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

{"title":"Dielectric liquids for subsea high voltage equipment","authors":"S. Singha, T. Laneryd, T. Gradinger, H. Lendenmann","doi":"10.1109/ICDL.2017.8124737","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124737","url":null,"abstract":"Pressure compensated high voltage power devices filled with a dielectric liquid are being developed for supplying electrical power to subsea factories extracting oil and gas from deep sea reservoirs. The dielectric breakdown behavior of a liquid improves at high pressure so the thermal properties will determine the reliability of the power device and the size of the pressure compensated enclosure. The selection of a suitable dielectric liquid is therefore critical. In this article, the appropriate Figures of Merit are established to compare the thermal performance of dielectric liquids for subsea use. Four different commercially available dielectric liquids (a natural ester, a synthetic ester, a mineral transformer oil, and an isoparaffinic liquid) are evaluated using a thermal network model representing natural convection circulation in an electrical power device at 300 bar. The isoparaffinic liquid performs best, closely followed by mineral oil.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"114 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":"132211478","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":"Breakdown properties of mineral oil-based nanofluids","authors":"F. Negri, A. Cavallini, Luca Marsigli","doi":"10.1109/ICDL.2017.8124602","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124602","url":null,"abstract":"A previous paper proved that conductive nanoparticles-based nanofluids have a better performance than the host mineral oil, but the obtained results still left doubts about their origin and if they are really statistically significant. In this work, we analyzed the impulse breakdown strength of different concentration nanofluids, and the effect moisture has on sinusoidal AC breakdown tests. The results highlight a concentration dependent behavior of the breakdown measurements, and a stronger resistance of nanofluids against moisture contamination.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"52 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":"129379656","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":"A comparison of oil-impregnated pressboard electrical conductivity behavior for two different high density pressboards","authors":"F. Vahidi, S. Haegele, S. Tenbohlen","doi":"10.1109/ICDL.2017.8124661","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124661","url":null,"abstract":"Estimation of material parameters is an essential step during design of high voltage direct current (HVDC) insulation systems. The key role of insulation coordination in power transformers is to provide the required insulation among different voltage classes to prevent undesirable phenomena like breakdown. The design of feasible insulation for transformer requires understanding field distributions in insulating materials. HVDC equipment is normally stressed with AC, DC and superimposed stresses during its operation time. As a result, deep knowledge of permittivity and conductivity of the insulation materials is necessary for construction of reliable insulation systems. In this investigation, conductivity of two oil-impregnated high density pressboard plates with a thickness of 2 mm from different manufacturers is compared. During the polarization and depolarization currents measurement, the oil-impregnated pressboard samples are located in a cylindrical cell with plate electrodes, which is filled with oil. The preparation of the pressboard plates is a very sensitive step during these measurements, because small amounts of impurities and imperfect impregnated samples cause a significant difference on the measurement results. Hence, the preparation of the samples is precisely described in different steps to insure the same treatment of the pressboard samples. Moreover, the electrical conductivity of two groups of high density pressboards is investigated depending on field strength, temperature and moisture content of the specimens. For this purpose, a step voltage is applied to the pressboard sample and the polarization current is measured over 10,000 s. Furthermore, the behavior of board conductivity is studied at three different field strengths, 0.5, 1 and 3 kV/mm, at 30 °C. Finally, a comparison takes the influence of temperature on electrical conductivity into account. In addition, the measurement results of the relative permittivity for oil-impregnated pressboard are presented depending on the moisture content of the samples.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"1 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":"129396685","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":"Oil-paper insulation characteristic and maintenance measures of oil-immersed transformer in cold environment","authors":"Jiantao Sun, Shuqi Zhang, Zhengyu Xu, Chao Wu, Xinru Yu, Y. Qiu, Z. Gao","doi":"10.1109/ICDL.2017.8124667","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124667","url":null,"abstract":"This paper highlights the operating performance of oil-immersed transformer in extreme cold environment along with the researches on the moisture variations in oil-paper insulation system and its effects on transformer caused by ambient temperature. As one of the main factors that affect the electric strength of oil-paper insulation, the effects of moisture on electric strength for oil and oil immersed paperboard are experimental studied, as well as the researches of moisture transfer rule between oil and paperboard caused by the variation in temperature. The experimental results showed that along with the decreasing of operating temperature, the electric strength of oil-paper insulation reduces first and then increase, with an extreme value occurs at the temperature between −10 °C and −0 °C and so as to the low temperature breakdown characteristics or partial discharge (PD) inception voltage characteristics is generally changing as a U-shaped curve. Moreover, the water solubility in transformer oil decreases and the precipitated water unevenly distributed in transformer oil which lead to the dispensability of insulation strength. After the investigating on the problem may appear while transformer operating in an extreme cold environment, maintenance measures are proposed aim to method of cold start, and avoiding oil spills, oil plug, stop of moving components at low temperature.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"38 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":"133432073","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":"Creeping discharge at vegetable-based oil/pressboard interface under rectangular impulse voltage","authors":"T. Nishikawa, R. Hanaoka, K. Miyagi, K. Takamoto, Seiichi Nishikawa","doi":"10.1109/ICDL.2017.8124668","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124668","url":null,"abstract":"The behavior of creeping streamer propagating the pressboard surface in vegetable-based oils; PFAE (palm fatty acid ester) oil and CRS (crude rapeseed) oil was studied under the applied rectangular-impulse voltage. The discharge shape, streamer length, discharge current and discharge light have been measured as a function of the voltage and its pulse width. These characteristics are compared with those in mineral oil.