This book is an original study aimed at understanding how vacuum magnetic fields change with time. Specifically, it describes the waves that radiate from a sphere when the electric current on its surface is turned on or off, either suddenly, gradually, or periodically. Numerical simulations are an invaluable source of information about this and related subjects, but they are often more difficult to interpret than exact, closed-form solutions that can easily be applied to a variety of situations. Thus, the objective here is to obtain an exact solution of Maxwell’s equations in closed form—something simple, yet rigorous, which can be used as a model for understanding transient magnetic fields in more complicated situations. The work therefore stands as a self-contained solution of Maxwell’s equations for an electric current wrapped around the surface of a sphere. This study assumes a strong background in electromagnetism or a related research area. Online animations are available for each figure to better illustrate the motions of magnetic field lines.

The receiving and transmitting properties of small linear antennas, conical antennas, and loops for transient electromagnetic fields were investigated experimentally. Short electrical dipoles loaded by a capacitance represented by a cathode follower can be used successfully for the measurement of transient fields with rise times of less than 1 nanosecond, if the first antenna resonance is suppressed by a series resistor at the base of the antenna. The currents induced on nonresonant structures by transient electromagnetic fields are investigated and their application to a direct measurement of the time sequence of the electromagnetic field is discussed. Signals with a simple and known time dependence such as a unidirectional pulse can be radiated into space if the reflection of current waves at discontinuities of the antenna structure is avoided. In a manner similar to that useful for the absorption of continuous waves in media with a stratified conductivity, it is shown that reflections at discontinuities can be avoided by dipoles with tapered resistive loading. (Author).

Paperback. This is a comprehensive description of deep transient electromagnetics which allows the geophysicist to learn about the technique from the beginning of instrument design to the final interpretation. It covers the application of deep transient electromagnetics to oil exploration, geothermal exploration and deep crustal studies. Case histories are used to explain the concepts shown. Problems are included at the end of each chapter. Also, demonstration software is enclosed. The book may be used as a textbook as well as for design and development of a field system. In particular it will be of interest to research and exploration geophysicists and students.

As a slag heap, the result of strip mining, creeps closer to his house in the Ohio hills, fifteen-year-old M. C. is torn between trying to get his family away and fighting for the home they love.

From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables. Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises, solutions and examples in order to develop a practical understanding of the topics. Harmonic analysis of cable-based networks and instructions on how to accurately model a cable-based network are also covered, including several “tricks” and workarounds to help less experienced engineers perform simulations and analyses more efficiently. Electromagnetic Transients in Power Cables is an invaluable resource for students and engineers new to the field, but also as a point of reference for more experienced industry professionals.

This book is the collection of the contributions offered at the International Symposium on Electromagnetic Fields in Electrical Engineering, ISEF '87, held in Pavia, Italy, in September 1987. The Symposium was attended by specialists engaged in both theoretical and applied research in low-frequency electromagnetism. The charming atmosphere of Pavia and its ancient university provided a very effective environment to discuss the latest results in the field and, at the same time, to enjoy the company or colleagues and friends coming from over 15 countries. The contributions have been grouped into 7 chapters devoted to fundamental problems, computer programs, transformers, rotating electrical machines, mechanical and thermal effects, various applications and synthesis, respectively. Such a classification is merely to help the reader because a few papers could be put in several chapters. Over the past two decades electromagnetic field computations have received a big impulse by the large availability of digital computers with better and better performances in speed and capacity. Many various methods have been developed but not all of them appear convenient enough for practical engineering use. In fact, the technical and industrial challenges set some principal attributes and criteria for good computation methods. They should be relatively easy to use, fit into moderately sized computers, yield useful design data, maintain flexibility with m1n1mum cost in time and effort.

The Propagation of Electromagnetic Waves in Multiconductor Transmission Lines presents the study of the problems relating to the propagation of electromagnetic waves along multi-conductor transmission line. This book examines the theoretical investigations into the propagation of electromagnetic waves in transmission line systems involving two or more conductors. Organized into 12 chapters, this book begins with an overview of the rigorous method based on Maxwell's equations for solving the basic problem in the theory of the steady-state propagation of electromagnetic waves in a multi-conductor system. This text then examines the significant practical problem of determining the electromagnetic fields of symmetrical and non-symmetrical two-wire lines in free space. Other chapters consider the methods of calculating the parameters of non-uniform lines. This book discusses as well the problem of transient electromagnetic processes in a multi-conductor system. The final chapter deals with the asymptotic representation of cylindrical functions of two-imaginary variables. Electrical engineers will find this book useful.