DOCSLIB.ORG

A Compact and Portable EMP Generator Based on Tesla Transformer Technology

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Loughborough University Institutional Repository A compact and portable EMP generator based on Tesla transformer technology This item was submitted to Loughborough University's Institutional Repository by the/an author. Additional Information: • A Doctoral Thesis. Submitted in partial fullment of the requirements for the award of Doctor of Philosophy of Loughborough University. Metadata Record: https://dspace.lboro.ac.uk/2134/10902 Publisher: c Partha Sarkar Please cite the published version. This item was submitted to Loughborough University as a PhD thesis by the author and is made available in the Institutional Repository (https://dspace.lboro.ac.uk/) under the following Creative Commons Licence conditions. For the full text of this licence, please go to: http://creativecommons.org/licenses/by-nc-nd/2.5/ •• LO';1ghh.orough .,UmverSlty University Library AuthorlFiling Title ........... ?A8.~f.H:?, ... .e................. I ~;~~~.~~;~.::::::::::::::::::~:!.::::::::::::::::::::::::::::::::::::::::::::: Please note that fines are charged on ALL overdue items. ~il~~lli\iU~1 I'11 II II IIll' I11'11111 A Compact and Portable EMP Generator based on Tesla Transformer Technology by Partha Sarkar B.E (Hons) MIEEE, M/ET A Doctoral Thesis submitted in partial fulfilment ofthe requirement for the award ofDoctor ofPhilosophy ofLoughborough University, UK July 2008 © by Partha Sarkar, 2008 Ace No. / Dedicated To My Father ACKNOWLEDGEMENTS I would like to express my sincere gratitude and to acknowledge the assistance and continuous support received from my supervisor, Professor Ivor Smith. I am grateful for his efforts even before I began my studies at Loughborough, in being instrumental in helping me to obtain Departmental funding, without which it would not have been possible for me to undertake the research described in this thesis. I am also grateful to him for his reviews and advice during the writing of the thesis. Special thanks are due to Dr. Bucur Novac, who was a constant source of inspiration, expert advice and assistance during my research work. I am very fortunate to have been associated with him. I am very grateful to Mr. lon Brister and Mr. Charles Greenwood for their technical assistance in designing and constructing the experimental systems. Without their help none of the systems described would have been built. Mr. Greenwood also deserves special mention as he not only helped me with his technical inputs but also in various other matters as well as being a constant source of encouragement. I am also grateful to Dr. Sean Braidwood for his assistance in the initial phase of the research work and for his readiness to help me with his expert advice even after he returned to Australia. I would also like to thank Dr. Marko Istenic, Mr. Peter Senior, Dr. ling Luo and Mr. Rajesh Kumar colleagues in the Pulsed Power Group at Loughborough University for providing friendly help. Finally, but most importantly, I would like to thank my wife Sweta, our son Saumil and my entire family for their constant support and patience during this period. ii Abstract ABSTRACT High power electromagnetic pulses are of great importance in a variety of applications such as transient radar, investigations of the effect of strong radio-frequency impulses on electronic systems and modem bio-medical technology. In response to the current trend, a simple, compact, and portable electromagnetic pulse (EMP) radiating source has been developed, based on pulsed transformer technology and capable of producing nanosecond rise-time pulses at voltages exceeding 0.5 MY. For this type of application pulsed transformer technology offers a number of significant advantages over the use of a Marx generator, e.g. design simplicity, compactness and cost effectiveness. The transformer is operated in a dual resonance mode to achieve a high energy transfer efficiency, and although the output voltage inevitably has a slower rise-time than that of a Marx generator, this can be improved by the use of a pulse forming line in conjunction with a fast spark-gap switch. The transformer design is best achieved using a filamentary modeling technique, that takes full account of bulk skin and proximity effects and accurately predicts the self and mutual inductances and winding resistances of the transformer. One main objective of the present research was to achieve a high-average radiated power, for which the radiator has to be operated at a high pulse repetition frequency (pRF), with the key component for achieving this being the spark-gap switch in the primary circuit of the pulsed transformer. Normally a spark-gap switch has a recovery time of about ten milliseconds, and a PRF above 100 Hz is difficult to achieve unless certain special techniques are