Pub Date : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9280049
Y. Miao, Mingxuan Zhang, F. Zeng, Ju Tang, Haotian Li, Liangjun Dai, Q. Yao
The SF6 gas insulation medium will decompose under the partial over-thermal fault (POF) inside the GIS equipment, which declines the insulation performance, thereby endangering the safety of the equipment. Although the decomposition characteristics under several degrees of POF are obtained, the problem of describing the continuous process of SF6 decomposition under POF has not been solved. The difficulty lies in the lack of a force field that can effectively describe the decomposition process of SF6. To this end, this paper first calculates the main molecular systems of fluoride-sulfides based on density functional theory, and obtains a training set for establishing a force field file. Based on the training set, the Reax FF force field is optimized using a fitting algorithm, and the correctness of the force field is verified. Then, the molecular dynamic simulations of SF6 under the over-thermal state is studied. The breaking and bonding process of SF6, SF5, SF4, SF3, and SF2 is clarified and compared with the macro experimental data of SF6 decomposition under partial over-thermal fault. The results show that the established force field can accurately describe the breaking and bonding process of SF6, SF5, SF4, SF3 and SF2 molecules. The simulation data is in good agreement with the actual experiments, and the research work in this paper lays a foundation for the systematic study of over-thermal decomposition of SF6.
{"title":"Construction of Reax FF Force Field for SF6 Gas Insulation Medium under Over-thermal Fault","authors":"Y. Miao, Mingxuan Zhang, F. Zeng, Ju Tang, Haotian Li, Liangjun Dai, Q. Yao","doi":"10.1109/ICHVE49031.2020.9280049","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9280049","url":null,"abstract":"The SF<inf>6</inf> gas insulation medium will decompose under the partial over-thermal fault (POF) inside the GIS equipment, which declines the insulation performance, thereby endangering the safety of the equipment. Although the decomposition characteristics under several degrees of POF are obtained, the problem of describing the continuous process of SF6 decomposition under POF has not been solved. The difficulty lies in the lack of a force field that can effectively describe the decomposition process of SF<inf>6</inf>. To this end, this paper first calculates the main molecular systems of fluoride-sulfides based on density functional theory, and obtains a training set for establishing a force field file. Based on the training set, the Reax FF force field is optimized using a fitting algorithm, and the correctness of the force field is verified. Then, the molecular dynamic simulations of SF<inf>6</inf> under the over-thermal state is studied. The breaking and bonding process of SF<inf>6</inf>, SF<inf>5</inf>, SF<inf>4</inf>, SF<inf>3</inf>, and SF<inf>2</inf> is clarified and compared with the macro experimental data of SF<inf>6</inf> decomposition under partial over-thermal fault. The results show that the established force field can accurately describe the breaking and bonding process of SF<inf>6</inf>, SF<inf>5</inf>, SF<inf>4</inf>, SF<inf>3</inf> and SF<inf>2</inf> molecules. The simulation data is in good agreement with the actual experiments, and the research work in this paper lays a foundation for the systematic study of over-thermal decomposition of SF<inf>6</inf>.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"25 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75322522","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}
The shared tower integrates power and communication equipment, and its new base station antenna makes the passive interference mechanism and level of transmission line to the radio station adjacent to the line change. Therefore, the passive interference mechanism of the shared tower to the station is analyzed. Compared with the traditional transmission line, the shared tower is the combination of the scatterers with discontinuous electricity, and the second-order coupling scattering will occur among the scatterers. The compound scattering field model of the shared tower under the coupling effect is established, and the scattering field under the coupling background is solved by using the equivalent principle and reciprocity theorem, so as to realize the solution of passive interference level. Taking the tower type, incident angle and antenna power of the shared tower as variables, the passive interference levels of stations with different frequencies under three factors are solved respectively, and the change rule of passive interference of the shared tower is obtained. It is suggested that the shared tower should take some passive interference protection measures for the stations adjacent to the base station antenna frequency.
