Smart Grid Technology and Applications PDF

P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono SMART GRID TECHNOLOGY AND APPLICATIONS Janaka Ekanayake Cardiff University, UK Kithsiri Liyanage University of Peradeniya, Sri Lanka Jianzhong Wu Cardiff University, UK Akihiko Yokoyama University of Tokyo, Japan Nick Jenkins Cardiff University, UK A John Wiley & Sons, Ltd., Publication P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono This edition ﬁrst published 2012 © 2012 John Wiley & Sons, Ltd Registered ofﬁce John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom For details of our global editorial ofﬁces, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com. 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This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloging-in-Publication Data Smart grid : technology and applications / Janaka Ekanayake... [et al.]. p. cm. Includes bibliographical references and index. ISBN 978-0-470-97409-4 (cloth) 1. Smart power grids. I. Ekanayake, J. B. (Janaka B.) TK3105.S677 2012 621.31–dc23 2011044006 A catalogue record for this book is available from the British Library. Print ISBN: 978-0-470-97409-4 Typeset in 10/12pt Times by Aptara Inc., New Delhi, India. P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono Contents About the authors xi Preface xiii Acknowledgements xv List of abbreviations xvii 1 The Smart Grid 1 1.1 Introduction 1 1.2 Why implement the Smart Grid now? 2 1.2.1 Ageing assets and lack of circuit capacity 2 1.2.2 Thermal constraints 2 1.2.3 Operational constraints 3 1.2.4 Security of supply 3 1.2.5 National initiatives 4 1.3 What is the Smart Grid? 6 1.4 Early Smart Grid initiatives 7 1.4.1 Active distribution networks 7 1.4.2 Virtual power plant 9 1.4.3 Other initiatives and demonstrations 9 1.5 Overview of the technologies required for the Smart Grid 12 References 14 Part I INFORMATION AND COMMUNICATION TECHNOLOGIES 2 Data communication 19 2.1 Introduction 19 2.2 Dedicated and shared communication channels 19 2.3 Switching techniques 23 2.3.1 Circuit switching 24 2.3.2 Message switching 24 2.3.3 Packet switching 24 2.4 Communication channels 25 2.4.1 Wired communication 27 2.4.2 Optical ﬁbre 29 P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono vi Contents 2.4.3 Radio communication 33 2.4.4 Cellular mobile communication 34 2.4.5 Satellite communication 34 2.5 Layered architecture and protocols 35 2.5.1 The ISO/OSI model 36 2.5.2 TCP/IP 40 References 43 3 Communication technologies for the Smart Grid 45 3.1 Introduction 45 3.2 Communication technologies 46 3.2.1 IEEE 802 series 46 3.2.2 Mobile communications 59 3.2.3 Multi protocol label switching 60 3.2.4 Power line communication 62 3.3 Standards for information exchange 62 3.3.1 Standards for smart metering 62 3.3.2 Modbus 63 3.3.3 DNP3 64 3.3.4 IEC 61850 65 References 66 4 Information security for the Smart Grid 69 4.1 Introduction 69 4.2 Encryption and decryption 70 4.2.1 Symmetric key encryption 71 4.2.2 Public key encryption 75 4.3 Authentication 76 4.3.1 Authentication based on shared secret key 76 4.3.2 Authentication based on key distribution centre 77 4.4 Digital signatures 77 4.4.1 Secret key signature 77 4.4.2 Public key signature 77 4.4.3 Message digest 78 4.5 Cyber security standards 79 4.5.1 IEEE 1686: IEEE standard for substation intelligent electronic devices (IEDs) cyber security capabilities 79 4.5.2 IEC 62351: Power systems management and associated information exchange – data and communications security 80 References 80 Part II SENSING, MEASUREMENT, CONTROL AND AUTOMATION TECHNOLOGIES 5 Smart metering and demand-side integration 83 5.1 Introduction 83 P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono Contents vii 5.2 Smart metering 84 5.2.1 Evolution of electricity metering 84 5.2.2 Key components of smart metering 86 5.3 Smart meters: An overview of the hardware used 86 5.3.1 Signal acquisition 87 5.3.2 Signal conditioning 89 5.3.3 Analogue to digital conversion 90 5.3.4 Computation 94 5.3.5 Input/output 95 5.3.6 Communication 96 5.4 Communications infrastructure and protocols for smart metering 96 5.4.1 Home-area network 96 5.4.2 Neighbourhood area network 97 5.4.3 Data concentrator 98 5.4.4 Meter data management system 98 5.4.5 Protocols for communications 98 5.5 Demand-side integration 99 5.5.1 Services provided by DSI 100 5.5.2 Implementations of DSI 104 5.5.3 Hardware support to DSI implementations 107 5.5.4 Flexibility delivered by prosumers from the demand side 109 5.5.5 System support from DSI 110 References 111 6 Distribution automation equipment 113 6.1 Introduction 113 6.2 Substation automation equipment 114 6.2.1 Current transformers 116 6.2.2 Voltage transformers 121 6.2.3 Intelligent electronic devices 121 6.2.4 Bay controller 124 6.2.5 Remote terminal units 124 6.3 Faults in the distribution system 125 6.3.1 Components for fault isolation and restoration 127 6.3.2 Fault location, isolation and restoration 132 6.4 Voltage regulation 135 References 139 7 Distribution management systems 141 7.1 Introduction 141 7.2 Data sources and associated external systems 142 7.2.1 SCADA 143 7.2.2 Customer information system 144 7.3 Modelling and analysis tools 144 7.3.1 Distribution system modelling 144 P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono viii Contents 7.3.2 Topology analysis 149 7.3.3 Load forecasting 151 7.3.4 Power ﬂow analysis 152 7.3.5 Fault calculations 156 7.3.6 State estimation 160 7.3.7 Other analysis tools 165 7.4 Applications 165 7.4.1 System monitoring 165 7.4.2 System operation 166 7.4.3 System management 168 7.4.4 Outage management system (OMS) 168 References 171 8 Transmission system operation 173 8.1 Introduction 173 8.2 Data sources 173 8.2.1 IEDs and SCADA 173 8.2.2 Phasor measurement units 174 8.3 Energy management systems 177 8.4 Wide area applications 179 8.4.1 On-line transient stability controller 181 8.4.2 Pole-slipping preventive controller 181 8.5 Visualisation techniques 183 8.5.1 Visual 2-D presentation 184 8.5.2 Visual 3-D presentation 185 References 186 Part III POWER ELECTRONICS AND ENERGY STORAGE 9 Power electronic converters 189 9.1 Introduction 189 9.2 Current source converters 191 9.3 Voltage source converters 195 9.3.1 VSCs for low and medium power applications 196 9.3.2 VSC for medium and high power applications 199 References 203 10 Power electronics in the Smart Grid 205 10.1 Introduction 205 10.2 Renewable energy generation 206 10.2.1 Photovoltaic systems 206 10.2.2 Wind, hydro and tidal energy systems 209 10.3 Fault current limiting 213 10.4 Shunt compensation 217 P1: TIX/XYZ P2: ABC JWST134-fm JWST134-Ekanayake January 12, 2012 13:12 Printer Name: Markono Contents ix 10.4.1 D-STATCOM 218 10.4.2 Active ﬁltering 224 10.4.3 Shunt compensator with energy storage 224 10.5 Series compensation 228 References 231 11 Power electronics for bulk power ﬂows 233 11.1 Introduction 233 11.2 FACTS 234 11.2.1 Reactive power compensation 235 11.2.2 Series compensation 241 11.2.3 Thyristor-controlled phase shifting transformer 243 11.2.4 Uniﬁed power ﬂow controller 245 11.2.5 Interline power ﬂow controller 246 11.3 HVDC 248 11.3.1 Current source converters 249 11.3.2 Voltage source converters 253 11.3.3 Multi-terminal HVDC 256 References 257 12 Energy storage 259 12.1 Introduction 259 12.2 Energy storage technologies 263 12.2.1 Batteries 263 12.2.2 Flow battery 264 12.2.3 Fuel cell and hydrogen electrolyser 266 12.2.4 Flywheels 267 12.2.5 Superconducting magnetic energy storage systems 270 12.2.6 Supercapacitors 270 12.3 Case study 1: Energy storage for wind power 271 12.4 Case study 2: Agent-based control of electrical vehicle battery charging 273 References 277 Index 279 P1: TIX/XYZ P2: ABC JWST134-babout JWST134-Ekanayake January 11, 2012 0:18 Printer Name: Markono About the Authors Janaka Ekanayake received his BSc Eng Degree in Electrical and Electronic Engineering from the University of Peradeniya, Sri Lanka, in 1990 and his PhD in Electrical Engineering from the University of Manchester Institute