Pub Date : 2006-10-01DOI: 10.1109/CEIDP.2006.312009
L. Hao, P. Lewin, S. Dodd
Partial discharge (PD) measurement is an important technique for assessing the health of power apparatus. Previous published work (Hao et al., 2006) has shown that an electro-optic system can be used for PD measurement of oil-filled power transformers. The PD signal within an oil-filled power transformer may reach a winding, and then travel along the winding to the bushing core bar. The bushing, acting like a capacitor, can transfer the high frequency components of the partial discharge signal to its tap point. Therefore, an effective PD measurement can be implemented at the bushing tap by using a radio frequency current transducer around the bushing tap earth cable. The use of an optical transmission technique not only improves the noise immunity and provides the possibility of remote measurement but also realizes electrical isolation and enhances the safety for operators. The noise induced by the electro-optic modulator may influence the measurement sensitivity. This paper investigates the use of a machine learning technique to extract the useful PD signals from the noise signals.
局部放电测量是评估电力设备健康状况的一项重要技术。以前发表的工作(Hao et al.， 2006)表明，电光系统可用于油浸电力变压器的局部放电测量。充油电力变压器内的PD信号可能到达一个绕组，然后沿着绕组传播到套管芯棒。该套管的作用类似于电容器，可以将局部放电信号的高频成分转移到其分接点。因此，通过在套管抽头接地电缆周围使用射频电流传感器，可以在套管抽头处实现有效的PD测量。采用光传输技术不仅提高了抗噪声能力，为远程测量提供了可能，而且实现了电气隔离，提高了操作人员的安全性。电光调制器产生的噪声会影响测量灵敏度。本文研究了利用机器学习技术从噪声信号中提取有用的PD信号。
{"title":"Extraction of PD Signals from an Electro-optic Modulator Based PD Measurement System","authors":"L. Hao, P. Lewin, S. Dodd","doi":"10.1109/CEIDP.2006.312009","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.312009","url":null,"abstract":"Partial discharge (PD) measurement is an important technique for assessing the health of power apparatus. Previous published work (Hao et al., 2006) has shown that an electro-optic system can be used for PD measurement of oil-filled power transformers. The PD signal within an oil-filled power transformer may reach a winding, and then travel along the winding to the bushing core bar. The bushing, acting like a capacitor, can transfer the high frequency components of the partial discharge signal to its tap point. Therefore, an effective PD measurement can be implemented at the bushing tap by using a radio frequency current transducer around the bushing tap earth cable. The use of an optical transmission technique not only improves the noise immunity and provides the possibility of remote measurement but also realizes electrical isolation and enhances the safety for operators. The noise induced by the electro-optic modulator may influence the measurement sensitivity. This paper investigates the use of a machine learning technique to extract the useful PD signals from the noise signals.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115287018","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.312061
T. Oakamoto, T. Shindou, M. Sugiura, S. Nakamura
Heat resistive, electrical insulating and mechanical properties of hybrids made with polydimethylsiloxane (PDMS) and tetraethoxysilane (TEOS) through the sol-gel reaction method have been studied by changing the mole ratio of TEOS to PDMS. It has been found that the weight loss of the hybrids is less than 3 % regardless of the mole ratio after ageing at 200 degC for 480 h in air. The expected weight loss of the hybrids after ageing for 20,000 h at 200 degC is less than 7 %. It has been found that the elastic modulus and the stress at break of the hybrids increases with increasing the mole ratio. Those mechanical properties are improved after the ageing because of further dehydration and condensation polymerization reactions through the ageing. The volume resistivity decreases and the dielectric loss tangent increases with increasing the mole ratio. Even at the mole ratio of 10, the resistivity is in the order of 1013 ohm-m at room temperature. Relative permittivity and AC dielectric breakdown strength of the hybrids are about 3 and 25 kV/mm. respectively. After the ageing, increases of volume resistivity, relative permittivity and a decrease of dielectric loss tangent of the hybrids have been observed and AC breakdown strength of them shows little change. It has been concluded that the hybrid made with TEOS and PDMS has the potential of a higher heat resistive insulating material.
