Ze Huang, K. Sun, Bo Hu, Yulai Zhao, Mingpeng He, Jianlin Hu, Xingliang Jiang
{"title":"Influence of Insulation Material Parameters of Large Hydro-generator on Electric Field Distribution and Potential Distribution at the End of Stator Bar","authors":"Ze Huang, K. Sun, Bo Hu, Yulai Zhao, Mingpeng He, Jianlin Hu, Xingliang Jiang","doi":"10.1109/ICEMPE51623.2021.9509004","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509004","url":null,"abstract":"Stator winding of large motors are usually coated with multi-stage anti-corona on the end insulation surface to solve the corona discharge problem. The conductivity parameter coordination of semi-conductive anti-corona on the insulating surface of the winding outlet has great significance. A 3D finite element model of a three-segment nonlinear corona protection structure was established by COMSOL. The influence of insulation material parameters on the distribution of surface potential and electric field at the stator winding was simulated.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"2 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":"76388903","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}
{"title":"Effect of Secondary Drying Impregnation on the Breakdown Characteristics of Oil-Paper","authors":"Pengfei Xu, Lijun Yang, Huanchao Cheng","doi":"10.1109/ICEMPE51623.2021.9509066","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509066","url":null,"abstract":"During the production and operation of oil-immersed transformers, oil-paper is often subjected to secondary drying impregnation due to the associated damp conditions. The influence of secondary drying impregnation on the insulation performance of oil-paper is a general concern of equipment manufacturers and operation departments. This study focused on the influence of initial and secondary drying impregnations on the breakdown strength of oil-paper under different temperatures and water content conditions. A comparison analysis between the breakdown strengths after secondary and initial drying impregnations revealed that the percent decrease of the breakdown strength of oil-paper first increase and then decrease with the increase of the water content; moreover, a higher temperature leads to higher peaks in the percent decrease trend. An analysis of variance of the results of orthogonal experiments showed that secondary drying impregnation significantly influences the breakdown strength of oil-paper (significance level = 0.9); additionally, an interaction diagram of secondary drying impregnation, temperature, and water content indicated that these three factors are coupled.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"393 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":"86825229","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}
Jin Yuqi, Yang Yong, Shao Xianjun, W. Shaoan, Zhao Lin, Xu Ning
{"title":"On Site Test Research and Application of Flexible Short-circuit Current Suppression Technology Based on 220kV Fast Circuit Breaker","authors":"Jin Yuqi, Yang Yong, Shao Xianjun, W. Shaoan, Zhao Lin, Xu Ning","doi":"10.1109/ICEMPE51623.2021.9509107","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509107","url":null,"abstract":"The world's first set of 220kV SF6 fast circuit breaker with flexible short-circuit current suppression has been commercialized. In view of this, the basic principle of flexible suppression of short-circuit current is explained, and the coordination sequence and action strategy of fast circuit breaker and conventional circuit breaker are proposed. In order to realize fast opening, the fast eddy current drive technology and the fast identification technology of short circuit fault are introduced. In order to verify the effectiveness of the proposed action sequence and control strategy, a single-phase artificial short-circuit test of 220kV line was carried out. The test results show that when a single-phase short-circuit fault occurs on the 220kV line of the Tianyi substation, the fast circuit breaker realizes the system splitting operation within 20ms and the short-circuit current is reduced from 30.8kA to 24.2kA, which effectively reduce the short-circuit current level. The protection action time of the fast circuit breaker is shortened by 78% and the full breaking time of the fast circuit breaker is shortened by 64.4% compared with the conventional circuit breaker. The research results provide an important reference for the effective development of short-circuit current suppression and 550kV fast circuit breaker.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"18 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":"88205288","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}
{"title":"Effects of Conductor Pre-tension on Seismic Performance of ConverterTransformer Bushing","authors":"Shan Wang, Jianwei Cheng, Yunlong Chen, Q. Xie","doi":"10.1109/ICEMPE51623.2021.9508990","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9508990","url":null,"abstract":"UHV converter transformer is a critical equipment in converter substation, and bushing is an essential component affecting the seismic performance of it. The refined finite element modeling in ABAQUS software and seismic dynamic analysis was carried out on a ±800kV converter transformer bushing system to evaluate the bushing's seismic performance. The influence of the conductor's pre-tension on the dynamic performance and seismic response of bushing was studied. All parts of the model are simulated by the C3D4R solid elements. The simulation process shows that when the conductor's pre-tension is relatively small, the fundamental vibration mode is the vibration of the conductor it self. Increasing the pre-tension can effectively increase the natural vibration frequency. With the increase of pre-tension, the relative displacement of the valve-side conductor decreased by up to 31.9%, and the air-side conductor reached 31.6%. However, the stress in line-side bushing only increased by 5.9%. Based on the FE model analysis, the following conclusion can be drawn: 1) Appropriately increasing the pre-tension of the conductor can significantly reduce the relative displacement response between the conductor and the inner wall of the bushing. 2) Seismic displacement responses at the end of the valve side bushing are relatively large. It should be paid attention to in the engineering design to prevent traction damage or other problems affecting electrical functions.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"365 ","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":"91519331","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}
