Editorial

Because electrical engineering is developing rapidly, it is inevitable that at certain times some of its many branches will become more prominent than others. Although high-voltage engineering may not always be the centre of special attention, it has for long been of importance and is likely to remain so. Teaching and research in high-voltage engineering at universities will thus retain a valuable place in the training of young electrical engineers, and will help to stimulate and encourage interest in electrical power engineering.

physica status solidi (a)Volume 8, Issue 2 p. 335-374 Review Article Electrical breakdown in semiconductors Sudha Mahadevan, Sudha Mahadevan Departments of Physics and High Voltage Engineering, Indian Institute of Science, BangaloreSearch for more papers by this authorS. M. Hardas, S. M. Hardas Departments of Physics and High Voltage Engineering, Indian Institute of Science, BangaloreSearch for more papers by this authorG. Suryan, G. Suryan Departments of Physics and High Voltage Engineering, Indian Institute of Science, BangaloreSearch for more papers by this author Sudha Mahadevan, Sudha Mahadevan Departments of Physics and High Voltage Engineering, Indian Institute of Science, BangaloreSearch for more papers by this authorS. M. Hardas, S. M. Hardas Departments of Physics and High Voltage Engineering, Indian Institute of Science, BangaloreSearch for more papers by this authorG. Suryan, G. Suryan Departments of Physics and High Voltage Engineering, Indian Institute of Science, BangaloreSearch for more papers by this author First published: 16 December 1971 https://doi.org/10.1002/pssa.2210080202Citations: 38AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume8, Issue216 December 1971Pages 335-374 RelatedInformation

The following books are reviewed: High-Frequency Magnetic Components, 2nd Edition by M. K. Kazimierczuk; Electric Power Distribution Engineering, 3rd Edition by T. Gonen; GIS Gas-Insulated Substations by H. Koch, editor; Filamentary Ion Flow by F. Lattarulo and V. Amoruso; Fundamentals of Picoscience by K. D. Sattler, Editor; High-Voltage Test and Measuring Techniques by W. Hauschild and E. Lemke; High Voltage Engineering by F. A. M. Rizk and G. N. Trinh; Chemistry of Nanomaterials by C. N. R. Rao.

Technological developments in electrical engineering in recent years include substantial progress in the power fields of transmission, distribution, and utilization. Consequently, in common with other disciplines of electrical engineering, these advances make necessary some changes in existing tertiary courses if they are to keep abreast of developing technology. This is the case both in the undergraduate and graduate programs and is generating an increasing need for continuing education courses. This paper describes changes made in the power courses, at all levels, at the University of New South Wales in response to these pressures. Particular emphasis is given to laboratory developments in the high voltage and high current field, as this is seen as one area in particular need of development.

Polymer nanocomposites have been a topic of intensive research regarding High Voltage Engineering since the nineties of the last century.They present an alternative to conventional polymers since the latter were diagnosed with certain drawbacks.In this paper, a short review is given as to the basic characteristics of the polymer nanocomposites and some comments are offered as to the possible applications of the said materials in High Voltage Engineering.

"The book is written for students as well as for teachers and researchers in the field of High Voltage and Insulation Engineering. It is based on the advance level courses conducted at TU Dresden, Germany and Indian Institute of Technology Kanpur, India. The book has a novel approach describing the fundamental concept of field dependent behavior of dielectrics subjected to high voltage. There is no other book in the field of high voltage engineering following this new approach in describing the behavior of dielectrics. The contents begin with the description of fundamental terminology in the subject of high voltage engineering. It is followed by the classification of electric fields and the techniques of field estimation. Performance of gaseous, liquid and solid dielectrics under different field conditions is described in the subsequent chapters. Separate chapters on vacuum as insulation and the lightning phenomenon are included"--

A survey was conducted on the availability of high-voltage educational laboratories in the universities of various countries. The purpose of the survey was to establish whether education in this area of electrical engineering has kept pace with industrial growth. The results show that in the United States only five such laboratories are known to be in active existence. These are not used for instruction but only for research. Elsewhere, 70 percent of all institutional laboratories were built after 1960. The survey has also revealed many interesting and surprising figures regarding the use, the equipment, the size, and the staff of their laboratories. It is concluded that a great need for such facilities to ameliorate the quality of instruction and research in high-voltage engineering exists in the United States.

