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Dispersion characteristics of switching transients from large‐scale experiments in a 1100 kV gas insulated switchgear circuit

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High Voltage 2023年第6期8卷 1253-1263页

作者： Zihan Teng Weijiang Chen Jiangong Zhang baoquan wan Jun Zhao Kejie Li Zhenghai Liao Zheyuan Gan State Key Laboratory of Power Grid Environmental Protection China Electric Power Research InstituteWuhanChina State Grid Corporation of China BeijingChina School of Electrical Engineering and Automation Hefei University of TechnologyHefeiChina

The switching operation of gas insulated switchgear(GIS)disconnector will produce multiple random spark discharges between the gas gaps of the disconnector.Each spark discharge can be affected by various random factors,such as trapped charge on the load side,the initial operating phase,gap distance and operating speed of the disconnector,leading to dispersion characteristics.At present,some studies have mentioned this dispersion,but its impact is still unclear due to the lack of experimental data,resulting in a deviation between the simulation results and the measured results.In this study,thousands of switching operations were carried out based on the 1100 kV full‐scale GIS circuit in Wuhan ultra‐high voltage alternating current Test Base.The maximal information coeffi-cient analysis,linear regression fitting and other statistical methods were used to discuss the dispersion characteristics of very fast transient overvoltage(VFTO)and transient enclosure voltage(TEV)from large‐scale experimental data.The results show that the dispersion of VFTO and TEV in amplitude aspects both increase gradually as the breakdown voltage increases,with the maximum difference of five times of TEV amplitude at normalised breakdown voltage.In terms of frequency characteristics,the dispersion of different fre-quency components in TEV is always greater than that of VFTO,especially for the high‐frequency components.Moreover,by comparing the frequency characteristics of TEV at different positions,we notice that the dispersion is almost independent of the spatial po-sition but only determined by the randomness of spark discharges.These discoveries reveal the importance of the dispersion in switching transients and make up for the lack of theoretical understanding of the correlation among them.

关键词： characteristics transient breakdown

Recyclability and Self-Healing of Dynamic Cross-Linked Polyimide with Mechanical/Electrical Damage

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Energy & Environmental Materials 2023年第1期6卷 401-407页

作者： baoquan wan Ming-Sheng Zheng Xing Yang Xiaodi Dong Yuchao Li Yiu-Wing Mai George Chen Jun-Wei Zha School of Chemistry and Biological Engineering University of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology Beijing 100083China Shunde Graduate School of University of Science and Technology Beijing Foshan 528300China School of Materials Science and Engineering Liaocheng UniversityLiaocheng 252059China Centre for Advanced Materials Technology(CAMT) School of AerospaceMechanical and Mechatronic EngineeringThe University of SydneySydney New South Wales 2006Australia Department of Electronics and Computer Science University of SouthamptonSouthampton SO171BJUK

Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste.In this work,a dynamic cross-linked polyimide insulation film with full closed-loop recyclability is successfully prepared,which also possesses good self-healing ability after being mechanical/electrical damaged depending on the Schiff base dynamic covalent bonds.The recycled and self-healed polyimide film still maintain its good tensile strength(r t)>60 MPa with Young’s modulus(E)>4 GPa,high thermal stability with glass transition temperature(T g)>220℃,and outstanding insulation property with breakdown strength(E 0)>358 kV mm^(-1),making it a very promising low energy consumption and high temperature resistant insulation material.The strategy of using Schiff base dynamic covalent bonds for reversible repairing the structure of high T g polyimides promotes the wider application of such sustainable and recyclable material in the field of electrical power and micro-electronics.

关键词： electrical damage polyimide recyclability self-healing

Improved breakdown strength and energy density of polyimide composites by interface engineering between BN and BaTiO3 fibers

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Journal of Materials Science & Technology 2021年第15期74卷 1-10页

作者： baoquan wan Haiyu Li Yunhui Xiao Zhongbin Pan Qiwei Zhang Inner Mongolia Key Laboratory of Ferroelectric-related New Energy Materials and Devices Inner Mongolia University of Science and Technology.7#Arding StreetKun DistrictBaotou 014010China School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315000ZhejiangChina Key Laboratory of Integrated Exploitation ofBayan Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou 014010China

Conventionally,interface effects between polymers and fillers are essential for determining the breakdown strength and energy storage density of polymer-based dielectric composites.In this study,we found that interface effects between different fillers have similar behavior.BN and Ba TiO3 fiber composite fillers with three different interface bonding strengths were successfully achieved by controlling composite processes(BT-fiber/BN

关键词： Interface effects Breakdown strength Energy storage density Polyimide

Statistical Analysis of Radio Interference of 1000 kV UHV AC Double-circuit Transmission Lines in Foul Weather