of Science and Technology (UMIST), UK in 1995. He is presently a Senior Lecturer at Cardiff University, UK. Prior to that he was a Professor in the Department of Electrical and Electronic Engineering, University of Peradeniya. His main research interests include power electronic applications for power systems, renewable energy generation and its integration. He is a Chartered Engineer, a Fellow of the IET, a Senior Member of IEEE, and a member of the IESL. He has published more than 30 papers in refereed journals and has also co-authored three books. Kithsri M. Liyanage is attached to the Department of Electrical and Electronic Engineering, University of Peradeniya, Sri Lanka, as a Professor. He obtained his BSc Eng from the University of Peradeniya in 1983 and his Dr Eng from the University of Tokyo in 1991. He was a Visiting Scientist at the Department of Electrical Engineering, the University of Washington, from 1993 to 1994 and a Visiting Research Fellow at the Advanced Centre for Power and Environmental Technology, the University of Tokyo, Japan, from 2008 to 2010. He has authored or co-authored more than 30 papers related to Smart Grid applications and control since 2009. His research interest is mainly in the application of ICT for the realisation of the Smart Grid. Jianzhong Wu received his BSc, MSc and PhD in 1999, 2001 and 2004 respectively, from Tianjin University, China. He was an Associate Professor in Tianjin University, and then moved to the University of Manchester as a research fellow in 2006. Since 2008, he has been a lecturer at the Cardiff School of Engineering. His main research interests include Energy Infrastructure and Smart Grids. He has a track record of undertaking a number of EU and other funded projects. He is a member of the IET, the IEEE and the ACM. He has published more than 30 papers and co-authored one book. Akihiko Yokoyama received his BS, MS and PhD in 1979, 1981 and 1984 respectively, from the University of Tokyo, Japan. Since 2000, he has been a Professor in the Department of Electrical Engineering, the University of Tokyo. He has been a Visiting Scholar at the University of Texas at Arlington and the University of California at Berkeley. His main research interests include power system analysis and control and Smart Grids. He is a Senior P1: TIX/XYZ P2: ABC JWST134-babout JWST134-Ekanayake January 11, 2012 0:18 Printer Name: Markono xii About the Authors Member of the Institute of Electrical Engineers of Japan (IEEJ), the Japan Society for Industrial and Applied Mathematics (JSIAM), the IEEE and a member of CIGRE. Nick Jenkins was at the University of Manchester (UMIST) from 1992 to 2008. He then moved to Cardiff University where he is now Professor of Renewable Energy. His previous career had included 14 years industrial experience, of which ﬁve years were in developing countries. While at Cardiff University he has developed teaching and research activities in electrical power engineering and renewable energy. He is a Fellow of the IET, the IEEE and the Royal Academy of Engineering. He is a Distinguished Member of CIGRE and from 2009 to 2011 was the Shimizu Visiting Professor to the Atmosphere and Energy Program at Stanford University, USA. P1: TIX/XYZ P2: ABC JWST134-Preface JWST134-Ekanayake December 30, 2011 21:4 Printer Name: Markono Preface Electric power systems throughout the world are facing radical change stimulated by the pressing need to decarbonise electricity supply, to replace ageing assets and to make effective use of rapidly developing information and communication technologies (ICTs). These aims all converge in the Smart Grid. The Smart Grid uses advanced information and communication to control this new energy system reliably and efﬁciently. Some ICT infrastructure already exists for transmission voltages but at present there is very little real-time communication either to or from the customer or in distribution circuits. The Smart Grid vision is to give much greater visibility to lower voltage networks and to enable the participation of customers in the operation of the power system, particularly through Smart Meters and Smart Homes. The Smart Grid will support improved energy efﬁciency and allow a much greater utilisation of renewables. Smart Grid research and development is currently well funded in the USA, the UK, China, Japan and the EU. It is an important research topic in all parts of the world and the source of considerable commercial interest. The aim of the book is to provide a basic discussion of the Smart Grid concept and then, in some detail, to describe the technologies that are required for its realisation. Although the Smart Grid concept is not yet fully deﬁned, the book will be valuable in describing the key enabling technologies and thus permitting the reader to engage with the immediate development of the power system and take part in the debate over the future of the Smart Grid. This book is the outcome of the authors’ experience in teaching to undergraduate and MSc students in China, Japan, Sri Lanka, the UK and the USA and in carrying out research. The content of the book is grouped into three main technologies: 1. Part I Information and communication systems (Chapters 2–4) 2. Part II Sensing, measurement, control and automation (Chapters 5–8) 3. Part III Power electronics and energy storage (Chapters 9–12). These three groups of technologies are presented in three Parts in this book and are relatively independent of each other. For a course module on an MEng or MSc in power systems or energy Chapters 2-4, 5-7 and 9-11 are likely to be most relevant, whereas for a more general module on the Smart Grid, Chapters 2–5 and Chapters 9 and 12 are likely to be most appropriate. The technical content of the book includes specialised topics that will appeal to engineers from various disciplines looking to enhance their knowledge of technologies that are making an increasing contribution to the realisation of the Smart Grid. P1: TIX/XYZ P2: ABC JWST134-back JWST134-Ekanayake December 30, 2011 21:8 Printer Name: Markono Acknowledgements We would like to acknowledge contributions from colleagues and individuals without whom this project will not be a success. Particular thanks are due to Toshiba, S&C Electric Europe Ltd., Tokyo Electric Power Co., Japan Wind and Tianda Qiushi Power New Technol- ogy Co. Ltd. for generously making available a number of photographs. Also we would like to thank John Lacari for checking the numerical examples; Jun Liang, Lee Thomas, Alasdair Burchill, Panagiotis Papadopoulos, Carlos Ugalde-Loo and Iñaki Grau for providing informa- tion for Chapters 5, 11 and 12; Mahesh Sooriyabandara for checking some chapters; and Luke Livermore, Kamal Samarakoon, Yan He, Sugath Jayasinghe and Bieshoy Awad who helped in numerous ways. P1: TIX/XYZ P2: ABC JWST134-blistofabbreviations JWST134-Ekanayake December 30, 2011 21:17 Printer Name: Markono List of Abbreviations 2-D 2-dimensional 3-D 3-dimensional 3G 3rd Generation mobile systems 3GPP 3rd Generation Partnership Project ACL Asynchronous Connectionless Link ADC Analogue to Digital Conversion or Converter ADMD After Diversity Maximum Demand ADSL Asymmetric Digital Subscriber Line ADSS All-Dielectric Self-Supporting AES Advanced Encryption Standard AGC Automatic Generation Control AM Automated Mapping AMM Automatic Meter Management AMR Automatic Meter Reading ARIMA Autoregressive Integrated Moving Average ARIMAX Autoregressive Integrated Moving Average with exogenous variables ARMA Autoregressive Moving Average ARMAX Autoregressive Moving Average with exogenous variables ARPANET Advanced Research Projects Agency Network ASDs Adjustable Speed Drives ASK Amplitude Shift Keying AVC Automatic Voltage Control BES Battery Energy Storage BEV Battery Electric Vehicles BPL Broadband over Power Line CB Circuit Breaker CC Constant Current CI Customer Interruptions CIM Common Information Model CIS Customer Information System CML Customer Minutes Lost COSEM Companion Speciﬁcation for Energy