Pub Date : 2021-04-11DOI: 10.1109/ICEMPE51623.2021.9509185
Yang Su, Gang Liu, Xiaoming Zhang, Song Yan, Kai Ma, Daojun Huang, Yushun Zhao
The centralized distribution of a large number of power equipment in the switchyard of 500kV substations leads to complicated magnetic field distribution in the switchyard. High-voltage open circuit breakers under maintenance will generate induced currents, which is a safety hazard for circuit breaker maintenance workers. This article first measures the induced current of the circuit breaker, cable, grounding grid, and two grounding wires and the grounding switch in the 500kV switchyard of the substation, and then measures the power frequency magnetic field in the 500kV switchyard of the substation. simulation Research. The measurement and calculation results show that the peak-to-peak value of the induced current generated by the circuit breaker in the 500kV switching field in the 500kV switching field is 3.93∼7.33A, the magnetic induction intensity ranges between 0.44∼8.76µT, and the maximum power frequency magnetic field intensity is mainly concentrated Below the second bus, the closer to the normal working bus, the greater the magnetic induction intensity, which leads to the greater the induced current generated in the high-voltage open circuit breaker. When the high-voltage open circuit breaker is under maintenance, the ground wire is suspended at both ends of the circuit breaker to effectively reduce the induced voltage, thereby ensuring the safety of the operators.
{"title":"Calculation and Analysis of Induced Current of Open Circuit Breaker in 500kV Substation","authors":"Yang Su, Gang Liu, Xiaoming Zhang, Song Yan, Kai Ma, Daojun Huang, Yushun Zhao","doi":"10.1109/ICEMPE51623.2021.9509185","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509185","url":null,"abstract":"The centralized distribution of a large number of power equipment in the switchyard of 500kV substations leads to complicated magnetic field distribution in the switchyard. High-voltage open circuit breakers under maintenance will generate induced currents, which is a safety hazard for circuit breaker maintenance workers. This article first measures the induced current of the circuit breaker, cable, grounding grid, and two grounding wires and the grounding switch in the 500kV switchyard of the substation, and then measures the power frequency magnetic field in the 500kV switchyard of the substation. simulation Research. The measurement and calculation results show that the peak-to-peak value of the induced current generated by the circuit breaker in the 500kV switching field in the 500kV switching field is 3.93∼7.33A, the magnetic induction intensity ranges between 0.44∼8.76µT, and the maximum power frequency magnetic field intensity is mainly concentrated Below the second bus, the closer to the normal working bus, the greater the magnetic induction intensity, which leads to the greater the induced current generated in the high-voltage open circuit breaker. When the high-voltage open circuit breaker is under maintenance, the ground wire is suspended at both ends of the circuit breaker to effectively reduce the induced voltage, thereby ensuring the safety of the operators.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"54 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77455089","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 : 2021-04-11DOI: 10.1109/ICEMPE51623.2021.9509167
Zhenqiang Li, Min Dai, Chuanquan Liu, Ying Lou
With the increasing scale of distribution network and the large number of cable applications, the capacitive current of the system increases continuously. The conventional compensation method of arc suppression coil is limited by the capacity of the device or the space of the substation, so many substations cannot meet the compensation requirements. Distribution network arc suppression coil parallel resistance grounding has the advantages of both arc suppression coil grounding mode and resistance grounding mode. However, the arc suppression coil parallel resistance grounding is not pieced together simply by the two grounding modes, and there are some technology problems needed to study deeply. These are studied for arc suppression coil parallel resistance grounding mode in the paper, including resistance value, put into time and run time of the resistance and so on. Based on protection tripping and isolating fault quickly after single phase grounding fault, and considering to sensitivity of protection and personal safety (touch voltage and step voltage), these control strategies are put forward, which include resistance value of parallel resistance, using adjustable resistance technology proposal and its adjustable range, put into time and run time of the resistance, and the fault line selection characteristic quantity. It is suggested that the distributed compensation device should be installed on the bus or the first end of the line. If it is installed at the end of the line, in order not to affect the fault line selection, its capacity should be selected according to the undercompensated capacitance current of the line.
