1. CHEN JIDAN AWARD& MEMORIAL LECTURE

 

Studies on Space Charge Accumulation Properties in Dielectric Materials

－Measurement Methods and Quantum Chemical Calculation Ana

 

 

Emeritus ProfessorTatsuo Takada

Tokyo City University, Japan

 

 

 

Individual Contributions

Prof. T. Takada has made outstanding contributions to the developing for measurement techniques of space charge distribution in solid and liquid dielectric materials. The measurement techniques of space charge distribution great contribute to the scientists in the field of dielectric materials and the engineers in the field of insulating engineering.

He has published more than one hundred papers in leading Journals in US, UK, Japan. As he has been an extremely active researcher, he was asked to serve as Chairman for the Technical Committee on Dielectrics and Electrical Insulation, IEEJ, the Tokyo Chapter of the DEI Society, IEEE and Convener of TF15-12-01 (space charge measurement), CIGRE.

 

Synopsis

With the development of HVDC Light project since 1990’s, it is necessary to construct the large scale electric power grid with reliable DC insulation system, connecting wind farms to power grid, underground power links, connecting asynchronous grids, etc. Therefore, it is important to propose advanced detection technique under DC high electrical stress, evaluate the space charge characteristics and explore novel insulating materials. This article describes the short developing history of the electric charge accumulation measurement techniques in insulating materials using acoustic and optical methods, and the analytical methods using quantum chemical calculation.

 

Biography

Tatsuo Takada was born in August 8, 1939, received his B.E. degree in electrical engineering from Musashi Institute of Technology, Japan, in 1963, his M.E. degree from Tohoku University, Japan, in 1966, and his doctoral degree from Tohoku University in 1975. Appointed a lecturer at Musashi Institute of Technology in 1967, he became an associate professor at the same university in 1974 and a professor in 1987. He was a visiting scientist at MIT (USA) from 1981 to 1983 and he is a consulting professor of Xian Jiaotong University, China.

He has now undertaken several research projects on the development of acoustic and optical advanced methods for measuring electric charge distribution in dielectrics. For example, in order to investigate the space charge effect in solid dielectric material, the dynamic surface charge distribution on solid dielectrics and the electric field vector distribution in liquid insulating materials. He received the progress award from the IEE of Japan in 1996. He has also received Whitehead Memorial Award in 1999 by his pioneering work on PEA, and gave an Award Lecture in IEEE CEIDP (Conference on Electrical Insulation and Dielectric Phenomena). He is a Life Fellow member of IEEE.

His e-mail: takada@me.musashi-tech.ac.jp  

 

2. INVITED SPEAKERS

 

 

Several Important Issues and Thinking about Engineering Dielectrics

 

 

 

 

Professor Shengtao Li

Xi'an Jiaotong University, China

 

 

Synopsis

The specific meaning of Lewis interface and Tanaka interface is analyzed, hard/soft interface of nano polymeric composites is proposed, new concepts of structural complexity, uncertainty and mutability are described, and the scale and physical and chemical properties of hard and soft surfaces are analyzed. New thoughts are inspired from the perspective of Einstein reductionism, emergent phenomena of P W Anderson, and scientific prediction of R P Feynmann. Constraints of existent conditions of space charge limited current (SCLC) are studied, and hierarchical levels of its self-structure, complex interface, electrode contact, concomitant electronic and ionic conductivity and other factors in polymers or their composites have serious impacts on SCLC. It is proposed that SCLC is not solely determined by carriers which are the same as injected carriers in the transition from ohmic region to high field region, i.e., electrode injection SCLC region. In particular, the contribution of ionic conductivity to the current in low and high field region is of close scrutiny when measurement conditions are determined. Therefore, the main features and distinction methods of ionic and electronic conductivity are listed. In view of pulse related space charge measurement methods, especially pulsed electroacoustic (PEA) method has been mainly adopted in the world, advantages and disadvantages of PEA, and the method for verifying the accuracy and repeatability of measurement results are proposed. According to the features of polymer structure, a pressure stimulated current (PSC) device should be built up for distinguishing space charges derived from concentration gradient of electrons, ions, and dipoles to compensate the serious shortcomings of PEA measurements.

