2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)最新文献

{"title":"Prediction of Breakdown Voltage Value in SF6-N2 Gases Mixture Under DC Voltage with the Influence of Conducting Particles by Analyzing Experimental Data using ANN","authors":"Hafiz Muhammad Azib Khan, Qingmin Li, Jian Wang, Jingrui Wang, Yanan Chang","doi":"10.1109/ICDL.2019.8796807","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796807","url":null,"abstract":"Sulphur hexafluoride (SF6) is the most commonly used dielectric gas in electrical systems, DC-GIL is considered as a new type of transmission lines has the potential to replace the overhead lines and cables in the future for use in DC distribution networks. It deserves great concern that abundant amount of SF6 use in the earth’s atmosphere because this gas is known to be a kind of “greenhouse gas”. Also, metal particles inevitably appearing in the pipeline of DC GIL which may do damage to GIL and cause a serious threat to its insulation safe and reliable operation. This paper aims to focus on experimental study on the difference in insulation strength of SF6 gas and the mixture of two gases (SF6 and N2) with and without using conducting particle under DC voltage in the ball-bowl electrode arrangement. Moreover, spherical conducting particle is selected to simulate metal particle defects in GIL and they are set to the floating position. Breakdown characteristics of SF6 gas and (SF6-N2) gas mixtures have been measured in non-uniform electric field when the SF6 gas mixture ratio (70%, 50%, 30% and 20%) and the pressure is between 0.1MPa and 0.5MPa under the positive and negative polarity of DC voltage. The experiment results show that DC negative polarity is more severe as compared with positive polarity. In addition, it is found that there is no significant increase in breakdown voltage when the pressure is more than 0.3MPa in the presence of particle but the growth trend is clear without particle. The equivalencies between the breakdown voltage of SF6 and SF6-N2 gas mixtures were analyzed with and without the presence of conducting spherical particle and tried to predict the improved breakdown voltage SF6-N2 gases mixture using Artificial Neural Network technique.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116124969","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}

{"title":"Investigation on Gassing Behavior of Various Insulation Liquids in Power Transformers","authors":"K. Homeier, M. Imani, M. Kuhnke, T. Kinkeldey, Peter Werl","doi":"10.1109/ICDL.2019.8796796","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796796","url":null,"abstract":"Under normal operating conditions hermetically sealed power transformers undergo load cycles resulting in pressure and temperature variation. With decreasing pressure, the dissolved gases diffuse out of the insulation liquid and accumulate in gas phase. This gas leakage may be diagnosed as a fault in transformer by monitoring systems. However, it should be differentiated from a fault decomposing the insulation material. It is known that the conventional insulating liquid exhibit to some extent a different degassing behavior in comparison to the new alternatives. In addition to the erroneous fault indication, the gassing properties as well as the solubility of gasses influence the accuracy of the dissolved gas analysis. By determining the concentration of key gases and specific ratios among them, the type of fault can be classified. The gassing behavior of various liquids depends on many factors, such as pressure, temperature and of course the type of the insulation liquid. Therefore, the specification of the gassing and degassing behavior of new alternative insulating fluids is of critical importance.In this study, two different test vessels were built to determine the different gassing characteristics under laboratory conditions. On the one hand a simple arrangement with glass vessels was constructed to represent a kind of gas trap and on the other hand a scaled model of the transformer tank with a long diffusion way and a small contact to the gas phase above the liquid. The tests were performed at different pressure and temperature values by using a vacuum oven. To analyze the influence of these parameters on the gassing behavior, the pressure was kept at three different values: 800 mbar, 900 mbar and 950 mbar. Furthermore, the measurements were performed at various temperatures namely, $40^{circ}C$ and $80^{circ}C$. A synthetic ester, an uninhibited mineral oil and a gas-to-liquid (GtL) oil were investigated. Before and after each test a dissolved gas analysis was performed. Moreover, the time, in which gas bubbles appeared, were registered","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117309467","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}

{"title":"Discharge Characteristics with Impulse Voltage Application in Ester Oil/Pressboard Composite","authors":"Taichi Yamada, Y. Nakano, M. Kozako, M. Hikita, S. Yoshida, S. Kainaga, M. Yoshimura, Kenichi Suga","doi":"10.1109/ICDL.2019.8796623","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796623","url":null,"abstract":"Partial discharge characteristics as well as breakdown phenomena in a power transformer insulation, i.e. oil and paper insulation, has to be clarified for miniaturization of the apparatus. In recent years, environmental-friendly transformers using ester oil, which shows excellent biodegradability, receive much attention due to the worldwide growing environmental awareness. Considering this, researches on fundamental characteristics of discharge phenomena within the ester oil are required. Although various papers on discharge characteristics in the ester oil have been published by many researchers, there are still few reports on these researches using ester oil and pressboard (PB) composite insulation system. In this paper, the discharge inception field and starting point in the ester oil and PB composite insulation configuration are investigated and the results are compared with those in the mineral oil to discuss the detailed discharge mechanisms.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"22 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120895074","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}