employed. As the aim of the present study is to develop a compact system, the use of a pump for providing a fluid flow between the electrodes of the spark gap is iii Abstract ruled out, and a novel spark-gap switch was therefore developed based on the principle of corona-stabilization. For simplicity, an omnidirectional dipole-type structure was used as a transmitting antenna. Radiated electric field measurements were performed using a time-derivative sensor, with data being collected by a suitable fast digitizing oscilloscope. Post-numerical processing of the collected data was necessary to remove the ground reflected wave effect. Measurements of the radiated electric field at 10 m from the radiating element indicated a peak amplitude of 12.4 kV/m. Much of the work detailed in the thesis has already been presented in peer reviewed journals and at prestigious international conferences. iv Contents CONTENTS ACKNOWLEDGMENTS .................................................................... ii ABSTRACT ............................................................................. iii LIST OF FIGURES .................................................................... X LIST OF ACRONYMN ................................................................... xvi 1. INTRODUCTION ..................................................................... 1 References .............................................................................. 7 2. COMPUTATIONAL TECHNIQUE .................................................. 9 2.1 Introduction .................................................................... 9 2.2 Filamentary Modelling ........................................................... 10 2.3 Electrical properties of B-current circuits ........................................ 13 2.3.1 Magnetic vector potential of a circular current loop ...................... 13 2.3.2 Magnetic induction ofa circular loop ............................... 14 2.3.3 Forces between two parallel coaxial loops ............................... 15 2.3.4 Mutual inductance of two parallel and coaxial circular loops ........... 16 2.3.5 Self-inductance of circular loop ........................................ 17 2.3.5.1 Finite circular cross-section conductors ...................... 17 2.3.5.2 Finite rectangular cross-section conductor ..................... 17 2.3.5.3 Ribbon cross-section conductor with finite width ............. 18 2.3.6 Resistance ................................................................... 18 2.4 Electrical properties ofz-current circuits ........................................ 19 2.4.1 Magnetic flux density of a long straight conductor ...................... 19 2.4.2 Self-inductance of coaxial structures ............................... 20 v Contents 2.4.3 Inductance of straight conductors ........................................ 20 2.4.4 Resistance of cylindrical conductor geometry ...................... 20 2.5 Skin and proximity effects .......................................................... 21 2.6 Lumped inductance and resistance calculation ............................... 22 2.6.1 Energy method .......................................................... 22 2.6.2 Using simple formulae ................................................. 23 2.6.3 Resistance calculation ..................................................23 2.7 Stray capacitance modelling of an inductor ............................... 24 2.7.1 Stray capacitance calculation using Maxwell 2D electrostatic field solver ................................................................... 25 2.7.1.1 Capacitance computation ............................... 28 2.7.1.2 Lumped equivalent stray capacitance by node reduction method ..................................................................... 29 2.8 Modelling of high-voltage pulse transformer ............................... 30 2.8.1 Helical winding .......................................................... 30 2.8.2 Spiral winding .......................................................... 36 2.9 Results and discussions ........................................ 39 2.9.1 Inductance and resistance calculations ............................... 39 2.9.2 Stray capacitance calculation ........................................ 45 2.10 Summary ................................................................... 46 References ............................................................................ 47 3. TESLA TRANSFORMER DESIGN ................................................. 49 3.1 Introduction ................................................................... 49 vi Contents 3.2 Briefreview of previous work on Tesla transformers ...................... 50 3.3 Circuit theory ...................................................... : ...........
Recommended publications
  • Evaluation of Monte Carlo Tools for High Energy Atmospheric Physics

