2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)最新文献

{"title":"Bulk-phase chemistry induced by nanosecond discharge plasma in water","authors":"P. Lukeš, M. Člupek, V. Babický, B. Pongrác, M. Šimek","doi":"10.1109/ICDL.2017.8124702","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124702","url":null,"abstract":"We have evaluated chemical activity of the nanosecond discharge in bulk liquid water by measuring the plasmachemical production of hydrogen peroxide and oxidation of phenol used as chemical probe of OH radicals. Nanosecond pulse generator was used as a source of high voltage pulses (6 ns FWHM) with adjustable amplitude of the positive polarity (60–110 kV) and pulse energy 50–150 mJ/pulse. Obtained results gave clear evidence about the plasmachemical production of OH radicals by nanosecond discharge in water.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115901874","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":"Electrical properties of PPLP insulation impregnated with DDB oil","authors":"Z. Xu, G. Chen, M. Praeger, P. Lewin","doi":"10.1109/ICDL.2017.8124665","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124665","url":null,"abstract":"To understand the electrical properties of PPLP (polypropylene laminated paper) insulation within MI cable, low PP ratio, planar geometry, PPLP samples were made in the laboratory, impregnated with DDB oil (Dodecyl benzene) and characterised by PEA (pulsed electro acoustic) analysis. In this study we compare the electrical performance of samples impregnated with different types of DDB oil. Three factors were identified as being key in determining the electrical properties of PPLP, these are: the water content, the viscosity of the impregnating oil and the operating temperature.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125103811","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":"Analysis of the charge-nanoparticle interaction in nanofluids","authors":"F. Negri, A. Cavallini, Luca Marsigli","doi":"10.1109/ICDL.2017.8124610","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124610","url":null,"abstract":"Recent papers have shown controversial aspects regarding nanofluids conduction properties. Therefore, in this work, we have analyzed these apparent incongruencies proposing a simple field model and invoking the possibility charge carriers may be directly transferred from one nanoparticle to the following one when the distances are small enough. The results of the model show that the postulated conduction mechanisms may explain the measured conductivities.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127115419","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":"Measurements of mobility in aged mineral oil in the presence of nanoparticles","authors":"Guan-He Chen, M. Given, I. Timoshkin, Mark P. Wilson, S. Macgregor","doi":"10.1109/ICDL.2017.8124645","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124645","url":null,"abstract":"The addition of nanoparticles into insulating liquids has been a popular area of research for the last 20 years as improvements have been observed in the breakdown strength of aged insulating liquids. This paper reports on the changes in the conductivity and the mobility of charge carriers in oil as a result of ageing and how these are effected by the addition of nanoparticles to the aged insulation.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125249662","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":"Effect of water depth on propagation characteristics of surface discharge on water generated by pulsed power","authors":"Shotaro Yamashita, T. Furusato, H. Koreeda, T. Fujishima, T. Yamashita","doi":"10.1109/ICDL.2017.8124701","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124701","url":null,"abstract":"The effect of water depth on surface discharge propagation characteristics was investigated by varying applied voltage. Maximum length of discharge propagation was proportional to the applied voltage, but the length tended to relatively small under small water depth. In addition, the discharge propagation was discussed from the aspect of the resistance evaluation of water solution. The voltage drop at water solution was calculated from subtracting an electrode fall voltage from the measured voltage. The resistance variation was calculated by dividing the voltage drop at water by current. The resistance value on the maximum discharge length was extremely small under water depth of 2 mm irrespective of its small discharge length. The reason was presumed to be caused by a lot of branching under small water depth.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123097958","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":"Influence of temperature variation of oil contamination on electrical performance of power transformer","authors":"S. Saaidon, George Chen, I. Golosnoy","doi":"10.1109/ICDL.2017.8124616","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124616","url":null,"abstract":"This paper describes an experimental study of the influence of temperature variation associated with a transformer oil impurity on the electrical performance of HVDC power transformer under a DC field stress. Spherical-spherical electrodes configuration system has been setup to investigate the bridging formation across a 10mm gap distance at 15kV. Cellulosic fiber dust were dispersed into transformer mineral oil with 0.004% weight concentration level. The temperature electromagnetic agitator was used to heat up the contaminated samples to predetermined temperature. Images obtained from a digital optical microscopy during experiments show that the bridge formation behavior changes with temperature variation. It is preceded with initiated on the electrode surfaces and leads to dense bridges across the gap. Electrical current measurements indicate that the current in contaminated oil increases with the temperature. It is also found that the activation energy to initiate the kinetic process for contaminated oil is 0.21ev.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"2007 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116902504","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":"Magnetite nanofluid as alternative for conventional insulating liquids","authors":"M. Imani, P. Werle, J. F. Miethe, N. Bigall","doi":"10.1109/ICDL.2017.8124604","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124604","url":null,"abstract":"This attempt aims at scrutinizing the merit and potential of magnetite modified mineral oil as an alternative for conventional mineral oil. In order to enhance the properties of base fluids, incorporation of nano-sized particles in the matrix of the oil would be an innovative approach. This work primarily focuses on fabrication of stable magnetite doped nano-fluids (NFs) in different concentrations. The morphology and stability of the prepared samples are studied using transmission electron microscopy (TEM) and dynamic light scattering (DLS) in a former study. The electrical and rheological characteristics of NFs are investigated regarding the impact of the degree of enrichment. The breakdown voltage has shown a significant improvement by suspending the magnetite nano-powder. Moreover, the partial discharge behavior of the developed fluids is characterized under divergent ac electric field, which uncovers a minor increase of partial discharge inception voltage with addition of iron-oxide nano-additive. In addition, no variation in dynamic viscosity of those colloids could be detected.