Electric Power Systems

The creation of a European liberalized electricity internal market and EU commitments for the reduction of greenhouse gas emissions (Kyoto Protocol) and for the use of renewable energy generation technologies induce new important constraints and problems on the electric power systems in Europe. This then creates the need for more research and development to engage with these new challenges in order to preserve the reliability of these systems. This book aims to provide advanced tools, covering major aspects, for people involved with such research and development. Split into two parts (the first covering the operation and control of electric power systems and the second the stability and defence of electric power systems), this book gathers together contributions from numerous well-known European specialists in academia and the electrical industry and will be an illuminating read for those involved in this field or who have some knowledge of the fundamental notions.

Table of Contents:
Preface 1 Chapter 1. General Aspects of the Control, Regulation and Security of the Energy Network in Alternating Current 5 Noël JANSSENS and Jacques TRECAT 1.1. Introduction 5 1.1.1. History 5 1.1.2. Network architecture 6 1.2. Power flow calculation and state estimation 7 1.2.1. Introduction 7 1.2.2. Modeling the components of the network 7 1.2.3. Power flow calculation 9 1.2.4. State estimation 11 1.3. Planning and operation criteria 13 1.3.1. Introduction 13 1.3.2. Power generation units 14 1.3.3. Transmission network 15 1.3.4. Electrical power distribution system 17 1.4. Frequency and power adjustments 18 1.4.1. Objectives and classification of the adjustments 18 1.4.2. Primary regulation 20 1.4.3. Secondary regulation 22 1.4.4. Tertiary regulation 23 1.4.5. Generating unit schedule 24 1.4.6. Load management 25 1.5. Voltage regulation 25 1.5.1. Case of short lines 26 1.5.2. Case of the line with capacity 28 1.5.3. Traditional methods of reactive energy compensation and voltage regulation 31 1.6. Bibliography 35 Chapter 2. Evolution of European Electric Power Systems in the Face of New Constraints: Impact of Decentralized Generation 37 Michel CRAPPE 2.1. Introduction: a new paradigm 37 2.2. Structure of modern electric transmission and distribution networks 38 2.2.1. Modern transmission networks 38 2.2.2. Electrical distribution networks 42 2.3. Recent development in the European networks and new constraints 43 2.3.1. Deregulation of the electricity market in accordance with European directives 44 2.3.2. Reducing greenhouse gas emissions in the generation of electrical energy 45 2.3.3. Generation of electricity using renewable energy sources 46 2.3.4. Energy dependency of the European Union 46 2.4. The specific characteristics of electrical energy 47 2.4.1. Storage and production/consumption balance 48 2.4.2. Laws of physics on flow of energy 49 2.4.3. Strategic role of electrical energy 51 2.4.4. Voltage regulation in the electrical transmission and distribution networks 51 2.4.5. Ancillary services 52 2.5. Decentralized power generation 52 2.5.1. Definition 52 2.5.2. Decentralized power generation techniques in Europe, potential and costs 54 2.5.3. Decentralized power generation and CO2 emissions, indirect emissions from so-called “zero emission” power plants 72 2.5.4. Decentralized production and ancillary services 74 2.6. Specific problems in integrating decentralized production in the networks 78 2.6.1. Connection conditions 78 2.6.2. Influence on the design of the HV/MV stations 79 2.6.3. Influence on the protection of the distribution networks 80 2.6.4. Stability problems 82 2.6.5. Influence on the voltage plan 83 2.6.6. Impacts on transmission networks 85 2.6.7. Harmonic disturbances 86 2.7. New requirements in research and development 86 2.7.1. Technical domain 87 2.7.2. Economics 91 2.8. Conclusion: a challenge and an opportunity for development for the electrical sector 92 2.9. Bibliography 92 Chapter 3. Planning Methods for Generation and Transmission of Electrical Energy 95 Jean-Marie DELINCÉ 3.1. Introduction 95 3.1.1. Generation functions 96 3.1.2. Functions of a transmission network 96 3.2. Planning in integrated systems and in a regulated market 97 3.2.1. Generation planning 98 3.2.2. Transmission network planning 103 3.3. Generation