Generación automática de la configuración de subestaciones eléctricas según el Estándar IEC 61850 a partir de una herramienta de diseño gráfico

La evolución de las redes eléctricas se dirige hacia lo que se conoce como “Smart Grids” o “Redes Eléctricas Inteligentes”. Estas “Smart Grids” se componen de subestaciones eléctricas, que a su vez se componen de unos dispositivos llamados IEDs (Dispositivos Electrónicos Inteligentes – Intelligent Electronic Devices). El diseño de IEDs se encuentra definido en la norma IEC 61850, que especifica además un Lenguaje de Configuración de Subestaciones (Substation Configuration Language SCL) para la definición de la configuración de subestaciones y sus IEDs. Hoy en día, este estándar internacional no sólo se utiliza para diseñar correctamente IEDs y asegurar su interoperabilidad, sino que también se utiliza para el diseño de otros dispositivos de la red eléctrica, como por ejemplo, medidores inteligentes. Sin embargo, aunque existe una tendencia cada vez mayor del uso de este estándar, la comprensión y el manejo del mismo resulta difícil debido al gran volumen de información que lo compone y del nivel de detalle que utiliza, por lo que su uso para el diseño de IEDs se hace tedioso sin la ayuda de un soporte software. Es por ello que, para facilitar la aplicación del estándar IEC 61850 en el diseño de IEDs se han desarrollado herramientas como “Visual SCL”, “SCL Explorer” o “61850 SCLVisual Design Tool”. En concreto, “61850 SCLVisual Design Tool” es una herramienta gráfica para el modelado de subestaciones electricas, generada mediante el uso de los frameworks Eclipse Modeling Framework (EMF) y Epsilon Generative Modeling Technologies (GMT) y desarrollada por el grupo de investigación SYST de la UPM. El objetivo de este proyecto es añadir una nueva funcionalidad a la herramienta “61850 Visual SCL DesignTool”. Esta nueva funcionalidad consiste en la generación automática de un fichero de configuración de subestaciones eléctricas según el estándar IEC 61850 a partir de de una herramienta de diseño gráfico. Este fichero, se denomina SCD (Substation Configuration Description), y se trata de un fichero XML conforme a un esquema XSD (XML Schema Definition) mediante el que se define el lenguaje de configuración de subestaciones SCL del IEC 61850. Para el desarrollo de este proyecto, es necesario el estudio del lenguaje para la configuración de subestaciones SCL, así como del lenguaje gráfico específico de dominio definido por la herramienta “61850 SCLVisual Design Tool”, la estructura de los ficheros SCD, y finalmente, del lenguaje EGL (Epsilon Generation Language) para la transformación y generación automática de código a partir de modelos EMF. ABSTRACT Electrical networks are evolving to “Smart Grids”. Smart Grids are composed of electrical substations that in turn are composed of devices called IEDs (Intelligent Electronic Devices). The design of IEDs is defined by the IEC 61850 standard, which also specifies a Substation Configuration Languaje (SCL) used to define the configuration of substations and their IEDs. Nowadays, this international standard is not only used to design properly IEDs and guarantee their interoperability, but it is also used to design different electrical network devices, such as, smart meters. However, although the use of this standard is growing, its compression as well as its management, is still difficult due to its large volume of information and its level of detail. As a result, designing IEDs becomes a tedious task without a software support. As a consequence of this, in order to make easier the application of the IEC 61850 standard while designing IEDs, some software tools have been developed, such as: “Visual SCL”, “SCL Explorer” or “61850 SCLVisual Design Tool”. In particular, “61850 SCLVisual Design Tool” is a graphical tool used to make electrical substations models, and developed with the Eclipse Modeling Framework (EMF) and Epsilon Generative Modeling Technologies (GMT) by the research group SYST of the UPM. The aim of this project is to add a new functionality to “61850 Visual SCL DesignTool”. This new functionality consists of the automatic code generation of a substation configuration file according to the IEC 61850 standard. This file is called SCD (Substation Configuration Description), and it is a XML file that follows a XSD (XML Schema Definition) that defines the Substation Configuration Language (SCL) of the IEC 61850. In order to develop this project, it is necessary to study the Substation Configuration Language (SCL), the domain-specific graphical languaje defined by the tool “61850 SCLVisual Design Tool”, the structure of a SCD file, and the Epsilon Generation Language (EGL) used for the automatic code generation from EMF models

