Pub Date : 2003-10-19DOI: 10.1109/CEIDP.2003.1254809
P. Irwin, Y. Cao, A. Bansal, L. Schadler
Interest has grown in recent years on the effects of nano-sized fillers on the thermal, mechanical, and electrical properties of polymeric systems. In particular, we are interested in studying the changes in mechanical and thermal properties of thermosetting polyimides as nano-sized fillers are added in increasing levels of concentration. The results are compared to micron-sized filled polyimides of similar compositions. We have observed dramatic increases in elongation to failure, scratch hardness and thermal conductivity while the tensile modulus does not change significantly. A change in stress state around nanoparticles during deformation is the possible reason for the observed improvement in tensile properties. Thermal conductivity of the filled polymer systems seemed to be most affected by the surface treatment of the nano-fillers. Improved interactions between the filler and the matrix is suggested as a possible explanation for these conductivity differences.
{"title":"Thermal and mechanical properties of polyimide nanocomposites","authors":"P. Irwin, Y. Cao, A. Bansal, L. Schadler","doi":"10.1109/CEIDP.2003.1254809","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254809","url":null,"abstract":"Interest has grown in recent years on the effects of nano-sized fillers on the thermal, mechanical, and electrical properties of polymeric systems. In particular, we are interested in studying the changes in mechanical and thermal properties of thermosetting polyimides as nano-sized fillers are added in increasing levels of concentration. The results are compared to micron-sized filled polyimides of similar compositions. We have observed dramatic increases in elongation to failure, scratch hardness and thermal conductivity while the tensile modulus does not change significantly. A change in stress state around nanoparticles during deformation is the possible reason for the observed improvement in tensile properties. Thermal conductivity of the filled polymer systems seemed to be most affected by the surface treatment of the nano-fillers. Improved interactions between the filler and the matrix is suggested as a possible explanation for these conductivity differences.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126674015","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254892
X. B. Li, A. Zyuzin, Alexander V. Mamishev
Real-time non-invasive moisture content sensing techniques are needed for online moisture measurement and control in food products. In this investigation, a dielectric spectroscopy based system is used for moisture determination in cookie dough. Experiments were conducted with a concentric ring dielectric sensor in the frequency range from 10 Hz to 10 kHz. The system is calibrated based on a linear model, where the functional dependence of capacitance on moisture content is determined. The calibrated system allows for both online moisture content sensing and moisture distribution profile imaging.
{"title":"Measuring moisture content in cookies using dielectric spectroscopy","authors":"X. B. Li, A. Zyuzin, Alexander V. Mamishev","doi":"10.1109/CEIDP.2003.1254892","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254892","url":null,"abstract":"Real-time non-invasive moisture content sensing techniques are needed for online moisture measurement and control in food products. In this investigation, a dielectric spectroscopy based system is used for moisture determination in cookie dough. Experiments were conducted with a concentric ring dielectric sensor in the frequency range from 10 Hz to 10 kHz. The system is calibrated based on a linear model, where the functional dependence of capacitance on moisture content is determined. The calibrated system allows for both online moisture content sensing and moisture distribution profile imaging.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122315725","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254917
M. Shwehdi, Y. Al-Hawi
Partial Discharges (PD) on insulation in general is among the most vulnerable processes in the AC system that can cause a failure. Therefore, an effective early detection of insulation failure will significantly reduce chances of catastrophic failure in power system apparatus avoiding costly repair and power outage impact. The capacitive network representation of insulation has long been used for the study of impulse voltage distribution along the windings and, for PD detection and location. A Partial discharge (PD) model using Pspice as to generate void signals is used in this paper. The model includes the equivalent electrical circuit of solid inhomogeneous dielectrics with voids. This signal is then detected by a digital signal processing tool, which is the wavelet, under different noise intensities.
{"title":"Pspice double void partial discharge simulation and detection using wavelet","authors":"M. Shwehdi, Y. Al-Hawi","doi":"10.1109/CEIDP.2003.1254917","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254917","url":null,"abstract":"Partial Discharges (PD) on insulation in general is among the most vulnerable processes in the AC system that can cause a failure. Therefore, an effective early detection of insulation failure will significantly reduce chances of catastrophic failure in power system apparatus avoiding costly repair and power outage impact. The capacitive network representation of insulation has long been used for the study of impulse voltage distribution along the windings and, for PD detection and location. A Partial discharge (PD) model using Pspice as to generate void signals is used in this paper. The model includes the equivalent electrical circuit of solid inhomogeneous dielectrics with voids. This signal is then detected by a digital signal processing tool, which is the wavelet, under different noise intensities.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122711146","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254793
A. Goel, W. Foshee, Hulya Kirkici
Chemical weed control accounts for oyer /spl Bscr/ in costs to the American farmer. Non-chemical alternatives offer many advantages such as protecting the environment and safety for applicators. Studies have shown that high voltage, pulsed electric field (PEF) treatment of biodielectrics is an effective method to inactivate micro-organisms and bacteria. Therefore, the PEF technology might be used as an effective alternative to chemical weed control. In this work, we have studied the breakdown characteristics of weed seeds using single and repetitive pulsed electric fields. Breakdown of seeds as a function of various parameters of the pulsed system such as its duration, rise/fall time, repetition rate, and field strength, are studied. Two types of weed seeds, namely yellow foxtail and smallflower morningglory, were used in the experiment. Preliminary results suggest that the PEF method can reduce the percent germination of the yellow foxtail. Conversely, the smallflower morningglory had increased percent germination. This trend is most likely due to the presence or absence of a hardened seed coat of which the smallflower morninglory possesses.