{"title":"Distribution Network Arc Suppression Coil Distributed Compensation and Its Influence on Fault Line Selection","authors":"Zhenqiang Li, Min Dai, Chuanquan Liu, Ying Lou","doi":"10.1109/ICEMPE51623.2021.9509167","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509167","url":null,"abstract":"With the increasing scale of distribution network and the large number of cable applications, the capacitive current of the system increases continuously. The conventional compensation method of arc suppression coil is limited by the capacity of the device or the space of the substation, so many substations cannot meet the compensation requirements. Distribution network arc suppression coil parallel resistance grounding has the advantages of both arc suppression coil grounding mode and resistance grounding mode. However, the arc suppression coil parallel resistance grounding is not pieced together simply by the two grounding modes, and there are some technology problems needed to study deeply. These are studied for arc suppression coil parallel resistance grounding mode in the paper, including resistance value, put into time and run time of the resistance and so on. Based on protection tripping and isolating fault quickly after single phase grounding fault, and considering to sensitivity of protection and personal safety (touch voltage and step voltage), these control strategies are put forward, which include resistance value of parallel resistance, using adjustable resistance technology proposal and its adjustable range, put into time and run time of the resistance, and the fault line selection characteristic quantity. It is suggested that the distributed compensation device should be installed on the bus or the first end of the line. If it is installed at the end of the line, in order not to affect the fault line selection, its capacity should be selected according to the undercompensated capacitance current of the line.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"434 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77034627","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}
In the accessories of the HVDC cables, cross-linked polyethylene (XLPE) as the main insulation and silicone rubber (SIR) as the accessory insulation form a composite insulation structure. Due to the mismatch of the conductivity and permittivity of the two materials, interface charges will accumulate and affect the electrical properties of the composite insulation under DC voltage. Nano-doping of SIR is one of the means to improve its electrical properties. This paper compares the space charge distribution of the composite insulation composed of nano-TiO2 doped SIR and XLPE and the composite insulation composed of pure SIR and XLPE under different DC electric fields. The experiment results show that nano-doping of SIR can reduce the accumulation of the interface charge in the composite insulation structure when the electric field strength is high, while the interface between pure SIR and XLPE accumulates more charges when electric field strength increases.
{"title":"Effect of Nano-doping on the Interface Charge Characteristics of SIR/XLPE Composite Insulation","authors":"Chunmiao Ma, Yunxiao Zhang, Yuanxiang Zhou, Ling Zhang, Xin Huang","doi":"10.1109/ICEMPE51623.2021.9509050","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509050","url":null,"abstract":"In the accessories of the HVDC cables, cross-linked polyethylene (XLPE) as the main insulation and silicone rubber (SIR) as the accessory insulation form a composite insulation structure. Due to the mismatch of the conductivity and permittivity of the two materials, interface charges will accumulate and affect the electrical properties of the composite insulation under DC voltage. Nano-doping of SIR is one of the means to improve its electrical properties. This paper compares the space charge distribution of the composite insulation composed of nano-TiO2 doped SIR and XLPE and the composite insulation composed of pure SIR and XLPE under different DC electric fields. The experiment results show that nano-doping of SIR can reduce the accumulation of the interface charge in the composite insulation structure when the electric field strength is high, while the interface between pure SIR and XLPE accumulates more charges when electric field strength increases.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"153 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78145994","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}
Hot water is a kind of deicing medium with wide sources, and the impact force of its ejection is easy to control to avoid damaging the surface of glass insulator. In order to reveal the influencing factors of hot water deicing and their effect on the deicing time of glass insulator, an experiment was conducted where LXY-120 glass insulator was selected to measure the hot water deicing time under different circumstances. The results show that initial water temperature has significant effect on deicing time. At certain range, deicing time can be greatly reduced as initial water temperature increases, and it also affects deicing time increasement caused by heavier ice weight. Ejection distance and outlet pressure both have near linear relation with deicing time. It concluded that when conducting hot water deicing, on the premise of ensuring safety distance, shortening deicing distance, optimizing outlet pressure and initial water temperature can improve the ice melting efficiency.