Metering CSC Current Source Converter CSC-HVDC Current Source Converter High Voltage DC P1: TIX/XYZ P2: ABC JWST134-blistofabbreviations JWST134-Ekanayake December 30, 2011 21:17 Printer Name: Markono xviii List of Abbreviations CSMA/CD Carrier Sense Multiple Access/Collision Detect CT Current Transformer CTI Computer Telephony Integration CV Constant Voltage CVT Capacitor Voltage Transformers DAC Digital to Analogue Converter DARPA Defense Advanced Research Project Agency DB Demand Bidding DCC Diode-Clamped Converter DER Distributed Energy Resources DES Data Encryption Standard DFIG Doubly Fed Induction Generators DG Distributed Generation DLC Direct Load Control DMS Distribution Management System DMSC Distribution Management System Controller DNO Distribution Network Operators DNS Domain Name Server DR Demand Response DSB Demand-Side Bidding DSI Demand-Side Integration DSL Digital Subscriber Lines DSM Demand-Side Management DSP Digital Signal Processor DSR Demand-Side Response DVR Dynamic Voltage Restorer EDGE Enhanced Data Rates for GSM Evolution EMI Electromagnetic Interference EMS Energy Management System ESS Extended Service Set EU European Union EV Electric Vehicles FACTS Flexible AC Transmission Systems FCL Fault Current Limiters FCS Frame Check Sequence FFD Full Function Device FM Facilities Management FPC Full Power Converter FSIG Fixed Speed Induction Generator FSK Frequency Shift Keying FTP File Transfer Protocol GEO Geostationary Orbit GGSN Gateway GPRS Support Node GIS Gas Insulated Substations GIS Geographic Information System GPRS General Packet Radio Service P1: TIX/XYZ P2: ABC JWST134-blistofabbreviations JWST134-Ekanayake December 30, 2011 21:17 Printer Name: Markono List of Abbreviations xix GPS Global Positioning System GSM Global System for Mobile Communications GTO Gate Turn-off (Thyristor) HAN Home-Area Network HDLC High-Level Data Link Control HMI Human Machine Interface HTTP Hypertext Transfer Protocol HVAC Heating, Ventilation, Air Conditioning HVDC High Voltage DC ICT Information and Communication Technology IED Intelligent Electronic Device IGBT Insulated Gate Bipolar Transistor IGCT Insulated Gate Commutated Thyristor IP Internet Protocol IPFC Interline Power Flow Controller IPng IP Next Generation IPsec Internet Protocol Security ITE Information Technology Equipment KDC Key Distribution Centre LAN Local Area Network LCD Liquid Crystal Displays LED Light Emitting Diodes LLC Logical Link Control LMU Line Matching Unit LOLP Loss of Load Probability M2C Multi-Modular Converter MAS Multi Agent System MD Message Digest MDM Metre Data Management system METI Ministry of Economy, Trade and Industry MGCC MicroGrid Central Controllers MMS Manufacturing Message Speciﬁcation MOSFET Metal Oxide Semiconductor Field Effect Transistor MPLS Multi Protocol Label Switching MPPT Maximum Power Point Tracking MSB Most Signiﬁcant Bit MTSO Mobile Telephone Switching Ofﬁce NAN Neighbourhood Area Network NERC CIP North America Electric Reliability Corporation – Critical Infrastructure Protection NOP Normally Open Point NPC Neutral-Point-Clamped OCGT Open Cycle Gas Turbines OFDM Orthogonal Frequency Multiplexing OFDMA Orthogonal Frequency Division Multiple Access OLTCs On-Load Tap Changers P1: TIX/XYZ P2: ABC JWST134-blistofabbreviations JWST134-Ekanayake December 30, 2011 21:17 Printer Name: Markono xx List of Abbreviations OMS Outage Management System OPGW OPtical Ground Wires PCM Pulse Code Modulation PDC Phasor Data Concentrator PET Polyethylene Terephathalate PGA Programmable Gain Ampliﬁer PHEV Plug-in Hybrid Electric Vehicles PLC Power Line Carrier PLL Phase Locked Loop PMU Phasor Measurement Units PSK Phase Shift Keying PSS Power System Stabilisers PSTN Public Switched Telephone Network PV Photovoltaic PWM Pulse Width Modulation RFD Reduced Function Device RMU Ring Main Unit RTU Remote Terminal Unit SAP Session Announcement Protocol SCADA Supervisory Control and Data Acquisition SCE Southern California Edison SCO Synchronous Connection Orientated SGCC State Grid Corporation of China SGSN Serving GPRS Support Node SHA Secure Hash Algorithm SMES Superconducting Magnetic Energy Storage SMTP Simple Mail Transfer Protocol SNR Signal to Noise Ratio SOC State Of Charge SVC Static Var Compensator TCP Transmission Control Protocol TCR Thyristor Controlled Reactor TCSC Thyristor Controlled Series Capacitor THD Total Harmonic Distortion TSC Thyristor Switched Capacitor TSSC Thyristor Switched Series Capacitor UHV Ultra High Voltage UML Uniﬁed Modelling Language UPFC Uniﬁed Power Flow Controller UPS Uninterruptable Power Supplies URL Uniform Resource Locator UTP Unshielded Twisted Pair VPN Virtual Private Network VPP Virtual Power Plant VSC Voltage Source Converter VSC-ES Voltage Source Converters with Energy Storage P1: TIX/XYZ P2: ABC JWST134-blistofabbreviations JWST134-Ekanayake December 30, 2011 21:17 Printer Name: Markono List of Abbreviations xxi VSC-HVDC Voltage Source Converter HVDC VT Voltage Transformer WAMPAC Wide Area Monitoring, Protection and Control WAMSs Wide-Area Measurement Systems WAN Wide Area Network WiMax Worldwide Interoperability for Microwave Access WLAN Wireless LAN WLAV Weighted Least Absolute Value WLS Weighted Least Square WPAN Wireless Public Area Networks XOR Exclusive OR P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 1 The Smart Grid 1.1 Introduction Established electric power systems, which have developed over the past 70 years, feed electrical power from large central generators up through generator transformers to a high voltage inter- connected network, known as the transmission grid. Each individual generator unit, whether powered by hydropower, nuclear power or fossil fuelled, is large with a rating of up to 1000 MW. The transmission grid is used to transport the electrical power, sometimes over consid- erable distances, and this power is then extracted and passed through a series of distribution transformers to ﬁnal circuits for delivery to the end customers. The part of the power system supplying energy (the large generating units and the transmis- sion grid) has good communication links to ensure its effective operation, to enable market transactions, to maintain the security of the system, and to facilitate the integrated operation of the generators and the transmission circuits. This part of the power system has some automatic control systems though these may be limited to local, discrete functions to ensure predictable behaviour by the generators and the transmission network during major disturbances. The distribution system, feeding load, is very extensive but is almost entirely passive with little communication and only limited local controls. Other than for the very largest loads (for example, in a steelworks or in aluminium smelters), there is no real-time monitoring of either the voltage being offered to a load or the current being drawn by it. There is very little interaction between the loads and the power system other than the supply of load energy whenever it is demanded. The present revolution in communication systems, particularly stimulated by the internet, offers the possibility of much greater monitoring and control throughout the power system and hence more effective, ﬂexible and lower cost operation. The Smart Grid is an opportunity to use new ICTs (Information and Communication Technologies) to revolutionise the electrical power system. However, due to the huge size of the power system and the scale of investment that has been made in it over the years, any signiﬁcant change will be expensive and requires careful justiﬁcation. The consensus among climate scientists is clear that man-made greenhouse gases are leading to dangerous climate change. Hence ways of using energy more effectively and generating electricity without the production of CO2 must be found. The effective management of loads Smart Grid: Technology and Applications, First Edition. Janaka Ekanayake, Kithsiri Liyanage, Jianzhong Wu, Akihiko Yokoyama and Nick Jenkins. © 2012 John Wiley & Sons, Ltd. Published 2012 by John Wiley & Sons, Ltd. 1 P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 2 Smart Grid: Technology and Applications and reduction of losses and wasted energy needs accurate information while the use of large amounts of renewable generation requires the integration of the load in the operation of the power system in order to help balance supply and demand. Smart meters are an important element of the Smart Grid as they can provide information about the loads and hence the power ﬂows throughout the network. Once all the parts of the power system are monitored, its state becomes observable and many possibilities for control emerge. In the UK, the anticipated future de-carbonised electrical power system is likely to rely on generation from a combination of renewables, nuclear generators and fossil-fuelled plants with carbon capture and storage. This combination of generation is difﬁcult to manage as it consists of variable renewable generation and large nuclear and fossil generators with carbon capture and storage that, for technical and commercial reasons, will run mainly at constant output. It is hard to see how such a power system can be operated cost-effectively without the monitoring and control provided by a Smart Grid. 1.2 Why implement the Smart Grid now? Since about 2005, there has been increasing interest in the Smart Grid. The recognition that ICT offers signiﬁcant opportunities to modernise the operation of the electrical networks has coincided with an understanding that the power sector can only be de-carbonised at a realistic cost if it is monitored and controlled effectively. In addition, a number of more detailed reasons have now coincided to stimulate interest in the Smart Grid. 1.2.1 Ageing assets and lack of circuit capacity In many parts of the world (for example, the USA and most countries in Europe), the power system expanded rapidly from the 1950s and the transmission and distribution equipment that was installed then is now beyond its design life and in need of replacement. The capital costs of like-for-like replacement will be very high and it is even questionable if the required power equipment manufacturing capacity and the skilled staff are now available. The need to refurbish the transmission and distribution circuits is an obvious opportunity to innovate with new designs and operating practices. In many countries the overhead line circuits, needed to meet load growth or to connect renewable generation, have been delayed for up to 10 years due to difﬁculties in obtaining rights-of-way and environmental permits. Therefore some of the existing power transmission and distribution lines are operating near their capacity and some renewable generation cannot be connected. This calls for more intelligent methods of increasing the power transfer capacity of circuits dynamically and rerouting the power ﬂows through less loaded circuits. 1.2.2 Thermal constraints Thermal constraints in existing transmission and distribution lines and equipment are the ultimate limit of their power transfer capability. When power equipment carries current in excess of its thermal rating, it becomes over-heated and its insulation deteriorates rapidly. This leads to a reduction in the life of the equipment and an increasing incidence of faults. P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono The Smart Grid 3 If an overhead line passes too much current, the conductor lengthens, the sag of the catenary increases, and the clearance to the ground is reduced. Any reduction in the clearance of an overhead line to the ground has important consequences both for an increase in the number of faults but also as a danger to public safety. Thermal constraints depend on environmental conditions, that change through the year. Hence the use of dynamic ratings can increase circuit capacity at times. 1.2.3 Operational constraints Any power system operates within prescribed voltage and frequency limits. If the voltage exceeds its upper limit, the insulation of components of the power system and consumer equipment may be damaged, leading to short-circuit faults. Too low a voltage may cause malfunctions of customer equipment and lead to excess current and tripping of some lines and generators. The capacity of many traditional distribution circuits is limited by the variations in voltage that occur between times of maximum and minimum load and so the circuits are not loaded near to their thermal limits. Although reduced loading of the circuits leads to low losses, it requires greater capital investment. Since about 1990, there has been a revival of interest in connecting generation to the distribution network. This distributed generation can cause over-voltages at times of light load, thus requiring the coordinated operation of the local generation, on-load tap changers and other equipment used to control voltage in distribution circuits. The frequency of the power system is governed by the second-by-second balance of generation and demand. Any imbalance is reﬂected as a deviation in the frequency from 50 or 60 Hz or excessive ﬂows in the tie lines between the control regions of very large power systems. System operators maintain the frequency within strict limits and when it varies, response and reserve services are called upon to bring the frequency back within its operating limits. Under emergency conditions some loads are disconnected to maintain the stability of the system. Renewable energy generation (for example. wind power, solar PV power) has a varying output which cannot be predicted with certainty hours ahead. A large central fossil-fuelled generator may require 6 hours to start up from cold. Some generators on the system (for example, a large nuclear plant) may operate at a constant output for either technical or commercial reasons. Thus maintaining the supply–demand balance and the system frequency within limits becomes difﬁcult. Part-loaded generation ‘spinning reserve’ or energy storage can address this problem but with a consequent increase in cost. Therefore, power system operators increasingly are seeking frequency response and reserve services from the load demand. It is thought that in future the electriﬁcation of domestic heating loads (to reduce emissions of CO2 ) and electric vehicle charging will lead to a greater capacity of ﬂexible loads. This would help maintain network stability, reduce the requirement for reserve power from part-loaded generators and the need for network reinforcement. 1.2.4 Security of supply Modern society requires an increasingly reliable electricity supply as more and more critical loads are connected. The traditional approach to improving reliability was to install additional redundant circuits, at considerable capital cost and environmental impact. Other than discon- necting the faulty circuit, no action was required to maintain supply after a fault. A Smart Grid P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 4 Smart Grid: Technology and Applications approach is to use intelligent post-fault reconﬁguration so that after the (inevitable) faults in the power system, the supplies to customers are maintained but to avoid the expense of multiple circuits that may be only partly loaded for much of their lives. Fewer redundant circuits result in better utilisation of assets but higher electrical losses. 1.2.5 National initiatives Many national governments are encouraging Smart Grid initiatives as a cost-effective way to modernise their power system infrastructure while enabling the integration of low-carbon energy resources. Development of the Smart Grid is also seen in many countries as an important economic/commercial opportunity to develop new products and services. 