{"title":"Pulsed electric field studies of bio-dielectrics","authors":"A. Goel, W. Foshee, Hulya Kirkici","doi":"10.1109/CEIDP.2003.1254793","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254793","url":null,"abstract":"Chemical weed control accounts for oyer /spl Bscr/ in costs to the American farmer. Non-chemical alternatives offer many advantages such as protecting the environment and safety for applicators. Studies have shown that high voltage, pulsed electric field (PEF) treatment of biodielectrics is an effective method to inactivate micro-organisms and bacteria. Therefore, the PEF technology might be used as an effective alternative to chemical weed control. In this work, we have studied the breakdown characteristics of weed seeds using single and repetitive pulsed electric fields. Breakdown of seeds as a function of various parameters of the pulsed system such as its duration, rise/fall time, repetition rate, and field strength, are studied. Two types of weed seeds, namely yellow foxtail and smallflower morningglory, were used in the experiment. Preliminary results suggest that the PEF method can reduce the percent germination of the yellow foxtail. Conversely, the smallflower morningglory had increased percent germination. This trend is most likely due to the presence or absence of a hardened seed coat of which the smallflower morninglory possesses.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126982805","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254867
R. Joshi, Q. Hu, K. Schoenbach, V. Lakdawala
The dynamics of electroporation in biological cells subjected to nanosecond, high intensity pulses are studied based on a coupled scheme involving current continuity and Smoluchowski equations. A new distributed current model is presented for potential distribution to includes dynamic conductivities of cell membranes and substructures caused by pore formation. Different cell responses of normal and malignant (Farage) tonsillar B-cells are compared and discussed. It is shown that ultrashort, high-intensity electric pulses could selectively damage cancer cells.
{"title":"Modeling studies of cellular response to ultrashort, high-intensity electric fields","authors":"R. Joshi, Q. Hu, K. Schoenbach, V. Lakdawala","doi":"10.1109/CEIDP.2003.1254867","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254867","url":null,"abstract":"The dynamics of electroporation in biological cells subjected to nanosecond, high intensity pulses are studied based on a coupled scheme involving current continuity and Smoluchowski equations. A new distributed current model is presented for potential distribution to includes dynamic conductivities of cell membranes and substructures caused by pore formation. Different cell responses of normal and malignant (Farage) tonsillar B-cells are compared and discussed. It is shown that ultrashort, high-intensity electric pulses could selectively damage cancer cells.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127333031","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254819
M. Lança, C. Dias, D. D. Das Gupta, J. Marat-Mendes
Low-density polyethylene (LDPE) films were thermally aged in a sodium chloride aqueous solution at constant temperature (thermal aging). Some of the samples were simultaneously immersed in solution and subjected to an electric AC field (electrical aging). The dielectric relaxation spectra at 30/spl deg/C in the range of 10/sup -5/ Hz to 10/sup 5/ Hz were obtained for unaged and aged samples. For the low frequency (LF) region (10/sup -5/ Hz to 10/sup -1/ Hz) the time domain technique was used. A lock-in amplifier was used for the 10/sup -1/ Hz to 10/sup 1/ Hz medium frequency (MF) region. While for the high frequency (HF), 10/sup -1/ Hz to 10/sup 5/ Hz, RLC bridge measurements were performed. The main differences can be seen between electrically, thermally aged and unaged LDPE in the HF and LF regions. The LF peak is a broad peak related to localized space charge injection driven by the electric field. For electrically aged samples this peak increases in an earlier stage of electrical aging, decreasing afterwards. While in thermally aged samples the peak amplitude always increases with aging time. Finally the HF shows the beginning of a peak due to the /spl gamma/ and /spl beta/ transitions. This peak decreases with aging disappearing for the most aged samples.