{"title":"Characteristics of Glass Insulator Hot Water Deicing","authors":"Xiaohong Ma, Bingzhe He, Zhijin Zhang, Qi Yang, Lusong Zhang, Huan Huang","doi":"10.1109/ICEMPE51623.2021.9509086","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509086","url":null,"abstract":"Hot water is a kind of deicing medium with wide sources, and the impact force of its ejection is easy to control to avoid damaging the surface of glass insulator. In order to reveal the influencing factors of hot water deicing and their effect on the deicing time of glass insulator, an experiment was conducted where LXY-120 glass insulator was selected to measure the hot water deicing time under different circumstances. The results show that initial water temperature has significant effect on deicing time. At certain range, deicing time can be greatly reduced as initial water temperature increases, and it also affects deicing time increasement caused by heavier ice weight. Ejection distance and outlet pressure both have near linear relation with deicing time. It concluded that when conducting hot water deicing, on the premise of ensuring safety distance, shortening deicing distance, optimizing outlet pressure and initial water temperature can improve the ice melting efficiency.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"19 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78873808","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 : 2021-04-11DOI: 10.1109/ICEMPE51623.2021.9509149
B. Du, J. Xing, M. Xiao, Z. Ran, Haoliang Liu, J. Dong
In the paper, the polypropylene (PP) films doping with m-amino benzoic acid (MAA) were prepared for increasing the dielectric strength of power capacitors. In order to investigate the effect of MAA on electrical properties, the DC breakdown strength and conductivity under different temperatures were tested and analyzed. The results show that by addition of 0.01 wt% MAA in PP films, the breakdown strength increased 18.6% than that of the pure PP film at 25 °C. DC conductivity also possessed a superior at different temperatures, which means the lower conductance loss and less heat accumulation. Besides, the isothermal discharge current (IDC) testing and quantum chemistry method were used to analyze the mechanisms and provide an effective criterion to assess the efficiency of aromatic compounds. The aromatic compounds may be a feasible way to optimize the insulation property of PP films and show great potential in the power capacitors.
{"title":"Improved Dielectric Properties of Polypropylene Films Based on Aromatic Compounds","authors":"B. Du, J. Xing, M. Xiao, Z. Ran, Haoliang Liu, J. Dong","doi":"10.1109/ICEMPE51623.2021.9509149","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509149","url":null,"abstract":"In the paper, the polypropylene (PP) films doping with m-amino benzoic acid (MAA) were prepared for increasing the dielectric strength of power capacitors. In order to investigate the effect of MAA on electrical properties, the DC breakdown strength and conductivity under different temperatures were tested and analyzed. The results show that by addition of 0.01 wt% MAA in PP films, the breakdown strength increased 18.6% than that of the pure PP film at 25 °C. DC conductivity also possessed a superior at different temperatures, which means the lower conductance loss and less heat accumulation. Besides, the isothermal discharge current (IDC) testing and quantum chemistry method were used to analyze the mechanisms and provide an effective criterion to assess the efficiency of aromatic compounds. The aromatic compounds may be a feasible way to optimize the insulation property of PP films and show great potential in the power capacitors.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"88 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79978574","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 : 2021-04-11DOI: 10.1109/ICEMPE51623.2021.9509003
Wei Hu, Chunyang Li, Hong Zhao, Zhenguo Yue, S. Hou, M. Fu
Voltage stabilizers are widely used to improve the electrical tree resistance and breakdown strength of cross-linked polyethylene (XLPE) insulating materials. Ethylene-Propylene-Diene Monomer rubber (EPDM), as a frequently-used material for the enhanced insulation of cable accessories or medium voltage power cable insulation, has also an urgent need for higher breakdown strength. Under working temperature, XLPE is a semi-crystalline polymer while EPDM is an amorphous polymer. As regards whether voltage stabilizers have positive effects in EPDM and whether they are easy to migrate and precipitate out of the rubber which has a loose aggregation structure, little is known. In this work, the effects of four voltage stabilizers on the AC and DC breakdown strengths of EPDM were investigated, and whether the voltage stabilizers are easy to migrate out of EPDM was verified by testing the DC breakdown strength of the samples after degassed in 80 °C vacuum oven for 100 days. Among the selected aromatic voltage stabilizers, only RBBT and AOHBP are slightly effective on improving the AC breakdown strengths of EPDM, while the four voltage stabilizers can all significantly improve the DC breakdown strength, and they are all unlikely to precipitate out of the rubber despite its looser aggregation structure than XLPE, which was confirmed by the further improved DC breakdown strength after degassed for 100d. It is proposed that voltage stabilizers can be expansively used in EPDM rubber to improve its breakdown strength.