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"88 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":"124169448","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":"Electroconvective cavity flow patterns created by a cylinder-plane configuration","authors":"C. Louste, H. Romat, P. Traoré, P. Vázquez, M. Daaboul","doi":"10.1109/ICDL.2017.8124595","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124595","url":null,"abstract":"The presented work is an experimental study on electroconvective cavity flow patterns produced by a cylinder-plane electrode geometry. Flows are recorded by the use of the well-known Particle Image Velocimetry technique. The main objective of this work is to develop flow control methods in order to enhance heat transfer and mixing efficiency in fluidic and microfluidic systems. In this study, the electrohydrodynamic flow motion is obtained by applying a DC voltage to a set of electrodes immersed in a working liquid. It is shown that the produced velocity fields strongly depend on the applied voltage and a reverse flow is obtained when the polarity is inverted. An analysis of the velocity field is then realized in order to highlight the electric force map.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"33 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":"124549226","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 DC conductivity of alternative insulating oils as an application for HVDC converter transformers","authors":"Patrick Rumpelt, F. Jenau","doi":"10.1109/ICDL.2017.8124607","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124607","url":null,"abstract":"The application of alternative insulating oils in HVDC converter transformers is new and is still at the beginning of the realization. Alternative insulating liquids such as Midel7131 and FR3 promise the use of environmentally friendly and resource-saving insulation systems. In order to be able to use these ester-based insulating liquids in HVDC equipment, it is necessary to characterize the DC conductivity among others. For this purpose, the investigations deal with the statistical evaluation of the leakage currents at different polarities. The temperature dependence of the insulating liquids is also considered in detail and conductivity minima are shown. In addition, deviations between end values are displayed after different times. The modelling and simulation of the results shows a possibility of predicting the newly gained insights.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"220 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":"116446266","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 insulation performance evaluation of PVF wire under thermal and electrical accelerated aging","authors":"Tomoki Uchimura, Tomohiro Kubo, M. Kozako, M. Hikita, Kosuke Shimomura, S. Kawakami, Takeshi Tanaka","doi":"10.1109/ICDL.2017.8124729","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124729","url":null,"abstract":"It is crucial to understand degradation factors under actual operation in the lifetime evaluation of the coil winding of transformer. Polyvinyl formal (PVF) wire is used in oil-immersed transformer. Main degradation factor is considered to be oxidation and damage of the insulation coating due to thermal stress and partial discharge (PD). This paper deals with electrical insulation performance evaluation of twisted-pair specimen with PVF wire after thermal and electrical stress in the insulating oil. This research also deals with evaluation of a relation between the thermal stress and PD inception voltage (PDIV). Furthermore, Voltage-time (V-t) characteristics of twisted-pair specimen is investigated.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"42 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":"123411416","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 paper properties on streamers creeping in mineral oil","authors":"D. Ariza, M. Becerra, R. Methling, S. Gortschakow, R. Hollertz, L. Wågberg","doi":"10.1109/ICDL.2017.8124659","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124659","url":null,"abstract":"This work presents an experimental study of second mode positive streamers propagating along mineral oilpaper interfaces. A point-plane arrangement immersed in mineral oil with the paper inclined 60 degrees to the plane electrode is used to create the liquid-solid interface. Kraft paper and a kraft fibril paper, made from cellulosic micro and nano fibrils, with higher density and lower surface roughness are used as the solid materials. High speed shadowgraphy and charge recordings are used to compare the propagation of second mode positive streamers along the mineral oil-kraft paper and mineral oil-kraft fibril paper. Streamers creeping along the mineral oil-kraft paper interface propagate mainly into the liquid, with one or two main filaments. In comparison, the streamers propagating along the kraft fibril paper show a strong reduction of the branching; these streamers consist of a single filament that propagates exactly on the solid surface. Streamers along the kraft fibril paper also have longer propagation time than for the case with kraft paper. Mutual electrostatic shielding between filaments is observed for the streamers creeping on the kraft paper. An electrostatic analysis of the influence of permittivity, density and surface roughness of the solid in the electrical properties of the streamer filaments is also performed.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"28 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":"117159852","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":"Ultrasonic detection coherence of fiber Bragg grating for partial discharge in transformers","authors":"Cheng Shi, G. Ma, N. Mao, Qiang Zhang, Qing Zheng, Chengrong Li, Shu-jing Zhao","doi":"10.1109/ICDL.2017.8124639","DOIUrl":"https://doi.org/10.1109/ICDL.2017.8124639","url":null,"abstract":"As a traditional approach of partial discharge (PD) in power transformers, ultrasonic detection with piezoelectric transducers (PZT) has drawbacks of low sensitivity and low detection efficiency. In order to overcome these disadvantages, an ultrasonic detection system based on fiber Bragg grating (FBG) is developed for PD in power transformers. Take the advantage of good insulation ability and immunity to electromagnetic interference, the optical sensor can be put into the transformers and detect the weak PD signal directly. In this paper, ultrasonic detection theory of FBG was analyzed, and PD detection experiments in transformer oil were carried out to test the performance of this FBG ultrasonic detection system. Furthermore, in order to demonstrate the coherence and distributed measuring ability, PD detection experiments based on multi-point FBG string with different center wavelength were conducted. Study results show the performance of FBG ultrasonic detection system is better than traditional PZT sensor, and satisfactory detection coherence of FBG with different center wavelength is proved. Moreover, distributed ultrasonic measuring of PD in power transformers can be realized by multi-point FBG string with application of wavelength-division and time-division multiplexing technology.","PeriodicalId":439228,"journal":{"name":"2017 IEEE 19th International Conference on Dielectric Liquids (ICDL)","volume":"52 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":"125918413","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}