 

Biography

Shengtao Li received the Ph.D. degree in electrical engineering from Xi’an Jiaotong University (XJTU), China, in 1990. He was a Lecturer, Associate Professor, and Professor of XJTU in 1990, 1993, and 1998, respectively. He was a Research Fellow at Waseda University, Japan, in 1996, and was also a Senior Visiting Scholar at University of Southampton, UK, in 2001. From 1993 to 2003, he was a deputy director of the State Key Laboratory of Electrical Insulating and Power Equipment (SKLEIPE) at XJTU. Since 2003, he has been an executive deputy director of SKLEIPE. He was awarded a Distinguished Young Scholar of China by the National Science Foundation in 2006. He gave Liu Ziyu Memorial Lecture on the 11th International Conference on the Properties and Applications of Dielectric Materials (ICPADM) in 2015. He was the chair of the 6th International Conference on Conditional Monitoring and Diagnosis (CMD) in 2016, the 1st International Conference on Electrical Materials and Power Equipment (ICEMPE) in 2017 and the 12th International Conference on the Properties and Applications of Dielectric Materials (ICPADM) in 2018. His research interests include dielectrics and their application, insulating materials, and electrical insulation. He can be reached by email at sli@mail.xjtu.edu.cn.

 

 

 

Transformer Liquids Research: Transforming Industry

 

 

 

Professor Zhongdong Wang

The University of Manchester, UK

 

 

Synopsis

Research on Ester based transformer liquids and oil regeneration at the University of Manchester has been transforming the UK transformer industry over the last decade. Key studies on electrical and thermal characteristics are introduced in this presentation, as well as the resulting solutions for design and operation. Successful engineering projects and impacts are given as examples.

 

Biography

Received the B.Eng. and M. Eng. degrees in high-voltage engineering from Tsinghua University, Beijing, China, in 1991 and 1993, respectively, and the Ph.D. degree in electrical engineering from UMIST, Manchester, U.K., in 1999. She is currently a Professor of High Voltage Engineering at the University of Manchester. Her research interests include transformer modeling, oil/paper insulation aging mechanisms, condition assessment, and transformer life management.

 

 

 

Structure-Activity Relationship and Molecular design for Discovery of Environmentally Sustainable Dielectric Gases

 

 

 

Professor Keli Gao

China Electric Power Research Institute, China

 

Synopsis

Novel environmentally sustainable dielectric gases are highly desired for electric applications to replace sulfur hexafluoride (SF6) which is the most potent greenhouse gas. The state-of-the-art structure-activity relationship for high-through screening of the dielectric gases has been obtained successfully using the electron density and electrostatic potential parameters. Moreover, a new strategy to discover the environment-friendly dielectric gases has been achieved by means of a priori molecular design. A series of viable alternative dielectric gases with the unique combination and balance of the paradoxical properties of performance are presented and will greatly inspire experimental synthesis and field tests on the new chemistry for dielectric use.

 

Biography

Executive Vice President of China Electric Power Research Institute, Professor, Ph.D. Supervisor, CSEE (Chinese Society for Electrical Engineering) Fellow, IEEE Senior Member, long-term engagement in the research of EHV&UHV power transmission and electrical equipment operation technology.

 

 

 

Origins of Chemiluminescence in Polymeric Insulating Materials

 

 

 

Professor Yoshimichi Ohki

Waseda University, Japan

 

 

 

Synopsis

One of inevitable weak points of electrical insulation with industrially synthesized organic polymers is oxidative degradation. For detecting such oxidation induced in polymeric materials, a spectroscopic analysis method called chemilumi- nescence (CL) is known. It has widely been believed that singlet molecular oxygen and electronically excited triplet carbonyl products are its two luminous sources. To confirm the validity of this assumption, CL was measured for a variety of polymers. Fourier-transform mid-infrared absorption spectroscopy was also conducted before and after the CL measurements. As a result, it has become clear that the formation process of the cross-linked structure in silicone rubber by bridging two neighboring siloxane backbones via oxygen and the curing process of epoxy resin as well induce the CL.

 

Biography

Yoshimichi Ohki is a Professor of Waseda University, Japan and is also an honorary Professor of Xi’an Jiaotong University, China. He was a Visiting Scientist at the Massachusetts Institute of Technology (MIT).