Rapidly increasing growth and automation of power are given the opportunity to power engineers to incorporate new ideas in the field of online monitoring of power apparatus for reliable operation of electrical system. As a part of new innovation in power system, photonics play an important role for driving innovation toward the sensor development, optical data communication to imaging, lighting and displays. In any power apparatus, degradation of insulation occurs due to the accumulation of mechanical, thermal and electrical effects for a long period. As the insulation of high voltage (HV) power apparatus are deteriorated by partial discharges (PDs), detection and measurement of PDs are of utmost important for the quality assessment of HV power equipment. In this chapter, an attempt has been made to detect the PDs with the help of photonic technology which eliminates the electrical interference; a challenge is being faced by power engineers in recent decades. It is understood from the several studies, PDs of HV power apparatus can be detected by electrical, chemical and acoustic methods. Electrical detection focuses on capturing the electrical impulses created by the current streamer in the void and impurities. Electrical detection method has some limitations. The primary limitation is its susceptibility to noise. The high voltage transformer (HVT) environment contains high levels of electrical noise, both narrowband and broadband. Chemical detection has also some drawbacks. Firstly, this detection method does not give any information about the location of the PD and the insulation condition. Secondly, the main problem is that chemical tests cannot be performed continuously when the HV equipment are in working operation. To explore the detection of PDs through acoustic method, acoustic phenomenon of PDs has been studied, and it is found that it leads to the propagation of acoustic waves having frequencies typically between 30 and 1000 kHz inside the transformer. The propagation of acoustic wave modulates the refractive index of the medium, which modulates the intensity of the laser beam in sympathy with the acoustic waves. Acoustic methods have many advantages over other methods in that they are immune to electromagnetic interference (EMI), which can greatly reduce the sensitivity of electrical methods and they can be applied to find failure spot and location of discharges. Optical technique is also capable to couple PDs with the optical signal. To capture the acoustic waves, an optical method is demonstrated in this chapter for detection and localization of PD sources by using photo detector inside the HV power apparatus. In this work, a new concept such as direct optical partial discharge detection technique has been introduced, where the energy exchange mechanism of electrical to acoustic is used for online monitoring of PDs. The acoustic signals are collected directly through the photonic technology, which is free from electrical interference, and finally they are converted to electrical signals for detection of amplitude as well as location of PDs occurring inside the HV power apparatus. This is a cost-effective tool for online monitoring of PDs and can be used as a predictive maintenance tool for utilities.

Partial discharge (PD) characterization is one of the key diagnostic tool while designing insulation system for high voltage (HV) apparatus or development of novel insulating material. This acts as a fingerprint for its performance during its life cycle. That is why HV lab has immense importance in terms of characterizing novel insulating material, HV insulators and condition monitoring PD sensors. Modern HV apparatus demands for a stringent limit for PD magnitude. The allowable limits are almost comparable with the basic electrical noise level present in any power system. On the other hand, more and more usage of power electronic devices, wireless gadgets increases conductive noises and radioactive noise, concurrently. Setting up a PD measurement lab in an industrial environment is a challenging task. High voltage lab of Raychem innovation center is situated very close to the manufacturing plant and surround by high power equipment of power electronics and material processing laboratory. A case study has been presented in this paper and step by step procedure has been given how the PD noise level has been brought down to less than 2pC level from an initial value of more than 500pC.

