367 research outputs found

    Towards the Smart Grid: Substation Automation Architecture and Technologies

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    Integrating Low Voltage Distribution Systems to Distribution Automation

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    The aim of this thesis is to define and study the key elements and the main characteris-tics of the integration of the low voltage (LV) distribution systems to distribution auto-mation (DA). The key elements are defined by studying the development of essential systems in LV distribution networks as well as by studying the development of the net-works by way of evolution phases. The key elements and the main characteristics of the integration to DA are illustrated by a certain model of a LV distribution network under its development. For a start DA is reviewed by generally used functions and by technologies. The review includes the data and the information systems and in addition the communication net-works are studied generally. Thereafter the main elements of LV distribution networks are presented and their evolution visions are introduced. The main elements comprises of the distribution network, distributed generation, smart energy metering, electric vehicles and energy storages. The approach to the integration is the evolution of LV distribution networks, so four main evolution phases are introduced; traditional, boom of distributed generation, mi-crogrid and intelligent microgrid. The evolution phases bases on general research publi-cations and visions of Smart Grids. Management architectures for the networks are pre-sented. Also requirements for communication are evaluated by studying the number of nodes, capacity requirements for transferred data types and fault and event frequencies. In order to define a proposal for integrating LV distribution networks to DA, the man-agement architectures and the studied requirements are compared to produce functions for DA. As a result, the proposal is presented based on the studied architectures and re-quirements. In addition considerable issues are introduced relating to the functions in devices or sub-systems, which are needed for DA applications. This thesis indicates the need for further studies, such as: Which are the desired DA functions to be extended to LV distribution networks? Which device or system should offer the desired functions? How well the potential protocols using some media type serves the functions?fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

    Security Analysis of Phasor Measurement Units in Smart Grid Communication Infrastructures

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    Phasor Measurement Units (PMUs), or synchrophasors, are rapidly being deployed in the smart grid with the goal of measuring phasor quantities concurrently from wide area distribution substations. By utilizing GPS receivers, PMUs can take a wide area snapshot of power systems. Thus, the possibility of blackouts in the smart grid, the next generation power grid, will be reduced. As the main enabler of Wide Area Measurement Systems (WAMS), PMUs transmit measured values to Phasor Data Concentrators (PDCs) by the synchrophasor standard IEEE C37.118. IEC 61850 and IEC 62351 are the communication protocols for the substation automation system and the security standard for the communication protocol of IEC 61850, respectively. According to the aforementioned communication and security protocols, as well as the implementation constraints of different platforms, HMAC-SHA1 was suggested by the TC 57 WG group in October 2009. The hash-based Message Authentication Code (MAC) is an algorithm for verifying both message integrity and authentication by using an iterative hash function and a supplied secret key. There are a variety of security attacks on the PMU communications infrastructure. Timing Side Channel Attack (SCA) is one of these possible attacks. In this thesis, timing side channel vulnerability against execution time of the HMAC-SHA1 authentication algorithm is studied. Both linear and negative binomial regression are used to model some security features of the stored key, e.g., its length and Hamming weight. The goal is to reveal secret-related information based on leakage models. The results would mitigate the cryptanalysis process of an attacker. Adviser: Yi Qia

    ASGARDS-H: Enabling Advanced Smart Grid cyber-physical Attacks, Risk and Data Studies with HELICS

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    Smart infrastructures are increasingly built with cyber-physical systems that connect physical operational technology (OT) devices, networks and systems over a cyberspace of ubiquitous information technology (IT). A key objective of such interconnection is to offer a data coverage that will enable comprehensive visibility of dynamic environments and events. The arrival of Internet-of-Things, 5G, and beyond in smart infrastructures will enable the collection of unprecedented volumes of data from these various sources for critical visibility of the entire infrastructure with advanced situational awareness. To break the barriers between the different data silos that limit advanced machine learning techniques against cyber-physical attacks and damages and to allow the development of advanced cross-domain awareness models, the thesis tried to develop a modular, complete and scalable co-simulation platform allowing the generation of standardized datasets for research and development of smart distribution grid security. It addresses the lack of realistic training and testing data for machine learning models to enable the development of more advanced techniques. Our contributions are as follows. First, a modular platform for software-based co-simulation testbed generation is developed using the HELICS co-simulation framework. Second, scenarios of instabilities, faults, cyber-physical attacks are built to allow the generation of a realistic and multi-sourced dataset. Third, well-defined datasets are generated from the developed scenarios to enable and empower data-driven approaches toward smart distribution grid security

