{"title":"Transformation of nitrogen SPS spectra emitted from streamer discharge head within a sub-nanosecond — Nanosecond range","authors":"Y. Shcherbakov, L. Nekhamkin","doi":"10.1109/CEIDP.2011.6232649","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232649","url":null,"abstract":"The paper presents some results on spectroscopic studies of the filamentary streamer discharge in short air gap in stage of primary streamer propagation. Basically, we have found that the mid-resolved (with spectral resolution around 0.2-0.3 nm) nitrogen second positive system (SPS) spectra emitted from the primary streamer head changes essentially in form within some nanoseconds. Namely, main peak near the band head formed by the P-branches of Pi3-to-Pi3 transition turns almost into a widened twin-peak hump, relative intensities of each sub-peaks change in time resulting finally in a quite usual one-peak form; with inessential modification of short-wave part of the SPS-band as whole formed mainly by the R-branches. In attempt to give an appropriate realistic interpretation of this phenomenon we have analyzed different possible instrumental factors as well as mechanisms applied in streamer theory and molecular spectroscopy, such as: 1) dynamic breaking of the spin-axis coupling of the Pi3-states resulting in an appearance of Pi3(a)-to-Pi3(b)- and Pi3(b)-to-Pi3(b)-transitions additionally to a standard Pi3(a)-to-Pi3(a)-transition; 2) modeling of luminosity emitted from the actual high-gradient too narrow streamer head propagating with very high speed; 3) fast eventual heating of neutral gas within streamer head; 4) possible non-even illumination of the monochromator entrance slit due to very strong gradient of all physical parameters within streamer head and finally as well as actual sub-nanosecond temporal resolution of the measuring system; 5) Zeeman and Stark-effects. Stark-effect and instrumental peculiarities are supposed to be most adequate reasons for the phenomenon, which after development of relevant detailed theory might be applicable to determine/estimate electric field and its spatial gradient, respectively","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"95 1","pages":"271-274"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86018793","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":"Combined effect of different fields on the motion characteristics of dust particles around the insulators","authors":"Jing Wang, Xidong Liang, Lin Chen, Yu Liu","doi":"10.1109/CEIDP.2011.6232673","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232673","url":null,"abstract":"Pollution flashover of the insulators threatens the safety and operation security of the power system severely. Contamination accumulation on the insulators is the precondition of the pollution flashover, while the contamination accumulation characteristics of the insulators depend on the motion characteristics of the dust particles moving around the insulators in service to a great degree. This paper researched the combined effect of the electric field, the air fluid field and the gravitational field on the dust particles' motion by means of experiments and numerical calculation. The distribution of the electric field and the electric potential around an actual insulator were calculated. The results indicate that the polarization force is very weak. Once the particles are charged, the electric field force acts and can drive the particles to move along the electric field lines. When there is a strong wind, the steady-state drag force is dominant and the particles move with the wind. These results can better explain the contamination accumulation characteristics of the insulators, and some measures are suggested to reduce the contamination accumulation.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"94 1","pages":"373-376"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77042444","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 of PD characteristics and degradation in PET insulation with vented and unvented voids","authors":"D. Adhikari, D. Hepburn, B. Stewart","doi":"10.1109/CEIDP.2011.6232690","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232690","url":null,"abstract":"Partial Discharge (PD) results from faults in power insulation systems and exacerbates failure. It is known that the presence of voids in solid and liquid insulation give rise to PD. Factors which control the PD activity include pressure and type of gas present. When PD occurs in insulation, pressure is created and gaseous products changed due to the energy input. A series of experiments is being carried out on artificial voids, created from layered sections of polymer. One set of samples has a void inside the polymer with no access to the outer atmosphere; a second set of samples is created with a vent connecting the void to the outer atmosphere. Both sample sets are stressed at the same electrical conditions for same period of time. Investigation of the physical and chemical differences and PD patterns recorded follows.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"99 1","pages":"444-447"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82599411","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":"Electronic conduction properties of TiO2 thin films under UV light irradiation","authors":"Y. Watanabe, Y. Muramoto, N. Shimizu","doi":"10.1109/CEIDP.2011.6232610","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232610","url":null,"abstract":"TiO2 has photocatalysis. When UV light is irradiated, electron-hole pairs are generated in TiO2. The source of photocatalysis is oxidation and reduction reactions at the surface due to electrons and holes. Therefore, it is considered that the photocatalytic activities are closely related to electronic properties of the TiO2 under UV light irradiation. In this paper, we obtained Hall voltage properties in anatase TiO2 thin films under UV light irradiation. Furthermore, we successfully separated two current components due to electrons and holes using a new technique. We obtained the following results; 1. The measured values and polarity of the Hall voltage were not stable compared with those of n-type silicon. 2. The current component of electrons was almost the same with that of holes. From these results, it is suggested that the values of electron mobility and hole mobility are close.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"65 1","pages":"117-120"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87210522","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}
Wei Wang, Yan Xue, Yangchun Cheng, Bing Zhou, Jianfeng Xu, Chengrong Li
