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CSEE Journal of Power and Energy Systems 2020年第3期6卷 638-648页

作者： Mingyao Ma Bing Ji Jinsong Han Jianing Wang Mingyue Zhan nianwen xiang Heifei University of Technology HeifeiChina University of Leicester LeicesterU.K

Requirements of the Internet of things for the network includes the ability to monitor the equipment and ***,the reliability of a power electronics converter has raised concerns of both academia and *** particular,power semiconductor devices are continuously exposed to excessive stress while being designed with high power handling capability and are considered as the most fragile component in power converters suffering from a high failure *** to find an effective monitoring method which is also helpful for the Internet of Things and improve the reliability of a three-level neutral-point-clamped power inverter,an in-situ health monitoring method is proposed by harnessing the inverter operational characteristics and degradation sensitive electrical parameters to address the IGBT wire bonding *** zero voltage state provides an inherent redundant feature that allows for a power switch to be diagnosed during its normal operation in a neutralpoint-clamped power *** proposed prognostic approach obtains both the wire bonding failure features and junction temperature from the terminals of an IGBT module,which is regarded as non-invasive on-line health *** system performance can be affected by the designated testing point and testing window,which is discussed and experimentally *** proposed technique allows unhealthy wire bonding in IGBT modules online monitoring during the operational period of the *** the proposed in-situ health monitoring of IGBT modules can be used for the industrial Internet of things.

关键词： IGBT health monitoring temperature sensitive electrical parameter(TSEP) three-level inverters reliability

Simulation of positive streamer propagation in an air gap with a GFRP composite barrier

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High Voltage 2021年第6期6卷 1079-1091页

作者： Hengxin He Dezhi Xia Bin Luo Weijiang Chen Kai Bian nianwen xiang State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhanChina State Grid Corporation of China BeijingChina School of Electrical Engineering and Automation Hefei University of TechnologyHefeiChina

The puncture of glass fibre reinforced polymer(GFRP)laminate is a primary damage pattern of wind turbine blades due to lightning strikes.A numerical simulation model of positive streamer propagation in a needle‐to‐plate air gap with a GFRP laminate is established to investigate the breakdown mechanism of GFRP *** model not only considers the dynamics of charged particles in the air and the composite laminate,but also the current continuity at gas-solid *** simulated streamer discharge pattern and the surface streamer length are in good agreement with the observation *** distributions and evolutions of the electron number density,electric field,and surface charge densities during streamer propagation are *** is found that the enhancement of the electric field on the GFRP laminate is caused by the rapid deposition of positive and negative space charges on the GFRP laminate after a secondary streamer incepts on the lower surface of the GFRP *** effects of the applied voltage,relative permittivity,and thickness of the GFRP laminate on the electric field on the GFRP laminate are *** obtained results could assist in further under-standing of the mechanism of GFRP wind blade breakdown due to lightning strikes.

关键词： GFRP laminate composite

Fully Decoupled Branch Energy Balancing Control Method for Modular Multilevel Matrix Converter Based on Sequence Circulating Components

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 235-247页

作者： Zexin Zhao Weijiang Chen Zhichang Yang Guoliang Zhao Bin Han Yunfei Xu nianwen xiang Shulai Wang China Electric Power Research Institute Beijing 100192China State Grid Corporation of China Beijing 100031China State Grid Smart Grid Research Institute Beijing 102209China State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research InstituteBeijing 102211China Hefei University of Technology Hefei 230009China

The modular multilevel matrix converter(M3C)is a potential frequency converter for low-frequency AC ***,capacitor voltage control of high-voltage and largecapacity M3C is more difficult,especially for voltage balancing between *** solve this problem,this paper defines sequence circulating components and theoretically analyzes the influence mechanism of different sequence circulating components on branch capacitor voltage.A fully decoupled branch energy balancing control method based on four groups of sequence circulating components is *** method can control capacitor voltages of nine branches in horizontal,vertical and diagonal *** influences of both circulating current and voltage,a cross decoupled control is designed to improve control *** results are taken from a low-frequency transmission system based on PSCAD/EMTDC,and effectiveness and precision of the proposed branch energy balancing control method are verified in the case of nonuniform parameters and an unbalanced power system.

