135","url":null,"abstract":"The accelerated thermal aging test with controlled air was performed at 170°C for 216 hours, using the oil-paper insulation samples which were composed of BIOTEMP oil, NOMEX paper and pressboard. Some aging indicators including degree of polymerization of pressboard, dielectric strength of oil, acid value of oil, furfural concentration of oil, and water content, etc, were measured and recorded during the aging process. The variation of the parameters against the aging time, the correlation among these parameters and reasons for them are analyzed systematically. The results show that: with the increase of aging time, the breakdown voltage of oil decreases gradually, the acid value of oil increases, the moisture content of oil and paper first increase and then decrease but the moisture content of pressboard fluctuates; the logarithm of the furfural has a good linear relationship with the DP.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"25 1","pages":"405-409"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79123060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357044
S. Balaji, L. Lavanya, S. Usa
Oil impregnated cellulose paper (OIP) constitute major insulation of transformer windings. The cellulose insulation determines the lifespan of a transformer. Many of the transformer failures are mainly due to frequent application of over-voltages. It is necessary to analyze the degradation of OIP with respect to time interval between the impulse overvoltages. Cellulose degradation is usually characterized in terms of scission fraction which is given by degree of polymerization (DP). In this paper, an attempt has been made to analyze the degradation of OIP for different impulse voltages and time interval between the successive impulse voltages. Detailed experimental analyses are carried out for impulse overvoltages of 1.2/50μs, 0.4/50μs and 0.064/50μs by maintaining the time interval of 1 second, 3 seconds and 5 seconds between the successive impulses.
{"title":"Effect of repeated impulses on OIP","authors":"S. Balaji, L. Lavanya, S. Usa","doi":"10.1109/ICHVE.2012.6357044","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357044","url":null,"abstract":"Oil impregnated cellulose paper (OIP) constitute major insulation of transformer windings. The cellulose insulation determines the lifespan of a transformer. Many of the transformer failures are mainly due to frequent application of over-voltages. It is necessary to analyze the degradation of OIP with respect to time interval between the impulse overvoltages. Cellulose degradation is usually characterized in terms of scission fraction which is given by degree of polymerization (DP). In this paper, an attempt has been made to analyze the degradation of OIP for different impulse voltages and time interval between the successive impulse voltages. Detailed experimental analyses are carried out for impulse overvoltages of 1.2/50μs, 0.4/50μs and 0.064/50μs by maintaining the time interval of 1 second, 3 seconds and 5 seconds between the successive impulses.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"1 1","pages":"558-561"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77336457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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