{"title":"Mechanism and solution of passive interference of shared tower to adjacent radio station","authors":"X. Liu, Yong Peng, Qiaosha Xiao, Ding Zhou, Zhongyuan Zheng, B. Tang","doi":"10.1109/ICHVE49031.2020.9279609","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279609","url":null,"abstract":"The shared tower integrates power and communication equipment, and its new base station antenna makes the passive interference mechanism and level of transmission line to the radio station adjacent to the line change. Therefore, the passive interference mechanism of the shared tower to the station is analyzed. Compared with the traditional transmission line, the shared tower is the combination of the scatterers with discontinuous electricity, and the second-order coupling scattering will occur among the scatterers. The compound scattering field model of the shared tower under the coupling effect is established, and the scattering field under the coupling background is solved by using the equivalent principle and reciprocity theorem, so as to realize the solution of passive interference level. Taking the tower type, incident angle and antenna power of the shared tower as variables, the passive interference levels of stations with different frequencies under three factors are solved respectively, and the change rule of passive interference of the shared tower is obtained. It is suggested that the shared tower should take some passive interference protection measures for the stations adjacent to the base station antenna frequency.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77971707","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}
The U-type bushing adopts a modular structure, which consists of the indoor bushing, outdoor bushing and the gas-insulated metal-enclosed switchgear (GIS) bus. Its electrical, thermal and mechanical characteristics, as well as structural requirements are different from the conventional horizontal wall bushing. Taking the commonly used ±800kV/5000A bushing as an example, a design case is presented, which is compared with a horizontal bushing applied in real HVDC project. The distribution of electric-thermal-mechanical stress in key positions of the two types of bushing under various testing conditions is obtained by 3d finite element simulation. Based on the simulation results, the electric-thermal-mechanical properties of the two kinds of bushing are compared, which illustrated the distinctive characteristics of the U-type busing. Comparison shows that the U-type busing is slightly better in the electrical and thermal performance, and significantly better in mechanical stability than the horizontal one.
{"title":"Comparative Study of Electric-thermal-mechanical of ±800kV U-type and Horizontal wall bushing","authors":"Kejie Huang, Jianwei Cheng, Shuaibing Wang, X. Sun, Junlin Zhu, W. Zhang","doi":"10.1109/ICHVE49031.2020.9279648","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279648","url":null,"abstract":"The U-type bushing adopts a modular structure, which consists of the indoor bushing, outdoor bushing and the gas-insulated metal-enclosed switchgear (GIS) bus. Its electrical, thermal and mechanical characteristics, as well as structural requirements are different from the conventional horizontal wall bushing. Taking the commonly used ±800kV/5000A bushing as an example, a design case is presented, which is compared with a horizontal bushing applied in real HVDC project. The distribution of electric-thermal-mechanical stress in key positions of the two types of bushing under various testing conditions is obtained by 3d finite element simulation. Based on the simulation results, the electric-thermal-mechanical properties of the two kinds of bushing are compared, which illustrated the distinctive characteristics of the U-type busing. Comparison shows that the U-type busing is slightly better in the electrical and thermal performance, and significantly better in mechanical stability than the horizontal one.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"317 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78289258","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 : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279967
Zuoming Xu, Wei Hu, P. Yin, Xiongjie Xie, Xiaoqing Luo, B. Wan
Dampness is one of the common failures of epoxy Resin Impregnated Paper (RIP) bushings. In order to study the influence of moisture on the insulation performance of RIP bushing, samples were made by cutting from the actual bushing. The moisture content was measured with a precise moisture tester which can dry and weigh the samples. The dielectric loss factor (tanδ), insulation resistance, dielectric absorption ratio, frequency domain dielectric spectrum and other parameters of the sample with different moisture content were measured in a three electrode system. The test results indicate that the insulation resistance and dielectric absorption ratio of the sample both decreases with the increase of moisture content. When the moisture content is less than 0.67%, the dielectric absorption ratio is above 1.5. The dielectric loss factor and the relative permittivity of the sample increase exponentially with the increase of the moisture content. The measurement results of frequency domain dielectric spectrum show that the tanδ in 1Hz-100Hz frequency band is more sensitive to the moisture content of the sample piece. When the moisture content is lower than 0.5%, the tanδ -f curve shows a V-shaped change trend in this frequency band, and the inflection point appears at 10Hz. The relationship between integral value of tanδ-f curve and moisture content can also be expressed by exponential function. And the real part of complex permittivity increases with the increasing of moisture content but decreases with the frequency increasing. The research results can provide reference for RIP bushing insulation diagnosis and operation maintenance.
