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High Voltage 2024年第1期9卷 22-34页

作者： Haichuan Yu Qiang Liu zhongdong wang Department of Electrical and Electronic Engineering The University of ManchesterManchesterUK Department of Engineering University of ExeterExeterUK

Ester liquids(ELs),as the alternative transformer liquids to the conventional mineral oils(MOs),have been increasingly used in power transformers with high voltage *** various properties,the lightning impulse breakdown voltages(LIBDVs)have been studied elaborately in the past two decades under different electric field *** electric field uniformities do have an effect on the breakdown characteristics,for example,breakdown mechanisms,polarity effects,and differences of LIBDV between ELs and MOs,which is quantitatively investigated based on the LIBDVs collected from the *** breakdown mechanism transition phenomenon between streamer initiation dominated breakdown and streamer propagation dominated breakdown has been reviewed ***,the transition field factor boundaries to observe the polarity effect on LIBDVs are taken at around 20 for ELs and 10 for ***,the transition field factor boundaries to observe the LIBDV distinctions between ELs and MOs are about 109 and 14 under positive and negative lightning impulse,*** systematic analysis and interpretation on the transition field factor boundaries among different phenomena can provide insights on insulation design of ELs filled power transformers.

关键词： field lightning breakdown

基于误差状态模糊分析的电容式电压互感器内绝缘状态评价方法

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电测与仪表 2024年第4期61卷 73-80页

作者：王欢王忠东卢树峰陆子刚刘俭中国电力科学研究院有限公司武汉分院武汉430074 国网江苏省电力有限公司营销服务中心南京210019 华中科技大学武汉430074

电容式电压互感器(CVT)的内绝缘状态是保证其计量准确性和运行稳定性的关键因素。然而,在长期运行过程中,电老化、热老化以及系统过电压等因素会导致CVT的内绝缘状态出现劣化。针对此问题,文中提出了一种数据驱动的CVT内绝缘状态评价方... 详细信息

电容式电压互感器(CVT)的内绝缘状态是保证其计量准确性和运行稳定性的关键因素。然而,在长期运行过程中,电老化、热老化以及系统过电压等因素会导致CVT的内绝缘状态出现劣化。针对此问题,文中提出了一种数据驱动的CVT内绝缘状态评价方法。该方法利用高压CVT群体之间的电气连接关系构建CVT误差状态的特征参量,基于CVT误差状态与内绝缘状态的相关性,通过模糊分析方法匹配CVT的误差状态与内绝缘状态,实现了在线评价CVT异常内绝缘状态的异常程度和异常类型。

关键词：电容式电压互感器误差状态内绝缘状态模糊分析

Comparison of Parameter Estimation Methods for Transformer Weibull Lifetime Modelling

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高电压技术 2013年第5期39卷 1170-1177页

作者： ZHOU Dan LI Chengrong wang zhongdong Beijing Key Laboratory of High Voltage and Electromagnetic Compatability School of Electric and Electronic EngineeringNorth China Electric Power UniversityBeijing 102206China The University of Manchester Manchester M13 9PLUnited Kingdom

Two-parameter Weibull distribution is the most widely adopted lifetime model for power *** appropriate parameter estimation method is essential to guarantee the accuracy of a derived Weibull lifetime *** popular parameter estimation methods(*** maximum likelihood estimation method,two median rank regression methods including the one regressing X on Y and the other one regressing Y on X,the Kaplan-Meier method,the method based on cumulative hazard plot,and the Li ’ s method) are reviewed and compared in order to find the optimal one that suits transformer ’ s Weibull lifetime *** comparison took several different scenarios into consideration : 10 000sets of lifetime data,each of which had a sampling size of 40~1 000and a censoring rate of 90%,were obtained by Monte-Carlo simulations for each *** and shape parameters of Weibull distribution estimated by the six methods,as well as their mean value,median value and 90% confidence band are *** cross comparison of these results reveals that,among the six methods,the maximum likelihood method is the best one,since it could provide the most accurate Weibull parameters,*** having the smallest bias in both mean and median values,as well as the shortest length of the 90% confidence *** maximum likelihood method is therefore recommended to be used over the other methods in transformer Weibull lifetime modelling.