关键词： Branch energy balancing control decoupled control low-frequency AC transmission modular multilevel matrix converter(M3C) sequence circulating components

Simplified Cluster Voltage Balancing Control Based on Zero-sequence Voltage Injection for Star-connected Cascaded H-bridge STATCOM

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 2255-2264页

作者： Kai Hu Guoliang Zhao Daorong Lu Zhengang Lu nianwen xiang Shulai Wang Jintian Lin School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China School of Electrical and Automation Engineering Nanjing Normal UniversityNanjing 210023China State Grid Smart Grid Research Institute(SGRI) Beijing 102209China Power grid Technology Center of State Grid Zhejiang Electric Power Research Institute Hangzhou 310004China

The cluster DC voltage balancing control adopting zero-sequence voltage injection is appropriate for the starconnected cascaded H-bridge STATCOM because no zerosequence currents are generated in the three-phase three-wire ***,as the zero-sequence voltage is expressed in trigonometric form,traditional control methods involve many complicated operations,such as the square-root,trigonometric operations,and inverse tangent *** simplify cluster voltage balancing control,this paper converts the zero-sequence voltage to the dq frame in a DC representation by introducing a virtually orthogonal variable,and the DC components of the zero-sequence voltage in the dq frame are regulated linearly by proportional integral regulators,rather than being calculated from uneven active powers in traditional *** removes all complicated ***,this paper presents simulation and experimental results for a 400 V±7.5 kvar star-connected STATCOM,in balanced and unbalanced scenarios,thereby verifying the effectiveness of the proposed control.

关键词： Cluster DC voltage balancing control DC representation of zero-sequence voltage star-connected cascaded H-bridge STATCOM zero-sequence voltage injection

Reliability improvement of gas discharge tube by suppressing the formation of short-circuit pathways

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Plasma Science and Technology 2022年第3期24卷 138-151页

作者： Lingyun CHENG nianwen xiang Kejie LI Weijiang CHEN Kai BIAN Jin YANG Zongqi XU Congying HAN Hongyang GU Chun YANG Heifei University of Technology Hefei 230009People's Republic of China Institute of Energy Hefei Comprehensive National Science CenterHefei 230031People's Republic of China State Grid Corporation of China Beijing 100031People's Republic of China Beijing National Railway Research&Design Institute of Signal&Communication Group Co. Ltd.Beijing 100070People's Republic of China

After cumulative discharge of gas discharge tube(GDT),it is easy to form a short circuit pathway between the two electrodes,which increases the failure risk and causes severe influences on the protected *** reduce the failure risk of GDT and improve cumulative discharge times before failure,this work aims to suppress the formation of two short-circuit pathways by optimizing the tube wall structure,the electrode materials and the electrode structure.A total of five improved GDT samples are designed by focusing on the insulation resistance change that occurs after the improvement;then,by combining these designs with the microscopic morphology changes inside the cavity and the differences in deposition composition,the reasons for the differences in the GDT failure risk are also *** experimental results show that compared with GDT of traditional structure and material,the method of adding grooves at both ends of the tube wall can effectively block the deposition pathway of the tube wall,and the cumulative discharge time before device failure is increased by 149%.On this basis,when the iron-nickel electrode is replaced with a tungsten-copper electrode,the difference in the electrode’s surface splash characteristics further extends the discharge time before failure by 183%.In addition,when compared with the traditional electrode structure,the method of adding an annular structure at the electrode edge to block the splashing pathway for the particles on the electrode surface shows no positive effect,and the cumulative discharge time before the failure of the two structures is reduced by 22.8%and 49.7%,*** these improved structures,the samples with grooves at both ends of the tube wall and tungsten-copper as their electrode material have the lowest failure risk.