{"title":"Effects of Voltage Stabilziers on the AC and DC Breakdown Strengths of EPDM","authors":"Wei Hu, Chunyang Li, Hong Zhao, Zhenguo Yue, S. Hou, M. Fu","doi":"10.1109/ICEMPE51623.2021.9509003","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509003","url":null,"abstract":"Voltage stabilizers are widely used to improve the electrical tree resistance and breakdown strength of cross-linked polyethylene (XLPE) insulating materials. Ethylene-Propylene-Diene Monomer rubber (EPDM), as a frequently-used material for the enhanced insulation of cable accessories or medium voltage power cable insulation, has also an urgent need for higher breakdown strength. Under working temperature, XLPE is a semi-crystalline polymer while EPDM is an amorphous polymer. As regards whether voltage stabilizers have positive effects in EPDM and whether they are easy to migrate and precipitate out of the rubber which has a loose aggregation structure, little is known. In this work, the effects of four voltage stabilizers on the AC and DC breakdown strengths of EPDM were investigated, and whether the voltage stabilizers are easy to migrate out of EPDM was verified by testing the DC breakdown strength of the samples after degassed in 80 °C vacuum oven for 100 days. Among the selected aromatic voltage stabilizers, only RBBT and AOHBP are slightly effective on improving the AC breakdown strengths of EPDM, while the four voltage stabilizers can all significantly improve the DC breakdown strength, and they are all unlikely to precipitate out of the rubber despite its looser aggregation structure than XLPE, which was confirmed by the further improved DC breakdown strength after degassed for 100d. It is proposed that voltage stabilizers can be expansively used in EPDM rubber to improve its breakdown strength.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"11 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80426391","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}
At present, the application of functionally graded materials (FGM) in the field of solid insulation objects has become a hot issue. Applying dielectric functionally graded material (d-FGM) into insulation objects can effectively improve the insulation performance without complicating the physical structure of insulation objects. In the application of d-FGM insulators, how to select the optimal spatially distribution of dielectric parameters (conductivity or permittivity) is one of the key issues. In this paper, two typical types of algorithms (iterative algorithm and topology algorithm) are used to optimize the dielectric parameter distribution of the truncated cone insulator model. It can be seen from the optimization results that the two optimization algorithms have effectively reduced the electric field strength at triple junctions and improved the insulation performance of the insulator. Finally, the optimization effects of the two algorithms are compared, and it is found that topology optimization algorithm has better effect, with higher flexibility and advancement.
{"title":"Comparison of Optimization Methods used in the Design of Functionally Graded Insulation Objects","authors":"Haoyang Yin, Wen-Dong Li, Chao Wang, Zhi-hui Jiang, Wang Guo, Guanjun Zhang","doi":"10.1109/ICEMPE51623.2021.9509090","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509090","url":null,"abstract":"At present, the application of functionally graded materials (FGM) in the field of solid insulation objects has become a hot issue. Applying dielectric functionally graded material (d-FGM) into insulation objects can effectively improve the insulation performance without complicating the physical structure of insulation objects. In the application of d-FGM insulators, how to select the optimal spatially distribution of dielectric parameters (conductivity or permittivity) is one of the key issues. In this paper, two typical types of algorithms (iterative algorithm and topology algorithm) are used to optimize the dielectric parameter distribution of the truncated cone insulator model. It can be seen from the optimization results that the two optimization algorithms have effectively reduced the electric field strength at triple junctions and improved the insulation performance of the insulator. Finally, the optimization effects of the two algorithms are compared, and it is found that topology optimization algorithm has better effect, with higher flexibility and advancement.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83164813","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 : 2021-04-11DOI: 10.1109/ICEMPE51623.2021.9509234
Jia Guimin, Zhou Yuanxiang, Sui Jiang Yuan, Ma Xudong, Jiang Ling, Wang Shengfu
UHV DC transmission lines have large transmission capacity and have networking functions. Large-scale use of insulators in DC UHV lines is an significant part of ensuring the safe and stable operation of transmission lines. Once a pollution flashover occurs, the losses will be huge. The northwestern region has the characteristics of frequent sand and dust weather and high wind speed. In the sand and dust weather, pollution flashovers and other accidents may occur, causing large-scale blackouts and train delays. In response to the above problems, with the sand and dust environment in Xinjiang Uygur Autonomous Region and Qinghai province as the background, the impact of sand and dust on the electric field distribution of insulators under DC field was studied, and a numerical simulation model of insulator operating characteristics under wind and sand environment was established to analyze wind speed, particle size and concentration of sand dust. The influence of peripheral flow