Pub Date : 2012-11-26DOI: 10.1109/ICHVE.2012.6357120
Qing-zhou Zhao, Qing Yang, Hao-yuan Zheng, W. Sima, T. Yuan, Jianbiao Li
Calculating shielding failure flashover rate of transmission line with regulation method, EGM method and LPM method, the height of conductor and ground wire are often expressed by average height, the terrain feature are often expressed by ground obliquity. If the actual line parameters are beyond the scope of the effective calculation conditions, traditional methods can't reflect the influence of sag and line corridor's complex terrain area. In recent years, some scholars put forward to select multiple tangent planes of a line span, then calculated the shielding failure flashover rates of every tangent planes to reflect the line span's lightning protection performance, but it was complicated to get the ground obliquities of every tangent planes. A new approach for calculating shielding failure flashover times in complex terrain area was presented, which was based on the electro-geometric model (EGM), the new method considered of the line corridor's micro-topography and the relative position among the ground wire, the conductor wire and the ground, a line span was taken as the research object, got the shielding failure flashover times of the line span through calculating the conductor exposed surface's horizontally-projected area. A 500kV transmission line in complex terrain area was taken as an example, the calculation results shown that using this method can obtain a line span's lightning protection performance simple and exactly, and reflect the influence of line corridor's complex terrain area better, which also provide a reference for differentiation technology and strategy of lightning protection.
{"title":"Method of calculating shielding failure flashover times of transmission line in complex terrain area","authors":"Qing-zhou Zhao, Qing Yang, Hao-yuan Zheng, W. Sima, T. Yuan, Jianbiao Li","doi":"10.1109/ICHVE.2012.6357120","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357120","url":null,"abstract":"Calculating shielding failure flashover rate of transmission line with regulation method, EGM method and LPM method, the height of conductor and ground wire are often expressed by average height, the terrain feature are often expressed by ground obliquity. If the actual line parameters are beyond the scope of the effective calculation conditions, traditional methods can't reflect the influence of sag and line corridor's complex terrain area. In recent years, some scholars put forward to select multiple tangent planes of a line span, then calculated the shielding failure flashover rates of every tangent planes to reflect the line span's lightning protection performance, but it was complicated to get the ground obliquities of every tangent planes. A new approach for calculating shielding failure flashover times in complex terrain area was presented, which was based on the electro-geometric model (EGM), the new method considered of the line corridor's micro-topography and the relative position among the ground wire, the conductor wire and the ground, a line span was taken as the research object, got the shielding failure flashover times of the line span through calculating the conductor exposed surface's horizontally-projected area. A 500kV transmission line in complex terrain area was taken as an example, the calculation results shown that using this method can obtain a line span's lightning protection performance simple and exactly, and reflect the influence of line corridor's complex terrain area better, which also provide a reference for differentiation technology and strategy of lightning protection.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"29 1","pages":"330-333"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84761100","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357078
Yong Liu, B. Du, Zhuoran Yang
Hydrophobicity performance of polymeric insulator in severe condition has caused more concern about reliability of power system, which increasingly requires the evaluation method for the surface hydrophobicity. In this research, based on the dynamic dropping test (DDT) method, infrared characteristics of surface discharges induced by dynamic behaviors of water droplet were investigated to carry out the hydrophobicity evaluation for different ageing levels of silicone rubber insulator. Both the dynamic morphology of water droplet and the induced discharge phenomena on the sample surface were captured by using an infrared camera to establish the relationship between the infrared radiation along the sample surface and the surface hydrophobicity. Methods of image processing and fractal dimension were employed to quantitatively analyze the infrared images. It is found that the maximum temperature and thermal distribution of discharges increase with the decrease of hydrophobicity. The increasing tendency in discharge strength and fractal dimension of thermal pattern can reveal the decrease of hydrophobicity. The results obtained indicate that the infrared characteristics of discharges in DDT method are sensitive to the hydrophobic properties, which can be applied as non-contact method for hydrophobicity evaluation of polymeric insulators.