Aplicações híbridas entre sistemas multiagentes e técnicas de inteligência artificial para redes inteligentes de distribuição de energia elétrica

Os smart grids representam a nova geração dos sistemas elétricos de potência, combinando avanços em computação, sistemas de comunicação, processos distribuídos e inteligência artificial para prover novas funcionalidades quanto ao acompanhamento em tempo real da demanda e do consumo de energia elétrica, gerenciamento em larga escala de geradores distribuídos, entre outras, a partir de um sistema de controle distribuído sobre a rede elétrica. Esta estrutura modifica profundamente a maneira como se realiza o planejamento e a operação de sistemas elétricos nos dias de hoje, em especial os de distribuição, e há interessantes possibilidades de pesquisa e desenvolvimento possibilitada pela busca da implementação destas funcionalidades. Com esse cenário em vista, o presente trabalho utiliza uma abordagem baseada no uso de sistemas multiagentes para simular esse tipo de sistema de distribuição de energia elétrica, considerando opções de controle distintas. A utilização da tecnologia de sistemas multiagentes para a simulação é baseada na conceituação de smart grids como um sistema distribuído, algo também realizado nesse trabalho. Para validar a proposta, foram simuladas três funcionalidades esperadas dessas redes elétricas: classificação de cargas não-lineares; gerenciamento de perfil de tensão; e reconfiguração topológica com a finalidade de reduzir as perdas elétricas. Todas as modelagens e desenvolvimentos destes estudos estão aqui relatados. Por fim, o trabalho se propõe a identificar os sistemas multiagentes como uma tecnologia a ser empregada tanto para a pesquisa, quanto para implementação dessas redes elétricas.

Adaptive Signal Processing for Power Line Communications

This thesis represents a significant part of the research activity conducted during the PhD program in Information Technologies, supported by Selta S.p.A, Cadeo, Italy, focused on the analysis and design of a Power Line Communications (PLC) system. In recent times the PLC technologies have been considered for integration in Smart Grids architectures, as they are used to exploit the existing power line infrastructure for information transmission purposes on low, medium and high voltage lines. The characterization of a reliable PLC system is a current object of research as well as it is the design of modems for communications over the power lines. In this thesis, the focus is on the analysis of a full-duplex PLC modem for communication over high-voltage lines, and, in particular, on the design of the echo canceller device and innovative channel coding schemes.

An adaptive IEEE 802.15.4 MAC layer transmission scheme for applications with heterogeneous traffic

IEEE 802.15.4 networks has the features of low data rate and low power consumption. It is a strong candidate technique for wireless sensor networks and can find many applications to smart grid. However, due to the low network and energy capacities it is critical to maximize the bandwidth and energy efficiencies of 802.15.4 networks. In this paper we propose an adaptive data transmission scheme with CSMA/CA access control, for applications which may have heavy traffic loads such as smart grids. The adaptive access control is simple to implement. Its compatibility with legacy 802.15.4 devices can be maintained. Simulation results demonstrate the effectiveness of the proposed scheme with largely improved bandwidth and power efficiency. © 2013 International Information Institute.

Digital geometric-sequence control technique for bidirectional dual active bridge DC-DC converters used in future electric vehicles

