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Breakdown Electric Field of Hot 30% CF_3I/CO_2 Mixtures at Temperature of 300–3500 K During Arc Extinction Process

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Plasma Science and Technology 2016年第11期18卷 1095-1100页

作者： ZHAO xiaoling JIAO Juntao xiao dengming Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200030 China

We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field strengths are decided by a balance of electron generation and loss based on chemical reactions estimated by the electron energy distribution function （EEDF）, which employs the Boltzmann equation method with two-term expanding approximation in the steady-state Townsend （SST） condition. During the insulation recovery phase, the hot CF3I/CO2 gas mixtures have maximum dielectric strength at a temperature of about 1500 K. At room temperature 300 K, the electric strength after arc extinction （90.3 Td, 1 Td=10-21 V.m2） is only 38% of the original value before arc （234.9 Td）. The adverse insulation recovery ability of CF3I/CO2 gas mixtures in arc extinction hinders its application in electric circuit breakers and other switchgears as an arc quenching and insulating medium.

关键词： limiting electric field strength electron swarm parameters Boltzmannequation hot CF3I/CO2 gas mixtures

Characteristic analysis of CO_2 switching arcs under a DC current

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Plasma Science and Technology 2018年第8期20卷 42-49页

作者： xiaoling ZHAO J D YAN dengming xiao Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200030People＇s Republic of China Department of Electrical Engineering and Electronics University of LiverpoolBrownlow HillLiverpool L69 3GJUnited Kingdom

The current interruption capability of a gas, when used in high voltage gas-blast circuit breakers,depends not only on its material properties but also the flow field since turbulence plays a dominant role in arc cooling during the interruption process. Based on available experimental results, a study of CO2 switching arcs under a DC（direct current） current in the model circuit breaker has been conducted to calibrate CO2 arc model and to analyse its electric and thermal property. Through detailed analysis of the results mechanisms responsible for the temperature distribution are identified and the domain energy transportation process of different region discussed. The present work provides significant coefficients for CO2 switching arc simulation and gives a better understanding of CO2 arc burning mechanisms.

关键词： energy transportation thermal and electric property CO2 switching arc

Breakdown characteristics of CF_3I/N_2/CO_2 mixture in power frequency and lightning impulse voltages

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Plasma Science and Technology 2019年第1期21卷 36-43页

作者： Qiming LIN Su ZHAO dengming xiao Baijie ZHOU Department of Electrical Engineering Shanghai Jiao Tong University Department of Intelligent Electrical Equipment Nari Group Corporation

Trifluoroiodomethane(CF_3I) and its mixtures are believed to be prospective alternatives to sulfur hexafluoride(SF6), which has been included as a greenhouse gas. In this paper, the breakdown properties of a CF_3I/N_2/CO_2 mixture with the volume fraction of CF_3I fixed at 10% are investigated under power frequency and lightning impulse voltages. The experimental result shows that N_2 possesses higher power frequency and negative lightning impulse breakdown voltages than CO_2, but the power frequency and more negative lightning impulse breakdown voltages of the CF_3I/N_2/CO_2 mixture do not increase with the content of N_2. For the purpose of explaining this abnormal phenomenon, the ionization energies and excitation energies of CF_3I,N_2and CO_2 are calculated. The computation results indicate that the ionization energy of CF_3I is lower than the first excitation energy of N_2, but higher than the lowest excitation energy of CO_2,which means that CF_3I molecules are easily ionized by metastable N_2 molecules. The first excitation energy of N_2 is too high, which hinders its application as the buffer gas of CF_3I.