{"title":"Infrared characteristics of surface discharges in dynamic dropping test for hydrophobicity evaluation of polymeric insulator","authors":"Yong Liu, B. Du, Zhuoran Yang","doi":"10.1109/ICHVE.2012.6357078","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357078","url":null,"abstract":"Hydrophobicity performance of polymeric insulator in severe condition has caused more concern about reliability of power system, which increasingly requires the evaluation method for the surface hydrophobicity. In this research, based on the dynamic dropping test (DDT) method, infrared characteristics of surface discharges induced by dynamic behaviors of water droplet were investigated to carry out the hydrophobicity evaluation for different ageing levels of silicone rubber insulator. Both the dynamic morphology of water droplet and the induced discharge phenomena on the sample surface were captured by using an infrared camera to establish the relationship between the infrared radiation along the sample surface and the surface hydrophobicity. Methods of image processing and fractal dimension were employed to quantitatively analyze the infrared images. It is found that the maximum temperature and thermal distribution of discharges increase with the decrease of hydrophobicity. The increasing tendency in discharge strength and fractal dimension of thermal pattern can reveal the decrease of hydrophobicity. The results obtained indicate that the infrared characteristics of discharges in DDT method are sensitive to the hydrophobic properties, which can be applied as non-contact method for hydrophobicity evaluation of polymeric insulators.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"19 1","pages":"237-240"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81997755","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357011
W. Bing, Xiaohong Huang, Zhengcai Fu, Chen Jian, Sun Wei
Lightning protection design is still an important challenge for modern planes. With reference to the US Mil-Std-1757 and SAE ARP 5416 2005 and other standards, lightning flashes differ mainly in current amplitude, the transferred charge and the impulse shapes of lightning current. The standards prescript related test waveforms of aircraft lightning environment. For meeting the requirement of lightning protection for aircraft requires of high-current waveforms, a developed high-current generator design that consists of four current generators and a measurement-control unit. The combination continuously produce four impulse current waveforms that required in lightning protection test and more specific test charge conditions. The proposed generator is applicable for simulation and validation of lightning protection measures. The quantitative experiment results will provide actual reference for the aircraft design and structural optimization of air craft lightning protection.
{"title":"Design and implementation of continuous multiple impulse current generator for aircraft lightning protection tests","authors":"W. Bing, Xiaohong Huang, Zhengcai Fu, Chen Jian, Sun Wei","doi":"10.1109/ICHVE.2012.6357011","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357011","url":null,"abstract":"Lightning protection design is still an important challenge for modern planes. With reference to the US Mil-Std-1757 and SAE ARP 5416 2005 and other standards, lightning flashes differ mainly in current amplitude, the transferred charge and the impulse shapes of lightning current. The standards prescript related test waveforms of aircraft lightning environment. For meeting the requirement of lightning protection for aircraft requires of high-current waveforms, a developed high-current generator design that consists of four current generators and a measurement-control unit. The combination continuously produce four impulse current waveforms that required in lightning protection test and more specific test charge conditions. The proposed generator is applicable for simulation and validation of lightning protection measures. The quantitative experiment results will provide actual reference for the aircraft design and structural optimization of air craft lightning protection.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"1 1","pages":"89-91"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88534163","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357146
Peng Wang, Jian Li, Linjie Zhao, T. Jiang, Zhiman He
Ultra-high-frequency (UHF) approaches, when used to detect partial discharge in converter transformers, can avoid the impulse interference generated by converter valve, thus contributing to high sensitivity. The electromagnetic waves (EM-waves) propagation in transformer could be affected by transformer components and other factors. In this paper, a simulation model of converter transformer was built up based on a reasonable simplification of transformer components. And then the EM-waves propagation characteristics in transformer was simulated and studied with Finite Difference Time Domain (FDTD) method. The simulation results explained the propagation characteristics of EM-waves between the core and windings, the attenuation and distortion of EM-waves caused by the core, windings and bushings.
{"title":"Investigation on the propagation characteristic of electromagnetic waves in converter transformers","authors":"Peng Wang, Jian Li, Linjie Zhao, T. Jiang, Zhiman He","doi":"10.1109/ICHVE.2012.6357146","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357146","url":null,"abstract":"Ultra-high-frequency (UHF) approaches, when used to detect partial discharge in converter transformers, can avoid the impulse interference generated by converter valve, thus contributing to high sensitivity. The electromagnetic waves (EM-waves) propagation in transformer could be affected by transformer components and other factors. In this paper, a simulation model of converter transformer was built up based on a reasonable simplification of transformer components. And then the EM-waves propagation characteristics in transformer was simulated and studied with Finite Difference Time Domain (FDTD) method. The simulation results explained the propagation characteristics of EM-waves between the core and windings, the attenuation and distortion of EM-waves caused by the core, windings and bushings.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"217 1","pages":"353-357"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89100870","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357118
S. Kocamaz, O. Kalenderli, O. Altay
High voltage insulators are important part of power transmission and distribution network. Design of an insulator has importance in terms of both reliable operation of equipment and systems. However, various parameters have to be considered during an insulator design such as electric field distribution, mechanical strength, dimensions, which affect each other. Therefore, an optimization is necessary for the design of an insulator. In this study, Fuzzy Inference System (FIS), which is less time consuming and simpler when compared with iterative solutions, has been proposed for design of two different shape post insulators to obtain electric field distribution along the insulators as uniform as possible. The results show that proposed method based on FIS in order to optimize the high voltage insulator design is successful and can also be used for design of other high voltage apparatus.
