Lecture Script: "EMI Risk Management"

Content of the lecture: Fundamentals and methods of risk analysis; Basic design and technology of IEMI sources (e.g., VIRCATOR, Magnetron, Klystron, …); Modelling of IEMI threat scenarios; EMI effects on electric systems; Protective measure; Discussion and assessment of the risk for critical infrastructures; Case studies on a generic infrastructur

Contribution to the study of the vulnerability of critical systems to Intentional Electromagnetic Interference (IEMI)

The progress of high power electromagnetic (HPEM) sources during the late 1990s raised the concern in the electromagnetic compatibility (EMC) community that they could be deployed for criminal purposes to interfere with the operation of modern electronic systems. It is well established that sufficiently intense electromagnetic fields can cause upset or damage in electronic systems and therefore, can affect almost every critical infrastructure (CI) that is based on information and communication technologies (ICT). This field of study was initially known as electromagnetic terrorism, but was changed to the more encompassing term of intentional electromagnetic interference (IEMI). This thesis is a contribution to the assessment techniques of the vulnerability of CIs against IEMI. In order to quantify their impact, the electromagnetic environment created by IEMI sources needs to be characterized, the susceptible components and subsystems of the CIs should be identified, and the expected disturbances have to be evaluated. We present a qualitative methodology to carry out the so-called IEMI audit of a facility. Given the complexity of the problem, it was decided that the vulnerability of an infrastructure should be evaluated in a qualitative manner by regarding the consequences of interrupting the normal provision of a service, the probability of occurrence of an IEMI attack, and the preparedness of the infrastructure to withstand an attack. An updated survey and classification of potential IEMI sources that were collected from a large number of scientific publications is presented. The sources have been classified according to their electromagnetic environment, their transportability, technological development, and cost level. The expected disturbances due to a high frequency illumination of representative cabling systems inside an office were studied through measurements performed using a plastic raceway containing several types of cables found in commercial buildings. The tests revealed that at low and intermediate frequencies, low voltage power cables are more susceptible compared to telephone or network cables. At high frequencies, the coupling is dominated by connector apertures and discontinuities and load unbalance. The applicability of the TL theory in evaluating differential mode signals in two-wire lines floating above a ground plane was studied through comparisons with full-wave simulations. The results showed that the validity of the TL theory is conditioned upon an electrically short distance between the differential wires, regardless of the distances above the ground plane. TL theory is also used to assess the effect of conductive and dielectric losses in the dispersion of injected IEMI signals along power and communication cables as a function of the propagation length. A TL model of the low voltage power cabling of the plastic raceway was developed and in order to validate the models, the numerical results were compared against measurements obtained using frequency and time domain techniques. General considerations and guidelines for the application of the TL theory for evaluating the overall transfer impedance of complex cable assemblies are given. The obtained simulation results were found to be in good agreement with the experimental data up to frequencies of about 500 MHz. Finally, an improved model for estimating the transfer impedance of a two-layer braided shield is also proposed and validated using experimental data

IEMI Vulnerability Analysis for Different Smart Grid-enabled Devices

The smart grid concept aims to improve power systems’ robustness, efficiency, and reliability. The transition from conventional power grids to smart grids has been achieved mainly by integrating Smart Electronic Devices (SEDs) and advanced automatic control and communication systems. On the one hand, electronic devices have been integrated to make the system more decentralised from the national electrical grid. On the other hand, from the point of view of protection and control equipment, there is a growing tendency to replace arrays of analog devices with single digital units that perform multiple functions in a more integrated and efficient way. Despite the perceived benefits of such modernisation, security issues have arisen with substantial concern as electronic devices can be susceptible to Intentional Electromagnetic Interference (IEMI) [2]. The number of IEMI sources has grown significantly in recent decades. In 2014, 76 different types were reported, in which 21 sources were conducted, and 55 were irradiated. From a technical perspective, they can present different features, including band type, average / centre frequency, peak voltage (for conducted sources), or peak field (for irradiated sources) [4]. These sources also differ in technology level, associated cost, and mobility in approaching the target system. Therefore, they can be characterized by the easiness of occurrence in a given scenario and the increased probability of successful attacks on a target system. Under this perspective, a self-built jammer built with off-the-shelf components is more likely to be employed by an offender than a High-Power Electromagnetic (HPEM) source. On the other hand, despite being less probable on account of higher technological level, cost and mobility, a HPEM source may have a higher success rate to affect the target system than the self-built jammer. Coupled with this, based on the different characteristics of the IEMI sources, the electronic devices may present distinct effects, which may trigger severe impacts on a smart grid at a higher level [8]. Therefore, this study compares the IEMI vulnerability of three devices used in smart grid applications. The first device is a Wi-Fi-based smart home meter. It can read voltage and current signals of consumer units and remotely display real power, reactive power, and power factor. These measurements can be used in-house or transmitted to a Supervisory Control and Data Acquisition (SCADA) system from Distribution System Operators (DSOs). The second device is a Power Line Communication (PLC) unit, which enables data to be carried over conductors intended primarily for electrical power transmission. This technology is used in buildings to reduce the communication network’s material and installation costs and provide flexibility and faster data communication. The final device considered is a digital protection relay designed to trip circuit breakers when faults are detected. The latest digital relay units feature many protection functionalities, including overload and under-voltage/over-voltage protection, temperature monitoring, fault location, self-reclosure, among others. The three devices are subjected to self-built low-power jamming signals. As an extension, the protection relay is also subjected to a narrowband High Power Electromagnetic (HPEM) source