    Evaluation of Monte Carlo Tools for High Energy Atmospheric Physics

    Evaluation of Monte Carlo tools for high energy atmospheric physics Casper Rutjes1, David Sarria2, Alexander Broberg Skeltved3, Alejandro Luque4, Gabriel Diniz5,6, Nikolai Østgaard3, and Ute Ebert1,7 1Centrum Wiskunde & Informatica (CWI), Amsterdam, The Netherlands 2Astroparticules et Cosmologie, University Paris VII Diderot, CNRS/IN2P3, France 3Department of Physics and Technology, University of Bergen, 5020 Bergen, Norway 4Instituto de Astrofisica de Andalucia (IAA-CSIC), PO Box 3004, Granada, Spain 5Instituto Nacional de Pesquisas Espaciais, Brazil 6Instituto de Física, Universidade de Brasília, Brazil 7Eindhoven University of Technology, Eindhoven, The Netherlands Correspondence to: Casper Rutjes ([email protected]) Abstract. The emerging field of high energy atmospheric physics (HEAP) includes Terrestrial Gamma-ray Flashes, electron- positron beams and gamma-ray glows from thunderstorms. Similar emissions of high energy particles occur in pulsed high voltage discharges. Understanding these phenomena requires appropriate models for the interaction of electrons, positrons and photons of up to 40 MeV energy with atmospheric air. In this paper we benchmark the performance of the Monte Carlo codes 5 Geant4, EGS5 and FLUKA developed in other fields of physics and of the custom made codes GRRR and MC-PEPTITA against each other within the parameter regime relevant for high energy atmospheric physics. We focus on basic tests, namely on the evolution of monoenergetic and directed beams of electrons, positrons and photons with kinetic energies between 100 keV and 40 MeV through homogeneous air in the absence of electric and magnetic fields, using a low energy cut-off of 50 keV. We discuss important differences between the results of the different codes and provide plausible explanations.
  • Design and Performance of a Tesla Transformer Type Relativistic Electron Beam Generator

    Design and Performance of a Tesla Transformer Type Relativistic Electron Beam Generator

    SFuthan~, VoL 9, Part 1, February 1986, pp. 19-29. © Printed in India. Design and performance of a Tesla transformer type relativistic electron beam generator K K JAIN, D CHENNAREDDY, P I JOHN and Y C SAXENA Plasma Physics Programme, Physical Research Laboratory, Navrangpura, Ahmedabad 380009, India MS received 25 October 1984; revised 29 July 1985 Abstract. A relativistic electron beam generator driven by an air core Tesla transformer is described. The Tesla transformer circuit analysis is outlined and computational results are presented for the case when the co- axial water line has finite resistance. The transformer has a coupling co- efficient of~56 and a step-up ratio of 25. The Tesla transformer can provide 800 kV at the peak of the second half cycle of the secondary output voltage and has been tested up to 600 kV. A 100-200 keV, 15-20 kA electron beam having 150 ns pulse width has been obtained. The beam generator described is being used for the beam injection into a toroidal device aETA. Keywords. Relativistic electron beam; Tesla transformer; coaxial water line; drift injection technique. 1. Introduction In the last decade, the technology of the intense relativistic electron beam (REB) has received much attention in the field of plasma physics. Intense electron beams have been used for heating of plasma to high temperatures (Korn et a11973; Roberson 1978; Jain & John 1984a), for plasma confinement by creating a close field-reversed configuration (Kapetanakos et al 1975; Sethian et al 1978; Jain & John 1984b), for collective acceleration of ions (Olsen 1975; Roberson et a11976; Sprangle et a11976) and for pellet fusion (Yonas et al 1974, 1983, p.
  • What Is a Balun?

    What Is a Balun?