field on the pressure and electric field distribution of composite insulators. The study found that wind and sand have a significant impact on the electric field and potential distribution along the insulator. In a dusty environment, the electric field along the shed at both ends of the insulator is still the largest, and the particle charging makes the electric field at both ends increase, and the field strength distortion intensity near the middle shed Compared with the same position in a clean environment, the field strength value becomes lower; the arc is prone to occur at the high voltage end during sandstorm, and the increase of dust particles can directly distort the field strength along the surface; the effect of wind speed on the surface pressure of the insulator is obvious. With the increase of particle size and concentration, its effect on surface pressure tends to be stable. Severe electric field distortion may cause the insulation performance of insulators to fail. Therefore, it is necessary to pay attention to the influence of wind and sand on the electric field changes of insulators during power grid operation to prevent pollution flashover caused by this.
{"title":"Numerical Simulation of Influence of Dust on Electric Field Distribution of Insulators in Northwest China","authors":"Jia Guimin, Zhou Yuanxiang, Sui Jiang Yuan, Ma Xudong, Jiang Ling, Wang Shengfu","doi":"10.1109/ICEMPE51623.2021.9509234","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509234","url":null,"abstract":"UHV DC transmission lines have large transmission capacity and have networking functions. Large-scale use of insulators in DC UHV lines is an significant part of ensuring the safe and stable operation of transmission lines. Once a pollution flashover occurs, the losses will be huge. The northwestern region has the characteristics of frequent sand and dust weather and high wind speed. In the sand and dust weather, pollution flashovers and other accidents may occur, causing large-scale blackouts and train delays. In response to the above problems, with the sand and dust environment in Xinjiang Uygur Autonomous Region and Qinghai province as the background, the impact of sand and dust on the electric field distribution of insulators under DC field was studied, and a numerical simulation model of insulator operating characteristics under wind and sand environment was established to analyze wind speed, particle size and concentration of sand dust. The influence of peripheral flow field on the pressure and electric field distribution of composite insulators. The study found that wind and sand have a significant impact on the electric field and potential distribution along the insulator. In a dusty environment, the electric field along the shed at both ends of the insulator is still the largest, and the particle charging makes the electric field at both ends increase, and the field strength distortion intensity near the middle shed Compared with the same position in a clean environment, the field strength value becomes lower; the arc is prone to occur at the high voltage end during sandstorm, and the increase of dust particles can directly distort the field strength along the surface; the effect of wind speed on the surface pressure of the insulator is obvious. With the increase of particle size and concentration, its effect on surface pressure tends to be stable. Severe electric field distortion may cause the insulation performance of insulators to fail. Therefore, it is necessary to pay attention to the influence of wind and sand on the electric field changes of insulators during power grid operation to prevent pollution flashover caused by this.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"6 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80287001","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 : 2021-04-11DOI: 10.1109/ICEMPE51623.2021.9509049
Li Xining, T. Hao, Yang Fan, Cheng Huanchao, Zhang Shuqi
At present, a typical type oil-paper insulation bushing with draw rod system is widely used as grid side bushing of UHV converter transformer in China. The current carrying and mechanical compensation structure of this special draw rod system is complex, and its internal pulling force and expansion size are affected by environmental temperature, structural size, elastic modulus, expansion coefficient and other factors, which leads to several draw rod system failures. It is urgent to accurately evaluate and verify the influence of draw rod system on the performance of that typical type bushing. Firstly, the calculation model of the draw rod system of the typical type grid side bushing is established. Then, the influence of temperature on the top size expansion and the pressure of the current carrying contact surface in draw rod system are measured, through sensors of temperature, pressure and displacement which are placed on actual gird side bushing. Finally, the calculated results should be compared with the experimental results. It is indicated that these two results are close to each other. The pulling force of the draw rod system increase with the increase of environmental temperature, and the axial load on the bottom contact increases, which accelerates the failure of screw connection. At last, serious discharge fault occurs due to the falling off of bottom contact. The failure mechanism of the current carrying structure at the bottom of the draw rod system under high ambient temperature is analyzed in this paper. The provided results can be a foundation to improve the reliability of the draw rod system of that typical type gird side bushing, as well as condition assessment and quality inspection methods.