Dr. Ohki is at present President of Japanese Electrotechnical Committee and was President of the Institute of Engineers on Electrical Discharges in Japan and also Vice President of the Institute of Electrical Engineers of Japan. He is a recipient of Prize for Science and Technology awarded by the Minister of Education of Japan, IEEE DEIS Forster and Whitehead Memorial Awards, Outstanding Achievement Award and Best Paper Award (2 times) of IEE Japan, Research Award of Waseda University (3 times) , and other awards.

He has written more than 450 papers (in English: more than 350, in Japanese: more than 100, in Chinese: 1).

For example click

https://www.researchgate.net/scientific-contributions/73051193_Yoshimichi_Ohki

 

 

Prospect of Computational High Voltage Engineering (CHVE)

 

 

 

 

Doctor  Xuzhu Dong

China Southern Power Grid, China

 

 

 

Synopsis

With research and development of high voltage technologies, electrical materials, computational simulation technologies, and plasma physics, the concept of the computational high voltage engineering (CHVE) is proposed, as a new discipline, to solve or explain practical problems of high voltage engineering with support of applied mathematics and computer science. This paper introduces the technical and engineering application drivers of CHVE, elaborates its definition, research scope and discipline architecture, and discusses the theoretical research foci and potential engineering application of this subject. CHVE will cover the study of discharge modeling, computation of multi physical field coupling, application of cloud computing and super computers, 3D printing of insulation components, and the precision testing and measurement of multi physical fields. On this basis, we look forward to future development of CHVE and its challenges.

 

Biography

Dr. Xuzhu Dong was born in Shaanxi, China. He received his first PhD in high voltage engineering from Tsinghua University in 1998, and the second PhD in electrical engineering from Virginia Tech in 2002. He is Deputy Chief Engineer of CSG EPRI. He was Director of Smart Grid Institute at CSG EPRI. Before joined CSG in 2010, he worked with Progress Energy, FirstEnergy, and EPRI solutions in USA, as senior engineer, stuff engineer, and lead engineer. His research interests were high voltage engineering, smart grid and power equipment asset management. He is involved into several key smart grid demonstration projects at CSG. Dr. Dong is senior member of IEEE, and member of CIGRE.

 

 

 

Space Charge Accumulation Properties in Various Insulating Materials under DC High Electric Field at High Temperature

 

 

 

Professor Yasuhiro Tanaka

Tokyo City University, Japan

 

 

 

Synopsis

While many kinds of polymeric materials have been developed for being used at high temperature in various devices, there is a few cases that they are used as an electric insulating material for dc high electric stress. However, according to the development of power electric devices in recent years, the demand of an insulating material which show a good performance even at high temperature more than 100 ˚C has been increasing. Under such severe condition, especially in HVDC (high voltage DC) systems, the space charge accumulation property must be a key factor to evaluate the performance of them. Therefore, we tried to measure the space charge distributions in many kinds of polymers at high temperature (~ 150 ˚C) under high electric stress (~ 120 kV/mm) using the originally developed PEA (pulsed electro-acoustic) system for high temperature measurement. Judging from the results, the obtained data can be available to evaluate the performance of them under such severe condition.

 

Biography

Yasuhiro Tanaka was born in Fukuoka, Japan in 1961. He received the B.E., the M.E. and Ph. D. degrees in Electrical Engineering from Waseda University, Japan, in1986, 1988 and 1991, respectively.  He became a Lecturer, an Associate Professor and a Professor at Musashi Institute of Technology (presently Tokyo City University), in 1992, 1998 and 2004, respectively. He was a Visiting Scientist at University of Southampton from 1999 to 2000. He received the Excellent Paper Award from the IEE of Japan in 2009, the IEC1906 Award in 2013, Liu Ziyu Memeorial Lecture Award in 2018, and IEEE Caixin Sun and Stan Grzybowski Lifetime Achievement Award in 2018. Currently, he is researching and developing the measurement system for the space charge distribution in various solid dielectric materials at high temperature, under ultra-high electric field or under high energy e-beam irradiation. He was a chair of Technical Committee of Dielectrics and Insulating Materials in IEEJ from June 2013 to May 2018, a vice president of The Institute of Engineers on Electrical Discharges in Japan from April 2016, and a vice chair of IEEE DEIS Japan Chapter from April 2017. He is a member of CIGRE SC D1, and he is also IEEE DEIS Society Administrative Committee Members-at-large (2015-2017, 2018-2020), and a convener of IEC TC 112 WG8 from Sept. 2015.