关键词：电力变压器寿命模型电力技术估计方法

高导热氮化铝/环氧树脂复合材料的高频沿面放电特性

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中国电机工程学报 2024年第13期44卷 5374-5385,I0030页

作者：解曾祺韩耀萱李志辉任瀚文李庆民王忠东新能源电力系统国家重点实验室(华北电力大学) 北京市昌平区102206 埃克塞特大学数学与物理工程学院英国埃克塞特EX44QJ

环氧树脂(epoxy resin,EP)因其优异的绝缘性能被用作高频变压器的主绝缘材料,但受限于材料的散热能力在强电-热耦合应力下容易发生沿面放电,采用三维导热网络法进行改性是有效的解决方案。该文采用硅烷偶联剂接枝改性氮化铝颗粒,分别制... 详细信息

环氧树脂(epoxy resin,EP)因其优异的绝缘性能被用作高频变压器的主绝缘材料,但受限于材料的散热能力在强电-热耦合应力下容易发生沿面放电,采用三维导热网络法进行改性是有效的解决方案。该文采用硅烷偶联剂接枝改性氮化铝颗粒,分别制备填料随机分布与含导热网络的氮化铝/环氧树脂复合材料,与纯环氧树脂同时进行高频沿面绝缘特性与放电过程温度分布测试。实验结果表明,含氮化铝三维导热网络的EP复合材料可在提升高频绝缘性能的同时抑制材料表面的高频致热效应,在10kV/10kHz高频正弦电压下,相比于纯环氧树脂,总放电幅值从81.47V下降到了24.01V,放电后材料表面最大温升由145.9℃下降至117.6℃。进一步给出环氧复合材料的导热-绝缘协同提升机理:(1)导热网络结构在提供规整的热流传输通道的同时,抑制了填料与基体界面的电场畸变;(2)导热网络结构能显著提升表面浅陷阱密度,减少电荷脱陷的势垒,增强对放电的抑制作用;(3)在高频沿面放电过程中,f/K-AlN/EP自身导热率提升迅速,电导率提升缓慢,消散热量与抑制放电的趋势提升显著,提升了高频沿面放电寿命。

关键词：高频变压器氮化铝导热网络环氧树脂沿面放电

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New approach to training support vector machine

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Journal of Systems Engineering and Electronics 2006年第1期17卷 200-205,219页

作者： Tang Faming Chen Mianyun wang zhongdong Dept. of Control Science & Engineering Huazhong Univ. of Science and Technology Wuhan 430074 P. R. China

Support vector machine has become an increasingly popular tool for machine learning tasks involving classification, regression or novelty detection. Training a support vector machine requires the solution of a very large quadratic programming problem. Traditional optimization methods cannot be directly applied due to memory restrictions. Up to now, several approaches exist for circumventing the above shortcomings and work well. Another learning algorithm, particle swarm optimization, for training SVM is introduted. The method is tested on UCI datasets.

关键词： support vector machine quadratic programming problem particle swarm optimization.

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泥岩生物气有利储层的识别及含气性评价

测井技术 2024年第2期48卷 240-247页

作者：王忠东张笑维王慧博中国石油集团测井有限公司辽河分公司辽宁盘锦124011 中国石油集团测井有限公司地质研究院陕西西安710077 中国石油天然气集团有限公司测井重点实验室陕西西安710077

随着开发的不断深入,研究区SH地区作为非主力层的第四系泥岩生物气田已经成为油田增储上产的重要勘探开发目标。这类储层由于岩性颗粒细小、泥质含量高、厚度小、成岩性差、孔隙结构复杂、非均质性强,导致储层与非储层的测井响应对比度... 详细信息

随着开发的不断深入,研究区SH地区作为非主力层的第四系泥岩生物气田已经成为油田增储上产的重要勘探开发目标。这类储层由于岩性颗粒细小、泥质含量高、厚度小、成岩性差、孔隙结构复杂、非均质性强,导致储层与非储层的测井响应对比度低、有利储层识别困难。同时,高地层水矿化度及富集黄铁矿造成储层流体识别评价困难。利用自然伽马、中子等常规测井曲线,构建含砂指数F_(SD)来表征储层含砂特征,计算泥质含量,识别划分有利储层。利用三孔隙度曲线差值比值法、合成声波时差差值法以及改进的中子-声波时差交会含气指示法等多种方法综合识别储层的含气性。在试气、生产数据刻度下,利用构建的储层含气指数FGAS建立储层含气饱和度计算模型。多种方法综合应用,效果良好,为泥岩生物气的测井精细综合评价提供了技术支撑。

关键词：泥岩生物气测井响应储层识别含砂指数含气指示

Failure investigation and asset management of combined measuring instrument transformers

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High Voltage 2021年第1期6卷 61-70页

作者： ShengJi Tee Qiang Liu zhongdong wang Fikri Hafid Pierre Tournet Department of Electrical&Electronic Engineering The University of ManchesterManchesterUK Research&Development Réseau de Transport d'ElectricitéParisFrance

Asset management of instrument transformers(ITs)has gained momentum in recent years due to their large population in the network and the potential adverse impacts of their increasing number of *** study investigates the failure cause of a family of combined measuring ITs via temperature profile simulations and consideration of moisture migration behaviour in an oil‐impregnated paper insulation *** tem-perature difference experienced by an IT,particularly throughout summer,together with a relative saturation hysteresis phenomenon could have caused a lower dielectric strength that led to *** study also offers insights into factors influencing the probability of failures through analysis on the lifetime data from both graphical survival function plots and statistical Cox ***‐service age,operating voltage level and environment appear to have an influence on failure rate.