    What is a Balun? A balun is a small transformer which converts an audio or video signal from unbalanced to balanced and vice-versa. By doing so, baluns make the necessary impedance adjustment for A/V signal transmission between different types of wiring. An example is to use the Cables for Less 052-122 model to send HDTV signals on component video cables up to 500’ away using a single CAT5e wire! Why would I use a Balun? Baluns extend transmission distances. Baluns allow you to extend audio/video signals which are limited to short lengths when utilizing standard cables. For example using baluns from Cables for Less allows you to send: • Analog audio as far as 500 feet • Digital audio as far as 500 feet • Composite video as far as 500 feet • Component video at up to 1080i/p HDTV resolutions as far as 500 feet • All of this using reliable passive (no power supply) Baluns! Baluns can use existing wiring. Many buildings and homes already have CAT5e wiring installed! If this is the case for you, the hard work is already done. Just connect a Balun at each end of the cable run with whichever signal wire you need, such as audio or video, to connect the baluns to source and destination equipment. Baluns lower installation cost. In many installations, the cost of your Cables for Less Baluns in addition to the required CAT5e or CAT6 cable is far less than the cost of standard cables, especially for longer distances. Increase efficiency and simplify installations. Traditionally, a single cable could not transmit both audio and video.
  • Active Balun with Center-Tapped Inductor and Double-Balanced Gilbert Mixer for GNSS Applications

    Active Balun with Center-Tapped Inductor and Double-Balanced Gilbert Mixer for GNSS Applications

    electronics Article Active Balun with Center-Tapped Inductor and Double-Balanced Gilbert Mixer for GNSS Applications Daniel Pietron 1,* , Tomasz Borejko 1,2 and Witold Adam Pleskacz 1 1 Institute of Microelectronics & Optoelectronics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warsaw, Poland; [email protected] or [email protected] (T.B.); [email protected] (W.A.P.) 2 ChipCraft Sp. z o.o., ul. Dobrza´nskiego3, lok. BS073, 20-262 Lublin, Poland * Correspondence: [email protected] Abstract: A new 1.575 GHz active balun with a classic double-balanced Gilbert mixer for global navigation satellite systems is proposed herein. A simple, low-noise amplifier architecture is used with a center-tapped inductor to generate a differential signal equal in amplitude and shifted in phase by 180◦. The main advantage of the proposed circuit is that the phase shift between the outputs is always equal to 180◦, with an accuracy of ±5◦, and the gain difference between the balun outputs does not change by more than 1.5 dB. This phase shift and gain difference between the outputs are also preserved for all process corners, as well as temperature and voltage supply variations. In the balun design, a band calibration system based on a switchable capacitor bank is proposed. The balun and mixer were designed with a 110 nm CMOS process, consuming only a 2.24 mA current from a 1.5 V supply. The measured noise figure and conversion gain of the balun and mixer were, respectively, NF = 7.7 dB and GC = 25.8 dB in the band of interest.
  • Development of a 18- Megavolt Marx Generator

    Development of a 18- Megavolt Marx Generator

    © 1969 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. DEVELOPMENTOF AN l&MEGAVOLT MARK GENERATOR* K. R. Prestwich and D. L. Johnson Sandia Laboratories Albuquerque, New Mexico Summary approaches pVo, the generator is called an n-p generator and it would trigger down to 100/p per- An l&megavolt, 1 megajoule Marx generator cent of VB. has been constructed and tested to 11 MV as the primary energy store of the Hermes II flash x-ray To gain a more thorough knowledge of the oper- machine.1 A geometrical arrangement for the capa- ation of Marx generators, several model Marx gen- citors that takes advantage of the stray capaci- erators were built. A capacitor arrangement was ties to provide a wide triggering range and fast sought that would trigger over a large voltage Marx erection time was developed from model and range for any given spark gap setting, that would circuit studies. The design parameters of the switch very rapidly, that could be easily assembled Marx were checked by constructing and testing a 4 and maintained when constructed with 1/2uF, 100 kV MV, 100 kJ generator using components proposed for capacitors, and that would have a reasonably low the 18 MV system. Spark gaps were developed spe- inductance. The Marx models were constructed with cifically for the generator and have operated 10 kV, l/4 pF capacitors.
  • The Study of Electromagnetic Processes in the Experiments of Tesla