Bidirectional DC-DC converters are widely used in different applications such as energy storage systems, Electric Vehicles (EVs), UPS, etc. In particular, future EVs require bidirectional power flow in order to integrate energy storage units into smart grids. These bidirectional power converters provide Grid to Vehicle (V2G)/ Vehicle to Grid (G2V) power flow capability for future EVs. Generally, there are two control loops used for bidirectional DC-DC converters: The inner current loop and The outer loop. The control of DAB converters used in EVs are proved to be challenging due to the wide range of operating conditions and non-linear behavior of the converter. In this thesis, the precise mathematical model of the converter is derived and non-linear control schemes are proposed for the control system of bidirectional DC-DC converters based on the derived model. The proposed inner current control technique is developed based on a novel Geometric-Sequence Control (GSC) approach. The proposed control technique offers significantly improved performance as compared to one for conventional control approaches. The proposed technique utilizes a simple control algorithm which saves on the computational resources. Therefore, it has higher reliability, which is essential in this application. Although, the proposed control technique is based on the mathematical model of the converter, its robustness against parameter uncertainties is proven. Three different control modes for charging the traction batteries in EVs are investigated in this thesis: the voltage mode control, the current mode control, and the power mode control. The outer loop control is determined by each of the three control modes. The structure of the outer control loop provides the current reference for the inner current loop. Comprehensive computer simulations have been conducted in order to evaluate the performance of the proposed control methods. In addition, the proposed control have been verified on a 3.3 kW experimental prototype. Simulation and experimental results show the superior performance of the proposed control techniques over the conventional ones.

Random Forest Based Approach for Concept-Drift Handling

Algorithms for concept drift handling are important for various applications including video analysis and smart grids. In this paper we present decision tree ensemble classication method based on the Random Forest algorithm for concept drift. The weighted majority voting ensemble aggregation rule is employed based on the ideas of Accuracy Weighted Ensemble (AWE) method. Base learner weight in our case is computed for each sample evaluation using base learners accuracy and intrinsic proximity measure of Random Forest. Our algorithm exploits both temporal weighting of samples and ensemble pruning as a forgetting strategy. We present results of empirical comparison of our method with îriginal random forest with incorporated replace-the-looser forgetting andother state-of-the-art concept-drift classiers like AWE2.

Redes elétricas inteligentes: desenvolvimento de modelos computacionais e aplicações para a gestão do lado da procura

Esta tese incide sobre o desenvolvimento de modelos computacionais e de aplicações para a gestão do lado da procura, no âmbito das redes elétricas inteligentes. É estudado o desempenho dos intervenientes da rede elétrica inteligente, sendo apresentado um modelo do produtor-consumidor doméstico. O problema de despacho económico considerando previsão de produção e consumo de energia obtidos a partir de redes neuronais artificiais é apresentado. São estudados os modelos existentes no âmbito dos programas de resposta à procura e é desenvolvida uma ferramenta computacional baseada no algoritmo de fuzzy-clustering subtrativo. São analisados perfis de consumo e modos de operação, incluindo uma breve análise da introdução do veículo elétrico e de contingências na rede de energia elétrica. São apresentadas aplicações para a gestão de energia dos consumidores no âmbito do projeto piloto InovGrid. São desenvolvidos sistemas de automação para, aquisição monitorização, controlo e supervisão do consumo a partir de dados fornecidos pelos contadores inteligente que permitem a incorporação das ações dos consumidores na gestão do consumo de energia elétrica; SMART GRIDS - COMPUTATIONAL MODELS DEVELOPMENT AND DEMAND SIDE MANAGMENT APPLICATIONS Abstract: This thesis focuses on the development of computational models and its applications on the demand side management within the smart grid scope. The performance of the electrical network players is studied and a domestic prosumer model is presented. The economic dispatch problem considering the production forecast and the energy consumption obtained from artificial neural networks is also presented. The existing demand response models are studied and a computational tool based on the fuzzy subtractive clustering algorithm is developed. Energy consumption profiles and operational modes are analyzed, including a brief analysis of the electrical vehicle and contingencies on the electrical network. Consumer energy management applications within the scope of InovGrid pilot project are presented. Computational systems are developed for the acquisition, monitoring, control and supervision of consumption data provided by smart meters allowing to incorporate consumer actions on their electrical energy management.