Yufan Wang, Jin Li, M. Xiao, Hucheng Liang, H. Yao, B. Du
{"title":"The Improvement of Flashover Characteristics with Field Grading CCTO Coating for GIL Spacer","authors":"Yufan Wang, Jin Li, M. Xiao, Hucheng Liang, H. Yao, B. Du","doi":"10.1109/ICEMPE51623.2021.9509078","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509078","url":null,"abstract":"In gas insulated transmission line (GIL), the insulation failure often occurs due to flashover accidents induced by surface electric field distortion. An emerging coating with field grading CCTO is proposed to improve the electric field distribution and flashover voltage. In this paper, the CCTO coating with different layer thickness was fabricated on the spacer surface by magnetron sputtering. The electrical properties of emerging spacer under different voltage forms were studied through simulation and experiments. The results indicate that CCTO coating can significantly improve the electric field distribution, and the optimized effect is more obvious with the increase of sputtering time. The flashover voltage results show that the sputtered spacers have great insulation performance under AC voltage, DC voltage and polarity reversal voltage.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"203 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":"84616037","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}
{"title":"The Material Properties and Insulation Design for 35kV Flexible and Torsion Resistant Cable","authors":"Xiangyu Fan, Jingwen Xu, Jinghui Gao, L. Zhong, Liang Wang, Xiyuan Zhao","doi":"10.1109/ICEMPE51623.2021.9509122","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509122","url":null,"abstract":"Flexible and torsion resistant cable is one of the key components in wind turbine. Such a cable system needs to withstand the AC electric field and heat dissipation. Therefore, it is of great importance to study the electrical and thermal properties and apply these parameters in cable design. In order to characterize the electric and thermal properties, we measured the breakdown strength, resistance, loss, relative dielectric constant and thermal conductivity of four types of EPR. The breakdown strength of the four specimen ranges from 37 kV/mm to 49 kV/mm, while the resistance distributes in $1.5 times 10^{14} Omegacdot mathrm{m}$ to $2.5 times 10^{14}Omegacdot mathrm{m}$. Meanwhile, the relative dielectric constant keeps between 2.5 and 3.5, and the variation of loss is less than 1% when the temperature is below 90 °C. The thermal conductivity is maintained at 0.4 W/(m·K) at 20 °C-120 °C. In the simulation results, under the full-load operating condition, the maximum conductor temperature is 43.8 °C, which is close to 45.3 °C under the numerical calculation of the thermal circuit model. The highest electric field in this case is 3.9 kV/mm. In the case of a transient short circuit, the cable conductor temperature is 50.5 °C, and under the action of operating overvoltage, the maximum electric field strength is 15.6 kV/mm. All of these cases are within the material tolerance range. The result shows that the design structure is suitable for the flexible and torsion resistant cable.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"30 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90419555","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}
{"title":"Enhanced Thermoelectric Performance of Bi2Te3 through Uniform Dispersion of Ti3C2Tx","authors":"Jian-ying Zhao, Zhengyong Huang, Jian Li, Feipeng Wang, Huijun Liao, Wenjie Xu","doi":"10.1109/ICEMPE51623.2021.9509068","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509068","url":null,"abstract":"As traditional thermoelectric material, Bi<inf>2</inf>Te<inf>3</inf> exhibits excellent thermoelectric properties near room temperature. Thermoelectric properties include electrical properties and thermal properties. In the study, we focused on the improvement of electrical properties. The electrical conductivity and Seebeck coefficient are two parameters for electrical properties. By combining Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf> with high conductivity, the electrical conductivity and Seebeck coefficient of the material can be significantly improved. Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf> with different volume fraction(0.5, 1, 2vol%) was mixed with Bi<inf>2</inf>Te<inf>3</inf> by grinding and vigorously stirring. The bulk sample was obtained by cold sintering process. When the volume fraction of Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf> is 2vol%, the conductivity is significantly increased and the Seebeck coefficient is up to 225mV/K, which results in a high power factor of 1.35W/mK<sup>2</sup>. The results show that the power factor improvement due to the introduction of two-dimensional Ti<inf>2</inf>C<inf>2</inf>T<inf>x</inf> in Bi<inf>2</inf>Te<inf>3</inf> is attributed to the quantum confinement effect. Therefore, when the content of Ti<inf>3</inf>C<inf>2</inf>T<inf>x</inf> is 2 vol%, the thermoelectric performance at 500K has been significantly improved.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"28 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":"88477398","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}
Huan Huang, T. Liang, Xiaohong Ma, Jianrong Wu, Qi Yang, Ying Zhang, Bo Li