{"title":"The influence of moisture on the insulation performance of epoxy resin impregnated paper","authors":"Zuoming Xu, Wei Hu, P. Yin, Xiongjie Xie, Xiaoqing Luo, B. Wan","doi":"10.1109/ICHVE49031.2020.9279967","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279967","url":null,"abstract":"Dampness is one of the common failures of epoxy Resin Impregnated Paper (RIP) bushings. In order to study the influence of moisture on the insulation performance of RIP bushing, samples were made by cutting from the actual bushing. The moisture content was measured with a precise moisture tester which can dry and weigh the samples. The dielectric loss factor (tanδ), insulation resistance, dielectric absorption ratio, frequency domain dielectric spectrum and other parameters of the sample with different moisture content were measured in a three electrode system. The test results indicate that the insulation resistance and dielectric absorption ratio of the sample both decreases with the increase of moisture content. When the moisture content is less than 0.67%, the dielectric absorption ratio is above 1.5. The dielectric loss factor and the relative permittivity of the sample increase exponentially with the increase of the moisture content. The measurement results of frequency domain dielectric spectrum show that the tanδ in 1Hz-100Hz frequency band is more sensitive to the moisture content of the sample piece. When the moisture content is lower than 0.5%, the tanδ -f curve shows a V-shaped change trend in this frequency band, and the inflection point appears at 10Hz. The relationship between integral value of tanδ-f curve and moisture content can also be expressed by exponential function. And the real part of complex permittivity increases with the increasing of moisture content but decreases with the frequency increasing. The research results can provide reference for RIP bushing insulation diagnosis and operation maintenance.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"26 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78309374","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}
To compare different types of impulse currents on the degradation of Zinc-oxide varistors, 2 milliseconds square wave and 10/1000 microseconds impact current with the same impact energy were respectively applied to the same type of ZnO varistor samples. The three characteristic parameters' trends of samples with a diameter of 20 millimeters after multiple pulses are different, and the sample after 940 times impacts by 2 milliseconds square wave with an amplitude of 160 amperes remained intact, while the one exploded after 499 times impacts by 10/1000 microseconds impact current with an amplitude of 260 amperes. And the microstructure of samples with a diameter of 10 millimeters after the single pulse by using scanning electron microscopy (SEM) are observed. We find that with the same impact energy, the damage degree of 10/1000 microseconds impact current on ZnO varistor is relatively greater than that of 2 milliseconds square wave, which is more likely to cause the deterioration and aging of ZnO varistors.
{"title":"Comparison with the influence of different types of impulse currents on the degradation of Zinc-oxide varistors","authors":"Weikang Li, X. Yao, Jinru Sun, Qingqing Li, Hao Wang, Xin Zhu","doi":"10.1109/ICHVE49031.2020.9279444","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279444","url":null,"abstract":"To compare different types of impulse currents on the degradation of Zinc-oxide varistors, 2 milliseconds square wave and 10/1000 microseconds impact current with the same impact energy were respectively applied to the same type of ZnO varistor samples. The three characteristic parameters' trends of samples with a diameter of 20 millimeters after multiple pulses are different, and the sample after 940 times impacts by 2 milliseconds square wave with an amplitude of 160 amperes remained intact, while the one exploded after 499 times impacts by 10/1000 microseconds impact current with an amplitude of 260 amperes. And the microstructure of samples with a diameter of 10 millimeters after the single pulse by using scanning electron microscopy (SEM) are observed. We find that with the same impact energy, the damage degree of 10/1000 microseconds impact current on ZnO varistor is relatively greater than that of 2 milliseconds square wave, which is more likely to cause the deterioration and aging of ZnO varistors.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"121 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78427437","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 : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279808
Zhou Feng, Wan Fu, Jianxin Wang, Hu Jin, Hangyin Mao, Wang Pinyi, Chengzhi Zhu, Weigen Chen
As the insulating medium, sulfur hexafluoride (SF6) is widely applied in gas insulation equipment. Over longterm operation, the solid insulation of the equipment is damaged by PD, causing it to react with SF6 to generate COS and CF4 which are critical SF6decomposition products inside the equipment. The detection of these two SF6 decomposition products can help in assessment of the type and severity of insulation defects. Compared to the absorption spectroscopy and photoacoustic spectroscopy, FERS can using a single wavelength laser to simultaneously achieve the high sensitivity detection of mixture gases. In this paper, a highly sensitive SF6 decomposition based on fiber-enhanced Raman spectroscopy is built up. The Raman spectroscopy of COS and CF4 was acquired. The characteristic peak of COS at 859 cm−1 and that of CF4 at 909 cm−1 were observed respectively. We study the relationship between laser power, pressure of fiber core and Raman scattering intensity, experimentally. The Raman scattering intensity is linear related to laser power and pressure. The response time of FERS which includes the filling time and evacuating time. was also examined. The filling time of the fiber is defined as the point when the intensity of the Raman peak does not change. FERS is promising to achieve the online monitoring technique to detect the SF6 decomposition components with highly selective and sensitive.