    The Study of Electromagnetic Processes in the Experiments of Tesla

    The study of electromagnetic processes in the experiments of Tesla B. Sacco1, A.K. Tomilin 2, 1 RAI, Center for Research and Technological Innovation (Turin, Italy), [email protected] 2National Research Tomsk Polytechnic University (Tomsk, Russian Federation), [email protected] The Tesla wireless transmission of energy original experiment, proposed again in a downsized scale by K. Meyl, has been replicated in order to test the hypothesis of the existence of electroscalar (longitudinal) waves. Additional experiments have been performed, in which we have investigated the features of the electromagnetic processes between the two spherical antennas. In particular, the origin of coils resonances has been measured and analyzed. Resonant frequencies calculated on the basis of the generalized electrodynamic theory, are in good agreement with the experimental values found. Keywords: Tesla transformer, K. Meyl experiments, electroscalar waves, generalized electrodynamics, coil resonant frequency. 1. Introduction In the early twentieth century, Tesla conducted experiments in which he demonstrated unusual properties of electromagnetic waves. Results of experiments have been published in the newspapers, and many devices were patented (e.g. [1]). However, such work has not received suitable theoretical explanation, and so far no practical application of the results have been developed. One hundred years later, Professor K. Meyl [2] aimed to reproduce the same experiments using a miniature, laboratory version of the Tesla setup, arguing that it can help to detect unusual phenomena that are explained by the presence of electroscalar (longitudinal) waves, namely: • the reaction on the transmitter of the presence of the receiver; • the transmission of scalar waves with a speed of 1,5 times the speed of light; • the inefficiency of a Faraday cage in shielding scalar waves, and • the possibility of wireless transmission of electrical energy.
  • Download (PDF)

    Download (PDF)

    Nanotechnology Education - Engineering a better future NNCI.net Teacher’s Guide To See or Not to See? Hydrophobic and Hydrophilic Surfaces Grade Level: Middle & high Summary: This activity can be school completed as a separate one or in conjunction with the lesson Subject area(s): Physical Superhydrophobicexpialidocious: science & Chemistry Learning about hydrophobic surfaces found at: Time required: (2) 50 https://www.nnci.net/node/5895. minutes classes The activity is a visual demonstration of the difference between hydrophobic and hydrophilic surfaces. Using a polystyrene Learning objectives: surface (petri dish) and a modified Tesla coil, you can chemically Through observation and alter the non-masked surface to become hydrophilic. Students experimentation, students will learn that we can chemically change the surface of a will understand how the material on the nano level from a hydrophobic to hydrophilic surface of a material can surface. The activity helps students learn that how a material be chemically altered. behaves on the macroscale is affected by its structure on the nanoscale. The activity is adapted from Kim et. al’s 2012 article in the Journal of Chemical Education (see references). Background Information: Teacher Background: Commercial products have frequently taken their inspiration from nature. For example, Velcro® resulted from a Swiss engineer, George Mestral, walking in the woods and wondering why burdock seeds stuck to his dog and his coat. Other bio-inspired products include adhesives, waterproof materials, and solar cells among many others. Scientists often look at nature to get ideas and designs for products that can help us. We call this study of nature biomimetics (see Resource section for further information).
  • The Physics of Streamer Discharge Phenomena