{"title":"Change in Heat Resistive, Electrical Insulating and Mechanical Properties of Hybrid Made with PDMS and TEOS for the Mole Ratio of Them","authors":"T. Oakamoto, T. Shindou, M. Sugiura, S. Nakamura","doi":"10.1109/CEIDP.2006.312061","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.312061","url":null,"abstract":"Heat resistive, electrical insulating and mechanical properties of hybrids made with polydimethylsiloxane (PDMS) and tetraethoxysilane (TEOS) through the sol-gel reaction method have been studied by changing the mole ratio of TEOS to PDMS. It has been found that the weight loss of the hybrids is less than 3 % regardless of the mole ratio after ageing at 200 degC for 480 h in air. The expected weight loss of the hybrids after ageing for 20,000 h at 200 degC is less than 7 %. It has been found that the elastic modulus and the stress at break of the hybrids increases with increasing the mole ratio. Those mechanical properties are improved after the ageing because of further dehydration and condensation polymerization reactions through the ageing. The volume resistivity decreases and the dielectric loss tangent increases with increasing the mole ratio. Even at the mole ratio of 10, the resistivity is in the order of 1013 ohm-m at room temperature. Relative permittivity and AC dielectric breakdown strength of the hybrids are about 3 and 25 kV/mm. respectively. After the ageing, increases of volume resistivity, relative permittivity and a decrease of dielectric loss tangent of the hybrids have been observed and AC breakdown strength of them shows little change. It has been concluded that the hybrid made with TEOS and PDMS has the potential of a higher heat resistive insulating material.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121206465","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.312035
F. Aymonino, T. Lebey, D. Malec, C. Petit, J. Saint Michel, A. Anton
The machine thermal class is the main dimensioning factor for the insulating materials. Three main categories of insulation may be distinguished in rotating machines: namely turn to turn, turn to ground and phase to phase insulation. Nevertheless, most of the data available are given at room temperature. Little is known on their behavior versus the temperature. A better knowledge of these materials appears therefore necessary. In this paper, electrical characterizations are performed on turn to turn insulation materials. Formettes samples are realized. The enamel wire is the same for all the samples under study but different impregnation resins and the polymerization processes and mechanisms are envisaged. Conduction current measurements versus the type of impregnation varnish are presented and discussed. Changes in both transient and steady-state currents are studied versus temperature (up to 200 degC). Since most of the varnishes are synthesized with similar polymers but following different polymerization routes, the differences may been attributed to the polymerization process. Huge values of the conduction currents are measured at high temperature and are directly related to the chemistry of the polymerization process.
{"title":"Impact of the polymerization process on the electrical behavior of different impregnation varnishes","authors":"F. Aymonino, T. Lebey, D. Malec, C. Petit, J. Saint Michel, A. Anton","doi":"10.1109/CEIDP.2006.312035","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.312035","url":null,"abstract":"The machine thermal class is the main dimensioning factor for the insulating materials. Three main categories of insulation may be distinguished in rotating machines: namely turn to turn, turn to ground and phase to phase insulation. Nevertheless, most of the data available are given at room temperature. Little is known on their behavior versus the temperature. A better knowledge of these materials appears therefore necessary. In this paper, electrical characterizations are performed on turn to turn insulation materials. Formettes samples are realized. The enamel wire is the same for all the samples under study but different impregnation resins and the polymerization processes and mechanisms are envisaged. Conduction current measurements versus the type of impregnation varnish are presented and discussed. Changes in both transient and steady-state currents are studied versus temperature (up to 200 degC). Since most of the varnishes are synthesized with similar polymers but following different polymerization routes, the differences may been attributed to the polymerization process. Huge values of the conduction currents are measured at high temperature and are directly related to the chemistry of the polymerization process.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116742844","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.311973
B. Oyegoke
Well-known procedures using the isothermal relaxation current method (IRC) use an empirically-derived ageing factor (the A-factor) to estimate the condition of cables. The A-factor is calculated from plots of the product of instantaneous value of IRC and the time to that value from the start of the current, against the log of time. A-factors are computed from a standard formula using constants determined from curve fits of measured depolarization currents. From measurements of the breakdown strength of samples of real and degraded cables it has been found that A-factors do not provide reliable estimates of XLPE cable condition. However, if semi-conducting material of the cable insulation is known and cables are classified according to semi-conducting material type it is possible to get better correlation between conditions of cables as indicated by A-factors and AC breakdown voltage. This paper contains a novel analysis of result from previous researcher and also includes result from tests on other cables. The refined procedure is found to give reasonable value of A-factor for all cable tested.