    Microgrid energy management and monitoring systems: A comprehensive review

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    Microgrid (MG) technologies offer users attractive characteristics such as enhanced power quality, stability, sustainability, and environmentally friendly energy through a control and Energy Management System (EMS). Microgrids are enabled by integrating such distributed energy sources into the utility grid. The microgrid concept is proposed to create a self-contained system composed of distributed energy resources capable of operating in an isolated mode during grid disruptions. With the Internet of Things (IoT) daily technological advancements and updates, intelligent microgrids, the critical components of the future smart grid, are integrating an increasing number of IoT architectures and technologies for applications aimed at developing, controlling, monitoring, and protecting microgrids. Microgrids are composed of various distributed generators (DG), which may include renewable and non-renewable energy sources. As a result, a proper control strategy and monitoring system must guarantee that MG power is transferred efficiently to sensitive loads and the primary grid. This paper evaluates MG control strategies in detail and classifies them according to their level of protection, energy conversion, integration, benefits, and drawbacks. This paper also shows the role of the IoT and monitoring systems for energy management and data analysis in the microgrid. Additionally, this analysis highlights numerous elements, obstacles, and issues regarding the long-term development of MG control technologies in next-generation intelligent grid applications. This paper can be used as a reference for all new microgrid energy management and monitoring research

    COMMUNICATION IN SMART GRIDS USING LTE

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    The world today is focusing on the enhancement of efficient use of energy and it has compelled the energy industry to research and seek for measures for increasing energy efficiency. Out of various fields related to energy, Smart Grid has emerged itself as one of the effective contributor to fulfill the approach of efficient use of energy. The term smart grid has been evolved from power grid where the energy is generated, distributed and finally consumed by a consumer. The smart form of this power grid is actually smart grid which facilitates smart way of communication of smart devices between grids, so that the effective mode of controlling and monitoring can be achieved. In order to achieve this, the devices should be smart enough so that they can be interoperable and remotely accessed. For the smart devices to communicate in real time so that controlling and remote access becomes possible, it demands an advanced communicating medium. LTE is one of the most challenging, famous and widely adopted communication technology that meets the requirement imposed by broadband wireless mobile communications. Early tests, evaluations and their pre-commercial deployments have proved that they fulfil all the requirements like high-data-rate, low latency and optimized system that advanced communication demands. Thus, this paper focuses on the evaluation of integration of LTE in Smart Grids so that automation in Smart Grids can be achieved.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

    Co-design of Security Aware Power System Distribution Architecture as Cyber Physical System

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    The modern smart grid would involve deep integration between measurement nodes, communication systems, artificial intelligence, power electronics and distributed resources. On one hand, this type of integration can dramatically improve the grid performance and efficiency, but on the other, it can also introduce new types of vulnerabilities to the grid. To obtain the best performance, while minimizing the risk of vulnerabilities, the physical power system must be designed as a security aware system. In this dissertation, an interoperability and communication framework for microgrid control and Cyber Physical system enhancements is designed and implemented taking into account cyber and physical security aspects. The proposed data-centric interoperability layer provides a common data bus and a resilient control network for seamless integration of distributed energy resources. In addition, a synchronized measurement network and advanced metering infrastructure were developed to provide real-time monitoring for active distribution networks. A hybrid hardware/software testbed environment was developed to represent the smart grid as a cyber-physical system through hardware and software in the loop simulation methods. In addition it provides a flexible interface for remote integration and experimentation of attack scenarios. The work in this dissertation utilizes communication technologies to enhance the performance of the DC microgrids and distribution networks by extending the application of the GPS synchronization to the DC Networks. GPS synchronization allows the operation of distributed DC-DC converters as an interleaved converters system. Along with the GPS synchronization, carrier extraction synchronization technique was developed to improve the system’s security and reliability in the case of GPS signal spoofing or jamming. To improve the integration of the microgrid with the utility system, new synchronization and islanding detection algorithms were developed. The developed algorithms overcome the problem of SCADA and PMU based islanding detection methods such as communication failure and frequency stability. In addition, a real-time energy management system with online optimization was developed to manage the energy resources within the microgrid. The security and privacy were also addressed in both the cyber and physical levels. For the physical design, two techniques were developed to address the physical privacy issues by changing the current and electromagnetic signature. For the cyber level, a security mechanism for IEC 61850 GOOSE messages was developed to address the security shortcomings in the standard
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