On the Exploitation of Admittance Measurements for Wired Network Topology Derivation

The knowledge of the topology of a wired network is often of fundamental importance. For instance, in the context of Power Line Communications (PLC) networks it is helpful to implement data routing strategies, while in power distribution networks and Smart Micro Grids (SMG) it is required for grid monitoring and for power flow management. In this paper, we use the transmission line theory to shed new light and to show how the topological properties of a wired network can be found exploiting admittance measurements at the nodes. An analytic proof is reported to show that the derivation of the topology can be done in complex networks under certain assumptions. We also analyze the effect of the network background noise on admittance measurements. In this respect, we propose a topology derivation algorithm that works in the presence of noise. We finally analyze the performance of the algorithm using values that are typical of power line distribution networks.Comment: A version of this manuscript has been submitted to the IEEE Transactions on Instrumentation and Measurement for possible publication. The paper consists of 8 pages, 11 figures, 1 tabl

Inferring Power Grid Information with Power Line Communications: Review and Insights

High-frequency signals were widely studied in the last decade to identify grid and channel conditions in PLNs. PLMs operating on the grid's physical layer are capable of transmitting such signals to infer information about the grid. Hence, PLC is a suitable communication technology for SG applications, especially suited for grid monitoring and surveillance. In this paper, we provide several contributions: 1) a classification of PLC-based applications; 2) a taxonomy of the related methodologies; 3) a review of the literature in the area of PLC Grid Information Inference (GII); and, insights that can be leveraged to further advance the field. We found research contributions addressing PLMs for three main PLC-GII applications: topology inference, anomaly detection, and physical layer key generation. In addition, various PLC-GII measurement, processing, and analysis approaches were found to provide distinctive features in measurement resolution, computation complexity, and analysis accuracy. We utilize the outcome of our review to shed light on the current limitations of the research contributions and suggest future research directions in this field.Comment: IEEE Communication Surveys and Tutorials Journa

Machine Learning Tips and Tricks for Power Line Communications

4openopenTonello A.M.; Letizia N.A.; Righini D.; Marcuzzi F.Tonello, A. M.; Letizia, N. A.; Righini, D.; Marcuzzi, F

Anàlisi teòric de les debilitats de seguretat dels estàndards per a la Medició Intel·ligent

[ANGLÈS] This project has been accomplished in the Department of Telecommunications Engineering of the Czech Technical University, as a part of a collaborative work within the department to long-term study the development of software applications related to security in technologies for Smart Metering. This project aims to analyze the weaknesses, concerned in terms of security mechanisms, of the telecommunications standards that are used for communication with smart meter technology inside the Smart Metering. A wide range of these standards have been included in the draft standards based on different technologies such as the radio frequency, the PLC (PowerLine Communications) or infrared. For each of these technologies, there can be found an extensive description of the security mechanisms used for each of them for the purpose of encryption of messages, protect the keys used, authentication of terminals and network identification to access the network. To complete the description of each standard there can be found a description of possible attacks that may make possible to overcome the security barriers of these technologies. Once viewed in detail the characteristics of each of the standards, next steps for the analysis are the comparisons between them to highlight the weaknesses and strengths of each one of them towards the other technologies. And finally, there can be found a compilation of a wide range of tools, both software and hardware, developed for research of security professionals, which may allow performing various attacks that can affect the protocols described.[CASTELLÀ] Este proyecto realizado en el departamento de telecomunicaciones de la Czech Technical University, forma parte de un trabajo colaborativo dentro del departamento a largo plazo para el estudio y el desarrollo de aplicaciones software relacionadas con la seguridad de las tecnologías de Medición Inteligente. En este proyecto se pretende analizar los puntos débiles, en cuanto a mecanismos de seguridad se refiere, de los estándares de telecomunicaciones que se utilizan para la comunicación de los electrómetros inteligentes dentro del la tecnología del Smart Metering. Para ver un amplio abanico de estos estándares, se han incluido en el proyecto estándares basados en tecnologías dispares y diversas como pueden ser la radiofrecuencia, las PLC (PowerLine Communications) o los infrarrojos. Para cada una de estas tecnologías, podemos encontrar en el proyecto una amplia descripción de los mecanismos de seguridad utilizados en cada uno para la encriptación de los mensajes enviados, la protección de las claves que utiliza, la autentificación de los terminales de la red o la identificación para acceder a la red. Para terminar la descripción detallada de cada estándar podemos encontrar una descripción de los posibles ataques que es factible realizar para vencer las barreras de seguridad de estas tecnologías. Una vez vistas con detalle las características de cada uno de los estándares, se incluyen comparaciones entre todos ellos para destacar los puntos débiles y los puntos fuertes hacia el resto de tecnologías. Y, por último, podemos encontrar un recopilatorio de un amplio abanico de herramientas tanto de software como de hardware, desarrolladas para la investigación de los profesionales de la seguridad en telemática, que permiten realizar varios de los ataques que pueden afectar a los protocolos descritos.[CATALÀ] Aquest projecte realitzat en el Departament de Telecomunicacions de la Czech Technical University, forma part d'un treball col·laboratiu dins el departament a llarg plaç per a l'estudi i el desenvolupament d'aplicacions software relacionades amb la seguretat de les tecnologies de Medició Intel·ligent. En aquest projecte es pretén analitzar els punts dèbils, en quant a mecanismes de seguretat es refereix, dels estàndards de telecomunicacions que s'utilitzen per a la comunicació dels electròmetres intel·ligents dins del la tecnologia del Smart Metering. Per tal de veure un ampli ventall de aquests estàndards, s'han inclòs en el projecte estàndards basats en tecnologies dispars i diverses com poden ser la ràdiofreqüència, les PLC (PowerLine Communications) o els infrarojos. Per a cadascuna d'aquestes tecnologies, podem trobar en el projecte una amplia descripció dels mecanismes de seguretat utilitzats per a cadascun per a l'encriptació dels missatges enviats, la protecció de les claus que utilitza, l'autentificació del terminals de la xarxa o la identificació per accedir a la xarxa. Per acabar la descripció detallada de cada estàndard podem trobar una descripció dels possibles atacs que es factible realitzar per a vèncer les barreres de seguretat d'aquestes tecnologies. Un cop vistes amb detall les característiques de cadascun dels estàndards, s'inclouen comparacions entre tots ells per destacar els punts dèbils i els punts forts vers la resta de tecnologies. I, per últim, podem trobar un recopilatori d'un ampli ventall de eines tant de software com de hardware, desenvolupades per a la investigació dels professionals de la seguretat en telemàtica, que permeten realitzar varis dels atacs que poden afectar als protocols descrits