{"title":"Improved condition assessment of XLPE insulated cables using the isothermal relaxation current technique","authors":"B. Oyegoke","doi":"10.1109/CEIDP.2006.311973","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.311973","url":null,"abstract":"Well-known procedures using the isothermal relaxation current method (IRC) use an empirically-derived ageing factor (the A-factor) to estimate the condition of cables. The A-factor is calculated from plots of the product of instantaneous value of IRC and the time to that value from the start of the current, against the log of time. A-factors are computed from a standard formula using constants determined from curve fits of measured depolarization currents. From measurements of the breakdown strength of samples of real and degraded cables it has been found that A-factors do not provide reliable estimates of XLPE cable condition. However, if semi-conducting material of the cable insulation is known and cables are classified according to semi-conducting material type it is possible to get better correlation between conditions of cables as indicated by A-factors and AC breakdown voltage. This paper contains a novel analysis of result from previous researcher and also includes result from tests on other cables. The refined procedure is found to give reasonable value of A-factor for all cable tested.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"20 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114032714","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.312037
M.A. Brown, S. Dodd, B. Ahern, J. Pettinger, F. Waite
Although insulation based on synthetic resin bonded paper (SRBP) is regarded as an old technology, insulation systems based on this material are still used within the electrical power industry. Much of these are coming to the end of their expected 40 year asset life and techniques for assessing the condition need to be developed such that an effective replacement strategy can be put in place. In this paper, dielectric spectroscopy is to be used to characterize the condition of SRBP. The dielectric response of synthetic resin bonded paper (SRBP) as a function of oil content, and oil plus absorbed moisture is presented over the temperature range 30 degC to 60 degC, and frequency range 5 mHz to 100 kHz. The spectra will be analysed using the Havriliak and Negami semi-empirical form of the Debye dispersion relations, (including a conduction term). The temperature and moisture dependence of the conduction will be discussed, and the relaxation times (tau) for the dispersion mechanisms will then be evaluated for the range of temperatures used
{"title":"Dielectric response of SRBP as a function of oil and oil/moisture absorption.","authors":"M.A. Brown, S. Dodd, B. Ahern, J. Pettinger, F. Waite","doi":"10.1109/CEIDP.2006.312037","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.312037","url":null,"abstract":"Although insulation based on synthetic resin bonded paper (SRBP) is regarded as an old technology, insulation systems based on this material are still used within the electrical power industry. Much of these are coming to the end of their expected 40 year asset life and techniques for assessing the condition need to be developed such that an effective replacement strategy can be put in place. In this paper, dielectric spectroscopy is to be used to characterize the condition of SRBP. The dielectric response of synthetic resin bonded paper (SRBP) as a function of oil content, and oil plus absorbed moisture is presented over the temperature range 30 degC to 60 degC, and frequency range 5 mHz to 100 kHz. The spectra will be analysed using the Havriliak and Negami semi-empirical form of the Debye dispersion relations, (including a conduction term). The temperature and moisture dependence of the conduction will be discussed, and the relaxation times (tau) for the dispersion mechanisms will then be evaluated for the range of temperatures used","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113969032","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.311940
J. Castellon, S. Agnel, A. Toureille, M. Frechette, K. Cole, D. Desgagnes
Numerous studies have shown that the presence and/or development of electric charges within polymers affect their properties with a significant order. These charges, intrinsic or extrinsic, that are called space charges, have been first observed for polymers used for electrotechnical applications, thus, at high electric fields. In many other studies, it has been observed that space charges are present into the polymers, even if these polymers were not exposed to additional stresses other than those associated with their synthesis and making. Moreover, the increase of the space charges seems directly linked with the deterioration of the physical properties of these materials since charge trapping is mainly associated with structure defects. These defects may have several origins, namely fabrication, interfaces, and stresses applied to the material. In this work, electrical properties of epoxy microcomposites with and without nanoclay are investigated under different conditions: without initial stress, and with subsequent electrical and thermal stresses. Correlating space charge measurements obtained by the Thermal Step Method with results observed in thermally stimulated-current experiments, the nature of the observed electric charges and the influence of the nanostructures can be discussed. Results and their scattering for cases including samples with and without nanoclay point certainly at the importance of the quality of the fabrication process.