A NOVEL MODELING AND STATE OF CHARGE ESTIMATION SCHEME FOR LITHIUM-ION BATTERIES

Lithium Ion (Li-Ion) batteries have got attention in recent decades because of their undisputable advantages over other types of batteries. They are used in so many our devices which we need in our daily life such as cell phones, lap top computers, cameras, and so many electronic devices. They also are being used in smart grids technology, stand-alone wind and solar systems, Hybrid Electric Vehicles (HEV), and Plug in Hybrid Electric Vehicles (PHEV). Despite the rapid increase in the use of Lit-ion batteries, the existence of limited battery models also inadequate and very complex models developed by chemists is the lack of useful models a significant matter. A battery management system (BMS) aims to optimize the use of the battery, making the whole system more reliable, durable and cost effective. Perhaps the most important function of the BMS is to provide an estimate of the State of Charge (SOC). SOC is the ratio of available ampere-hour (Ah) in the battery to the total Ah of a fully charged battery. The Open Circuit Voltage (OCV) of a fully relaxed battery has an approximate one-to-one relationship with the SOC. Therefore, if this voltage is known, the SOC can be found. However, the relaxed OCV can only be measured when the battery is relaxed and the internal battery chemistry has reached equilibrium. This thesis focuses on Li-ion battery cell modelling and SOC estimation. In particular, the thesis, introduces a simple but comprehensive model for the battery and a novel on-line, accurate and fast SOC estimation algorithm for the primary purpose of use in electric and hybrid-electric vehicles, and microgrid systems. The thesis aims to (i) form a baseline characterization for dynamic modeling; (ii) provide a tool for use in state-of-charge estimation. The proposed modelling and SOC estimation schemes are validated through comprehensive simulation and experimental results.

Modelo de competencias en TIC para el personal de una organización del sector eléctrico

La presente investigación pretendió incorporar el uso intensivo de TIC en los procedimientos establecidos y necesarios en los procesos de generación, distribución y control de la energía, lo que se expresa en un manual para el sistema de gestión humana de la organización analizada. La investigación partió de un levantamiento de un estado del arte, continuó con la realización de un análisis de actitudes y aptitudes de los colaboradores, basado en propuestas teóricas y mejores prácticas existentes del medio, y, por último, concluyó con un manual de gestión humana en el que se indican las competencias en los diferentes perfiles de la organización para el uso de TIC y su aplicación, con el propósito de alinearse con las perspectivas y objetivos de la organización analizada al tener como base la perdurabilidad y la competitividad de la misma.

Load Profile Analysis Tool for Electrical Appliances in Households

This paper presents a methodology to forecast the hourly and daily consumption in households. The methodology was validated for households in Lisbon region, Portugal. The paper shows that the forecast tool allows obtaining satisfactory results for forecasting. Models of demand response allow the support of consumer’s decision in exchange for an economic benefit by the redefinition of load profile or changing the appliance consumption period. It is also in the interest of electric utilities to take advantage of these changes, particularly when consumers have an action on the demand-side management or production. Producers need to understand the load profile of households that are connected to a smart grid, to promote a better use of energy, as well as optimize the use of micro-generation from renewable sources, not only to delivering to the network but also in self-consumption.

A Networked Control Systems Perspective for Wide-Area Monitoring Control of Smart Power Grids

This paper presents a networked control systems (NCS) framework for wide area monitoring control of smart power grids. We consider a scenario in which wide area measurements are transmitted to controllers at remote locations. We model the effects of delays and packet dropouts due to limited communication capabilities in the grid. We also design a robust networked controller to damp wide-area oscillations based on information obtained from Wide Area Monitoring Systems (WAMS), and analyze the improvement in system stability due to networked control. With communication integration being an important feature of the smart grid, detailed consideration of the effects of communication is essential in the control design for future power systems. We believe that this work is an essential step in this direction.

Enhanced Operation of Electricity Distribution Grids Through Smart Metering PLC Network Monitoring, Analysis and Grid Conditioning

Low Voltage (LV) electricity distribution grid operations can be improved through a combination of new smart metering systems' capabilities based on real time Power Line Communications (PLC) and LV grid topology mapping. This paper presents two novel contributions. The first one is a new methodology developed for smart metering PLC network monitoring and analysis. It can be used to obtain relevant information from the grid, thus adding value to existing smart metering deployments and facilitating utility operational activities. A second contribution describes grid conditioning used to obtain LV feeder and phase identification of all connected smart electric meters. Real time availability of such information may help utilities with grid planning, fault location and a more accurate point of supply management.