{"title":"Diagnosis of severity degree for oil/pressboard insulation surface discharge","authors":"Wei Wang, Yan Xue, Yangchun Cheng, Bing Zhou, Jianfeng Xu, Chengrong Li","doi":"10.1109/CEIDP.2011.6232697","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232697","url":null,"abstract":"To research the diagnosis method based ultra high frequency (UHF) signal and dissolved gases analysis (DGA) in oil of severity degree for oil/pressboard insulation surface discharge, a surface discharge simulation and test equipment and measurement system have been set up in laboratory, which were consisted of surface discharge model, test tank, UHF sensor, gas-phase chromatographic instrument and partial discharge detector. Surface discharge growth from inception to breakdown has been simulated, test voltage was raised step by step, ultra high frequency signal and dissolved gases in oil have been measured in the growth. The results show that severity degree of surface discharge can be divided tree stages: inception stage, growth stage and critical stage according to statistics spectrum of the ultra high frequency signal; ultra high frequency signal and dissolved gases in oil both can indicate the oil/pressboard surface discharge severity degree, however, dissolved gases analysis method was not as sensitive as ultra high frequency method; C2H2/total hydrocarbon generated by oil/pressboard surface discharge was more than 10%; Surface discharge was in critical stage when C2H2/total hydrocarbon value more than 50% and raised rapidly.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"5 1","pages":"472-475"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87545989","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":"The comparison of sensitivity between the UHF and ultrasonic methods for partial discharge detecting in GIS","authors":"Bibo Geng, Chengrong Li, B. Qi, Le Yu, Jixin Gao","doi":"10.1109/CEIDP.2011.6232696","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232696","url":null,"abstract":"In order to compare the sensitivity between the UHF and ultrasonic methods for partial discharge detecting in GIS, a 252kV GIS experimental platform was established. Four typical defect models are taken into consideration, including metal particle stuck on the insulator surface; free metal particle on the insulator surface; ground electrode defect and poor contact of high voltage electrode. Through the PD inception voltage and the PRPD (phase resolved partial discharge) spectrogram of UHF and ultrasonic signals, the sensitivity and feature of UHF and ultrasonic methods could be compared. The results indicate that: 1) Compared to the ultrasonic method, the UHF method could detect all four defects mentioned above with high sensitivity. 2) The ultrasonic method could only detect some models with high sensitivity.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"10 1","pages":"468-471"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87556167","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":"Distribution class transformer insulation evaluation under distorted voltage waveforms","authors":"O. M. Hamid, S. Jayaram","doi":"10.1109/CEIDP.2011.6232652","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232652","url":null,"abstract":"The smart grid with state of the art technology is expected to facilitate ease of dispersed generators (DGs) connected to the distribution network. However, the fast switching power converter based interface of dispersed DGs to the distribution network is a potential source of harmonic injection; hence a considerable distortion in the voltage waveforms. With increased DG penetration, such harmonics may become a potential source of high frequency; high dv/dt stresses on the insulation system of vital power system. Additional stresses implies faster degradation rate of insulation system. Understanding such harmonic based stresses will help in designing an improved insulation system to withstand high stresses created by the switching devices. The paper presents the electric field simulation results, of a transformer model winding, which is a representative of a typical distribution class transformer, under various distorted voltage waveforms.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"37 1","pages":"284-287"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84779573","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":"Bonds breaking and molecular chains straining in the electrical aging of PE and PP","authors":"J. Crine","doi":"10.1109/CEIDP.2011.6232603","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232603","url":null,"abstract":"It is shown that under high fields, molecular straining becomes significant and that it affects the energy barrier equation for electrical aging of polymers. This implies that at high fields the time to go over the barrier varies not only with the stress (i.e. with the square of field) but also with the square of the stress. Examples are shown along with the corresponding calculated activation volume and the strained activation volume. The physical sense of the two activated volumes is discussed. The Kramers friction coefficient is also included in the life equation and the three main parameters affecting the energy barrier are calculated from various experiments with polyethylene and polypropylene. Discussion of dc and ac aging results are also made. The fact that the activation volume and the friction coefficient vary with the applied stress is illustrated and empirical approaches to determine them are suggested. Implications for other electrical properties are briefly discussed.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"116 1","pages":"89-92"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86085763","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}
H. Hoshina, Y. Morisawa, S. Ishii, H. Sato, I. Noda, Y. Ozaki, C. Otani
{"title":"Terahertz spectroscopy of poly(3-hydroxyalkanoate)s","authors":"H. Hoshina, Y. Morisawa, S. Ishii, H. Sato, I. Noda, Y. Ozaki, C. Otani","doi":"10.1109/CEIDP.2011.6232630","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232630","url":null,"abstract":"Terahertz (THz) absorption spectra of poly(3-hydroxyalkanotes) (PHA) were measured by a terahertz time-domain spectrometer and Fourier transform far-infrared spectrometer. Clear differences were observed between the spectra of crystalline and amorphous PHA, indicating that the absorption peaks observed in the THz spectra originated in the higher-order conformation of PHA. Direction of the vibrational transition moments was obtained by the polarization spectra of stretched sample in which the crystal axis were aligned. THz spectra were also measured over a temperature range from 10 K to 465 K with a liquid helium cryostat and a heating cell. The temperature dependences of the spectra reveal frequency shifts and broadening of the absorption peaks with temperature, suggesting large anharmonicity of the vibrational potential.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"26 1","pages":"195-198"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86424934","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}
T. Koltunowicz, A. Cavallini, D. Djairam, G. Montanari, J. Smit
{"title":"The influence of square voltage waveforms on transformer insulation break down voltage","authors":"T. Koltunowicz, A. Cavallini, D. Djairam, G. Montanari, J. Smit","doi":"10.1109/CEIDP.2011.6232593","DOIUrl":"https://doi.org/10.1109/CEIDP.2011.6232593","url":null,"abstract":"The use of Voltage Source Converters (VSCs) in HVDC transmission and, more generally, in flexible AC transmission systems (FACTS), raises concerns over the endurance of turn/turn insulation of grid/converter interface transformers. In this paper, tests performed on oil-impregnated paper specimens are discussed. The results indicate clearly that shorter rise times and higher repetition frequencies have a strong impact on both partial discharge inception voltage and breakdown voltage. These results suggest that deeper investigation might be important to understand the long term behavior of these insulation systems.","PeriodicalId":6317,"journal":{"name":"2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"2 1","pages":"48-51"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83891798","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}