planning in a deregulated market 111 3.4. Establishing a development plan of the transmission network 114 3.4.1. Reasons for investment 114 3.4.2. Constraints and uncertainties 115 3.4.3. Planning criteria 118 3.4.4. Elaboration of the development plan 121 3.5. Final observations 125 3.6. Bibliography 125 Chapter 4. Power Quality 127 Alain ROBERT 4.1. Introduction 127 4.1.1. Disturbances and power quality 127 4.1.2. Quality of electricity supply and electromagnetic compatibility (EMC) 128 4.2. Degradation of the voltage quality – disturbance phenomena 130 4.2.1. Frequency variations 130 4.2.2. Slow component of voltage variations 131 4.2.3. Voltage fluctuations – flicker 131 4.2.4. Voltage dips 131 4.2.5. Transients 132 4.2.6. Harmonics and interharmonics 134 4.2.7. Unbalance 135 4.2.8. Overall view of the disturbance phenomena 135 4.3. Basic concepts of standardization 136 4.4. Quality indices 139 4.4.1. Voltage continuity 139 4.4.2. Voltage quality 143 4.5. Evaluation of quality 146 4.5.1. Voltage continuity 146 4.5.2. Voltage quality 147 4.6. Connection of the disturbance facilities 148 4.6.1. Definition of the emission level of a disturbance facility 148 4.6.2. Concept of short circuit power 149 4.6.3. Determining the emission limits of a disturbance facility 151 4.6.4. Verification of the emission limits after commissioning 153 4.7. Controlling power quality 154 4.7.1. Voltage continuity 154 4.7.2. Voltage quality 156 4.8. Quality in a competitive market – role of the regulators 156 4.9. Bibliography 158 Chapter 5. Applications of Synchronized Phasor Measurements to Large Interconnected Electric Power Systems 161 Nouredine HADJSAID, Didier GEORGES and Aaron F. SNYDER 5.1. Introduction 161 5.2. Synchronized measurements 162 5.3. Applications of synchronized measurements 164 5.3.1. State estimation 164 5.3.2. Network supervision 165 5.3.3. Power system protection 166 5.3.4. Power system control 166 5.4. Application of synchronized measurements to damp power oscillations167 5.4.1. Power oscillations 167 5.4.2. Theory of PSS controllers 171 5.4.3. Controller tuning by residue compensation 172 5.4.4. Results 176 5.5. Conclusion 179 5.6. Bibliography 179 5.7. Appendices 182 Chapter 6. Voltage Instability 185 Thierry VAN CUTSEM 6.1. Introduction 185 6.2. Voltage instability phenomena 187 6.2.1. Maximum deliverable power for a load 187 6.2.2. PV and QV curves 188 6.2.3. Long-term voltage instability illustrated through a simple example 189 6.2.4. Load restoration 194 6.2.5. Classification of instabilities 196 6.3. Countermeasures for voltage instability 199 6.3.1. Compensation 199 6.3.2. Automatic devices and regulators 199 6.3.3. Operation planning 201 6.3.4. Real time 201 6.3.5. System protection schemes 201 6.4. Analysis methods of voltage stability and security 204 6.4.1. Contingency analysis 204 6.4.2. Determination of loadability limits 208 6.4.3. Determination of secure operation limits 210 6.4.4. Preventive control 213 6.5. Conclusion 214 6.6. Bibliography 215 Chapter 7. Transient Stability: Assessment and Control 219 Daniel RUIZ-VEGA and Mania PAVELLA 7.1. Introduction 219 7.2. Transient stability 220 7.2.1. Problem statement 220 7.2.2. Operating procedures 221 7.2.3. Deregulation of the electricity sector 223 7.3. Transient stability assessment methods: brief history 224 7.3.1. Conventional time domain approach: strengths and weaknesses 224 7.3.2. Direct approaches: a brief history 226 7.3.3. Note on automatic learning approaches 228 7.4. The SIME method 229 7.4.1. Origins 229 7.4.2. Formulation 230 7.4.3. Preventive SIME vs emergency SIME 235 7.5. Different descriptions of transient stability phenomena 236 7.6. The preventive SIME method 240 7.6.1. Stability limits 241 7.6.2. FILTRA: generic software for contingency filtering 243 7.6.3. Stabilization of contingencies (“control”) 245 7.6.4. Transient stability assessment and control: integrated software and example of application 247 7.6.5. Current status of the preventive SIME 252 7.7. Emergency SIME method 252 7.7.1. Aims 252 7.7.2. Origins 253 7.7.3. Estimation of time taken by the different tasks 256 7.7.4. Illustration 256 7.7.5. Note on corrective control in open loop 258 7.7.6. Conclusion 259 7.8. Bibliography 260 Chapter 8. Security of Large Electric Power Systems – Defense Plans – Numerical Simulation