This paper presents content of the lecture delivered on 27 September, 2011 at the occasion of the 40th anniversary of the Institute of High Voltage Engineering and System Management (ISH) and the 55th anniversary of the Test Institution of High Voltage Engineering Graz LLC (VAH) of the Graz University of Technology. Today’s greatest engineering challenge from a global perspective is to slow down the climate change by reducing the emission of greenhouse gases, which calls for a major transformation of the electricity infrastructure. In this context strengthening and upgrading the existing electric power networks is of crucial importance for integration of increasing generation of renewable energy, enhancing grid security and pushing forward energy savings and efficiency. For achieving these goals it will not only be necessary to build new lines and substations, but also to make the overall electricity system more flexible, stronger, secure, extensible and stable. The paper concentrates on the network aspect of future electric power grids in Europe and worldwide, by providing examples of new initiatives undertaken by different organizations and countries. Further, it also illustrates how European partners approach the problem of the necessary technological development, while special attention is put on a possibility to develop a high voltage direct current (HVDC) multi-terminal grid in Europe. This vision, though realistic today, still requires extensive multidisciplinary efforts of researchers and engineers for employing innovative products and services together with intelligent monitoring, control, communication and self-healing properties of electricity networks. The role of high voltage engineering in this task is of paramount importance and cannot remain underestimated.

The paper discusses selected problems related to application of energy harvesting (that is, generating electricity from surplus energy present in the environment) to supply autonomous ultra-low-power measurement systems applicable in high voltage engineering. As a practical example of such implementation a laboratory model of a remote temperature sensor is presented, which is self-powered by heat generated in a current-carrying busbar in HV- switchgear. Presented system exploits a thermoelectric harvester based on a passively cooled Peltier module supplying micro-power low-voltage dc-dc converter driving energy-efficient temperature sensor, microcontroller and a fibre-optic transmitter. Performance of the model in laboratory simulated conditions are presented and discussed.

Sulphur hexafluoride (SF6) has been the most commonly used gas in the electrical industry since 1960s. Due to the high environmental hazards reported by using SF6, the research on to investigate alternative gaseous insulation has become demanding research in high voltage engineering. The refrigerant gas chlorodifluoromethane (CHClF2) with low global warming potential and stable chemical properties possess high dielectric strength due to the presence of fluorine atoms. In this paper, the dielectric strength of CHClF2 and its mixtures with CO2, N2, and Air in the uniform field are investigated under AC, DC and impulse voltage. Buffer gases (CO2, N2, and Air) are added to improve the boiling point of base gas (CHClF2). The dielectric strength increase has also been reported by mixing base gas with N2. Moreover, the synergistic effect, liquefaction temperature, and self-recoverability test were also obtained proving the significance of the research.

Investigation on effects of electromagnetic fields on different aspects of biological systems had been done by much research. Our study, which has been carried out under the joint research between the Laboratory of High voltage and High current Engineering and Laboratory of Microbiology of the Institut Teknologi Bandung, investigates the influence of 50 Hz magnetic field on the growth of several species of mushroom. In this study, we observed growth of mushroom, from spora up to fully ripe stages, under magnetic field exposure of different intensity from 0.1 mT to 1.7 mT. During exposure the room condition was held constant at temperature of 20/spl deg/C and 95% humidity. We noted that some parameters such as: mushroom growth velocity, shape, dimension, quantity, color and period of mushroom ovary are significantly influenced by magnetic energy absorbed.

High-voltage compressed-gas capacitor is a type of precision equipment commonly used in high voltage laboratories. The voltage dependence of capacitance, in other words, the voltage coefficient of capacitance, is an important factor to ensure the measurement accuracy of capacitors. The simplified tilting method derived from PTB, which provides a solution for measuring the voltage coefficient of the high-voltage capacitor with compressed-gas coaxial cylindrical electrodes structure. However, it is not an easy work for most laboratories. In order to evaluate the voltage coefficient based on the simplified tilting method, a special experimental platform was developed. The high-voltage capacitor installed on the platform can be tilted and rotated at high voltage and be remote-controlled. Base on the developed platform, the voltage coefficient of a 350 kV high-voltage capacitor was measured. In order to verify, it was re-measured by the direct measurement method with a dummy high-voltage capacitor, and before that, the voltage coefficient of the dummy capacitor was calibrated with a near zero-voltage-coefficient capacitor. The results show a good agreement, the consistency of the measurement results is better than 1.2×10^-6 between the two methods. Furthermore, the evaluation of measurement uncertainty in the voltage coefficient determination of capacitor based on simplified tilting method is introduced in detail. The evaluation results show that the expanded uncertainty is significantly better than 2.0×10^-6, k=2.