关键词： gas discharge CF3I gas mixtures Penning effect buffer gas

Insulation characteristics of triple mixtures of c-C_4F_8/N_2/CO_2 under lightning impulse voltage

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Plasma Science and Technology 2018年第10期20卷 112-117页

作者： Zhouming ZHANG Zhaorui NI dengming xiao Yizhou WU Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200030 People's Republic of China Michigan-Shanghai Jiaotong University Joint Institute Shanghai Jiao Tong University Shanghai 200240 People's Republic of China

This paper has researched the insulation characteristics of 10% c-C4F8/N2/CO2 mixtures under lightning impulse voltage by experiment. It is shown that the positive and negative lightning impulse breakdown voltages of 10%c-C4F8/N2/CO2 gas mixtures rise linearly as the electrode gap distance and gas pressure increase and under the same conditions, the positive lightning impulse breakdown voltage of the gas mixtures is always higher than the negative lightning impulse breakdown voltage. As the gas mixtures have a little higher liquefied temperature than SF6 and the comprehensive GWP is about 5% of SF6, and the positive and negative lightning impulse breakdown voltages can both reach 60% of SF6, 10%c-C4F8/N2/CO2 gas mixtures can be applied as insulation gas in electrical equipment such as C-GIS, GIT, GIL and so on.

关键词： SF6 alternative insulation characteristics lightning impulse voltage c-C4F8 gas mixtures

Insulation Performance of CF3I-N2 Gas Mixtures as Alternative for SF6 in GIS/C-GIS

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高电压技术 2013年第9期39卷 2288-2293页

作者： DENG Yunkun xiao dengming CHEN Jiong Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200030 China School of Electric Power and Automation Engineering Shanghai University of Electric Power Shanghai 200090 China

CF3I has been widely considered as a potential alternative for SF6,because it has low global warming potential(GWP)but an insulation capability that is 1.2 times greater than that of *** this paper,the electron swarm parameters of CF3I and its gas mixture with N2,including the effective ionization coefficient and electron drift velocity,are examined theoretically through the Boltzmann equation method in the condition of steady-state Townsend(SST)*** on the derived data of the limiting field strength of CF3I-N2gas mixture,taking into consideration of environmental aspects such as GWP,ozone depletion potential(ODP),liquefaction temperature and toxicity,we studied the possibility of applying the gas mixture as the insulation medium in gas-insulated switchgears(GIS)or cubic type gas-insulated switchgears(C-GIS).It is found that CF3I-N2gas mixtures contained 30%～70%CF3I perform comprehensively better than pure SF6and compressed N2,and especially in medium and low voltage environments,the boiling point of CF3I-N2gas mixture meets the domestic and global requirements in mid-low latitude *** we conclude that the gas mixture is acceptable for replacing SF6as the insulation medium in C-GISs.

关键词： SF6气体 C-GIS 混合气体绝缘性能气体绝缘开关装置气体混合物玻尔兹曼方程地理信息系统

Investigation of the performance of CF3I/c-C4F8/N2 and CF3I/c-C4F8/CO2 gas mixtures from electron transport parameters

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Plasma Science and Technology 2020年第5期22卷 44-51页

作者： Ruishuang ZHONG Su ZHAO dengming xiao Hui WANG Xiuchen JIANG Zhongmin YU Yunkun DENG Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200030People's Republic of China State Grid Shanghai Electric Power Company Shanghai 200122People's Republic of China Yunnan Power Grid Corporation Kunming 650217People's Republic of China

CF3I gas mixtures have attracted considerable attention as potential environmentally-friendly alternatives to SF6 gas,owing to their excellent insulating *** paper attempts to study the CF3I ternary gas mixtures with c-C4F8 and buffer gases N2 and CO2 by considering dielectric strength from electron transport parameters based on the Boltzmann method and synergistic effect analysis,compared with SF6 gas *** results confirm that the critical electric field strength of CF3I/c-C4F8/70%CO2 is greater than that of 30%SF6/70%CO2 when the CF3I content is greater than 17%.Moreover,a higher content of c-C4F8 decreases the sensitivity of gas mixtures to an electric field,and this phenomenon is more obvious in CF3I/c-C4F8/CO2 gas *** synergistic effects for CF3I/c-C4F8/70%N2 were most obvious when the c-C4F8 content was approximately 20%,and for CF3I/c-C4F8/70%CO2 when the c-C4F8 content was approximately 10%.On the basis of this research,CF3I/c-C4F8/70%N2 shows better insulation performance when the c-C4F8 content is in the15%–20%*** CF3I/c-C4F8/70%CO2,when the c-C4F8 content is in the 10%–15%range,the gas mixtures have excellent ***,these gas systems might be used as alternative gas mixtures to SF6 in high-voltage equipment.

