ELECTRICAL GENERATION AND DISTRIBUTION SYSTEMS AND POWER QUALITY DISTURBANCES Edited by Gregorio Romero Rey and Luisa Martinez Muneta Electrical Generation and Distribution Systems and Power Quality Disturbances Edited by Gregorio Romero Rey and Luisa Martinez Muneta Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. 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Used under license from Shutterstock.com First published November, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Electrical Generation and Distribution Systems and Power Quality Disturbances, Edited by Gregorio Romero Rey and Luisa Martinez Muneta p. cm. ISBN 978-953-307-329-3 Contents Preface IX Part 1 Power Generation and Distribution Systems 1 Chapter 1 Integration of Hybrid Distributed Generation Units in Power Grid 3 Marco Mauri, Luisa Frosio and Gabriele Marchegiani Chapter 2 Optimal Location and Control of Multi Hybrid Model Based Wind-Shunt FACTS to Enhance Power Quality 31 Belkacem Mahdad Chapter 3 Modeling of Photovoltaic Grid Connected Inverters Based on Nonlinear System Identification for Power Quality Analysis 53 Nopporn Patcharaprakiti, Krissanapong Kirtikara, Khanchai Tunlasakun, Juttrit Thongpron, Dheerayut Chenvidhya, Anawach Sangswang, Veerapol Monyakul and Ballang Muenpinij Chapter 4 Reliability Centered Maintenance Optimization of Electric Distribution Systems 83 Dorin Sarchiz, Mircea Dulau, Daniel Bucur and Ovidiu Georgescu Chapter 5 Power Quality Improvement by Using Synchronous Virtual Grid Flux Oriented Control of Grid Side Converter 113 Vasanth Reddy Bathula and Chitti Babu B. Part 2 Disturbances and Voltage Sag 137 Chapter 6 Power Quality and Voltage Sag Indices in Electrical Power Systems 139 Alexis Polycarpou VI Contents Chapter 7 Electrical Disturbances from High Speed Railway Environment to Existing Services 161 Juan de Dios Sanz-Bobi, Jorge Garzón-Núñez, Roberto Loiero and Jesús Félez Part 3 Software Tools 183 Chapter 8 Design of a Virtual Lab to Evaluate and Mitigate Power Quality Problems Introduced by Microgeneration 185 Sonia Pinto, J. Fernando Silva, Filipe Silva and Pedro Frade Chapter 9 Understanding Power Quality Based FACTS Using Interactive Educational GUI Matlab Package 207 Belkacem Mahdad and K. Srairi Chapter 10 A Power Quality Monitoring System Via the Ethernet Network Based on the Embedded System 231 Krisda Yingkayun and Suttichai Premrudeepreechacharn Part 4 Industrial Applications 249 Chapter 11 Some Basic Issues and Applications of Switch-Mode Rectifiers on Motor Drives and Electric Vehicle Chargers 251 C. M. Liaw and Y. C. Chang Chapter 12 Battery Charger with Power Quality Improvement 291 Dylan Dah-Chuan Lu Preface Everything we consume or use requires energy to produce and package, to distribute to shops or front doors, to operate, and then to be got rid of i . The global demand for energy is expected to increase but conventional energy sources are limited and have carbon emissions to the environment. The utilization of renewable energy sources such as wind energy, or solar energy, among others, is currently of greater interest. Nevertheless, since their availability is arbitrary and unstable this can lead to frequency variation, to grid instability and to a total or partial loss of load power supply. On the other hand, the presence of a static converter as output interface of the generating plants introduces voltage and current harmonics into the electrical system that negatively affect system power quality, which is dealt with in another book. By integrating distributed power generation systems closed to the loads in the electric grid, we can eliminate the need to transfer energy over long distances through the electric grid. Moreover, they are an alternative source of energy to meet rapidly increasing energy consumption, but they are not appropriate to be directly connected to the main utility grid. At the same time, they have led to electrical problems. The non-linear components that are used in electronic equipment and other charges can considerably affect the efficiency of an electrical system. An analysis and understanding of the electrical problems and the damage that can be generated to the systems and infrastructures are at the focus of attention due to the progress and introduction of digital systems. Ensuring optimal power quality after a good design and good devices, means productivity, efficiency, competitiveness and profitability. In the following chapters the reader will be introduced to different power generation and distribution systems with