{"title":"The Effect of Powdered Layer on the Physicochemical Properties of Silicone Rubber Surface","authors":"Huan Huang, T. Liang, Xiaohong Ma, Jianrong Wu, Qi Yang, Ying Zhang, Bo Li","doi":"10.1109/ICEMPE51623.2021.9509231","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509231","url":null,"abstract":"In this paper, the pulverization phenomenon of composite insulator shed from three different environmental conditions was studied. Several methods were used to test the effect of powdered layer on the physical and chemical properties of silicone rubber surface. Scanning electron microscopy (SEM) was used to observe the surface morphology of the materials. The hydrophobicity of insulator shed is characterized by static contact angle. The surface profile parameters of composite insulator are obtained by detecting the surface of composite insulator with a stylus roughness meter. EDS and FTIR were used to study the elemental composition and chemical groups. The dielectric parameters at different frequencies were obtained by broadband dielectric spectrum scanner. It was observed that the hydrophobicity, roughness and dielectric properties of the composite insulator sample become worse after removing the powdered layer, the chemical composition of the surface can be restored to the fresh state of the silicone rubber. However, the influence trend of powdering on the surface hydrophobicity of composite insulator is not uniform. For composite insulator with serious pulverization, the hydrophobicity will not be improved after removing the powdered layer. The surface roughness of composite insulator will increase greatly due to pulverization. The powdered layer on the surface of composite insulator is mainly composed of small molecules formed by degradation of silicone rubber main chain and fillers separated from the material. The dielectric properties will decrease slightly after de-powdering.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"329 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":"75480022","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}
{"title":"Hydrophobicity Improvement of Polluted Silicone Rubber by Plasma Jet in High Humidity Environment","authors":"Shuang Li, Jianjun Li, Ruobing Zhang","doi":"10.1109/ICEMPE51623.2021.9509218","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509218","url":null,"abstract":"Atmospheric pressure plasma jet can improve the hydrophobicity of polluted silicone rubber in a short time, which is contrary to conventional studies. It offers great application potential in the power system to avoid flashover induced by the low surface hydrophobicity of composite insulators. It is necessary to study the influence of high humidity on the hydrophobicity improvement under plasma exposure for its application in hot and humid regions, e.g. southern China. In this paper, plasma is used to treat polluted silicone rubber to improve its hydrophobicity in a high humidity environment. The high temperature vulcanized silicone rubber is artificially polluted by the solid layer method. The relative humidity is set as 40%, 75%, and 100%. The atmospheric pressure plasma jet is applied to the polluted silicone rubber. Contact angles are measured to characterize the hydrophobicity property of silicone rubber. The results show that plasma can accelerate the hydrophobicity transfer of the silicone rubber covered by a wet pollution layer. The hydrophobicity transfer of treated samples is much faster than the untreated one and it increases with the increase of plasma exposure time. The high humidity environment decreases the hydrophobicity recovery of polluted silicone rubber after plasma treatment. While a longer-time plasma treatment accelerates it.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"93 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":"78331011","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}
{"title":"Interface defect breakdown property and electric field simulation of distribution cable accessories","authors":"Guoqiang Su, Xiaojian Liang, Guochang Li, Jiaxing Wang, Xuejing Li, Yanhui Wei","doi":"10.1109/ICEMPE51623.2021.9509076","DOIUrl":"https://doi.org/10.1109/ICEMPE51623.2021.9509076","url":null,"abstract":"Distribution cable accessories are the key equipment of distribution network system, XLPE/SIR dielectric interface is the weak link of cable accessory insulation. In the work, the interface defect model of XLPE/SIR double-layer structure has been designed, and breakdown properties of double-layer structure with different defects have been studied. Further, the interface defect simulation model of double-layer structure and the cable joint defect are established. The experimental results show the breakdown strength of the specimens with double-layer structure decreases obviously after the defects are introduced, among which the breakdown strength of metal defects and semi-conductive defects are 41.37kV /mm and 43.66kV /mm respectively, which are decreased by 14.2 % and 9.5 % than the samples without defects. The simulation results show the electric field distortion caused by metal defects and semi-conductive defects in the double-layer structure are 44.6 kV /mm and 44.3 kV /mm respectively. The distortion caused by insulation defects is relatively small about 28.3kV/mm, which is consistent with the experimental law. The simulation of cable accessory interface defect shows that the maximum distorted electric field caused by metal defects and semiconducting defects appear at 3.5mm away from the three junction points of “XLPE-SIR-stress cone”, which is about 3.56 kV /mm; In contrast, the maximum electric field distortion caused by insulation defects occurred at the three junction points, which was about 7.23 kV/mm.","PeriodicalId":7083,"journal":{"name":"2021 International Conference on Electrical Materials and Power Equipment (ICEMPE)","volume":"108 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":"75899836","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}