1.2.5.1 China The Chinese government has declared that by 2020 the carbon emission per-unit of GDP will reduce to 40∼45 per cent of that in 2008. Other drivers for developing the Smart Grid in China are the nation’s rapid economic growth and the uneven geographical distribution of electricity generation and consumption. The State Grid Corporation of China (SGCC) has released a medium–long term plan of the development of the Smart Grid. The SGCC interprets the Smart Grid as “a strong and robust electric power system, which is backboned with Ultra High Voltage (UHV) networks; based on the coordinated development of power grids at different voltage levels; supported by information and communication infrastructure; characterised as an automated, and interoperable power system and the integration of electricity, information, and business ﬂows.” 1.2.5.2 The European Union The SmartGrids Technology Platform of the European Union (EU) has published a vision and strategy for Europe’s electricity networks of the future. It states: “It is vital that Europe’s electricity networks are able to integrate all low carbon generation technologies as well as to encourage the demand side to play an active part in the supply chain. This must be done by upgrading and evolving the networks efﬁciently and economically.” The SmartGrids Technology Platform identiﬁed the following important areas as key chal- lenges that impact on the delivery of the EU-mandated targets for the utilisation of renewable energy, efﬁciency and carbon reductions by 2020 and 2050: r strengthening the grid, including extending it offshore; r developing decentralised architectures for system control; r delivering communications infrastructure; r enabling an active demand side; r integrating intermittent generation; P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono The Smart Grid 5 r enhancing the intelligence of generation, demand and the grid; r capturing the beneﬁts of distributed generation (DG) and storage; r preparing for electric vehicles. 1.2.5.3 Japan In 2009, the Japanese government declared that by 2020 carbon emissions from all sectors will be reduced to 75 per cent of those in 1990 or two-thirds of those in 2005. In order to achieve this target, 28 GW and 53 GW of photovoltaic (PV) generations are required to be installed in the power grid by 2020 and 2030. The Ministry of Economy, Trade and Industry (METI) has set up three study committees since 2008 to look into the Smart Grid and related aspects. These committees were active for a one-year period and were looking at the low-carbon power system (2008–2009), the next-generation transmission and distribution network, the Smart Grid in the Japanese context (2009–2010) and regulatory issues of the next-generation transmission and distribution system (2010–2011). The mandate given to these committees was to discuss the following technical and regulatory issues regarding the large penetration of renewable energy, especially PV generation, into the power grid: r surplus power under light load conditions; r frequency ﬂuctuations; r voltage rise on distribution lines; r priority interconnection, access and dispatching for renewable energy-based generators; r cost recovery for building the Smart Grid. Further, a national project called ‘The Field Test Project on Optimal Control Technologies for the Next-Generation Transmission and Distribution System’ was conducted by 26 electric utilities, manufacturing companies and research laboratories in Japan in order to develop the technologies to solve these problems. Since the Tohoku earthquake on 11 March 2011, the Smart Grid has been attracting much attention for the reconstruction of the damaged districts and the development of a low-carbon society. 1.2.5.4 The UK The Department of Energy and Climate Change document Smarter Grids: The Opportunity states that the aim of developing the Smart Grid is to provide ﬂexibility to the current electricity network, thus enabling a cost-effective and secure transition to a low-carbon energy system. The Smart Grid route map recognises a number of critical developments that will drive the UK electrical system towards a low carbon system. These include: r rapid expansion of intermittent renewables and less ﬂexible nuclear generation in conjunction with the retirement of ﬂexible coal generation; r electriﬁcation of heating and transport; r penetration of distributed energy resources which include distributed generation, demand response and storage; r increasing penetration of electric vehicles. P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 6 Smart Grid: Technology and Applications 1.2.5.5 The USA According to Public Law 110–140-DEC. 19, 2007 , the United States of America (the USA) “is supporting modernisation of the electricity transmission and distribution networks to main- tain a reliable and secure electricity infrastructure that can meet future demand growth and to achieve increased use of digital information and controls technology; dynamic optimisation of grid operations and resources; deployment and integration of distributed resources and generation; development and incorporation of demand response, demand-side resources, and energy-efﬁcient resources; development of ‘smart’ technologies for metering, communications and status, and distribution automation; integration of ‘smart’ appliances and consumer devices; deployment and integration of advanced electricity storage and peak-shaving technologies; provisions to con- sumers of timely information and control options and development of standards for communication and inter-operability.” 1.3 What is the Smart Grid? The Smart Grid concept combines a number of technologies, end-user solutions and addresses a number of policy and regulatory drivers. It does not have a single clear deﬁnition. The European Technology Platform deﬁnes the Smart Grid as: “A SmartGrid is an electricity network that can intelligently integrate the actions of all users connected to it – generators, consumers and those that do both – in order to efﬁciently deliver sustainable, economic and secure electricity supplies.” According to the US Department of Energy : “A smart grid uses digital technology to improve reliability, security, and efﬁciency (both economic and energy) of the electric system from large generation, through the delivery systems to electricity consumers and a growing number of distributed-generation and storage resources.” In Smarter Grids: The Opportunity , the Smart Grid is deﬁned as: “A smart grid uses sensing, embedded processing and digital communications to enable the electricity grid to be observable (able to be measured and visualised), controllable (able to manipulated and optimised), automated (able to adapt and self-heal), fully integrated (fully interoperable with existing systems and with the capacity to incorporate a diverse set of energy sources).” The literature [7–10] suggests the following attributes of the Smart Grid: 1. It enables demand response and demand side management through the integration of smart meters, smart appliances and consumer loads, micro-generation, and electricity storage (electric vehicles) and by providing customers with information related to energy use and prices. It is anticipated that customers will be provided with information and incentives to modify their consumption pattern to overcome some of the constraints in the power system. 2. It accommodates and facilitates all renewable energy sources, distributed generation, res- idential micro-generation, and storage options, thus reducing the environmental impact P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono The Smart Grid 7 of the whole electricity sector and also provides means of aggregation. It will provide simpliﬁed interconnection similar to ‘plug-and-play’. 3. It optimises and efﬁciently operates assets by intelligent operation of the delivery system (rerouting power, working autonomously) and pursuing efﬁcient asset management. This includes utilising asserts depending on what is needed and when it is needed. 4. It assures and improves reliability and the security of supply by being resilient to distur- bances, attacks and natural disasters, anticipating and responding to system disturbances (predictive maintenance and self-healing), and strengthening the security of supply through enhanced transfer capabilities. 