an analysis of some types of existing disturbances and a study of different industrial applications such as battery charges; additionally, different software tools developed for power quality understanding, evaluation or monitoring are analyzed. The book is divided into four sections: power generation and distribution systems, disturbances and voltage sag, software tools, and industrial applications; a brief discussion of each chapter is as follows. i Worldwatch Institute. X Preface Chapter 1 evaluates the possible drawbacks to power-supply stability and quality regarding the increasing number of renewable energy sources, both in grid-connected and stand-alone configurations, in order to prevent possible problems by using a proper design and management of these generation units. A first solution to a renewable source equipped with an energy storage system in stand-alone is presented; secondly, a grid connected application of diffused hybrid generation units comprising a wind turbine, a photovoltaic generator and a battery bank is analysed. From the study of both solutions some guidelines for the design of renewable generation units are obtained, focusing on the aspect that influences the power quality of the electrical system. Chapter 2 studies a combined flexible wind source-based model, considered as not having the capability to control voltages, and shunt Flexible AC Transmission Systems (FACTS) devices. This model is proposed to dynamically adjust the active power delivered from the wind source and the reactive power exchanged between the shunt FACTS and the network to enhance power quality. To do this, dynamic shunt compensators (STATCOM) modelled as a Solar Photovoltaic (PV) node are used to control the voltage by a flexible adjustment of the reactive power exchanged with the network. Chapter 3 presents the modelling and simulation of PV-based inverter systems. PV based-operating conditions are concerned with the real situation, such as the input effects of radiation and temperature on voltage and PV current and load and grid variation. In order to build models for nonlinear devices without prior information, system identification methods are set out, using only measured input and output waveforms to determine the model parameters by a Hammerstein-Wiener nonlinear model system identification process. After obtaining appropriate models, an analysis and prediction of power quality is carried out, taking account of steady state and transient condition from different scenarios. Chapter 4 presents a mathematical model of external interventions upon a system henceforth called Renewal Processes. It has been done after basic research in the field of operational research and maintenance management, with contributions and applications in optimization strategies of Reliability Based Maintenance (RCM) for Electrical Distribution Systems (EDS). These are performed in order to reduce the life-cycle cost of the electrical installations and prevent maintenance strategies belonging to RCM and solve the technical and economic objectives of the exploitation of distribution systems and systems that use electrical energy. Chapter 5 introduces the Distributed Power Generation System (DPGS) as an alternative source of energy to meet rapidly increasing energy consumption, but not suitable to be connected directly to the main utility grid. In the chapter a virtual grid flux oriented vector control (outer loop controller) is proposed together with three different types of current controllers (inner current loop) - hysteresis current controller, current regulated delta modulator and modified ramp type current controller - focusing on DC link voltage control, harmonic distortion, constant switching frequency and the unity power factor operation of the inverter. While the inner control loop controls the active and reactive grid current components, the outer control loop determines the active current reference by controlling the direct voltage. . ELECTRICAL GENERATION AND DISTRIBUTION SYSTEMS AND POWER QUALITY DISTURBANCES Edited by Gregorio Romero Rey and Luisa Martinez Muneta Electrical Generation and Distribution. Side Converter 11 3 Vasanth Reddy Bathula and Chitti Babu B. Part 2 Disturbances and Voltage Sag 13 7 Chapter 6 Power Quality and Voltage Sag Indices in Electrical Power Systems 13 9 Alexis Polycarpou. Contents Preface IX Part 1 Power Generation and Distribution Systems 1 Chapter 1 Integration of Hybrid Distributed Generation Units in Power Grid 3 Marco Mauri, Luisa Frosio and Gabriele Marchegiani