{"title":"Comparative Study of Furfural’s Raman Spectroscopy Detection in oil based on two kinds of Extractants","authors":"Weiran Zhou, Weigen Chen, Fu Wan, Haiyang Shi, Shuhua Zhang, Jiayi Zhang, Chengzhi Zhu","doi":"10.1109/ICDL.2019.8796789","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796789","url":null,"abstract":"How to accurately detect the concentration of furfural in transformer oil plays an important role in the analysis of the aging state of the transformer. As a fast and non-destructive detection method, Raman spectroscopy is the key to improving the sensitivity of Raman detection. In this paper, based on the extraction technique, the deionized water and methanol are used as extractants to carry out the comparative experiment of furfural Raman spectroscopy in oil. Firstly, the deionized water and methanol extract of furfural in oil are prepared and obtained. The Raman characteristic peaks of furfural are 1372 cm-1 and 1411 cm-1 and 1675 cm-1 by Raman detection, and qualitative analysis is discussed. The experimental results show that deionized water as an extractant has certain feasibility for Raman detection, and it has the lower limit of detection for Raman detection compared with methanol as extractant, which makes a certain contribution in order to improve the sensitivity of furfural Raman detection in transformer oil.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134031720","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}

{"title":"Study on Bubble Formation of Different Moisture Content Oil-immersed Cardboards in Natural Ester Oil","authors":"Nijie Chao, Tao Zhao, Minglin Fan, Yunpeng Liu","doi":"10.1109/ICDL.2019.8796614","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796614","url":null,"abstract":"Oil immersed transformers are widely applied in electric power systems. In view of the excellent insulation performance and environmental friendliness of plant dielectric oil, it has been gradually applied to power transformers in recent years. In oil-impregnated transformers, the paper insulation between turns in the winding often endures high temperature. As the rapid increase of temperature of the insulation paper over the conductor, the moisture in paper can be vaporized. It turns out a rapid rise in vapour and gas pressure within the inner layers of the paper. Finally, water vapour escapes from the surface of insulation paper in the form of gaseous bubbles, which constitutes a risk for transformer operation, especially when bubbles move into an area with high dielectric stress.This study experimentally investigated the evolution of gaseous bubbles in a wet oil-paper insulation system with FR3. The difference in inception temperature and heating rate between plant insulation oil and mineral insulation oil is emphatically compared. The effects of surface tension of oil, gradient of temperature rise and moisture content of dielectric oil on the inception temperature are analyzed. Suggestions on the application and maintenance of plant insulation oil in power transformers are put forward.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115971864","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}

{"title":"Optical Spectroscopy Analysis of Ester Oils under Thermal Aging Conditions","authors":"Abdelrahman M. Alshehawy, D. Mansour, M. Ghali","doi":"10.1109/ICDL.2019.8796836","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796836","url":null,"abstract":"Ester oils have been proposed recently as alternative insulating liquids to mineral oils inside oil-filled power transformers. They are environmentally friendly, biodegradable and harmless to human body. During the operation of power transformers, the insulating oil is subjected to thermal and electrical stresses. Consequently, it is decomposed, and the aging by-products are generated. As a result, the properties of insulating oil are degraded. This study aims to investigate the impact of thermal degradation on ester oils during the operation of power transformer using UV-Vis optical spectroscopy technique. First, several aged ester oil samples were prepared using an accelerated aging experiment. In addition, aged mineral oil samples were prepared to compare the impact of aging on both. Then, these samples were tested using optical spectroscopy test. The obtained optical spectra have been investigated and the aging by-products could be evaluated. Furthermore, dissipation factor test was carried out on the aged samples to correlate between the thermal degradation and the dielectric properties. The obtained results have assured that ester oils have great potential to substitute mineral oils in the future.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133023467","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}

{"title":"Oxidation Stability of Insulating Liquids by Rapid Small Scale Oxidation Test","authors":"Ann Pamla Cruze, K. Lokesh, R. Siva Prakash","doi":"10.1109/ICDL.2019.8796702","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796702","url":null,"abstract":"Insulation materials are an important component of transformers; the life of the electrical equipment depends on the quality of solid and liquid insulating materials used. Mineral insulating oils, synthetic esters and natural esters are different types of liquid insulating materials. During prolonged service in electrical apparatus these oils undergo deterioration, mainly due to continuous oxidation. Hence, the long-term performance of insulating oils depends on the stability to oxidation. This behaviour is usually termed as resistance to the oxidation process or oxidation stability. Oxidation stability test as per test method IEC 61125 and ASTM D2112 are familiar methods to test the oils. According to IEC 61125 (Method C) the insulating oil, is conditioned at 120°C, with copper catalyst and by bubbling zero air over a duration of 48 hours for natural esters, 164 hours for uninhibited oils and synthetic esters, 500 hours for Inhibited oils. Rotating Pressure Vessel Oxidation Test method (RPVOT) as per ASTM D2112 requires copper catalyst and oxygen pressure of 620 kpa is allowed to oxidize the oil sample at 140°C. Zero air bubbling method assesses the oil based on measurement of dissipation factor, acidity and and sludge development for mineral oil and synthetic esters and dissipation factor, acidity and viscosity for natural esters. RPVOT method measures the induction period. Although the IEC 61125 is conventional, it is time consuming and the RPVOT curve for natural esters cannot be distinguished due to the poor stability characteristics of natural esters. This paper presents the results carried out to measure oxidation stability by using a new method named as Rapid Small Scale Oxidation Test (RSSOT) as per ASTM D7545, using petroxy equipment to measure the induction period. Oxidation stability test has been carried out on mineral insulating oils, synthetic esters and natural esters. The results are compared to assess the suitability of the rapid small scale method for evaluating the stability of insulation oils. It is found that the rapid small scale method is suitable to measure the oxidation stability and the results are comparable to the conventional methods. Further, natural ester and synthetic ester was analyzed both with copper catalyst and without catalyst. It was found that presence of copper catalyst accelerates the rate of oxidation of both synthetic ester and natural ester. RSSOT has the advantage of being a rapid method, simple and easy to use, and where only a small quantity of sample is needed, thereby reducing the risks to safety and waste sample disposal problems.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134275473","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}