关键词： gas discharge tube short-circuit failure tube wall groove tungsten-copper electrode failure risk

Numerical simulation and experimental verification of plasma jet development in gas gap switch

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Plasma Science and Technology 2023年第5期25卷 159-169页

作者：董冰冰郭志远张泽霖文韬向念文 Hefei University of Technology Hefei 230009People’s Republic of China

Plasma jet triggered gas gap switch has obvious advantages in fast control *** development of the plasma in the ambient medium is the key factor affecting the triggering conduction of the gas ***,the plasma jet process and its characteristic parameters are complicated and the existing test methods cannot fully characterize its development *** this work,a two-dimensional transient fluid calculation model of the plasma jet process of the gas gap switch is established based on the renormalization-group k-εturbulence *** results show that the characteristic parameters and morphological evolution of the plasma jet are basically consistent with the experimental results,which verifies the accuracy of the simulation model *** plasma jet is a long strip with an initial velocity of 1.0 km·s-1and develops in both axial and radial *** jet velocity fluctuates significantly with axial *** the plasma jet enters the main gap,the pressure inside the trigger cavity drops by80%,resulting in a rapid drop in the jet *** the plasma jet head interacts with the atmosphere,the two-phase fluid compresses each other,generating a forward-propelled pressure *** plasma jet heads flow at high velocity,a negative pressure zone is formed in the middle part of the jet,and the pressure peak decreases gradually with *** the value of the inlet pressure increases,the characteristic parameters of the plasma jet *** entrainment phenomenon is evident,which leads to an increase in the pressure imbalance of the atmospheric gas medium,leading to a significant Coanda *** with air,the characteristic parameters of a plasma jet in SF6are lower,and the morphological evolution is significantly *** results of this study can provide some insight into the mechanism of action of the switch jet plasma development process.

关键词： gas gap switch plasma jet k-εturbulence model numerical calculation experimental verification

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高速铁路信号系统的雷电暂态模型研究

铁道学报 2018年第9期40卷 90-96页

作者：乔志超向念文阳晋张璐北京全路通信信号研究设计院集团有限公司基础院北京100070 华北电力大学电气工程学院北京102206

信号系统是高速铁路的控制中枢,也是容易遭受雷击的薄弱环节,为了实现信号系统防雷故障的定量分析,需要建立信号系统的雷击仿真模型。通过测试获得系统中设备的散射参数、进行导纳参数转换,采用矢量匹配法获得导纳函数的极点分布。利用... 详细信息

信号系统是高速铁路的控制中枢,也是容易遭受雷击的薄弱环节,为了实现信号系统防雷故障的定量分析,需要建立信号系统的雷击仿真模型。通过测试获得系统中设备的散射参数、进行导纳参数转换,采用矢量匹配法获得导纳函数的极点分布。利用电路综合理论建立系统的差模和共模雷电暂态仿真模型,并通过实验室暂态响应试验验证模型的有效性,仿真结果与试验结果误差在5%以内。基于该模型建立包括接触网在内的整个信号系统雷电暂态模型,分析雷击接触网时各信号设备的雷击过电压,并结合设备的绝缘耐受水平分析信号系统中雷电防护的薄弱环节,所获结果可以用于指导高铁信号系统的防雷设计和故障分析。

关键词：高速铁路信号系统矢量匹配雷电暂态模型

Detection of the Incipient Degradation for Aluminum Electrolytic Capacitors in Track Circuits

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Detection of the Incipient Degradation for Aluminum Electrol...

第三十九届中国控制会议

作者： Yusheng Guo Canghua Jiang nianwen xiang Bo Su Huiyuan Yin Zongqi Xu School of Electrical Engineering and Automation Hefei University of Technology China Railway Signal & Communication Research & Design Institute Group Co. Ltd.

Aluminum electrolytic capacitors used in the tuning and matching units of track circuits are prone to degrade. The decrease of capacitance results in the drop of main track output voltage（MTOV）. However, it is difficult to detect the incipient degradation by monitoring the MTOV because the impact of ambient factors such as variations of temperature and humidity is significant. This paper proposes a data-driven method to reduce the detection delay for the degradation of capacitors. As the fault data is difficult to be collected, this method depends only on a few days of historical data for capacitors undegraded. A model is trained by support vector regression based on the on-site data of MTOV in normal condition. Then, this model is used to generate a residual signal for on-line monitoring. In order to verify the effectiveness of the proposed method, it is assumed that the degradation rate is constant and the remaining useful life is 1000 hours when degradation starts. Then, voltage data for degraded capacitor can be synthesized by utilizing a simulated curve of MTOV vs. capacitance. Simulation results demonstrate that impacts of daily variations of temperature and humidity on the MTOV can be reduced considerably from the residual signal. By monitoring the residual with a small threshold, the detection delay for the degradation can be reduced by several thousand minutes compared to method by setting a threshold of 20% drop on the MTOV. Data preprocessing to eliminate the sudden voltage drop by train occupancy and threshold selection are also reported.