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CSEE Journal of Power and Energy Systems 2016年第2期2卷 47-55页

作者： Huichun Xie Xiang Cui baoquan wan Jiangong Zhang State Key Laboratory of Alternate Electrical Power System with Renewable Source(NCEPU) Beijing 102206China China Electric Power Research Institute Wuhan 430074China

Analyzing the impact of radio interference(RI)variation during foul weather conditions is an area that has received limited study.This paper provides a statistical analysis of RI measurements obtained from a long-term observation station close to the world’s first commercially operating 1000 kV UHV AC double-circuit transmission line in China.During six months of observations,the impact of RI was studied on the line during fog,drizzle,and light snow and rain.It was found that RI increases linearly with the natural logarithm of the precipitation intensity.The Levenberg-Marquardt algorithm(LMA)is employed to fit the RI value with the precipitation intensity.The reasonable distribution of RI in different foul weather is verified by one-sample K-S test.This test is seen as beneficial for further RI prediction based on statistical weather mode.

关键词： 1000 kV UHV AC double-circuit transmission line foul weather precipitation intensity radio interference statistical analysis

Corona Onset Voltage Gradient of Bundle Conductors for EHV/UHV AC Power Lines in Corona Cages Considering Altitude Correction

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CSEE Journal of Power and Energy Systems 2020年第3期6卷 693-703页

作者： Shilong Huang Yunpeng Liu Shaoshuai Chen Daran Liu wangling He baoquan wan School of Electrical Engineering North China Electric Power UniversityBaoding 071003China School of Electrical Engineering Wuhan UniversityWuhan 430072China China Electric Power Research Institute Beijing 10092China

The corona onset voltage gradient(COG)of conductors is a key parameter in the design of overhead transmission lines.The commonly used semi-empirical calculation formula proposed by Peek(1910s)at present can roughly estimate the COG of single conductors and is not applicable to large cross-section bundle conductors.In this paper,experiments are conducted to investigate the corona characteristics of a whole series of bundle conductors at different altitudes,and a prediction formula is proposed for the COG of large cross-section bundle conductors on AC transmission lines considering the altitude correction.The calculated values using the proposed prediction formula are compared with the experimental values of the COG in two cases:UHV eight-bundle conductors at an altitude of 19 m;500 kV UHV four-bundle conductors in Wuhan,Xining,Geermu,and Nachitai at four different altitudes.The results show that the use of the formula can predict the COG of bundle conductors with the radius of 1.34 cm to 1.995 cm and the number of subconductors of 4 to 12 at altitudes of 19 m to 4000 m above the mean sea level.The research findings can provide a reference for the design of EHV and UHV overhead transmission lines and even those in higher voltage levels.

关键词： Bundle conductor corona onset voltage gradient EHV and UHV transmission lines prediction formula

The characteristics of negative corona discharge and radio interference at different altitudes based on coaxial wire-cylinder gap

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Plasma Science and Technology 2024年第2期26卷 77-85页

作者：何旺龄魏宏宇张胤禄刘永聪刘云鹏万保权周阳王延召干喆渊 Hebei Key Laboratory of Green and Efficient New Electrical Materials and Equipment North China Electric Power UniversityBaoding 071000People's Republic of China State Grid Suzhou Power Supply Company Suzhou 215000People's Republic of China State Key Laboratory of Power Grid Environmental Protection(China Electric Power Research Institute) Wuhan 430000People's Republic of China

The corona discharge from transmission lines in high-altitude areas is more severe than at lower altitudes. The radio interference caused thereby is a key factor to be considered when designing transmission lines. To study the influence of altitude on negative corona characteristics, an experimental platform comprising a movable small corona cage was established: experiments were conducted at four altitudes in the range of 1120-4320 m, and data on the corona current pulse and radio interference level of 0.8-mm diameter fine copper wire under different negative voltages were collected. The experimental results show that the average amplitude, repetition frequency and average current of the corona current pulse increase with increasing altitude. The dispersion of pulse amplitude increases with increase in altitude, while the randomness of the pulse interval decreases continuously. Taking the average current as an intermediate variable,the relationship between radio interference level and altitude is obtained. The result of this research has some significance for understanding the corona discharge characteristics of ultra-highvoltage lines.