关键词： CF3I/c-C4F8/N2 gas mixtures CF3I/c-C4F8/CO2 gas mixtures Boltzmann method electron transport parameters synergistic effect

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环保型绝缘气体的发展前景

高电压技术 2016年第4期42卷 1035-1046页

作者：肖登明上海交通大学电子信息与电气工程学院上海200030

阐述了气体绝缘发展的3个阶段,描述了环保型气体绝缘的研究现状。分析了绝缘气体的基本物理化学性能,分析了碳碳双键结构的气体提高气体的绝缘性能的影响机理,指出了卤族元素对气体电气强度影响的特性,提出了几种具有潜力替代SF_6的环... 详细信息

阐述了气体绝缘发展的3个阶段,描述了环保型气体绝缘的研究现状。分析了绝缘气体的基本物理化学性能,分析了碳碳双键结构的气体提高气体的绝缘性能的影响机理,指出了卤族元素对气体电气强度影响的特性,提出了几种具有潜力替代SF_6的环保型绝缘气体。预测了环保型气体绝缘的发展前景,对两种目前最有有潜力取代SF_6的环保型气体c-C4F_8和CF_3I进行了的分析研究,提出了它们目前的应用可行性及适用范围,指出了进一步的研究方向。

关键词：环保气体替代气体 c-C4F8 CF3I 绝缘特性

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介电谱法监测贴壁细胞生长的研究

高技术通讯 2005年第12期15卷 52-57页

作者：胥飞肖登明上海交通大学电子信息与电气工程学院上海200030

使用介电谱方法监测了贴壁细胞培养过程中细胞数目的变化.贴壁细胞在经修饰过的培养皿底面生长,连续5天每隔12小时取样测量其在0.1～10MHz范围内的介电谱,同时检测培养液中谷氨酰胺、葡萄糖和乳酸的浓度变化.对测得的介电谱值进行了误... 详细信息

使用介电谱方法监测了贴壁细胞培养过程中细胞数目的变化.贴壁细胞在经修饰过的培养皿底面生长,连续5天每隔12小时取样测量其在0.1～10MHz范围内的介电谱,同时检测培养液中谷氨酰胺、葡萄糖和乳酸的浓度变化.对测得的介电谱值进行了误差修正,以消除杂散电容和电极极化的影响.经修正的细胞电容与细胞数间存在明显的线性相关性,而代谢产物及消耗物则与电容没有明显的关联.此实验为贴壁细胞的培养提供了一种可行的在线监测方法.

关键词：介电谱贴壁细胞细胞代谢在线监测

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脉冲电场对细胞作用的模型分析和实验研究

高电压技术 2006年第6期32卷 67-69,83页

作者：胥飞肖登明上海交通大学电子信息与电气工程学院上海200030

根据细胞结构及其电学参数提出了电阻电容电路模型模拟电场对细胞的作用,并利用该模型解释了实验研究中不同斜率的斜坡电场作用后,细胞死亡特性的差异现象。还利用该模型分析了特定斜率的斜坡电场对肿瘤细胞的选择性作用。结果表明由于... 详细信息

根据细胞结构及其电学参数提出了电阻电容电路模型模拟电场对细胞的作用,并利用该模型解释了实验研究中不同斜率的斜坡电场作用后,细胞死亡特性的差异现象。还利用该模型分析了特定斜率的斜坡电场对肿瘤细胞的选择性作用。结果表明由于亚性细胞其线粒体膜上的跨膜电压上升较正党细胞为快,而其细腻膜上的跨膜电压上升则较慢,说明这种选择性是存在的。

关键词：电穿孔电阻-电容电路模型纳秒脉冲电场肿瘤细胞凋亡