 

 

Measurement of Space Charge Distribution for a Real Long HV Cable and Uncertainties in Space Charge Measurement

 

 

Professor Yewen Zhang

Tongji University, China

 

 

 

Synopsis

To show three ways to measure space charge distribution for a real long HV cable: 2 ways by using PEA method, and one way by using laser PWP method.

To discuss uncertainties in the measurement of space charge distribution, and show some main possible error sources. 

 

Biography

Yewen Zhang was born in Zhejiang, China in 1955. He received the B.Eng., M.Sc. and the Ph.D. degrees in electrical engineering, from Xi’an Jiaotong University, China in 1982, 1984 and 1988 respectively. He then joined Ecole Supérieur de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI) as a Postdoctoral Research Fellow, subsequently being appointed Research Fellow. In 1996, he moved to the Department of Applied Physics, Hong Kong Polytechnic University, as a Research Fellow, and joined the Department of Physics, Tongji University, as a full professor in 1997. Since 2012, he is a full professor in Department of electrical Engineering, Tongji University. He was the senior member of IEEE DEI since 2013. His research interests lie mainly in the field of space charge in dielectrics. Recently, he has begun working on photonic crystals and metamaterials for microwave application.

 

 

 

 

Lessons from Three-Dimensional Imaging of Electrical Trees

 

 

 

Professor Simon Rowland

The University of Manchester, UK

 

 

 

Synopsis

Electrical trees are artifacts resulting from aging of polymeric insulation in high electrical fields which can lead to the ultimate failure of the host insulation. This paper reviews developments in observations of the growth of trees. In particular, consideration is given to the benefits of generating three-dimensional replicas of real trees from X-ray computed tomography (XCT) and serial block face scanning electron microscopy (SBFSEM), and how these can facilitate better understanding of tree development mechanisms. It is concluded that both two- and three-dimensional imaging are necessary, and these need correlating with partial discharge measurements to develop models of tree growth and effective asset management tools.

 

Biography

Simon Rowland graduated in physics from The University of East Anglia, and subsequently gained a PhD at London University in 1984. He worked in commercial research and manufacturing for STC, BICC and Corning before joining The School of Electrical and Electronic Engineering in The University of Manchester in 2003. He was appointed Professor of Electrical Materials in 2009, and Head of School in 2015. He was President of the IEEE Dielectric and Electrical Insulation Society in 2011 and 2012.

 

 

Post-Irradiation Effect Analysis on XLPE-Insulated LV Cables Used in Nuclear Power Plants

 

 

 

Professor Davide Fabiani

University of Bologna, Italy

 

 

Synopsis:

Low-voltage electrical cables are extensively used throughout nuclear power plants (NPPs) for instrumentation and control of equipment, power transmission and communication of signals and data. These cables can be exposed to an extensive range of severe environmental conditions and stresses, like e.g., temperature, radiation, mechanical stresses and humidity, mainly inside the containment area. Most of the NPP commissioned in ’70s and ’80s are now reaching end-of-life but, since decommissioning costs are very high, NPP regulators are trying to extend NPPs life up to other 60 (possibly even 80) years. Since electric cables are one of the long-life equipment that have not considered for replacement during the design life of a NPP, usually 40 years, evaluating degradation condition and predicting residual life are very critical issues.

Cable insulation and jackets are made of polymer-based compounds, whose degradation state is traditionally assessed through destructive methods, like tensile testing or thermal analysis. Non-destructive techniques based e.g. on electrical quantities are not commonly used in NPP to evaluate cable insulation condition. This was the aim of the European project FP7 ADVANCE (Aging Diagnostics and Prognostics of low voltage I&C cables). The project, finished in 2014, was focused on the study and the analysis of the results of accelerated aging tests performed on a representative selection of cables already installed in European NPPs in order to evaluate the ability of electrical Condition Monitoring (CM) techniques to detect local and global cable aging. The results were compared and correlated to those obtained with more conventional CM techniques for validation. Electrical permittivity, for instance, was found to be effectively associated with oxidation induced by aging. Post-irradiation effects have been also observed which may change material properties some months after irradiation, due to slow diffusion and reaction rate of some chemical radicals created by aging. Both phenomena must be taken into account to develop effective CM techniques for electrical insulation under such stress conditions.