    The Physics of Streamer Discharge Phenomena

    The physics of streamer discharge phenomena Sander Nijdam1, Jannis Teunissen2;3 and Ute Ebert1;2 1 Eindhoven University of Technology, Dept. Applied Physics P.O. Box 513, 5600 MB Eindhoven, The Netherlands 2 Centrum Wiskunde & Informatica (CWI), Amsterdam, The Netherlands 3 KU Leuven, Centre for Mathematical Plasma-astrophysics, Leuven, Belgium E-mail: [email protected] Abstract. In this review we describe a transient type of gas discharge which is commonly called a streamer discharge, as well as a few related phenomena in pulsed discharges. Streamers are propagating ionization fronts with self-organized field enhancement at their tips that can appear in gases at (or close to) atmospheric pressure. They are the precursors of other discharges like sparks and lightning, but they also occur in for example corona reactors or plasma jets which are used for a variety of plasma chemical purposes. When enough space is available, streamers can also form at much lower pressures, like in the case of sprite discharges high up in the atmosphere. We explain the structure and basic underlying physics of streamer discharges, and how they scale with gas density. We discuss the chemistry and applications of streamers, and describe their two main stages in detail: inception and propagation. We also look at some other topics, like interaction with flow and heat, related pulsed discharges, and electron runaway and high energy radiation. Finally, we discuss streamer simulations and diagnostics in quite some detail. This review is written with two purposes in mind: First, we describe recent results on the physics of streamer discharges, with a focus on the work performed in our groups.
  • Simulations of the Propagation of Streamers in Electrical Discharges in a 5Mm Water Filled Gap

    Simulations of the Propagation of Streamers in Electrical Discharges in a 5Mm Water Filled Gap

    Research Article Curr Trends Biomedical Eng & Biosci Volume 9 Issue 4 -september 2017 Copyright © All rights are reserved by Duaa A Uamran DOI: 10.19080/CTBEB.2017.09.555767 Simulations of the Propagation of Streamers in Electrical Discharges in a 5mm Water Filled Gap Thamir H Khalaf1 and Duaa A Uamran1,2* 1Department of Physics, College of Science, University of Baghdad, Iraq 2Department of Physics, College of Science, University of Kerbala, Iraq Submission: August 09, 2017; Published: September 27, 2017 *Corresponding author: Duaa A Uamran, Department of Physics, College of Science, University of Baghdad, Iraq, Email: Abstract This work is devoted to the modeling of streamer discharge, propagation in liquid dielectrics (water) gap using the bubble theory. This of the electrical discharge (streamer) propagating within adielectric liquid subjected to a divergent electric, using finite element method (in thetwo dielectric dimensions). liquid Solution gap and of indicates Laplace’s the equation minimum governs breakdown the voltage voltage andrequired electric for fielda 5mm distributions atmospheric within pressure the dielectricconfiguration, liquid the gap electrode as 22KV. configuration a point (pin) - plane configuration, the plasma channels were followed, step to step. That shows the streamer discharge bridges shown agreement with the streamer growth, according to the simulation development time. The initiated streamer grows and branches toward all elements that satisfy the required conditions. The electric potential and field distributions Keywords: Herbal; Phytochemical; Cytotoxic; Formulations Introduction and slow, heavy ions alter the propagation of discharge channels The breakdown of insulating liquids is not simple to explain [7-9]. and the mechanism responsible for the initiation of breakdown is still open to controversy.
  • The Capacitor: Posi- Tive on One Side, Negative on the Other