{"title":"Insulator design using fuzzy inference system","authors":"S. Kocamaz, O. Kalenderli, O. Altay","doi":"10.1109/ICHVE.2012.6357118","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357118","url":null,"abstract":"High voltage insulators are important part of power transmission and distribution network. Design of an insulator has importance in terms of both reliable operation of equipment and systems. However, various parameters have to be considered during an insulator design such as electric field distribution, mechanical strength, dimensions, which affect each other. Therefore, an optimization is necessary for the design of an insulator. In this study, Fuzzy Inference System (FIS), which is less time consuming and simpler when compared with iterative solutions, has been proposed for design of two different shape post insulators to obtain electric field distribution along the insulators as uniform as possible. The results show that proposed method based on FIS in order to optimize the high voltage insulator design is successful and can also be used for design of other high voltage apparatus.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"120 1","pages":"322-325"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79187948","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357087
Xiaoping Su, Weigen Chen, Chong Pan, Qu Zhou, L. Teng
The winding hot spot temperature of the oil-immersed power transformer is an important parameter factor in the long-term life of the transformer. It has a great influence on the transformer insulation aging and a close relationship to the transformer top oil temperature which is used to indicate the operating conditions of the transformer. In view of the hot-spot rise over top oil temperature is a function dependent on time as well as the transformer loading, this paper developed a simple thermal model to calculate transformer hot spot temperature based on thermal-electrical analogy, which incorporated the nonlinear thermal resistance and application of oil viscosity and winding losses changes with temperature. The model parameters are estimated by Levenberg-Marquardt method. In the end, The comparison of experimental data under various loadings and model outputs shows the accuracy and efficiency of the proposed model, which suggest that this presented model can describe the thermal behavior of oil-immersed transformer more accurately.
{"title":"A simple thermal model of transformer hot spot temperature based on thermal-electrical analogy","authors":"Xiaoping Su, Weigen Chen, Chong Pan, Qu Zhou, L. Teng","doi":"10.1109/ICHVE.2012.6357087","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357087","url":null,"abstract":"The winding hot spot temperature of the oil-immersed power transformer is an important parameter factor in the long-term life of the transformer. It has a great influence on the transformer insulation aging and a close relationship to the transformer top oil temperature which is used to indicate the operating conditions of the transformer. In view of the hot-spot rise over top oil temperature is a function dependent on time as well as the transformer loading, this paper developed a simple thermal model to calculate transformer hot spot temperature based on thermal-electrical analogy, which incorporated the nonlinear thermal resistance and application of oil viscosity and winding losses changes with temperature. The model parameters are estimated by Levenberg-Marquardt method. In the end, The comparison of experimental data under various loadings and model outputs shows the accuracy and efficiency of the proposed model, which suggest that this presented model can describe the thermal behavior of oil-immersed transformer more accurately.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"25 1","pages":"492-495"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75235673","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357098
Tian Ye, Cheng Yangchun, W. Dada, Zhang Shaoquan
This paper introduces a wideband transformer partial discharge (PD) online monitoring system which can be used under the substation environment. It consists of wideband current sensors, amplifiers, filters, a digital oscilloscope and a computer. The wideband current sensors' measuring ranges from 20kHz to 40MHz; the signal amplifiers' frequency bandwidth is 0 ~ 100MHz, the signal gain of it can reach 100 times; the digital oscilloscope is used to acquire and display the PD pulse signal, the sampling rate is set to 100Msps, and the data length is 100M; the computer controls the whole data collection process, and the software platform was written using the Labview. Use a power frequency cycle (20 ms) as a unit for data acquisition. The data collected by the oscilloscope gets into the computer through the USB interface, after filtering, pulse extraction, pulse equivalent time-frequency parameter calculation and other processes, and then conducts the next data collection cycle. After the acquisition of data from 50 power frequency cycles, doing pulse clustering analysis based on the pulse of the equivalent time-frequency parameters. After the completing of pulse clustering analysis, conducts the same kind of pulse of statistical analysis, exclusion of pulse disturbance and fault diagnosis. It can effectively reflect the internal PD change rule under the actual working state of the transformer, can judge the severity of the transformer internal discharge to determine whether maintenance or not, then effectively improve the capacity of safe operation and reduce the maintenance costs.