In this paper, crosslinked polyethylene (XLPE) cable samples aged through high temperature and two different radiation levels have been analyzed through dielectric spectroscopy technique in order to evaluate the change in electrical response of the insulation with aging. Tests have been carried out immediately after aging and years after the radiation source has been turned off. Significant changes in dielectric response and mechanical properties have been observed due to post-irradiation effects, suggesting that degradation continues even after the aging source has been removed. This implies that a loss-of-coolant accident (LOCA), for instance, could affect cable insulation degradation even years after the accident as occurred. Therefore, proper diagnostic techniques should be applied for long terms to monitor the insulation state of the affected cables.

 

Biography

Davide Fabiani received the M.Sc. and Ph.D. in Electrical Engineering with honors in 1997 and 2002, respectively. He is Associate Professor at the Department of Electrical Electronics and Information Engineering of University of Bologna His fields of research are mainly related to development, characterization and diagnosis of electrical insulation systems for applications in electrical and electronic apparatus. He is author or co-author of about 200 papers, most of them published on the major international journals and conference proceedings. He is Associate Editor of IET High Voltage Journal, Senior Member of IEEE DEIS, member of DEIS AdCom and Chair of the Meetings Committee since 2016.

 

 

 

Effect of Accelerated Thermal Aging on the Properties of Paper-Ester from Palm Oil Composite Insulation

 

 

Professor Harjo Suwarno

Institut Teknologi Bandung, Indonesia

 

 

 

 

Synopsis

Mineral oil is widely used for transformer liquid insulation. However, due to environmental consideration and the availability of the liquid in the future, many efforts are being done to find new type of insulations. Recently, new type liquid insulation from natural like ester is being investigated for possible application in high voltage transformers. This presentation reports experimental results on the effects of thermal aging on the kraft transformer paper in natural ester made from palm oil. The natural ester from palm oil with paper combined with copper strips were put in closed aging bottles. The sample composition was designed to simulate the condition in an actual transformer. The sample was subjected to an accelerated thermal aging at 120oC in a controllable oven. The aging period was done until up to 1008 hours. The effects of thermal aging on the paper characteristics was investigated by measuring the tensile strength and degree of polymerization of paper. Comparison among measured parameters was done. Chemical change in the paper was examined using energy dispersive X-ray spectroscopy (EDS). Experimental results showed the reduction of tensile strength as well as degree of polymerization (DP) with aging time.  The tensile strength and DP are strongly correlated each other. The EDS measurement indicated that the thermal aging increased the C element in the paper and inversely reduced the oxygen in the paper. At the later aging, small amount of K element was observed in the paper which was considered as the esterification by product during manufacturing the natural ester from palm oil. As comparison in mineral oil instead of K, small amount of S was detected.

 

Biography

Suwarno received BSc and MSc from Electrical Eng Dept. ITB, Bandung in 1988 and 1991 respectively and D. Eng from Nagoya University, Japan in 1996. His research interests are High Voltage Insulating Materials and Technology, Diagnostics of HV Equipments, and High Voltage Industrial Application. Currently, Suwarno is Professor and Head of Electrical Power Engineering Research Group Institut Teknologi Bandung, Indonesia. He is The General Chairman of ICPADM 2006, ICEEI 2007 and CMD 2012. Prof. Suwarno is a senior member of IEEE, Editor in Chief International Journal IJEEI and editor member of JET and reviewers of several international journals such as IEEE, IET, Elsevier, Simulation International and Springer Verlag. He has published over 150 international journal or conference papers and over 90 domestic papers. He can be reached at suwarno@ieee.org.

 

 

 

 

High Electric Field Behavior and Energetic Processes in Poly(ethylene naphthalate)

 

 

Doctor Gilbert Teyssèdre

Université de Toulouse, France

 

Synopsis

Poly(ethylene 2,6-naphthalate) -PEN is structurally similar to the most commercially important saturated polyester PET - Poly(ethylene terephthalate). PEN is competitive with PET in certain performance-driven markets based on its superior strength, heat stability and barrier properties.