{"title":"The Influence of Temperature on Draw Rod System of Converter Transformer Grid Side Bushing","authors":"Li Xining, T. Hao, Yang Fan, Cheng Huanchao, Zhang Shuqi","doi":"10.1109/ICEMPE51623.2021.9509049","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509049","url":null,"abstract":"At present, a typical type oil-paper insulation bushing with draw rod system is widely used as grid side bushing of UHV converter transformer in China. The current carrying and mechanical compensation structure of this special draw rod system is complex, and its internal pulling force and expansion size are affected by environmental temperature, structural size, elastic modulus, expansion coefficient and other factors, which leads to several draw rod system failures. It is urgent to accurately evaluate and verify the influence of draw rod system on the performance of that typical type bushing. Firstly, the calculation model of the draw rod system of the typical type grid side bushing is established. Then, the influence of temperature on the top size expansion and the pressure of the current carrying contact surface in draw rod system are measured, through sensors of temperature, pressure and displacement which are placed on actual gird side bushing. Finally, the calculated results should be compared with the experimental results. It is indicated that these two results are close to each other. The pulling force of the draw rod system increase with the increase of environmental temperature, and the axial load on the bottom contact increases, which accelerates the failure of screw connection. At last, serious discharge fault occurs due to the falling off of bottom contact. The failure mechanism of the current carrying structure at the bottom of the draw rod system under high ambient temperature is analyzed in this paper. The provided results can be a foundation to improve the reliability of the draw rod system of that typical type gird side bushing, as well as condition assessment and quality inspection methods.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"6 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80293234","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}
Epoxy resin is widely used as insulating materials in the electric power equipment; however, these properties are affected by the dielectric relaxation greatly. In this paper, three kinds of E51 bisphenol A epoxy resin with different epoxides were used to make samples for differential scanning calorimetry experiment, fourier transform infrared spectroscopy test and broadband dielectric spectroscopy experiment to research the effect of epoxide on molecular chain relaxation. The results demonstrate the relaxation of molecular chain determines the complex permittivity at high frequency when the temperature is over glass transition temperature ($T_{g}$). Through fitting the complex permittivity, it is found the molecular chain relaxation of epoxy is dipole relaxation polarization. Epoxy resin with higher epoxide has stronger polarization intensity.
{"title":"The Effect of Epoxide on Molecular Chain Relaxation on Bisphenol A Epoxy Resin after Curing","authors":"Mingru Li, Zhuoli Cai, Huan Niu, Shengtao Li, Yafang Gao, Bingnan Li, Hangyin Mao, Weiwang Wang, K. Shang","doi":"10.1109/ICEMPE51623.2021.9509079","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509079","url":null,"abstract":"Epoxy resin is widely used as insulating materials in the electric power equipment; however, these properties are affected by the dielectric relaxation greatly. In this paper, three kinds of E51 bisphenol A epoxy resin with different epoxides were used to make samples for differential scanning calorimetry experiment, fourier transform infrared spectroscopy test and broadband dielectric spectroscopy experiment to research the effect of epoxide on molecular chain relaxation. The results demonstrate the relaxation of molecular chain determines the complex permittivity at high frequency when the temperature is over glass transition temperature ($T_{g}$). Through fitting the complex permittivity, it is found the molecular chain relaxation of epoxy is dipole relaxation polarization. Epoxy resin with higher epoxide has stronger polarization intensity.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89416394","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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