of Electromechanical Transients 263 Marc STUBBE and Jacques DEUSE 8.1. Introduction 263 8.2. Degradation mechanisms of network operation 264 8.2.1. The system 264 8.2.2. Continuity of supply 267 8.2.3. Degradation mechanisms 270 8.2.4. Unfavorable factors causing spread of the incident 275 8.3. Defense action and the notion of a defense plan 277 8.3.1. Frequency instability 277 8.3.2. Voltage instability 280 8.3.3. Loss of synchronism 281 8.3.4. Cascade tripping 281 8.3.5. Notion of defense plan 282 8.4. The extended electromechanical model 282 8.4.1. Definition, validity domain 282 8.4.2. Numerical simulation 284 8.4.3. Mathematic properties 285 8.4.4. Algorithmic properties 285 8.5. Examples of defense action study 292 8.5.1. Methodological considerations 292 8.5.2. Load shedding due to voltage criteria [DEU 97] 293 8.5.3. Islanding plan in case of loss of synchronism 304 8.5.4. Industrial networks 306 8.6. Future prospects 310 8.6.1. Evolution of simulation tools 313 8.6.2. Real-time curative action 313 8.6.3. Load actions 314 8.6.4. Decentralized production 315 8.7. Bibliography 315 Chapter 9. System Control by Power Electronics or Flexible Alternating Current Transmission Systems 317 Michel CRAPPE and Stéphanie DUPUIS 9.1. Introduction: direct current links and FACTS 317 9.2. General concepts of power transfer control 319 9.2.1. Introduction 319 9.2.2. Power transmission through reactance 320 9.2.3. Modification of reactance in link X 322 9.2.4. Modification of voltage and the segmentation method 324 9.2.5. Modification of the transmission angle 325 9.2.6. Comparison of three methods in a simple case 325 9.3. Control of power transits in the networks 326 9.3.1. Circulation of power in a meshed network: power loop concept 326 9.3.2. Modification of transits on parallel lines of a corridor 329 9.4. Classification of control systems according to the connection mode in the network 330 9.4.1. Series type controller 330 9.4.2. Parallel or shunt type controller 331 9.4.3. Compensators of series-series and series-shunt types 332 9.5. Improvement of alternator transient stability 333 9.5.1. Introduction to transient stability 333 9.5.2. Simplified study of transient stability by area criterion 334 9.5.3. Study of an application case 337 9.5.4. Improvement of transient stability by ideal shunt compensation 339 9.5.5. SVC type shunt compensator 341 9.5.6. Shunt compensation with SVG (static var generator) compensator 343 9.5.7. Series type compensation by modification of link reactance 344 9.5.8. Series type compensation by modification of the transmission angle 345 9.6. Damping of oscillations 346 9.7. Maintaining the voltage plan 346 9.8. Classification and existing applications of FACTS 347 9.8.1. Classic systems with thyristors 347 9.8.2. Systems with fully controllable elements 353 9.8.3. Glossary 359 9.9. Control and protection of FACTS 360 9.10. Modeling and numerical simulation 362 9.10.1. UPFC modeled by two voltage sources 362 9.10.2. UPFC modeled by a series voltage source and a shunt current source 363 9.10.3. UPFC modeled by two current sources 364 9.10.4. UPFC modeled by two power injections 365 9.10.5. Internal models of the UPFC 366 9.11. Future prospects 367 9.12. Bibliography 368 List of authors 371 Index 373

About the Author :
Michel Crappe (1936) received the degrees in Civil Minning Engineering and Civil Electrical Engineering in 1959 and 1962 respectively, from the Faculté Polytechnique de Mons (Belgium). He joined the Faculté Polytechnique de Mons in 1963, where he has been from 1971 to 2001 full professor in charge of the Electrical Machine Department. He is currently emeritus professor. Editor of 3 books on electric power systems, author or co-author of over 100 journal and conference papers and chapters in 6 books, in the areas of large electrical machine, system identification concepts, electric power system dynamic behaviour, FACTS and electrical energy distributed generation. Member of several Scientific Committees and Editorial Boards. From 1985 to 2000, chairman of the Scientific Committee of the Royal Belgian Electrical Engineering Society (SRBE). Elected in November 2003 associate member of the Royal Belgian Academy Council of Applied Science. Member of SRBE, SEE (Emerite), EPE. Recipient of the 1998 PES Prize Paper Award of IEEE.