Whereas PET is widely produced for many applications ranging from textile, to packaging, to flexible electronics and to capacitors, PEN is relatively newer, more expensive such that its superior properties are not necessarily exploited. Replacing a phenyl ring by a naphtyl ring has some consequences on the mechanical properties, making the polymer chain stiffer. It also has great consequences on the optical, electronic, and vibrational response. Because of the naphtyl unit in its repeat unit, PEN is a relatively high luminescence yield material: Many recent studies focus on the application of PEN to scintillators for radiation detection.

From the dielectric properties point of view, Ohki et al. made recently a comparative study on the (low field) dielectric properties of PET and PEN: due to similar chemical structures, PET and PEN have many parallel dielectric properties controlled mainly by an increase about 50°C (from ≈70 to ≈120°C) of the glass transition temperature. Both are polar materials, producing relatively high dielectric losses in a given frequency range. We have investigated the high field behavior of PEN over the last 20 years, considering especially its electroluminescence (EL) properties. Indeed, owing to its high luminescence yield, strong nonlinear behavior at high field and high field withstanding, it has been considered as a model material for electroluminescence analysis.

Our purpose in this communication is to review the high field behavior of PEN in relation to its photo-physical properties. The topics addressed range from the optical and luminescence properties of PEN, to the electrical properties regarding current-voltage characteristics and orientation polarization and space charge. Finally, the question of electroluminescence vs. field characteristics and the dynamic response in electroluminescence, the nature of the emissions as revealed from the electroluminescence spectrum and the relation to ageing will be discussed.

 

Biography

Gilbert Teyssèdre was born in May 1966 in Rodez, France. He received his Engineer degree in materials physics and graduated in solid state physics in 1989 at the Institut National des Sciences Appliquées (INSA), Toulouse. Then he joined the Solid State Physics Lab in Toulouse and obtained the Ph.D. degree from Paul Sabatier University in 1993 for work on ferroelectric polymers. He entered the Centre National de Recherche Scientifique -CNRS in 1995 and has been working since then at the Electrical Engineering Lab (now Laplace – Laboratory on Plasma and Energy Conversion), a joint research unit between CNRS and University of Toulouse. His research activities concern the development of luminescence techniques in insulating polymers with focus on chemical and physical structure, degradation phenomena, space charge and transport properties. He is currently Senior Research at CNRS. He has been head of the Solid Dielectrics and Reliability group at Laplace from 2004 to 2015. He has held numerous governmental and industrial research grants in the field of electrical insulation and has co-authored about 140 contributions to scientific journals and book chapters and 200 conference proceedings. He is member of the scientific committee of several conference series as CEIDP since 2016, ICD, ICEMPE, and Ji Cable.

 

 

 

Dielectric Materials for Electro-Active (electret) and/or Electro-Passive (insulation) Applications

 

 

 

Professor Reimund Gerhard

University of Potsdam, Germany

 

 

Synopsis

Dielectric materials for electret applications usually have to contain a quasi-permanent space charge or dipole polarization that is stable over large temperature ranges and time periods. For electrical-insulation applications, on the other hand, a quasi-permanent space charge or dipole polarization is usually considered detrimental. In recent years, however, with the advent of high-voltage direct-current (HVDC) transmission and high-voltage capacitors for energy storage, new possibilities are being explored in the area of high-voltage dielectrics. Stable charge trapping (as e.g. found in nano-dielectrics) or large dipole polarizations (as e.g. found in relaxor ferroelectrics and high- permittivity dielectrics) are no longer considered to be necessarily detrimental in electrical-insulation materials. On the other hand, recent developments in electro-electrets (dielectric elastomers), i.e. very soft dielectrics with large actuation strains and high breakdown fields, and in ferroelectrets, i.e. polymers with electrically charged cavities, have resulted in new electret materials that may also be useful for HVDC insulation systems. Furthermore, 2-dimensional (nano-particles on surfaces or interfaces) and 3-dimensional (nano-particles in the bulk) nano-dielectrics have been found to provide very good charge-trapping properties that may not only be used for more stable electrets and ferroelectrets, but also for better HVDC electrical-insulation materials with the possibility to optimise charge-transport and field-gradient behaviour. In view of these and other recent developments, a first attempt will be made to review a small selection of electro-active (i.e. electret) and electro-passive (i.e. insulation) dielectrics in direct comparison. Such a comparative approach may lead to synergies in materials concepts and research methods that will benefit both areas. Furthermore, electrets may be very useful for sensing and monitoring applications in electrical-insulation systems, while high-voltage technology is essential for more efficient charging and poling of electret materials.