{"title":"Comparative study of dielectric relaxation spectra of electrically and thermally aged low density polyethylene","authors":"M. Lança, C. Dias, D. D. Das Gupta, J. Marat-Mendes","doi":"10.1109/CEIDP.2003.1254819","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254819","url":null,"abstract":"Low-density polyethylene (LDPE) films were thermally aged in a sodium chloride aqueous solution at constant temperature (thermal aging). Some of the samples were simultaneously immersed in solution and subjected to an electric AC field (electrical aging). The dielectric relaxation spectra at 30/spl deg/C in the range of 10/sup -5/ Hz to 10/sup 5/ Hz were obtained for unaged and aged samples. For the low frequency (LF) region (10/sup -5/ Hz to 10/sup -1/ Hz) the time domain technique was used. A lock-in amplifier was used for the 10/sup -1/ Hz to 10/sup 1/ Hz medium frequency (MF) region. While for the high frequency (HF), 10/sup -1/ Hz to 10/sup 5/ Hz, RLC bridge measurements were performed. The main differences can be seen between electrically, thermally aged and unaged LDPE in the HF and LF regions. The LF peak is a broad peak related to localized space charge injection driven by the electric field. For electrically aged samples this peak increases in an earlier stage of electrical aging, decreasing afterwards. While in thermally aged samples the peak amplitude always increases with aging time. Finally the HF shows the beginning of a peak due to the /spl gamma/ and /spl beta/ transitions. This peak decreases with aging disappearing for the most aged samples.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122892144","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254903
J. Amarnath, D. Paramahamsa, K. Narasimharao, B.P. Singh, K.D. Shrivastava
Gas Insulated Substations have found a broad range of applications in power systems over the last three decades because of their high reliability, easy maintenance, small ground space requirements etc. Although GIS have been in operation for several years, some of the problems are of more attention. These problems include generation of Very Fast Transient Overvoltages (VFTO) during switching operations or earthing faults, the secondary breakdown inside GIS caused by VFTO and Transient Enclosure Voltages (TEA) outside the GIS. In this paper the VFTO levels are estimated by using PSPICE models for all the equivalent circuits of the GIS components including the spark channel development. The results show that the spark lengths below 4 cm, will not affect the VFTO level in a GIS. Further, the maximum possible value of the VFTO level is 2.72 per unit in the case of a 245 KV GIS has been observed. Moreover, the maximum over voltages occur at the open ends of the gas insulated bus bars. However, the VFTO levels after the VFTO breakdown under highly non-uniform fields are low i.e.-1.7 per unit after introduction of spark resistance and hence the Over voltages are further reduced to 1.2 per unit.
{"title":"Very fast transient over-voltages and transient enclosure voltages in gas insulated substations","authors":"J. Amarnath, D. Paramahamsa, K. Narasimharao, B.P. Singh, K.D. Shrivastava","doi":"10.1109/CEIDP.2003.1254903","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254903","url":null,"abstract":"Gas Insulated Substations have found a broad range of applications in power systems over the last three decades because of their high reliability, easy maintenance, small ground space requirements etc. Although GIS have been in operation for several years, some of the problems are of more attention. These problems include generation of Very Fast Transient Overvoltages (VFTO) during switching operations or earthing faults, the secondary breakdown inside GIS caused by VFTO and Transient Enclosure Voltages (TEA) outside the GIS. In this paper the VFTO levels are estimated by using PSPICE models for all the equivalent circuits of the GIS components including the spark channel development. The results show that the spark lengths below 4 cm, will not affect the VFTO level in a GIS. Further, the maximum possible value of the VFTO level is 2.72 per unit in the case of a 245 KV GIS has been observed. Moreover, the maximum over voltages occur at the open ends of the gas insulated bus bars. However, the VFTO levels after the VFTO breakdown under highly non-uniform fields are low i.e.-1.7 per unit after introduction of spark resistance and hence the Over voltages are further reduced to 1.2 per unit.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127868167","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254856
T. P. Hong, P. Frayssines, O. Lesaint, F. Aitken, F. Devaux
This paper presents an experimental study of the influence of vapor bubbles on breakdown in liquid nitrogen. Vapor bubbles are initiated by creating a small hot spot at the surface of an electrode. The behavior of vapor bubbles is first investigated by visualization, versus power dissipated by the heater, pressure and electric field. When breakdown occurs in the presence of bubbles, it is due to formation of either a vapor bridge between the electrodes (at low pressure), or a vapor layer on the hot spot (at high pressure). The results are discussed in comparison with gas breakdown fields obtained from the Paschen's law.