{"title":"A new wideband transformer partial discharge online monitoring system","authors":"Tian Ye, Cheng Yangchun, W. Dada, Zhang Shaoquan","doi":"10.1109/ICHVE.2012.6357098","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357098","url":null,"abstract":"This paper introduces a wideband transformer partial discharge (PD) online monitoring system which can be used under the substation environment. It consists of wideband current sensors, amplifiers, filters, a digital oscilloscope and a computer. The wideband current sensors' measuring ranges from 20kHz to 40MHz; the signal amplifiers' frequency bandwidth is 0 ~ 100MHz, the signal gain of it can reach 100 times; the digital oscilloscope is used to acquire and display the PD pulse signal, the sampling rate is set to 100Msps, and the data length is 100M; the computer controls the whole data collection process, and the software platform was written using the Labview. Use a power frequency cycle (20 ms) as a unit for data acquisition. The data collected by the oscilloscope gets into the computer through the USB interface, after filtering, pulse extraction, pulse equivalent time-frequency parameter calculation and other processes, and then conducts the next data collection cycle. After the acquisition of data from 50 power frequency cycles, doing pulse clustering analysis based on the pulse of the equivalent time-frequency parameters. After the completing of pulse clustering analysis, conducts the same kind of pulse of statistical analysis, exclusion of pulse disturbance and fault diagnosis. It can effectively reflect the internal PD change rule under the actual working state of the transformer, can judge the severity of the transformer internal discharge to determine whether maintenance or not, then effectively improve the capacity of safe operation and reduce the maintenance costs.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"11 1","pages":"604-607"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75901219","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357064
A. Piantini, T. O. de Carvalho, P. F. Obase, J. M. Janiszewski, G. D. Santos, D. R. Fagundes, J. Uchoa, E. Kunz
The western part of the state of Rio Grande do Sul, in South Brazil, is characterized by high ground flash densities. In the period 2003-2011, lightning overvoltages accounted for about 47 % of the total number of distribution transformer failures observed in the service area of the power company AES Sul. This paper presents the results of an investigation on the influence of the distance between transformer and medium voltage arresters on the surges transferred to the secondary side. The analysis, performed through simulations using the Alternative Transients Program (ATP), shows that in general higher voltages are produced by subsequent strokes. Although the amplitudes of the voltages transferred to the secondary side tend to increase as the surge arrester approaches the transformer, the distance between these equipment should be as short as possible.
{"title":"The effect of the distance between transformer and MV arresters on the surges transferred to the LV side","authors":"A. Piantini, T. O. de Carvalho, P. F. Obase, J. M. Janiszewski, G. D. Santos, D. R. Fagundes, J. Uchoa, E. Kunz","doi":"10.1109/ICHVE.2012.6357064","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357064","url":null,"abstract":"The western part of the state of Rio Grande do Sul, in South Brazil, is characterized by high ground flash densities. In the period 2003-2011, lightning overvoltages accounted for about 47 % of the total number of distribution transformer failures observed in the service area of the power company AES Sul. This paper presents the results of an investigation on the influence of the distance between transformer and medium voltage arresters on the surges transferred to the secondary side. The analysis, performed through simulations using the Alternative Transients Program (ATP), shows that in general higher voltages are produced by subsequent strokes. Although the amplitudes of the voltages transferred to the secondary side tend to increase as the surge arrester approaches the transformer, the distance between these equipment should be as short as possible.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"1 1","pages":"105-109"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76358747","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357043
F. Pratomosiwi, N. Pattanadech, B. Wieser, M. Muhr
Dielectric properties including dissipation factor and dc resistivity has been used widely as a diagnostic parameter of insulation system. In measuring dielectric properties according to IEC 60093 and IEC 60250, the detail of cylindrical live electrode curvature corner shape is not fully explained. The effect from the electrode curvature shape on the electric field distribution should be reduced as small as possible when measuring the dissipation factor and dc resistivity of the oil immersed material. This paper focused on comparative study of the electric field distribution for three electrode configurations. The calculation of the electric field strength was done using finite element method. Then the simulation results were deepened with the laboratory experiment, partial discharges inception voltage (PDIV) and partial discharge (PD) pattern respectively, In this experiment, the dielectric interface configurations consists of oil immersed pressboard operated under oil in a test vessel. The pressboard samples were placed on a grounded plane under cylindrical live electrode with three types of corner shape. The live electrodes used were sharp-cornered electrode and rounded-cornered with radius 3 mm and 5 mm. The solid dielectric were oil immersed transformer board type B 3.1A with 2 mm and 4 mm thickness operated under mineral oil, Nynas Nytro 4000x. The test experiment was set up according to IEC 60270 and the PDIV test procedure performed in accordance with IEC 61294. We concluded that, eventhough round-cornered electrode yields more uniform electric field at the pressboard side, it also yields steep electric field enhancement at the oil side. This nature of rounded-corner electrode makes it easier to generate oil discharge in the wedge (small oil gap) when compared to sharp-cornered electrode. For measuring dielectric properties at high voltage level, this phenomenon should take into account. These results showed the effect of electrode corner shape on electric field enhancement at the contact point of dielectric interface. Furthermore, it could be used as a consideration on which electrode is suitable for measuring dielectric properties of pressboard immersed in oil in compliment with IEC 60093 and IEC 60250.
