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Radasky W.A.,Metatech Corporation
IEEE International Symposium on Electromagnetic Compatibility | Year: 2014

This paper summarizes the current understanding of geomagnetic storms and their impacts on the power grid. Accomplishments over the past 23 years are reviewed, and the remaining aspects to be resolved are mentioned. The second part of the paper describes the basic mitigation concepts that can be used to minimize or eliminate these impacts through operational and/or protective measures. © 2014 The Institute of Electronics, Information and Communication Engineer.

Hoad R.,QinetiQ | Radasky W.A.,Metatech Corporation
IEEE Transactions on Electromagnetic Compatibility | Year: 2013

Since the publication of the last IEEE Transactions on Electromagnetic Compatibility special issue on nuclear electromagnetic pulse in 1978, significant progress has been made in the development of high-altitude electromagnetic pulse (HEMP) standards. The standards cover HEMP environment definition, protection requirements, and test methods. In particular, civilian standards have been developed in recent times as it is recognized that the impact of HEMP disturbances is not just a concern for the military but also a concern for the largely civilian critical national infrastructure. This paper provides a summary of the HEMP standards that are presently available in the military and civilian domains. © 1964-2012 IEEE.

Radasky W.A.,Metatech Corporation
IEEE International Symposium on Electromagnetic Compatibility | Year: 2011

This paper provides an overview of the threat of intense geomagnetic storms created by solar activity to high voltage power grids on the Earth. Given a description of the time and spatial variation of the geomagnetic field (past, present or future), it is possible to model the response of any specific high-voltage grid with a high level of accuracy. It is also clear from the available data that the higher the voltage of the AC power system, the more vulnerable that system is to a particular geomagnetic storm. Given the ability to model and with an understanding of transformer behavior, it is possible to design protection for high-voltage grids against this unique threat. © 2011 IEEE.

Gilbert J.L.,Metatech Corporation
IEEE Transactions on Electromagnetic Compatibility | Year: 2015

In this paper, two models for the calculation of geomagnetically induced electric fields near the shoreline are compared. The first is an analytic model which requires the solution of an integral equation at each frequency, and the second is a simplified model that only requires Fourier transforms. The mechanism responsible for the differing results is determined, and it is suggested that one of the features of the analytic model should be included in the simplified model. This modification can be made without reducing the computational advantages of the second model. We also show the relative effect of the shoreline enhancement on the voltage impressed on cables for two different ground conductivities. © 1964-2012 IEEE.

Radasky W.A.,Metatech Corporation
2010 Asia-Pacific Symposium on Electromagnetic Compatibility, APEMC 2010 | Year: 2010

The International Electrotechnical Commission (IEC) has been working for nearly 20 years preparing standards and other publications dealing with the threat of high-altitude electromagnetic pulse (HEMP) from a high-altitude nuclear detonation and the threat of intentional electromagnetic interference (IEMI) produced by electromagnetic weapons used by criminals or terrorists. In addition to establishing the electromagnetic environments for each threat, the IEC has also developed generalized protection and test methods to be used for commercial installations. This paper examines the specific problem of a hypothetical commercial building with external power and communications entering the building; in addition the building is assumed to contain a computer server room that is crucial to the operation of the business. The paper applies the IEC standards for these two threats to illustrate how one could design protection for the building and how one would test to ensure that the protection is adequate. © 2010 IEEE.

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