{"title":"Highly sensitive fiber-enhanced Raman spectroscopy for simultaneous detection of SF6 decomposition","authors":"Zhou Feng, Wan Fu, Jianxin Wang, Hu Jin, Hangyin Mao, Wang Pinyi, Chengzhi Zhu, Weigen Chen","doi":"10.1109/ICHVE49031.2020.9279808","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279808","url":null,"abstract":"As the insulating medium, sulfur hexafluoride (SF6) is widely applied in gas insulation equipment. Over longterm operation, the solid insulation of the equipment is damaged by PD, causing it to react with SF6 to generate COS and CF4 which are critical SF6decomposition products inside the equipment. The detection of these two SF6 decomposition products can help in assessment of the type and severity of insulation defects. Compared to the absorption spectroscopy and photoacoustic spectroscopy, FERS can using a single wavelength laser to simultaneously achieve the high sensitivity detection of mixture gases. In this paper, a highly sensitive SF6 decomposition based on fiber-enhanced Raman spectroscopy is built up. The Raman spectroscopy of COS and CF4 was acquired. The characteristic peak of COS at 859 cm−1 and that of CF4 at 909 cm−1 were observed respectively. We study the relationship between laser power, pressure of fiber core and Raman scattering intensity, experimentally. The Raman scattering intensity is linear related to laser power and pressure. The response time of FERS which includes the filling time and evacuating time. was also examined. The filling time of the fiber is defined as the point when the intensity of the Raman peak does not change. FERS is promising to achieve the online monitoring technique to detect the SF6 decomposition components with highly selective and sensitive.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"45 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75530518","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 : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279563
Jia-yu Chen, Weilin Yang, Hong-yu Ni, Wen-xu Yan
Bridge crane system is widely used in production and life. Even so, we still have a lot of problems to solve on it, such as trajectory planning for the large vehicle and small vehicle and anti-swing of the hoist. However, the anti-swing problem of the bridge crane system is an issue of great value. A sliding mode control method is designed to solve this problem. Because of the characteristic that the bridge crane system is an under-actuated system, it is modeled on Lagrangian dynamics. The effect of the ordinary sliding mode control method for under-actuated systems is no longer satisfactory. A hierarchical sliding mode control is used instead of the ordinary sliding mode control. For under-actuated systems, the basic idea of the hierarchical sliding mode control method is to separate the driving part and under-acting part of the system into different subsystems. In this control method, the slip surface is divided into two layers. The first layer of slip surface includes two parts: one is the displacement error sub-sliding surface of vehicle, and the other is the suspended swing error sub-sliding surface. The second layer is the total slip surface. It contains two sub-sliding surfaces in the direction of the vehicle. The equivalent input term in the sense of Filippov is obtained according to the sliding mode surface of the first layer, and the switching control function term is obtained from the sliding mode surface of the second layer using the Lyapunov feedback function design method. The total system input can be got by combining the equivalent input term and the switching control function term. The simulation experiment by using the simulation module of Matlab is operated, and the simulation results prove the method has good control effect and robustness.