{"title":"The study of electrode corner shape for measuring dielectric properties of oil immersed material","authors":"F. Pratomosiwi, N. Pattanadech, B. Wieser, M. Muhr","doi":"10.1109/ICHVE.2012.6357043","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357043","url":null,"abstract":"Dielectric properties including dissipation factor and dc resistivity has been used widely as a diagnostic parameter of insulation system. In measuring dielectric properties according to IEC 60093 and IEC 60250, the detail of cylindrical live electrode curvature corner shape is not fully explained. The effect from the electrode curvature shape on the electric field distribution should be reduced as small as possible when measuring the dissipation factor and dc resistivity of the oil immersed material. This paper focused on comparative study of the electric field distribution for three electrode configurations. The calculation of the electric field strength was done using finite element method. Then the simulation results were deepened with the laboratory experiment, partial discharges inception voltage (PDIV) and partial discharge (PD) pattern respectively, In this experiment, the dielectric interface configurations consists of oil immersed pressboard operated under oil in a test vessel. The pressboard samples were placed on a grounded plane under cylindrical live electrode with three types of corner shape. The live electrodes used were sharp-cornered electrode and rounded-cornered with radius 3 mm and 5 mm. The solid dielectric were oil immersed transformer board type B 3.1A with 2 mm and 4 mm thickness operated under mineral oil, Nynas Nytro 4000x. The test experiment was set up according to IEC 60270 and the PDIV test procedure performed in accordance with IEC 61294. We concluded that, eventhough round-cornered electrode yields more uniform electric field at the pressboard side, it also yields steep electric field enhancement at the oil side. This nature of rounded-corner electrode makes it easier to generate oil discharge in the wedge (small oil gap) when compared to sharp-cornered electrode. For measuring dielectric properties at high voltage level, this phenomenon should take into account. These results showed the effect of electrode corner shape on electric field enhancement at the contact point of dielectric interface. Furthermore, it could be used as a consideration on which electrode is suitable for measuring dielectric properties of pressboard immersed in oil in compliment with IEC 60093 and IEC 60250.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"21 1","pages":"553-557"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76780613","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 : 2012-11-26DOI: 10.1109/ICHVE.2012.6357030
O. Arikan, C. F. Kumru, C. Kocatepe
In this study, the capacity, tan delta and dielectric loss of an IVT are measured for different voltage levels and frequency values. The measurement process is realized for the isolation between the primary and secondary windings of a 10kV/0,1 kV nominal rated IVT. As a measurement device, CPC100/CP TD1, which is frequently preferred especially in field applications, is used. Results indicated that, the dissipation factor changes according to the voltage levels. When voltage level gets closer to nominal value or exceeds it, it is seen that tan delta value increases rapidly. Moreover, it is found that the rising frequency has a negative effect on the dielectric loss of the material as a result of the measurements at different frequency values between 50 Hz - 400 Hz.
{"title":"Measurement of the dielectric performance of an instrument transformer at different voltage and frequencies","authors":"O. Arikan, C. F. Kumru, C. Kocatepe","doi":"10.1109/ICHVE.2012.6357030","DOIUrl":"https://doi.org/10.1109/ICHVE.2012.6357030","url":null,"abstract":"In this study, the capacity, tan delta and dielectric loss of an IVT are measured for different voltage levels and frequency values. The measurement process is realized for the isolation between the primary and secondary windings of a 10kV/0,1 kV nominal rated IVT. As a measurement device, CPC100/CP TD1, which is frequently preferred especially in field applications, is used. Results indicated that, the dissipation factor changes according to the voltage levels. When voltage level gets closer to nominal value or exceeds it, it is seen that tan delta value increases rapidly. Moreover, it is found that the rising frequency has a negative effect on the dielectric loss of the material as a result of the measurements at different frequency values between 50 Hz - 400 Hz.","PeriodicalId":6375,"journal":{"name":"2012 International Conference on High Voltage Engineering and Application","volume":"94 1","pages":"451-454"},"PeriodicalIF":0.0,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77532871","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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