关键词： altitude negative corona corona current pulse radio interference level

Radio Interference Characteristic of Ultra-high Voltage AC Transmission Lines by Using Stochastic Modeling

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高电压技术 2013年第10期39卷 2438-2444页

作者： HE wangling wan baoquan PEI Chunming ZHANG Jiangong HE Junjia GUO Haozhou School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China China Electric Power Research Institute Wuhan 430074 China

For developing ultra-high voltage(UHV) AC power transmission systems,it is important to precisely estimate and to limit the radio interference(RI) level of power lines.Based on the stochastic characteristics in amplitude and repetition rate of induced corona current,by using the probability theory and mathematical statistics,we establish a stochastic model for the wide-sense stationary random process of corona discharges.Then combining the stochastic model with model-propagation-analysis method,the RI levels under three-phase UHV AC transmission lines are calculated.The results of the calculation based on stochastic model method and International Council on Large Electric Systems(CIGRE) excitation function are compared with that based on semi-empirical method and some other excitation functions.The stochastic model based on different excitation functions is also adopted to simulate the RI levels under finite test lines with two opened terminations.The results indicate that with the same average maximum gradient on conductor surface and the same conductor type,the number of corona discharge per unit length is one of the main reasons that causes the difference between different excitation functions.It is also concluded that for a long test line,the effect of standing wave on RI field strength is negligible in the middle of the line,but obvious near both terminations: for a 10-km line,the maximum difference in RI field strength is 2.78 dB,between the peak value of the standing wave near the ends and the steady value near the middle of the line.

关键词：特高压输电线路交流输电线路无线电干扰随机建模干扰特性概率论与数理统计电力传输系统平稳随机过程

Preparation and Properties of Epoxy Piezoelectric Vibration Reduction Composites

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Journal of Wuhan University of Technology(Materials Science) 2021年第1期36卷 44-49页

作者：汤重郝华 wan baoquan CAO Minghe YAO Zhonghua LIU Hanxing State Key Laboratory of Power Grid Environmental Protection Wuhan 430070China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

The epoxy resin (E-51) was used as polymer matrix,conductive carbon black (CB) as conductive filler,and PZT was used to prepare a composite by curing.The effects of PZT and CB content on the properties of PZT/ CB/ EP piezoelectric composite were studied.When the PZT content reaches 40 wt%,the optimized vibration attenuation properties of PZT/CB/EP materials could be achieved with a loss factor of 0.9 from room temperature to 60 ℃.With the increase of PZT content,the bending strength of PZT/CB/EP piezoelectric composite vibration reduction material firstly increased from 45 MPa to 65 MPa and then decreased to 38 MPa.At room temperature,the dielectric constant increased from 7 to 50,and the dielectric loss increased from 0.1 to 0.5.

关键词： epoxy resin PZT piezoelectric vibration attenuation composites vibration reduction property

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动态可持续聚酰亚胺电介质材料应用与进展

工程科学与技术 2023年第3期55卷 30-39页

作者：万宝全查俊伟北京科技大学化学与生物工程学院北京100083 北京材料基因工程高精尖创新中心北京100083

聚酰亚胺(PI)电介质兼具优异的电气和机械性能以及高热、化学稳定性,被广泛应用于电力、电子设备的生产制造,是绝缘材料的重要组成部分。近年来,随着绿色能源和可持续发展的需求,社会发展更加需要材料在损伤后能够修复、回收等,以实现... 详细信息

聚酰亚胺(PI)电介质兼具优异的电气和机械性能以及高热、化学稳定性,被广泛应用于电力、电子设备的生产制造,是绝缘材料的重要组成部分。近年来,随着绿色能源和可持续发展的需求,社会发展更加需要材料在损伤后能够修复、回收等,以实现再利用。然而,由于PI自身分子结构具有超强的稳定性,分子链在低温条件下难运动,难以实现损伤后的主动修复、回收。因此,必须从本征分子结构角度出发,设计开发适用于PI的新型可逆分子结构来实现材料的动态特性。基于此,本文综述了以PI为基体的回收、修复等动态问题的研究,重点介绍目前动态PI的制备方法、发生动态反应的条件及评估多种损伤形式之间的关系;总结了自修复PI电介质材料,包括共混、共聚及设计制备新型结构单体等工艺手段实现材料的修复特性,以及自修复PI当前的发展现状及面临的困难与挑战;概述了可降解、可回收PI材料的设计制备,通过动态共价键和动态交联网络择优实现PI电介质的回收,对于目前动态PI体系中存在的问题及未来研究方向进行了总结和展望:可以使用新型动态交联剂结合微量有机或无机物料的复合实现PI材料的动态特性和综合性能的协同提升;通过改善工艺或选择动态交联剂实现PI单体和交联剂粉末级别回收,有效避免降解催化剂的影响;需要进一步设计新型功能性单体,从分子结构水平实现可逆以解决PI修复、降解、回收难的问题。

关键词：聚酰亚胺电/机械损伤动态反应可持续发展