{"title":"Influence of vapor bubbles initiated by steady heating on the breakdown of liquid nitrogen","authors":"T. P. Hong, P. Frayssines, O. Lesaint, F. Aitken, F. Devaux","doi":"10.1109/CEIDP.2003.1254856","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254856","url":null,"abstract":"This paper presents an experimental study of the influence of vapor bubbles on breakdown in liquid nitrogen. Vapor bubbles are initiated by creating a small hot spot at the surface of an electrode. The behavior of vapor bubbles is first investigated by visualization, versus power dissipated by the heater, pressure and electric field. When breakdown occurs in the presence of bubbles, it is due to formation of either a vapor bridge between the electrodes (at low pressure), or a vapor layer on the hot spot (at high pressure). The results are discussed in comparison with gas breakdown fields obtained from the Paschen's law.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121364666","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254958
Mohsen Saniei, S. J. MacGreggor, R. Fouracre
The breakdown of a triggered, plane-parallel electrode system with water dielectric has been investigated. The gap was triggered by a discharge initiated at an electrically isolated trigger pin, positioned in the center of one of the electrodes, using a 500 ns voltage pulse. A 5000 fps CCD-camera monitored events occurring in the gap during such a discharge and the intensity variations of a laser beam transmitted through the electrode gap was also monitored. The results indicate the initiation, expansion and collapse of a gas bubble generated at the trigger electrode. The subsequent application of a voltage between the plane electrodes results in the complete breakdown of the gap due to the trigger discharge. The effect of a delay time between the trigger pulse and the application of the main gap voltage was consistent with the growth and collapse of the trigger-initiated bubble.
{"title":"Investigation of the mechanisms leading to the electrical breakdown of a triggered water gaps","authors":"Mohsen Saniei, S. J. MacGreggor, R. Fouracre","doi":"10.1109/CEIDP.2003.1254958","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254958","url":null,"abstract":"The breakdown of a triggered, plane-parallel electrode system with water dielectric has been investigated. The gap was triggered by a discharge initiated at an electrically isolated trigger pin, positioned in the center of one of the electrodes, using a 500 ns voltage pulse. A 5000 fps CCD-camera monitored events occurring in the gap during such a discharge and the intensity variations of a laser beam transmitted through the electrode gap was also monitored. The results indicate the initiation, expansion and collapse of a gas bubble generated at the trigger electrode. The subsequent application of a voltage between the plane electrodes results in the complete breakdown of the gap due to the trigger discharge. The effect of a delay time between the trigger pulse and the application of the main gap voltage was consistent with the growth and collapse of the trigger-initiated bubble.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129337099","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 : 2003-10-19DOI: 10.1109/CEIDP.2003.1254849
B. Du
Surface dielectric breakdown phenomenon of printed circuit board (PCB) under dc magnetic field was investigated, we employed a dc magnetic field, which was made at 395 mT, and the electrical field was made at 60 kV/mm, 100 kV/mm and then up to 300 kV/mm. The experiment was carried out by dc pulse voltage with the frequencies in the range of 50 Hz to 150 Hz. PCB of epoxy resin laminate have been employed to investigate the effects of the magnetic field, the density of electrical field and the frequencies of applied voltage on discharge quantity. The relation between the time to insulation breakdown and the electrical fields under dc magnetic field were examined. Surface dielectric breakdown is caused by decomposed carbon on the sample surface, which is precipitated due to heat from discharge currents occurred between the electrodes. The study revealed that the time to breakdown decreases under magnetic field and decreases with increasing the density of electrical field. The characteristics of discharge currents were discussed by using a power spectral density. The results show that the power spectral density of discharge currents increases under magnetic field and with increasing the density of electrical fields.
{"title":"Surface breakdown of printed circuit board under dc magnetic field","authors":"B. Du","doi":"10.1109/CEIDP.2003.1254849","DOIUrl":"https://doi.org/10.1109/CEIDP.2003.1254849","url":null,"abstract":"Surface dielectric breakdown phenomenon of printed circuit board (PCB) under dc magnetic field was investigated, we employed a dc magnetic field, which was made at 395 mT, and the electrical field was made at 60 kV/mm, 100 kV/mm and then up to 300 kV/mm. The experiment was carried out by dc pulse voltage with the frequencies in the range of 50 Hz to 150 Hz. PCB of epoxy resin laminate have been employed to investigate the effects of the magnetic field, the density of electrical field and the frequencies of applied voltage on discharge quantity. The relation between the time to insulation breakdown and the electrical fields under dc magnetic field were examined. Surface dielectric breakdown is caused by decomposed carbon on the sample surface, which is precipitated due to heat from discharge currents occurred between the electrodes. The study revealed that the time to breakdown decreases under magnetic field and decreases with increasing the density of electrical field. The characteristics of discharge currents were discussed by using a power spectral density. The results show that the power spectral density of discharge currents increases under magnetic field and with increasing the density of electrical fields.","PeriodicalId":306575,"journal":{"name":"2003 Annual Report Conference on Electrical Insulation and Dielectric Phenomena","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128605692","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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