{"title":"FTIR-Spectroscopic and Electrical Analysis of Thermally Stressed Liquid Dielectrics","authors":"G. M. Smith, A. S. Holmes-Smith, S. McMeekin","doi":"10.1109/ICDL.2019.8796742","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796742","url":null,"abstract":"Mineral oils are employed as liquid dielectric insulators in many high voltage transformers. It is recognised that the dielectric properties of these oils degrade over time with continued exposure to high voltages and thermal stress. This breakdown can be monitored using FTIR spectroscopy or electrical techniques. In this work the mineral oils have been thermally stressed by exposure to 120°C over a prolonged time period with changes to the electrical breakdown voltage and FTIR spectra measured at frequent intervals. Different samples of oil were prepared with some exposed to Kraft paper, copper or a combination of the two. The ratio of oil: copper: Kraft paper was consistent with that commonly found in transformers. Results show that the growth of the carboxylic acid peak can be correlated with a total acid number (TAN) through a calibration process which is less time consuming, won’t overestimate TAN and is an alternative to titration.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127342257","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}

{"title":"Pollution Degree Detection of Insulators based on Hyperspectral Imaging Technology","authors":"Changjie Xia, M. Ren, Siyun Wang, Bin Wang, Jiacheng Xie, Ran Duan","doi":"10.1109/ICDL.2019.8796617","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796617","url":null,"abstract":"Present researches prove that the pollution flashover of operating insulators still threatens the safe and reliable operation of power system. However, traditional detection methods are difficult to achieve noncontact detection. The hyperspectral imaging technology is a nondestructive testing technology which combines image information and spectral information, therefore it has potential to become an important detection method for power device external insulation. In order to study the application of hyperspectral imaging technology in the detection of insulator pollution degree, a new data processing method is produced. On the one hand, the result of spectral processing shows that there are corresponding relationships between the pollution degree and the reflectivity value, the reflectivity waveform and base material. On the other hand, the result of image processing proves that it can distinguish between the polluted and nonpolluted areas by using principal components analysis and K-means clustering algorithm. The above parts prove that the application of hyperspectral imaging technology in the detection of insulator’s external insulation is feasible and it will have a broad application prospect.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122073212","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}

{"title":"Research on Transformer Oil Multi-frequency Ultrasonic Monitoring Technology Based on Convolutional Neural Network","authors":"Yaohong Zhao, Yihua Qian, Li Li, Zhong Zheng, Qi Wang, Yuan Zhou","doi":"10.1109/ICDL.2019.8796733","DOIUrl":"https://doi.org/10.1109/ICDL.2019.8796733","url":null,"abstract":"Facing the deficit of the effective measures to evaluate the insulation status of power transformers in service, this paper brought up a new method to estimate the physical and chemical properties of transformer oil through its transmission characteristics for ultrasonic signals under various frequencies. However, given the large volume of acquired ultrasound spectrum data by such technology, and the complexity as well as the variety of the transformer structures and conditions in which the transformer oil resides in, the interpretation of above data and the prediction of transformer health becomes enigmatic. Thus a recognition method was brought up by this paper to connect the ultrasonic spectrum to transformer oil conditions through Convolutional Neural Network. First of all, for the transformer oil test data, by using the density-based clustering method, the “ standard oil” and other “degraded oils” approaching the standard are distinguished to achieve the purpose of distinguishing the quality of the transformer oil. Then, the principal component analysis is used to reduce the dimensionality of the ultrasonic spectrum data of the transformer oil. The dimensionality classification results of the reduced dimensional ultrasonic spectrum data and transformer oil test parameters are used as the input and output data of the algorithm model. The Convolutional Neural Network is established and the model parameters are trained. The final accuracy rate of the assessment model is 92%. Finally, a transformer oil condition detection method based on multi-frequency ultrasonic spectroscopy was established.","PeriodicalId":102217,"journal":{"name":"2019 IEEE 20th International Conference on Dielectric Liquids (ICDL)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121074891","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}