{"title":"A Hierarchical Sliding Mode Control Method for Bridge Crane System","authors":"Jia-yu Chen, Weilin Yang, Hong-yu Ni, Wen-xu Yan","doi":"10.1109/ICHVE49031.2020.9279563","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279563","url":null,"abstract":"Bridge crane system is widely used in production and life. Even so, we still have a lot of problems to solve on it, such as trajectory planning for the large vehicle and small vehicle and anti-swing of the hoist. However, the anti-swing problem of the bridge crane system is an issue of great value. A sliding mode control method is designed to solve this problem. Because of the characteristic that the bridge crane system is an under-actuated system, it is modeled on Lagrangian dynamics. The effect of the ordinary sliding mode control method for under-actuated systems is no longer satisfactory. A hierarchical sliding mode control is used instead of the ordinary sliding mode control. For under-actuated systems, the basic idea of the hierarchical sliding mode control method is to separate the driving part and under-acting part of the system into different subsystems. In this control method, the slip surface is divided into two layers. The first layer of slip surface includes two parts: one is the displacement error sub-sliding surface of vehicle, and the other is the suspended swing error sub-sliding surface. The second layer is the total slip surface. It contains two sub-sliding surfaces in the direction of the vehicle. The equivalent input term in the sense of Filippov is obtained according to the sliding mode surface of the first layer, and the switching control function term is obtained from the sliding mode surface of the second layer using the Lyapunov feedback function design method. The total system input can be got by combining the equivalent input term and the switching control function term. The simulation experiment by using the simulation module of Matlab is operated, and the simulation results prove the method has good control effect and robustness.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"32 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75669423","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 : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279903
Wenbo Huang, Kang Ping Chen, Z. An, Xin Wang, F. Zheng, Yewen Zhang
Effective suppression of charge accumulation on epoxy spacers in high voltage gas insulated systems is one of the most concerned problems for the researchers and engineers in the field of electrical insulation, being of great significance for the development of HVDC/HVAC GIL or GIS. In order to suppress charge accumulation on the epoxy insulator and to improve its dc flashover performance, the first attempt to direct fluorination of epoxy insulators has been carried out as early as the second half of 2010 in Tongji University. In the next decade, a series of studies have been carried out, ranging from samples and model insulators to actual insulators, especially in terms of improving dc flashover performance and arc resistance. The research results achieved so far will provide strong support for the improvement by direct fluorination in practical performance of epoxy spacers in the future. This report reviews the results of a series of studies and the mechanisms behind the property/ performance improvements in terms of the changes in material composition and structure.
{"title":"Simultaneously Enhanced dc Flashover Performance and Arc Resistance of Epoxy Insulators by Direct Fluorination","authors":"Wenbo Huang, Kang Ping Chen, Z. An, Xin Wang, F. Zheng, Yewen Zhang","doi":"10.1109/ICHVE49031.2020.9279903","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279903","url":null,"abstract":"Effective suppression of charge accumulation on epoxy spacers in high voltage gas insulated systems is one of the most concerned problems for the researchers and engineers in the field of electrical insulation, being of great significance for the development of HVDC/HVAC GIL or GIS. In order to suppress charge accumulation on the epoxy insulator and to improve its dc flashover performance, the first attempt to direct fluorination of epoxy insulators has been carried out as early as the second half of 2010 in Tongji University. In the next decade, a series of studies have been carried out, ranging from samples and model insulators to actual insulators, especially in terms of improving dc flashover performance and arc resistance. The research results achieved so far will provide strong support for the improvement by direct fluorination in practical performance of epoxy spacers in the future. This report reviews the results of a series of studies and the mechanisms behind the property/ performance improvements in terms of the changes in material composition and structure.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"11 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75680481","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 : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279494
Jianwei Cheng, Ran Shi, Ao Gong, Wei Zhang, Guohua Yang, Zongren Peng
Fittings like spacers are vital parts in the valve hall which could connect lines and buses. However, spacers without proper arrangement and structure would result in unexpected flashover or discharge, thus to risk the safety of the whole valve hall. In this paper, the finite element simulation model of ± 800kV HVDC-flexible low voltage valve hall was established in the software Comsol. The overall electric field distribution was calculated and analyzed. In addition, e-field of several kinds of splitting spacer structure were also studied and compared, with experiments accomplished to verify the simulation results. The results could provide with evidence on designing fittings in the valve hall.