Modelling and analysis of networked control strategies in smart power distribution grids: development of co-simulation tools

This thesis is focused on Smart Grid applications in medium voltage distribution networks. For the development of new applications it appears useful the availability of simulation tools able to model dynamic behavior of both the power system and the communication network. Such a co-simulation environment would allow the assessment of the feasibility of using a given network technology to support communication-based Smart Grid control schemes on an existing segment of the electrical grid and to determine the range of control schemes that different communications technologies can support. For this reason, is presented a co-simulation platform that has been built by linking the Electromagnetic Transients Program Simulator (EMTP v3.0) with a Telecommunication Network Simulator (OPNET-Riverbed v18.0). The simulator is used to design and analyze a coordinate use of Distributed Energy Resources (DERs) for the voltage/var control (VVC) in distribution network. This thesis is focused control structure based on the use of phase measurement units (PMUs). In order to limit the required reinforcements of the communication infrastructures currently adopted by Distribution Network Operators (DNOs), the study is focused on leader-less MAS schemes that do not assign special coordinating rules to specific agents. Leader-less MAS are expected to produce more uniform communication traffic than centralized approaches that include a moderator agent. Moreover, leader-less MAS are expected to be less affected by limitations and constraint of some communication links. The developed co-simulator has allowed the definition of specific countermeasures against the limitations of the communication network, with particular reference to the latency and loss and information, for both the case of wired and wireless communication networks. Moreover, the co-simulation platform has bee also coupled with a mobility simulator in order to study specific countermeasures against the negative effects on the medium voltage/current distribution network caused by the concurrent connection of electric vehicles.

Increasing Utilization of US Electric Grids via Smart Technologies: Integration of Load Management, Real Time Pricing, Renewables, EVs and Smart Grid Sensors

Electric power grids throughout the world suffer from serious inefficiencies associated with under-utilization due to demand patterns, engineering design and load following approaches in use today. These grids consume much of the world’s energy and represent a large carbon footprint. From material utilization perspectives significant hardware is manufactured and installed for this infrastructure often to be used at less than 20-40% of its operational capacity for most of its lifetime. These inefficiencies lead engineers to require additional grid support and conventional generation capacity additions when renewable technologies (such as solar and wind) and electric vehicles are to be added to the utility demand/supply mix. Using actual data from the PJM [PJM 2009] the work shows that consumer load management, real time price signals, sensors and intelligent demand/supply control offer a compelling path forward to increase the efficient utilization and carbon footprint reduction of the world’s grids. Underutilization factors from many distribution companies indicate that distribution feeders are often operated at only 70-80% of their peak capacity for a few hours per year, and on average are loaded to less than 30-40% of their capability. By creating strong societal connections between consumers and energy providers technology can radically change this situation. Intelligent deployment of smart sensors, smart electric vehicles, consumer-based load management technology very high saturations of intermittent renewable energy supplies can be effectively controlled and dispatched to increase the levels of utilization of existing utility distribution, substation, transmission, and generation equipment. The strengthening of these technology, society and consumer relationships requires rapid dissemination of knowledge (real time prices, costs & benefit sharing, demand response requirements) in order to incentivize behaviors that can increase the effective use of technological equipment that represents one of the largest capital assets modern society has created.

Electrical energy storage and Smart Grid technologies to integrate the next generation of Renewable Power Systems

The growth of renewable power sources, distributed generation and the potential for alternative fuelled modes of transport such as electric vehicles has led to concerns over the ability of existing grid systems to facilitate such diverse portfolio mixes in already congested power systems. Internationally the growth in renewable energy sources is driven by government policy targets associated with the uncertainties of fossil fuel supplies, environmental issues and a move towards energy independence. Power grids were traditionally designed as vertically integrated centrally managed entities with fully dispatchable generating plant. Renewable power sources, distributed generation and alternative fuelled vehicles will place these power systems under additional stresses and strains due to their different operational characteristics. Energy storage and smart grid technologies are widely proposed as the tools to integrate these future diverse portfolio mixes within the more conventional power systems. The choice in these technologies is determined not only by their location on the grid system, but by the diversification in the power portfolio mix, the electricity market and the operational demands. This paper presents a high level technical and economic overview of the role and relevance of electrical energy storage and smart grid technologies in the next generation of renewable power systems.