关键词： Fault Detection Degradation Aluminum Electrolytic Capacitor Track Circuit Support Vector Regression

来源： cnki会议评论

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高压放电等离子体研究现状及发展趋势

高电压技术 2023年第8期49卷 3226-3239页

作者：文韬向念文章程沙致远邵涛合肥工业大学电气与自动化工程学院合肥230009 中国科学院电工研究所等离子体科学和能源转化北京市国际科技合作基地北京100190 西安交通大学电气工程学院西安710049

文中概述了2022年全国高电压与放电等离子体学术会议。根据会议的学术报告,并结合近年来高压放电等离子体领域的研究热点,从特性机理研究和应用研究两方面总结和分析了高压放电等离子体的研究现状和发展趋势。其中,特性机理研究主要围... 详细信息

文中概述了2022年全国高电压与放电等离子体学术会议。根据会议的学术报告,并结合近年来高压放电等离子体领域的研究热点,从特性机理研究和应用研究两方面总结和分析了高压放电等离子体的研究现状和发展趋势。其中,特性机理研究主要围绕等离子体激励源及其特性研究、等离子体诊断和等离子体数值仿真等3个方面进行展开,应用研究则主要集中在材料改性、能源转化、环境治理、生物医学和航空航天等领域。从会议相关内容来看,国内对于高压放电等离子体的研究业已取得了良好进展,特性机理研究和应用研究间彼此相互渗透、共同发展。在未来的研究中,需重点突破时空多尺度问题、等离子体剂量特性、等离子体参数精细化调控技术和面向不同工质的均匀稳定放电产生技术等共性科学问题;同时针对高压放电等离子体共性关键科学问题和特定领域应用研究开展重点攻关,建立面向实际应用的等离子体工艺技术。伴随着高压放电等离子体技术与其他研究领域间的联系日趋紧密,相信未来将有更高水平的优秀科研成果不断涌现。

关键词：高压放电等离子体特性机理应用学术交流

长间隙正极性放电流注-先导发展3维物理仿真研究

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高电压技术 2014年第9期40卷 2903-2910页

作者：谷山强谢施君向念文何俊佳严碧武李涛国网电力科学研究院武汉南瑞有限责任公司武汉430074 国网四川省电力公司电力科学研究院成都610072 华中科技大学电气与电子工程学院武汉430074

利用长间隙放电3维仿真模型对实际的放电现象进行机理分析、放电特性预测与绝缘设计评价具有指导意义。因此在流注-先导系统起始和动态发展的物理机制基础上,分析了初始电晕起始与流注发展的基本物理过程,推导了基于模拟电荷法与电位畸... 详细信息

利用长间隙放电3维仿真模型对实际的放电现象进行机理分析、放电特性预测与绝缘设计评价具有指导意义。因此在流注-先导系统起始和动态发展的物理机制基础上,分析了初始电晕起始与流注发展的基本物理过程,推导了基于模拟电荷法与电位畸变法的流注空间电荷增量对电位畸变贡献的计算方法,建立了基于热电离理论的流注-先导转化模型,并利用电介质击穿模型（DBM）模型将2维模型外延至3维空间,从而完成了对长间隙放电正极性流注-先导发展全过程的3维仿真模型构建。利用该模型进行仿真获得的先导平均轴向速度为1.58～1.62cm/μs,空间电荷电位畸变系数KQ的平均值介于3.8×10-11～4.4×10-11 C/（V m）之间,并得到了不同间隙长度下击穿电压与先导发展过程等的变化规律,与长间隙放电试验综合同步观测平台在平均轴向速度、末跃高度等方面所获得的试验数据较为符合,证明了模型在3 m棒-板间隙下模拟正极性流注-先导发展方面的适用性。

关键词：长间隙放电流注先导模拟电荷法热电离电位畸变