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128304297","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":"Transformer insulation structure for dielectric liquids with higher permittivity","authors":"A. Sbravati, K. Rapp, P. Schmitt, C. Krause","doi":"10.1109/ICDL.2017.8124705","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124705","url":null,"abstract":"Insulation structures based on cellulosic materials and mineral oil have been the standard solution for transformers for the last hundred years, both in distribution and power transformers. These structures typically consist of a solid-liquid arrangement, aimed to divide larger voltage drops in smaller steps, creating small volumes of liquid with high dielectric insulating performance and reaching the most compact design. The total potential difference is borne by sequential voltage drops defined according to the geometry and the permittivity of the materials. Standard arrangements and configurations have been developed by transformer manufacturers according to the voltage levels, as the analytical solution of the distribution of the electrical field may be extremely complex. Even nowadays, where numerical calculation models, mostly based on the Finite Elements Method, are available, the use of standardized solutions is not uncommon, as the detailed calculation may be highly time consuming. When the dielectric liquid is changed, replacing the traditional mineral oil by natural ester liquid, the distribution of stress in the insulation system is no longer the same. The permittivity of natural ester liquid is around 40% higher than that of mineral oil, while the permittivity of pressboard and paper made from kraft pulp, impregnated with natural ester liquids is just slightly higher. The result is a different distribution of voltage drops in the insulation system, which must be taken into consideration when designing a natural ester filled transformer. At first glance, the effect is positive, since the critical parameter is typically the stress, the field strength, in the liquid insulation and the higher permittivity shifts the stress from the liquid into the solid insulation. This modification of electrical field distribution may allow, in some cases, increasing the average field strength and thus a more compact design, as there is a better balance between the stress in the solid and liquid portions. However, the modification of the electrical field distribution may lead also to new critical regions. Corners and labyrinth constructions may have higher superficial dielectric field gradients. Additional edge protection may be required in regions where they were not required with mineral oil, as the stress in the paper will be increased. Less specialized engineers tend to take the breakdown voltage as the only relevant parameter for the insulation design. A large quantity of test data has indicated that the breakdown voltage of natural ester liquid, excluding the undesirable highly divergent field (needle to sphere), is similar to mineral oil. But this does not mean that adjustments in the insulation system design would not be required. This paper will present some common configurations, potential optimizations and areas requiring attention for designing insulation systems using cellulose and natural ester liquids.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130611954","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":"Preparation and dielectric properties of natural ester based insulating nano-oil modified by fullerene filler","authors":"Wei Yao, Jian Li, Zhengyong Haung, Liya Wu, Nuodong Li","doi":"10.1109/ICDL.2017.8124723","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124723","url":null,"abstract":"This paper is aimed at the study of preparation and dielectric properties of fullerene (C60) nano-modified natural ester based vegetable insulating oil. With the increasing demand for environmentally friendly liquid dielectrics, natural ester has applied more and more widely. However, some defects like high dielectric loss factor and low volume resistivity. C60 nanoparticles attracted tremendous attention due to its free radical scavenging capacity and electronegativity. The research prepared C60 modified vegetable insulating oil successfully, and as a comparison C60 modified mineral insulating oil was also prepared. To analyzed the dielectric properties of modified vegetable insulating oil, it confiemed that the most suitable concentration of C60 is 100 mg/L. In this concentration, dielectric loss factor, volume resistivity, AC breakdown voltage and lightning impulse breakdown voltage would be enhanced simultaneously. Meanwhile, dielectric loss factor of mineral insulating oil would be decreased clearly at 50 mg/L C60 added, and AC breakdown voltage could be increased to highest-level at 200 mg/L. However the volume resistivity was deteriorated by add C60 of mineral insulating oil. The specific mechanism of these phenomenon is not clear, but vegetable insulating oil should more suitable modified by C60 nanoparticles.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123978515","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":"Comparison between synthetic ester and mineral oil impregnated transformer paper aging markers","authors":"K. Liland, D. Linhjell, C. Lesaint, M. Ese, L. Lundgaard, P. Mavrommatis, Nenad Stjepanović","doi":"10.1109/ICDL.2017.8124699","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124699","url":null,"abstract":"For transformers in service, aging markers from cellulose in oil such as furans, water, methanol and acids are measured for diagnostic purposes. The content of these indicators, measured in oil, may therefore vary with load, temperature, solid and liquid insulation aging, as well as marker stability and evaporative loss. Correction factors estimating the level of the aging marker to a reference temperature would make the diagnostic more relevant. In this study, correction factors for temperature differences have been estimated for different aging markers in insulation systems impregnated with either mineral oil or synthetic ester. In the case of mineral oil based systems, we observe correction factors for water, methanol and furans in line with previously reported findings. On the other hand, for the synthetic ester system, novel correction factors for water and methanol are suggested while for furans, no temperature dependence was observed.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121194425","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}