5. It maintains the power quality of the electricity supply to cater for sensitive equipment that increases with the digital economy. 6. It opens access to the markets through increased transmission paths, aggregated supply and demand response initiatives and ancillary service provisions. 1.4 Early Smart Grid initiatives 1.4.1 Active distribution networks Figure 1.1 is a schematic of a simple distribution network with distributed generation (DG). There are many characteristics of this network that differ from a typical passive distribution network. First, the power ﬂow is not unidirectional. The direction of power ﬂows and the voltage magnitudes on the network depend on both the demand and the injected generation. Second, the distributed generators give rise to a wide range of fault currents and hence complex protection and coordination settings are required to protect the network. Third, the DMSC P, Q, V, £ P, Q Asynchronous P, Q P, Q, V, £ P, Q, V, £ generator P, –Q P, ±Q PV CHP ±Q Var compensation Synchronous generator P, ±Q Control signals Measurements Figure 1.1 Distribution network active management scheme P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 8 Smart Grid: Technology and Applications Constraints Control limits Voltage limits Thermal limits State estimation Control and bad data Optimal control schedules detection Measurements Optimal settings Available options OLTC ref, Q Local and RTU OLTC, Q inject/absorb, measurements; compensation, Regulator up/ Network topology Voltage regulator, down, Load shed/ controllable loads connect, DG up/ and DG down Figure 1.2 Architecture of a DMSC reactive power ﬂow on the network can be independent of the active power ﬂows. Fourth, many types of DGs are interfaced through power electronics and may inject harmonics into the network. Figure 1.1 also shows a control scheme suitable for achieving the functions of active control. In this scheme a Distribution Management System Controller (DMSC) assesses the network conditions and takes action to control the network voltages and ﬂows. The DMSC obtains measurements from the network and sends signals to the devices under its control. Control actions may be a transformer tap operation, altering the DG output and injection/absorption of reactive power. Figure 1.2 shows the DMSC controller building blocks that assess operating conditions and ﬁnd the control settings for devices connected to the network. The key functions of the DMSC are state estimation, bad data detection and the calculation of optimal control settings. The DMSC receives a limited number of real-time measurements at set intervals from the network nodes. The measurements are normally voltage, load injections and power ﬂow mea- surements from the primary substation and other secondary substations. These measurements are used to calculate the network operating conditions. In addition to these real-time measure- ments, the DMSC uses load models to forecast load injections at each node on the network for a given period that coincides with the real-time measurements. The network topology and impedances are also supplied to the DMSC. The state estimator (described in Chapter 7) uses this data to assess the network conditions in terms of node voltage magnitudes, line power ﬂows and network injections. Bad measurements coming to the system will be ﬁltered using bad data detection and identiﬁcation methods. When the network operating conditions have been assessed, the control algorithm identiﬁes whether the network is operating within its permissible boundaries. This is normally assessed by analysing the network voltage magnitudes at each busbar. The optimisation algorithm is supplied with the available active control options, the limits on these controls and the network P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono The Smart Grid 9 operating constraints. Limits on controls are the permissible lower and higher settings of the equipment. Operating constraints are usually voltage limits and thermal ratings of the lines and equipment. The optimal control algorithm calculates the required control settings and optimises the device settings without violating constraints and operating limits. The solution from the control algorithm is the optimal control schedules that are sent to the devices connected to the network. Such control actions can be single or multiple control actions that would alter the set point of any of the devices by doing any of the following: r alter the reference of an On-Load Tap Changer (OLTC) transformer/voltage regulator relay; r request the Automatic Voltage Regulator (AVR) or the governor of a synchronous generator to alter the reactive/active power of the machine; r send signals to a wind farm Supervisory Control and Data Acquisition (SCADA) system to decrease the wind farm output power; r shed or connect controllable loads on the network; r increase or decrease the settings of any reactive power compensation devices; r reconﬁgure the network by opening and closing circuit open points. 1.4.2 Virtual power plant Distributed energy resources (DER) such as micro-generation, distributed generation, electric vehicles and energy storage devices are becoming more numerous due to the many initiatives to de-carbonize the power sector. DERs are too small and too numerous to be treated in a similar way to central generators and are often connected to the network on a ‘connect-and-forget’ basis. The concept of a Virtual Power Plant (VPP) is to aggregate many small generators into blocks that can be controlled by the system operator and then their energy output is traded. Through aggregating the DERs into a portfolio, they become visible to the system operator and can be actively controlled. The aggregated output of the VPP is arranged to have similar technical and commercial characteristics as a central generation unit. The VPP concept allows individual DERs to gain access to and visibility in the energy markets. Furthermore, system operators can beneﬁt from the optimal use of all the available capacity connected to the network. The size and technological make-up of a VPP portfolio have a signiﬁcant effect on the beneﬁts of aggregation seen by its participants. For example, ﬂuctuation of wind generation output can lower the value of the energy sold but variation reduces with increasing geographical distance between the wind farms. If a VPP assembles generation across a range of technologies, the variation of the aggregated output of these generators is likely to reduce. 1.4.3 Other initiatives and demonstrations 1.4.3.1 Galvin electricity initiative The Galvin vision [12, 13] is an initiative that began in 2005 to deﬁne and achieve a ‘perfect power system’. The perfect power system is deﬁned as: “The perfect power system will ensure absolute and universal availability and energy in the quantity and quality necessary to meet every consumer’s needs.” P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 10 Smart Grid: Technology and Applications The philosophy of a perfect power system differs from the way power systems traditionally have been designed and constructed which assumes a given probability of failure to supply customers, measured by a reliability metric, such as Loss of Load Probability (LOLP). Con- sideration of LOLP shows that a completely reliable power system can only be provided by using an inﬁnite amount of plant at inﬁnite cost. Some of the attributes of the perfect power system are similar to those of the Smart Grid. For example, in order to achieve a perfect power system, the power system must meet the following goals: r be smart, self-sensing, secure, self-correcting and self-healing; r sustain the failure of individual components without interrupting the service; r be able to focus on regional, speciﬁc area needs; r be able to meet consumer needs at a reasonable cost with minimum resource utilisation and minimal environmental impact; r enhance quality of life and improve economic productivity. The development of the perfect power system is based on integrating devices (smart loads, local generation and storage devices), then buildings (building management systems and micro CHP), followed by construction of an integrated distribution system (shared resources and storage) and ﬁnally to set up a fully integrated power system (energy optimisation, market systems and integrated operation). 