The European Project STRUCTURES : Challenges and Results

The project STRUCTURES, funded by the European Union, started in July 2012 to study problems related to the emerging threats of electromagnetic attacks to critical infrastructures. Partners of the team have worked to list possible threats, identify the main characteristics of the critical infrastructures our way of living depends on, test current protection strategies with different simulation and measurement techniques, and condensate the results in guidelines accessible to an audience wider than the one of people working in the field. Here, we summarize the challenges, the solutions, and the results of almost three years of work

Overview of the European project STRUCTURES

An overview of the European project STRUCTURES and its main challenges is given. Current and foreseen Intentional Electromagnetic Interference (IEMI) threats are classified according to their availability, their technical characteristics (such as bandwidth) and their portability. Critical infrastructures are identified and their most characteristic aspects are highlighted, from an electromagnetic point of view. These concepts are used to establish a set of reference threats to be investigated and possible techniques to handle simulations and measurements in this complex environment are explored, emphasizing the use of the topological approach

Microcontroller (8051-core) instruction susceptibility to intentional electromagnetic interference (IEMI)

Intentional Electromagnetic Interference (IEMI) is a rising threat to the electronic systems that are used and depended upon in everyday life of civil society. To address this threat, it is important to develop an understanding of what IEMI is and how it can be used to disrupt sophisticated electronic systems. By understanding IEMI and its disruptive effects, predictive models and protection standard can be developed for various types of electronic systems to address the threat. The focus of this thesis is to detail the experimental results involved when investigating the susceptibility of a single microcontroller instruction. A microcontroller represents a system on a chip and provides an ideal starting point for developing a predictive model for the upset effects that can be caused by an IEMI attack on a digital system. The microcontroller device used in the experiment is the ATMEL AT89LP2052, which is an 8051-core based microcontroller device that processes instructions in parallel. The experiment involves targeting specific moments within an instruction cycle, based on the parallel processing of the LP2052, to determine whether or not different actions within the cycle have different susceptibility levels to IEMI

Fuzzy-Based Risk Analysis for IT-Systems and Their Infrastructure

This paper introduces a procedural method based on the fuzzy logic and set theory, which analyzes the risk of an IT-System in a facility and its surrounding area. The method analyzes the susceptibility of an electronic system with respect to intentional electromagnetic interferences and classifies the intentional electromagnetic environment (IEME). It extends the well-known statistical-based models fault tree analysis, electromagnetic topology and Bayesian networks (BN) with imprecise data, uncertainness with linguistic terms, and opinions of experts. In a final step, the critical scenarios and the elements and the location that contribute most to the risk are identified, which can be used to enhance the protection level

Circuit and Electromagnetic Modelling of a low cost IEMI Sensor

The design of a low cost broadband Intentional Electromagnetic Interference (IEMI) detector and antenna to achieve a flat frequency response over a broad range is considered. SPICE simulation of the antenna, detector and low power log-amplifier circuit is used to predict the detector performance. The SPICE Antenna model is derived from numerical electromagnetic simulation. Simulations are compared with measured performance

Focusing high-power electromagnetic waves using time-reversal

A main aspect of this work has been to develop analytical and statistical models of the power efficiency of a time-reversal amplification system (TRAS).It is also important to evaluate the efficiency of a reverberation chamber. This allows quantifying the power received by one or more antenna when the reverberation chamber is excited. This factor is important when considering construction of the most efficient chamber for time-reversal amplification.Measurements assessing the loading effect of antennas in reverberation chambers when the field can be considered diffused were also undertaken. The study focuses on the evaluation of the varying quality factor when adding loaded antennas in the chamber.Another focus of this work is to evaluate the ratios between signals during calibration and focusing phase. An important aspect of the studies presented in this work thus concerns evaluation of the maximum value of the impulse response in a complex propagation system.We also present the power gain of time-reversal techniques and its statistical advantages compared to a classic use of a reverberation chamber.The development of a prototype required the design and implementation of each of the branches of the complete systems.The first measurement campaigns allowed the complete validation of the models.L'objectif de la thèse a été de mettre en place dans un premier temps des modèles analytiques et statistiques permettant d'évaluer les performances d'un système à retournement temporel de fortes-puissances puis de les vérifier grâce à des mesures.Des campagnes de mesures ont alors permis de vérifier les modèles. Des simulations numériques ont aussi montrées les possibilités offertes par un tel système.En parallèle, des travaux sur l'impact des antennes dans une chambre réverbérantes ont été menés afin d'évaluer les performances d'un système ayant plusieurs sorties.Les résultats de thèses ont permis l'élaboration de nouvelles métriques des performances du système.Le développement d'un prototype a nécessité la conception et la réalisation de chacune des branches du système complet.Les premières campagnes de mesures ont permis la validation complète des modèles