Daniel Månsson

Vulnerability of European Rail Traffic Management System to Radiated Intentional EMI

In this paper, the vulnerability of the future electrified railway system in Europe from a high-power microwave (HPM) source is investigated. The scenario of in-band disturbances radiated toward a GSM-R antenna and damaging the connected communications system is evaluated for different classes of HPM sources and situations. The minimum realistic distances for the different HPM sources from the antenna to cause permanent damage is shown, and the severity of threat from the different sources is discussed.

Methodology for Classifying Facilities With Respect to Intentional EMI

It is argued that it is the intent behind the electromagnetic interference in intentional electromagnetic interference (IEMI) that causes problems to large distributed systems and facilities even if they are designed by traditional zoning concept rules. Hardening such facilities against IEMI requires a correspondence between the electromagnetic zone boundary and the physical access control boundary. The three characteristics of a facility, the accessibility, susceptibility , and consequence, are discussed in the context of vulnerability to IEMI. A methodology for classification of facilities with respect to IEMI is presented.

Susceptibility of Civilian GPS Receivers to Electromagnetic Radiation

Civilian handheld global positioning system receivers were tested for their susceptibility against radiated electromagnetic disturbances of different characteristics and field levels. This susceptibility data were compared to the existing electromagnetic compatibility (EMC) immunity requirements for electronic devices. Some of the receivers were disrupted by continues waves at in- as well as out-of-band frequencies, at field levels far below the existing EMC requirements. The possible reason for this is discussed. In general, due to the ever-growing use of commercial-off-the-shelf equipment even for critical functions, certificates of conformity to current EMC requirements may be inadequate.

Propagation of UWB Transients in Low-Voltage Installation Power Cables

This paper investigates the propagation of subnanosecond rise time (ultra wideband) voltage transients in low-voltage installation power cables. Experimental results are compared to simulations. It is concluded that the main mode of propagation of differentially injected transients in low-voltage installation power cables is transverse electromagnetic mode. Also, such transients would spread relatively unattenuated to any load or junction in the power system, received power primarily only limited by the impedance mismatches causing reflections. The effects of different types of bends in the cable have been studied. The study was conducted as a part of an assessment of the susceptibility of civilian facilities to intentional electromagnetic interference.

Propagation of UWB Transients in Low-Voltage Power Installation Networks

In this paper, the propagation of ultra-wideband (UWB) transients through different types of junctions of low-voltage power cables and one real power network of a building were investigated. For the laboratory test, it was seen that the main mode of propagation in the cables and through the junctions tested is transverse electromagnetic (TEM). The received voltage could thus be, within a small error, estimated from transmission-line theory. The main cause for decreased voltage received at the loads of the branches of the junctions is reflections due to impedance mismatch of the junctions. Large voltages can be delivered to many unprotected loads connected to the junctions. UWB transients were also injected into a residential house using a power outlet available on the outside wall of the house. It was seen that the complexity of this network creates deviation from the TEM mode. However, relatively large voltages were still received at the various outlets inside the house. It is recommended that power outlets or lamp sockets outside buildings are controlled from inside using two-pole switches that reduce the received voltage to reduce the risk of conducted intentional electromagnetic interference.

Suitability analysis of Fuzzy Logic as an evaluation method for the selection of energy storage technologies in Smart Grid applications

Energy storage systems are a key element in the development of the smart grid. The complexity of the power grid necessitates energy storages to provide various services with each having distinct requirements. Each energy storage technology comes with its own unique characteristics, which makes it difficult to select suitable energy storages for specified applications. This paper reviews the suitability of using Fuzzy Logic as a selection method. The main objective of this study is to compare the results of the multi-criteria analysis with the present experience and literature of energy storage applications.

On the Suitability of Using Halbach Arrays as Potential Energy Storage Media

In the work presented here, the suitability of an unusual energy storage medium is investigated. The energy storage system is based on the forceful compression of two magnetic Halbach arrays. The mass and volume energy density is obtained and compared to existing common energy storage systems. The charge and discharge times and depths are also discussed. In addition, limits and considerations, which are needed for practical implementation, e.g., risk of demagnetization, internal mechanical stresses, heating of the magnetic structure and flnancial e-ciency are investigated.

Modeling Shielding Effectiveness for Composite Walls of Concrete and Carbon Filaments

Concrete walls reinforced with rebars have poor shielding efiectiveness for telecommunication frequencies (frequencies above 0.5GHz). An efiective method to increase the shielding efiectiveness of the walls is to increase the complex permittivity of the concrete. This can be done by mixing in thin fllaments of a material with high conductivity. One such material is carbon. In this paper the Maxwell Garnett mixing rule is used to model a concrete material with carbon fllaments. The shielding efiectiveness computed with the mixing rule is found to agree with previously published measurement results.

Comparing Analytical and Numerical Calculations of Shielding Effectiveness of Planar Metallic Meshes with Measurements in Cascaded Reverberation Chambers

Large electrical systems or facilities can be satisfactorily shielded by using low-cost meshed metallic nets. Here the shielding efiectiveness for two such planar meshes is calculated analytically and verifled both experimentally by using cascaded reverberation chambers as well as numerically with results computed using a full wave electromagnetic solver. It is shown that all three methods agree and, in addition, that non-square shaped aperture meshes can be handled with an equivalent square area shaped aperture.

An Efficient Method for Solving Frequency Responses of Power-Line Networks

This paper presents a novel approach for solving the frequency responses of a powerline network, which is a two-parallel-conductor system with multiple junctions and branches. By correcting the ref ...