1.4.3.2 IntelliGridSM EPRI’s IntelliGridSM initiative [12, 14], which is creating a technical foundation for the Smart Grid, has a vision of a power system that has the following features: r is made up of numerous automated transmission and distribution systems, all operating in a coordinated, efﬁcient and reliable manner; r handles emergency conditions with ‘self-healing’ actions and is responsive to energy-market and utility business enterprise needs; r serves millions of customers and has an intelligent communications infrastructure enabling the timely, secure and adaptable information ﬂow needed to provide reliable and economic power to the evolving digital economy. To realise these attributes, an integrated energy and communication systems architecture should ﬁrst of all be developed. This will be an open standard-based architecture and tech- nologies such as data networking, communication over a wide variety of physical media and embedded computing will be part of it. This architecture will enable the automated monitoring and control of the power delivery system, increase the capacity of the power delivery system, and enhance the performance and connectivity of the end users. In addition to the proposed communication architecture, the realisation of the IntelliGridSM will require enabling technologies such as automation, distributed energy resources, stor- age, power electronic controllers, market tools, and consumer portals. Automation will be- come widespread in the electrical generation, consumption and delivery systems. Distributed energy resources and storage devices may offer potential solutions to relieve the necessity to P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono The Smart Grid 11 strengthen the power delivery system, to facilitate a range of services to consumers and to provide electricity to customers at lower cost, and with higher security, quality, reliability and availability. Power electronic-based controllers can direct power along speciﬁc corridors, in- crease the power transfer capacity of existing assets, help power quality problems and increase the efﬁcient use of power. Market tools will be developed to facilitate the efﬁcient planning for expansion of the power delivery system, effectively allocating risks, and connecting con- sumers to markets. The consumer portal contains the smart meter that allows price signals, decisions, communication signals and network intelligent requests to ﬂow seamlessly through the two-way portal. 1.4.3.3 Xcel energy’s Smart Grid Xcel Energy’s vision of a smart grid includes “a fully network-connected system that identiﬁes all aspects of the power grid and communicates its status and the impact of consumption decisions (including economic, environmental and reliability impacts) to automated decision-making systems on that network.” Xcel Energy’s Smart Grid implementation involved the development of a number of quick- hit projects. Even though some of these projects were not fully realised, they are listed below as they illustrate different Smart Grid technologies that could be used to build intelligence into the power grid: 1. Wind Power Storage: A 1 MW battery energy storage system to demonstrate long-term emission reductions and help to reduce impacts of wind variability. 2. Neural Networks: A state-of-the-art system that helps reduce coal slagging and fouling (build-up of hard minerals) of a boiler. 3. Smart Substation: Substation automation with new technologies for remote monitoring and then developing an analytics engine that processes data for near real-time decision-making and automated actions. 4. Smart Distribution Assets: A system that detects outages and restores them using advanced meter technology. 5. Smart Outage Management: Diagnostic software that uses statistics to predict problems in the power distribution system. 6. Plug-in Hybrid Electric Vehicles: Investigating vehicle-to-grid technology through ﬁeld trials. 7. Consumer Web Portal: This portal allows customers to program or pre-set their own energy use and automatically control their power consumption based on personal preferences including both energy costs and environmental factors. 1.4.3.4 SCE’s Smart Grid Southern California Edison (SCE)’s Smart Grid strategy encompasses ﬁve strategic themes namely, renewable and distributed energy resources integration, grid control and asset opti- misation, workforce effectiveness, smart metering, and energy-smart customer solutions. SCE anticipates that these themes will address a broad set of business requirements to better P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 12 Smart Grid: Technology and Applications position them to meet current and future power delivery challenges. By 2020, SCE will have 10 million intelligent devices such as smart meters, energy-smart appliances and customer devices, electric vehicles, DERs, inverters and storage technologies that are linked to the grid, providing sensing information and automatically responding to prices/event signals. SCE has initiated a smart meter connection programme where 5 million meters will be deployed from 2009 to 2012. The main objectives of this programme include adding value through information, and initiating new customer partnerships. The services and informa- tion they are going to provide include interval billing, tiered rates and rates based on time of use. 1.5 Overview of the technologies required for the Smart Grid To fulﬁl the different requirements of the Smart Grid, the following enabling technologies must be developed and implemented: 1. Information and communications technologies: These include: (a) two-way communication technologies to provide connectivity between different com- ponents in the power system and loads; (b) open architectures for plug-and-play of home appliances; electric vehicles and micro- generation; (c) communications, and the necessary software and hardware to provide customers with greater information, enable customers to trade in energy markets and enable customers to provide demand-side response; (d) software to ensure and maintain the security of information and standards to provide scalability and interoperability of information and communication systems. These topics are discussed in Chapters 2–4 of this book. 2. Sensing, measurement, control and automation technologies: These include: (a) Intelligent Electronic Devices (IED) to provide advanced protective relaying, measure- ments, fault records and event records for the power system; (b) Phasor Measurement Units (PMU) and Wide Area Monitoring, Protection and Control (WAMPAC) to ensure the security of the power system; (c) integrated sensors, measurements, control and automation systems and information and communication technologies to provide rapid diagnosis and timely response to any event in different parts of the power system. These will support enhanced asset management and efﬁcient operation of power system components, to help relieve congestion in transmission and distribution circuits and to prevent or minimise potential outages and enable working autonomously when conditions require quick resolution. (d) smart appliances, communication, controls and monitors to maximise safety, comfort, convenience, and energy savings of homes; (e) smart meters, communication, displays and associated software to allow customers to have greater choice and control over electricity and gas use. They will provide consumers with accurate bills, along with faster and easier supplier switching, to give consumers accurate real-time information on their