{"title":"Electrical properties analysis of nano-filled epoxy by space charge characterization","authors":"J. Castellon, S. Agnel, A. Toureille, M. Frechette, K. Cole, D. Desgagnes","doi":"10.1109/CEIDP.2006.311940","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.311940","url":null,"abstract":"Numerous studies have shown that the presence and/or development of electric charges within polymers affect their properties with a significant order. These charges, intrinsic or extrinsic, that are called space charges, have been first observed for polymers used for electrotechnical applications, thus, at high electric fields. In many other studies, it has been observed that space charges are present into the polymers, even if these polymers were not exposed to additional stresses other than those associated with their synthesis and making. Moreover, the increase of the space charges seems directly linked with the deterioration of the physical properties of these materials since charge trapping is mainly associated with structure defects. These defects may have several origins, namely fabrication, interfaces, and stresses applied to the material. In this work, electrical properties of epoxy microcomposites with and without nanoclay are investigated under different conditions: without initial stress, and with subsequent electrical and thermal stresses. Correlating space charge measurements obtained by the Thermal Step Method with results observed in thermally stimulated-current experiments, the nature of the observed electric charges and the influence of the nanostructures can be discussed. Results and their scattering for cases including samples with and without nanoclay point certainly at the importance of the quality of the fabrication process.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122731524","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.312082
H. C. Basso, C.V. Aquino, R. Altafim, R. Altafim, R. Gerhard-Multhaupt
Multi-void space-charge electrets that have been formed by two fluoroethylenepropylene (Teflonreg-FEP) films with internal surface charge layers of opposite polarity exhibit high piezoelectric coefficients. In these electrets, several charged bubbles are arranged in parallel. A significant voltage is generated between the electrodes when the arrangement is submitted to a mechanical force that acts perpendicular to the electrodes (direct piezoelectricity). The arrangement thus works in a similar manner as a large number of tiny electret microphones. In view of this mechanism, the size and the shape of the bubbles are important aspects for the design of sensor and actuator devices. In this paper, we therefore investigate the behavior of single air bubbles formed by two fluoroethylenepropylene (Teflonreg-FEP) films theoretically and experimentally.
{"title":"Piezoelectricity of a single bubble formed by two oppositely charged Teflon® -FEP films","authors":"H. C. Basso, C.V. Aquino, R. Altafim, R. Altafim, R. Gerhard-Multhaupt","doi":"10.1109/CEIDP.2006.312082","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.312082","url":null,"abstract":"Multi-void space-charge electrets that have been formed by two fluoroethylenepropylene (Teflonreg-FEP) films with internal surface charge layers of opposite polarity exhibit high piezoelectric coefficients. In these electrets, several charged bubbles are arranged in parallel. A significant voltage is generated between the electrodes when the arrangement is submitted to a mechanical force that acts perpendicular to the electrodes (direct piezoelectricity). The arrangement thus works in a similar manner as a large number of tiny electret microphones. In view of this mechanism, the size and the shape of the bubbles are important aspects for the design of sensor and actuator devices. In this paper, we therefore investigate the behavior of single air bubbles formed by two fluoroethylenepropylene (Teflonreg-FEP) films theoretically and experimentally.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127803895","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.311981
Ying Liang, L. Ding, C.R. Li, Kun Yang, Y. Tu
This paper has investigated the thermally stimulated current (TSC) characteristics of the deteriorated HTV silicone rubber under varied corona discharge duration, the hydrophobicity, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) of the corresponding test samples have also been measured. The experimental results show that the TSC characteristics of HTV silicone rubber gradually varied with the corona deterioration process, and it has relationship with the change of its hydrophobicity, SEM, and also FTIR. As a result, it could be suggested that the TSC characteristics might be used as an effective index for assessing the corona deterioration of HTV silicone rubber.