    The Capacitor: Posi- Tive on One Side, Negative on the Other

    TESLA COIL by George Trinkaus Third edition, originally ©1989 by George Trinkaus (ISBN 0-9709618-0-4) published by High Voltage Press in paper format High Voltage Press PO Box 1525 Portland, OR 97207 Content copyright ©2003 George Trinkaus Layout, design, and e-book creation are copyright ©2003 Good Idea Creative Services Published by Wheelock Mountain Publications, an imprint of Good Idea Creative Services Good Idea Creative Services 324 Minister Hill Road Wheelock VT 05851 www.tesla-ebooks.com i How To Use This Book Text links Click on red colored text to go to a link within the e-book. Click on blue colored text to go to an external link on the internet. The link will automatically open your browser. You must be connected to the internet to view the externally linked pages. Buttons The TOC button will take you to the table of contents. The left facing arrow will take you to the previous page. The right facing arrow will take you to the next page. ii Table Of Contents Preface . iv Tesla Free Energy . 1 How It Works. 5 How to Build It . 9 Tesla Lighting . 54 Magnifying Transmitter . 60 Tuning Notes. 66 For More Information. 69 Click on the red text or red page number to go to the page. iii Preface Invented by Nikola Tesla back in 1891, the tesla coil can boost power from a wall socket or battery to millions of high frequency volts. In this booklet, the only systematic treatment of the tesla coil for the electrical nonexpert, you’ll find a wealth of information on one of the best-kept secrets of electric technology, plus all the facts you need to build a tesla coil on any scale.
  • The Self-Resonance and Self-Capacitance of Solenoid Coils: Applicable Theory, Models and Calculation Methods

    The Self-Resonance and Self-Capacitance of Solenoid Coils: Applicable Theory, Models and Calculation Methods

    1 The self-resonance and self-capacitance of solenoid coils: applicable theory, models and calculation methods. By David W Knight1 Version2 1.00, 4th May 2016. DOI: 10.13140/RG.2.1.1472.0887 Abstract The data on which Medhurst's semi-empirical self-capacitance formula is based are re-analysed in a way that takes the permittivity of the coil-former into account. The updated formula is compared with theories attributing self-capacitance to the capacitance between adjacent turns, and also with transmission-line theories. The inter-turn capacitance approach is found to have no predictive power. Transmission-line behaviour is corroborated by measurements using an induction loop and a receiving antenna, and by visualising the electric field using a gas discharge tube. In-circuit solenoid self-capacitance determinations show long-coil asymptotic behaviour corresponding to a wave propagating along the helical conductor with a phase-velocity governed by the local refractive index (i.e., v = c if the medium is air). This is consistent with measurements of transformer phase error vs. frequency, which indicate a constant time delay. These observations are at odds with the fact that a long solenoid in free space will exhibit helical propagation with a frequency-dependent phase velocity > c. The implication is that unmodified helical-waveguide theories are not appropriate for the prediction of self-capacitance, but they remain applicable in principle to open- circuit systems, such as Tesla coils, helical resonators and loaded vertical antennas, despite poor agreement with actual measurements. A semi-empirical method is given for predicting the first self- resonance frequencies of free coils by treating the coil as a helical transmission-line terminated by its own axial-field and fringe-field capacitances.
  • Transformer Protection

    Transformer Protection

    Power System Elements Relay Applications PJM State & Member Training Dept. PJM©2018 6/05/2018 Objectives • At the end of this presentation the Learner will be able to: • Describe the purpose of protective relays, their characteristics and components • Identify the characteristics of the various protection schemes used for transmission lines • Given a simulated fault on a transmission line, identify the expected relay actions • Identify the characteristics of the various protection schemes used for transformers and buses • Identify the characteristics of the various protection schemes used for generators • Describe the purpose and functionality of Special Protection/Remedial Action Schemes associated with the BES • Identify operator considerations and actions to be taken during relay testing and following a relay operation PJM©2018 2 6/05/2018 Basic Concepts in Protection PJM©2018 3 6/05/2018 Purpose of Protective Relaying • Detect and isolate equipment failures ‒ Transmission equipment and generator fault protection • Improve system stability • Protect against overloads • Protect against abnormal conditions ‒ Voltage, frequency, current, etc. • Protect public PJM©2018 4 6/05/2018 Purpose of Protective Relaying • Intelligence in a Protective Scheme ‒ Monitor system “inputs” ‒ Operate when the monitored quantity exceeds a predefined limit • Current exceeds preset value • Oil level below required spec • Temperature above required spec ‒ Will initiate a desirable system event that will aid in maintaining system reliability (i.e. trip a circuit