 

Biography

1978 Dipl.-Phys. at Technical University of Darmstadt, Germany.

1978 – 1979 Research fellow at the Department of Physics, Collège Militaire Royal, Saint-Jean, Québec, Canada (sponsored by Studienstiftung des Deutschen Volkes).

1981/82/83 Exchange visitor at AT&T Bell Laboratories, Murray Hill and Holmdel, NJ, 1984 Dr.-Ing. in Communications Engineering at Technical University of Darmstadt, 1985 – 1994 Research scientist and project manager at the Heinrich-Hertz Institute for Communications Engineering Berlin, Germany (now a Fraunhofer Institute).

1988 Award (ITG-Preis) by the Information Technology Society (ITG) in the VDE.

1989 Award of a silver medal by the Foundation Werner-von-Siemens-Ring, 1992 Dr.rer.nat.habil. in Applied Solid-State Physics at University of Potsdam, 1992 – 1994 Lecturer at the Technical University of Berlin, Germany, 1993. Fellow of the Institute of Electrical and Electronics Engineers (IEEE), 1994 Appointment as University Professor (C3) at University of Potsdam, 1997 Appointment as Full University Professor (C4) at University of Potsdam.

2004 – 2012 Chairman of the Joint Board for the Master-of-Science Program in Polymer.

Science of FU Berlin, HU Berlin, TU Berlin and U of Potsdam, 2008 – 2012 Dean of the Faculty of Science at the University of Potsdam, 2012 Fellow of the American Physical Society (APS), 2018 President of the IEEE Dielectrics and Electrical Insulation Society (DEIS).

Guest Editor for the IEEE TDEI (repeatedly), Chair of ISE 7 (1991) and of ICSD 10 (2010). Reviewer for APL, JAP, PRL, PRB, Science, IEEE TDEI, IEEE T-UFFC, Journal of Polymer. Science, Journal of Physics D: Applied Physics, Applied Physics A, Advanced Materials, etc.

 

 

 

 

Study on Dielectric Recovery Characteristics of High Voltage SF6 Circuit Breaker

 

 

 

Professor Xin Lin

Shenyang University of Technology, China

 

Synopsis

Recently, breaking failures caused by the re-strike happened frequently, with the increasing of voltage level and transmission capacity, especially for the capacitor bank circuit breaker in UHV project used to interrupts arc with small current and short arcing time. In above situation, the transient recovery voltage is higher and electric field intensity is larger because of short clearance between arcing contacts, therefore re-strike is easy to happen and the electrical lifetime of circuit breaker is badly limited. So several research directions become of large urgency, like the dielectric recovery characteristics after arcing and the influences of gas flow on SF6 insulation strength in different breaking methods. In this speech, a two-temperature model about non-equilibrium SF6 arc plasma is built according to Navier-Stokes Equation and gas equation of state, and the influence of turbulence on gas flow is taken into consideration as well, thus forming a numerical computing method for the whole breaking process in SF6 circuit breaker. To prove this numerical computation method that calculate SF6 breaking voltage in the whole breaking process in circuit breaker, a testing circuit of dynamic breaking voltage of between contacts in circuit breaker is executed. By combining the testing and computing results, this method is proved, and the dielectric recovery characteristics of SF6 in circuit breaker for capacitor bank is analyzed meanwhile. The research results can provide reference for the selection and optimization of the breaking operation strategy of capacitor bank circuit breaker.

 

Biography

Xin Lin, received the M.S. degree and the Ph.D. degree in electrical engineering from Xi’an Jiaotong University in 1985 and 1989, respectively. Now she is a professor at Shenyang University of Technology in China. She is member of Chinese Society for Electrical Engineering(CSEE) and member of CIGRE A3 representing China, etc. During her career she has published two books and authored more than 300 articles in the field of high voltage switchgear breaking. As the first inventor, she holds over 20 invention patents. Her researches include insulation characteristics of high voltage switchgear, discharge mechanism of SF6 and its substitute gas, and the arc breaking performance in circuit breakers, etc. Most of her research results have been applied directly to the design, manufacture and operation of extra and ultra high voltage circuit breaker in China.