{"title":"Calculation and optimization of four splitting spacers and fittings in ± 800kV HVDC-Flexible low voltage valve hall","authors":"Jianwei Cheng, Ran Shi, Ao Gong, Wei Zhang, Guohua Yang, Zongren Peng","doi":"10.1109/ICHVE49031.2020.9279494","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279494","url":null,"abstract":"Fittings like spacers are vital parts in the valve hall which could connect lines and buses. However, spacers without proper arrangement and structure would result in unexpected flashover or discharge, thus to risk the safety of the whole valve hall. In this paper, the finite element simulation model of ± 800kV HVDC-flexible low voltage valve hall was established in the software Comsol. The overall electric field distribution was calculated and analyzed. In addition, e-field of several kinds of splitting spacer structure were also studied and compared, with experiments accomplished to verify the simulation results. The results could provide with evidence on designing fittings in the valve hall.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"2 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74539802","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 : 2020-09-06DOI: 10.1109/ICHVE49031.2020.9279520
Y. Ge, Liheng Xiang, Yongshuang Li, Rui He, Wenhua Liu, Chengrong Li
Nanomaterials have provided their superior properties on the insulation performance of HVDC transformer, which is helpful to ensure the safe and stable operation of the ultra-large-scale transmission system effectively. Especially, nanomaterials conduce to reduce the size and cost of the HVDC transformer. Their effectiveness is related to the microscopic properties of nanomaterials. However, the influences of nanomaterial microscopic properties on insulation performance are lacking. This paper focuses on the effect of nanomaterial surface modification on the insulation performance of transformer oil. Titanium dioxide nanomaterials with different surface modification (acetic acid, caproic acid and oleic acid) were prepared and added into the transformer oil evenly. The breakdown property and discharge streamer propagation of transformer oil and nanofluids under positive lightning impulse voltage were measured. The results show that the surface modification of nanomaterials has a significant impact on the lightning breakdown performance of transformer oil. Compared with transformer oil, the breakdown voltage and time to breakdown of nanofluid with acetic acid modifier are increased by 37.4% and 67.7%, respectively. The breakdown voltage of nanofluid increases with the decrease of the chain length of carboxylic acid molecule. Moreover, As the chain length of carboxylic acid molecule of the nanomaterial modifier decreases, the streamer branches are denser and the development speed is slower. Therefore, the nanomaterials with acetic acid modifier inhibit the development of the streamer propagation more obviously, thereby generating a better performance on the breakdown voltage of transformer.
{"title":"Effect of surface modification of nanomaterial on insulation performance for HVDC transformer","authors":"Y. Ge, Liheng Xiang, Yongshuang Li, Rui He, Wenhua Liu, Chengrong Li","doi":"10.1109/ICHVE49031.2020.9279520","DOIUrl":"https://doi.org/10.1109/ICHVE49031.2020.9279520","url":null,"abstract":"Nanomaterials have provided their superior properties on the insulation performance of HVDC transformer, which is helpful to ensure the safe and stable operation of the ultra-large-scale transmission system effectively. Especially, nanomaterials conduce to reduce the size and cost of the HVDC transformer. Their effectiveness is related to the microscopic properties of nanomaterials. However, the influences of nanomaterial microscopic properties on insulation performance are lacking. This paper focuses on the effect of nanomaterial surface modification on the insulation performance of transformer oil. Titanium dioxide nanomaterials with different surface modification (acetic acid, caproic acid and oleic acid) were prepared and added into the transformer oil evenly. The breakdown property and discharge streamer propagation of transformer oil and nanofluids under positive lightning impulse voltage were measured. The results show that the surface modification of nanomaterials has a significant impact on the lightning breakdown performance of transformer oil. Compared with transformer oil, the breakdown voltage and time to breakdown of nanofluid with acetic acid modifier are increased by 37.4% and 67.7%, respectively. The breakdown voltage of nanofluid increases with the decrease of the chain length of carboxylic acid molecule. Moreover, As the chain length of carboxylic acid molecule of the nanomaterial modifier decreases, the streamer branches are denser and the development speed is slower. Therefore, the nanomaterials with acetic acid modifier inhibit the development of the streamer propagation more obviously, thereby generating a better performance on the breakdown voltage of transformer.","PeriodicalId":6763,"journal":{"name":"2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE)","volume":"77 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73151598","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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