electricity and gas use and other related information and to enable demand management and demand side participation. These topics are discussed in Chapters 5–8. P1: TIX/XYZ JWST134-c01 Table 1.1 Application matrix of different technologies P2: ABC Information and Sensors, Power communications control and electronics and The Smart Grid Application area Requirement technologies automation energy storage JWST134-Ekanayake Plug-and-play of smart home appliances, electric vehicles, microgeneration Enabling customers to trade in energy markets Allowing customers to have greater choice and control over electricity use Providing consumers with accurate bills, along with faster and easier supplier switching Industries, homes Giving consumers accurate real-time information on their electricity use January 5, 2012 and other related information Enabling integrated management of appliances, electric vehicles (charging and energy storage) and microgeneration 20:43 Enabling demand management and demand side participation Transmission and Enabling rapid diagnosis and timely response to any event on different part distribution of the power system Supporting enhanced asset management Helping relieve congestion in transmission and distribution circuits and preventing or minimising potential outages Generation Supporting system operation by controlling renewable energy sources Printer Name: Markono Enabling long-distance transport and integration of renewable energy sources Providing efﬁcient connection of renewable energy sources Enabling integration and operation of virtual power plants Power system as a Providing greater ﬂexibility, reliability and quality of the power supply whole system Balancing generation and demand in real time Supporting efﬁcient operation of power system components 13 P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono 14 Smart Grid: Technology and Applications 3. Power electronics and energy storage: These include: (a) High Voltage DC (HVDC) transmission and back-to-back schemes and Flexible AC Transmission Systems (FACTS) to enable long distance transport and integration of renewable energy sources; (b) different power electronic interfaces and power electronic supporting devices to provide efﬁcient connection of renewable energy sources and energy storage devices; (c) series capacitors, Uniﬁed Power Flow Controllers (UPFC) and other FACTS devices to provide greater control over power ﬂows in the AC grid; (d) HVDC, FACTS and active ﬁlters together with integrated communication and control to ensure greater system ﬂexibility, supply reliability and power quality; (e) power electronic interfaces and integrated communication and control to support system operations by controlling renewable energy sources, energy storage and consumer loads; (f) energy storage to facilitate greater ﬂexibility and reliability of the power system. These topics are discussed in Chapters 9–12 of this book. Table 1.1 shows the application matrix of different technologies. References Erinmez, I.A., Bickers, D.O., Wood, G.F. and Hung, W.W. (1999) NGC Experience with frequency control in England and Wales: provision of frequency response by generator. IEEE PES Winter Meeting, 31 January–4 February 1999, New York, USA. Sun, Q., Wu, J., Zhang, Y. et al. (2010) Comparison of the development of Smart Grids in China and the United Kingdom. IEEE PES Conference on Innovative Smart Grid Technologies Europe, 11–13 October 2010, Gothenburg, Sweden. European Commission (2006) European SmartGrids Technology Platform:Vision and Strategy for Europe’s Electricity, http://ec.europa.eu/research/energy/pdf/ smartgrids_en.pdf (accessed on 4 August 2011). Department of Energy and Climate Change, UK, Smarter Grids: The Opportunity, December 2009, http://www.decc.gov.uk/assets/decc/what%20we%20do/uk%20 energy%20supply/futureelectricitynetworks/1_20091203163757_e_@@_smartergrid sopportunity.pdf (accessed on 4 August 2011). Electricity Networks Strategy Group, A Smart Grid Routemap, February 2010, http://www.ensg.gov.uk/assets/ensg_routemap_ﬁnal.pdf (accessed on 4 August 2011). Kaplan, S.M., Sissine, F., Abel, A. et al. (2009) Smart Grid: Government Series, The Capitol Net, Virginia. U.S. Department of Energy, Smart Grid System Report, July 2009, http://www.oe.energy.gov/sites/prod/ﬁles/oeprod/DocumentsandMedia/SGSRMain_090707_lowres.pdf (accessed on 4 August 2011). A Compendium of Modern Grid Technologies, July 2009, http://www.netl.doe.gov/ smartgrid/referenceshelf/whitepapers/Compendium_of_Technologies_APPROVED _2009_08_18.pdf (accessed on 4 August 2011). European Commission, ICT for a Low Carbon Economy: Smart Electricity Distribution Networks, July 2009, http://ec.europa.eu/information_society/activities/ P1: TIX/XYZ P2: ABC JWST134-c01 JWST134-Ekanayake January 5, 2012 20:43 Printer Name: Markono The Smart Grid 15 sustainable_growth/docs/sb_publications/pub_smart_edn_web.pdf (accessed on 4 Au- gust 2011) World Economic Forum (2009) Accelerating Smart Grid Investments, http:// www.weforum.org/pdf/SlimCity/SmartGrid2009.pdf (accessed on 4 August 2011). Pudjianto, D., Ramsay, C. and Strbac, G. (2007) Virtual power plant and system in- tegration of distributed energy resources. Renewable Power Generation, IET, 1 (1), 10–16. Gellings, C.W. (2009) The Smart Grid: Enabling Energy Efﬁciency and Demand Response, The Fairmont Press, Lilburn. Galvin, R., Yeager, K. and Stuller, J. (2009) Perfect Power: How the Microgrid Rev- olution Will Unleash Cleaner, Greener, More Abundant Energy, McGraw-Hill, New York. The Integrated Energy and Communication Systems Architecture, 2004, http://www.epri- intelligrid.com/intelligrid/docs/IECSA_VolumeI.pdf (accessed on 4 August 2011). XCel Energy Smart Grid: A White Paper, March 2007, http://smartgridcity.xcelenergy.com/media/pdf/SmartGridWhitePaper.pdf (accessed on 4 August 2011). Southern California Edison Smart Grid Strategy and Roadmap, 2007, http://asset.sce.com/Documents/Environment%20-%20Smart%20Grid/100712_SCE _SmartGridStrategyandRoadmap.pdf (accessed on 4 August 2011). P1: TIX/XYZ P2: ABC JWST134-c02 JWST134-Ekanayake January 5, 2012 21:41 Printer Name: Markono Part I Information and Communication Technologies P1: TIX/XYZ P2: ABC JWST134-c02 JWST134-Ekanayake January 5, 2012 21:41 Printer Name: Markono 2 Data Communication 2.1 Introduction Data communication systems are essential in any modern power system and their importance will only increase as the Smart Grid develops. As a simple example, a data communication system can be used to send status information from an Intelligent Electronic Device (IED) to a workstation (human–machine interface) for display (see Chapter 6). Any co-ordinated control of the power system relies on effective communications linking a large number of devices. Figure 2.1 shows a model of a simple point-to-point data communication system in which the communication channel is the path along which data travels as a signal. As can be seen from Figure 2.1, the communication channel could be a dedicated link between the Source and Destination or could be a shared medium. Using the power system as an example, some possible components of this model and the associated physical devices are listed in Table 2.1. Communication channels are characterised by their maximum data transfer speed, error rate, delay and communication technology used. Communication requirements for commonly used power systems applications are given in Table 2.2. 2.2 Dedicated and shared communication channels Certain applications require the transmission of data from one point to another and other uses may require the transmission of data from one point to multiple points. When a secure communication channel is required from one point to another, a dedicated link is used exclu- sively by the Source and Destination only for their communication. In contrast, when a shared communication channel is used, a message sent by the Source is received by all the devices connected to the

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