{"title":"A method to detect the deterioration of HTV silicone rubber under corona discharge","authors":"Ying Liang, L. Ding, C.R. Li, Kun Yang, Y. Tu","doi":"10.1109/CEIDP.2006.311981","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.311981","url":null,"abstract":"This paper has investigated the thermally stimulated current (TSC) characteristics of the deteriorated HTV silicone rubber under varied corona discharge duration, the hydrophobicity, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) of the corresponding test samples have also been measured. The experimental results show that the TSC characteristics of HTV silicone rubber gradually varied with the corona deterioration process, and it has relationship with the change of its hydrophobicity, SEM, and also FTIR. As a result, it could be suggested that the TSC characteristics might be used as an effective index for assessing the corona deterioration of HTV silicone rubber.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130327804","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.312039
J. A. Mergos, J. Daskalakis, C. Dervos
Perovskite mineral structure is cubic, with one formula-weight per unit cell. Its name was given by the mineral CaTiO3. A large number of double oxides (as well as some iodates and double halides) are classified as belonging to this type. In this work the dielectric properties of perovskite crystals are presented, namely the complex permittivity (real and imaginary part) and the loss factor (tan delta). Their values in the 20 Hz-1 MHz frequency range were obtained using the equivalent capacitance-conductance parallel circuit method. Specimens were prepared by mixing TiO2 (of predominantly anatase structure) and CaCO3 (calcite) powders and compressing them uniaxially to form pellets. These were sintered at temperatures as high as 1200 degC. According to the XRD results obtained, not only did the anatase convert to rutile and the calcite to lime (CaO), but also the double oxide CaTiO3 was formed, as in the natural perovskite mineral. Its formation was related to higher dielectric constant values and significantly lower losses compared to specimens sintered at lower temperatures, where the perovskite structure was less intense. Such high-K and low-loss dielectric materials have lately found significant attention in the quest of smart antennas for telecommunication applications
{"title":"Complex permittivity characterization of double oxides of the perovskite crystal structure","authors":"J. A. Mergos, J. Daskalakis, C. Dervos","doi":"10.1109/CEIDP.2006.312039","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.312039","url":null,"abstract":"Perovskite mineral structure is cubic, with one formula-weight per unit cell. Its name was given by the mineral CaTiO3. A large number of double oxides (as well as some iodates and double halides) are classified as belonging to this type. In this work the dielectric properties of perovskite crystals are presented, namely the complex permittivity (real and imaginary part) and the loss factor (tan delta). Their values in the 20 Hz-1 MHz frequency range were obtained using the equivalent capacitance-conductance parallel circuit method. Specimens were prepared by mixing TiO2 (of predominantly anatase structure) and CaCO3 (calcite) powders and compressing them uniaxially to form pellets. These were sintered at temperatures as high as 1200 degC. According to the XRD results obtained, not only did the anatase convert to rutile and the calcite to lime (CaO), but also the double oxide CaTiO3 was formed, as in the natural perovskite mineral. Its formation was related to higher dielectric constant values and significantly lower losses compared to specimens sintered at lower temperatures, where the perovskite structure was less intense. Such high-K and low-loss dielectric materials have lately found significant attention in the quest of smart antennas for telecommunication applications","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134190896","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 : 2006-10-01DOI: 10.1109/CEIDP.2006.311970
S. Ul Haq, S. Jayaram, E. Cherney
In this research work, the behavior of medium voltage stator bar groundwall insulation that is subjected to steep-front voltage pulses, at various repetition rates and temperatures, is studied. The test conditions include; pulse voltage amplitudes up to 3.5 kVp, pulse switching frequencies up to 3 kHz, and in ambient temperatures of 23 and 155 degC. During the aging process, the surface temperature is monitored with an infrared camera as a means for determining the locations of the highest temperature and therefore the highest regions of PD activity. Visual observations confirm degradation of the groundwall insulation in the regions of highest temperature and PD measurements show increased activity and reduced PD inception with aging.
{"title":"Evaluation of Medium Voltage Stator Bar Groundwall Insulation under Inverter-Fed Pulses","authors":"S. Ul Haq, S. Jayaram, E. Cherney","doi":"10.1109/CEIDP.2006.311970","DOIUrl":"https://doi.org/10.1109/CEIDP.2006.311970","url":null,"abstract":"In this research work, the behavior of medium voltage stator bar groundwall insulation that is subjected to steep-front voltage pulses, at various repetition rates and temperatures, is studied. The test conditions include; pulse voltage amplitudes up to 3.5 kVp, pulse switching frequencies up to 3 kHz, and in ambient temperatures of 23 and 155 degC. During the aging process, the surface temperature is monitored with an infrared camera as a means for determining the locations of the highest temperature and therefore the highest regions of PD activity. Visual observations confirm degradation of the groundwall insulation in the regions of highest temperature and PD measurements show increased activity and reduced PD inception with aging.","PeriodicalId":219099,"journal":{"name":"2006 IEEE Conference on Electrical Insulation and Dielectric Phenomena","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133691045","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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