关键词： instrument gained insulation

不同线宽电流阻挡层的GaN基LED芯片光电特性研究

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传感器与微系统 2024年第10期43卷 38-41页

作者：田媛刘叶锋陈晓冰王忠东闫晓密广西科技师范学院数学与计算机科学学院普瑞(无锡)研发有限公司上海科技大学量子器件中心

发光二极管（LED）由于具有低功耗、小体积、宽光谱范围等优点，被广泛应用于可见光通信、光电医疗、快速无损检测等微系统领域。为了进一步提高LED的发光效率，在图形化蓝宝石衬底上制备了具有不同线宽电流阻挡层（CBL）的氮化镓（GaN... 详细信息

发光二极管（LED）由于具有低功耗、小体积、宽光谱范围等优点，被广泛应用于可见光通信、光电医疗、快速无损检测等微系统领域。为了进一步提高LED的发光效率，在图形化蓝宝石衬底上制备了具有不同线宽电流阻挡层（CBL）的氮化镓（GaN）基LED,并研究其光电特性。结果表明，在120 mA测试电流作用下，由于CBL的插入增大了有源层有效光发射区域的电流密度，减少了p电极（p-pad）下的寄生光吸收，LED芯片的辐射功率与光电转换效率随着CBL线宽的增加而单调增加，在CBL线宽设计为13μm时，辐射功率与光电转换效率达到最大；正向电压（VF）随着CBL线宽的增加略有增加，表明绝缘的CBL层增大串联电阻。本文为CBL线宽的选择提供了新思路，可有效提高LED的发光效率。

关键词：发光二极管电流阻挡层氮化镓发光效率

Analysing the power transformer temperature limitation for avoidance of bubble formation

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High Voltage 2019年第3期4卷 210-216页

作者： James Hill zhongdong wang Qiang Liu Christoph Krause Gordon Wilson The University of Manchester ManchesterM139PLUK Weidmann Electrical Technology AG Rapperswil-JonaCH 8640Switzerland National Grid WarwickCV346DAUK

Failure of a transformer is a costly incident which can impact power system operation and result in loss of supply to *** can fail through a number of mechanisms,one of which is from the formation of bubbles within the ***,the loading guidance is set to avoid certain overload temperatures as high temperature is the main cause of bubbles *** paper analyses the limit set within the loading guides,comparing the most commonly cited temperature limit of 140℃ with values taken from across the full spectra of available studies in *** is concluded that there is sufficient evidence for further investigation into formation of bubbles from transformer insulation as employing a single temperature limit may be *** of a single temperature value is unsuitable,given the wide range of potential scenarios that the transformer fleet can *** has become the go-to rationale that the moisture content of the solid insulation is the key driver for transformer bubbling *** is true,however,it is shown that other factors such as solid insulation aged condition(determined through degree of polymerisation value)and the insulation type are also important considerations.

关键词： insulation limit power

原材料和烘焙方式对饼干品质影响的综合试验教学设计

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食品工业 2024年第2期45卷 121-126页

作者：陈碧王忠东郭松郭倩妙王小明广西科技师范学院来宾546199

为激发学生科学创新思维、提高学生研究实践能力,设计不同原材料和烘焙方式对酥性饼干品质影响综合性试验。该试验以普通饼干和混料饼干为原料,考察微波和烤箱两种烘焙方式对饼干品质的影响。采用感官评价、色差仪和质构仪,使学生掌握... 详细信息

为激发学生科学创新思维、提高学生研究实践能力,设计不同原材料和烘焙方式对酥性饼干品质影响综合性试验。该试验以普通饼干和混料饼干为原料,考察微波和烤箱两种烘焙方式对饼干品质的影响。采用感官评价、色差仪和质构仪,使学生掌握对食品色泽、气味和口感等品质的分析方法,借助原子吸收光谱、高效液相色谱、紫外-可见分光谱法,使学生掌握各种食品分析仪器测试的原理及操作流程。该试验涉及饼干制备、感官评定、食品分析和安全管理等知识,试验过程注重加强学、教、产、研的协同创新,有助于技能型、应用型和创新型复合人才培养。

关键词：食品专业综合试验教学设计人才培养