Event Abstract Back to Event Intrinsic Connectivity in Resting-State Networks is Related to Antisaccade Task Performance Sharna Jamadar1*, Joanne Fielding2, Beth P. Johnson2, Vince D. Calhoun3, 4 and Gary F. Egan1 1 Monash University, Monash Biomedical Imaging/School of Psychology & Psychiatry, Australia 2 Monash University, School of Psychology, Australia 3 The Mind Research Network, United States 4 University of New Mexico, Department of Electrical and Computer Engineering, United States BACKGROUND Saccadic eye movements represent one of the most automated and prepotent responses in our behavioural repertoire. When presented with a peripheral target, the prepotent response is to make a saccadic eye movement (prosaccade, PS) towards the target. The antisaccade (AS) task requires inhibition of this reflex and instead elicit a saccadic eye movement to the mirror opposite direction. Given the highly automated and prepotent nature of the PS response, we hypothesize that an individual’s ability to control saccadic eye movements may be related to intrinsic connectivity within neural networks. We examine relationships between AS performance with timecourse spectra of resting-state fMRI networks (RSNs) using high-dimensional ICA and a multivariate fusion approach (Allen et al. 2011 Front.Sys.Neurosci,5) METHOD Participants (n=23) underwent fMRI scanning during AS (50%) and PS (50%) trials and resting-state fMRI in separate runs. Resting-state T2*-weighted images were acquired using GRAPPA EPI (116volumes, TR=2.5s, TE=30ms, FOV=192mm, acquisition matrix=64x64, 44slices, 3x3x3mm voxels). fMRI data were preprocessed with SPM8 (slice time corrected, realigned to the first non-dummy image, coregistered and normalized to MNI space and smoothed 6mm FWHM). Preprocessed images were entered into a high-dimensional (IC=75) group ICA; 48 RSNs were identified. Timecourse spectra of RSNs were entered into a MANCOVA analysis with design matrix defined with the following factors: AS latency, AS error rate, PS latency, PS error rate, AS latency X error rate, PS latency X error rate, AS latency X PS latency, AS error rate X PS error rate, rotational and translational motion. Following multivariate analysis, univariate tests were performed to determine which spectral bins were related to behavioural covariates of interest (FDR p<.05) RESULTS AS trials were performed slower and more accurately than PS trials. AS latency and error rate were moderately related to timecourse spectra. AS latency showed positive relationship with low frequency power in ventrolateral prefrontal cortex and high frequency power in lingual gyri. AS error rate showed negative relationship with low frequency power in orbitofrontal cortex and medial motor regions and high frequency power in lateral motor and lingual gyri DISCUSSION Individual variability in intrinsic connectivity in orbitofrontal, motor and visual regions is related to the cognitive control of eye movements Keywords: Resting-state fMRI, Antisaccade performance, multivariate analysis, oculomotor control, intrinsic connectivity Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Motor Citation: Jamadar S, Fielding J, Johnson BP, Calhoun VD and Egan GF (2013). Intrinsic Connectivity in Resting-State Networks is Related to Antisaccade Task Performance. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00002 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Oct 2013; Published Online: 25 Nov 2013. * Correspondence: Dr. Sharna Jamadar, Monash University, Monash Biomedical Imaging/School of Psychology & Psychiatry, Clayton, VIC, 3977, Australia, sharna.jamadar@monash.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sharna Jamadar Joanne Fielding Beth P Johnson Vince D Calhoun Gary F Egan Google Sharna Jamadar Joanne Fielding Beth P Johnson Vince D Calhoun Gary F Egan Google Scholar Sharna Jamadar Joanne Fielding Beth P Johnson Vince D Calhoun Gary F Egan PubMed Sharna Jamadar Joanne Fielding Beth P Johnson Vince D Calhoun Gary F Egan Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.