Parameterized macromodeling of passive and active dynamical systems

L'abstract è presente nell'allegato / the abstract is in the attachmen

Power and Energy Student Summit 2019: 9 – 11 July 2019 Otto von Guericke University Magdeburg ; Conference Program

The book includes a short description of the conference program of the "Power and Energy Student Summit 2019". The conference, which is orgaized for students in the area of electric power systems, covers topics such as renewable energy, high voltage technology, grid control and network planning, power quality, HVDC and FACTS as well as protection technology. Besides the overview of the conference venue, activites and the time schedule, the book includes all papers presented at the conference

Autonomous Sensing Nodes for IoT Applications

The present doctoral thesis fits into the energy harvesting framework, presenting the development of low-power nodes compliant with the energy autonomy requirement, and sharing common technologies and architectures, but based on different energy sources and sensing mechanisms. The adopted approach is aimed at evaluating multiple aspects of the system in its entirety (i.e., the energy harvesting mechanism, the choice of the harvester, the study of the sensing process, the selection of the electronic devices for processing, acquisition and measurement, the electronic design, the microcontroller unit (MCU) programming techniques), accounting for very challenging constraints as the low amounts of harvested power (i.e., [μW, mW] range), the careful management of the available energy, the coexistence of sensing and radio transmitting features with ultra-low power requirements. Commercial sensors are mainly used to meet the cost-effectiveness and the large-scale reproducibility requirements, however also customized sensors for a specific application (soil moisture measurement), together with appropriate characterization and reading circuits, are also presented. Two different strategies have been pursued which led to the development of two types of sensor nodes, which are referred to as 'sensor tags' and 'self-sufficient sensor nodes'. The first term refers to completely passive sensor nodes without an on-board battery as storage element and which operate only in the presence of the energy source, provisioning energy from it. In this thesis, an RFID (Radio Frequency Identification) sensor tag for soil moisture monitoring powered by the impinging electromagnetic field is presented. The second term identifies sensor nodes equipped with a battery rechargeable through energy scavenging and working as a secondary reserve in case of absence of the primary energy source. In this thesis, quasi-real-time multi-purpose monitoring LoRaWAN nodes harvesting energy from thermoelectricity, diffused solar light, indoor white light, and artificial colored light are presented

Integrated Distributed Amplifiers for Ultra-Wideband BiCMOS Receivers Operating at Millimeter-Wave Frequencies

Millimetre-wave technology is used for applications such as telecommunications and imaging. For both applications, the bandwidth of existing systems has to be increased to support higher data rates and finer imaging resolutions. Millimetrewave circuits with very large bandwidths are developed in this thesis. The focus is put on amplifiers and the on-chip integration of the amplifiers with antennas. Circuit prototypes, fabricated in a commercially available 130nm Silicon-Germanium (SiGe) Bipolar Complementary Metal-Oxide-Semiconductor (BiCMOS) process, validated the developed techniques. Cutting-edge performances have been achieved in the field of distributed and resonant-matched amplifiers, as well as in that of the antenna-amplifier co-integration. Examples are as follows: - A novel cascode gain-cell with three transistors was conceived. By means of transconductance peaking towards high frequencies, the losses of the synthetic line can be compensated up to higher frequencies. The properties were analytically derived and explained. Experimental demonstration validated the technique by a Traveling-Wave Amplifier (TWA) able to produce 10 dB of gain over a frequency band of 170GHz.# - Two Cascaded Single-Stage Distributed Amplifiers (CSSDAs) have been demonstrated. The first CSSDA, optimized for low power consumption, requires less than 20mW to provide 10 dB of gain over a frequency band of 130 GHz. The second amplifier was designed for high-frequency operation and works up to 250 GHz leading to a record bandwidth for distributed amplifiers in SiGe technology. - The first complete CSSDA circuit analysis as function of all key parameters was presented. The typical degradation of the CSSDA output matching towards high frequencies was analytically quantified. A balanced architecture was then introduced to retain the frequency-response advantages of CSSDAs and yet ensure matching over the frequency band of interested. A circuit prototype validated experimentally the technique. - The first traveling-wave power combiner and divider capable of operation from the MHz range up to 200 GHz were demonstrated. The circuits improved the state of the art of the maximum frequency of operation and the bandwidth by a factor of five. - A resonant-matched balanced amplifier was demonstrated with a centre frequency of 185 GHz, 10 dB of gain and a 55GHz wide –3 dB-bandwidth. The power consumption of the amplifier is 16.8mW, one of the lowest for this circuit class, while the bandwidth is the broadest reported in literature for resonant-matched amplifiers in SiGe technology