Handbook of Power Quality

Edited by

Angelo Baggini University of Bergamo, Italy

John Wiley &. Sons, Ltd

Contents

List of Contributors xix

Preface xxiii

1 Frequency Variations 1 Hermina Albert, Nicolae Golovanov, Aleksander Kot and Janusz Bro'zek

1.1 Frequency Quality Indices 3 1.2 Frequency Measuring 4 1.3 Load-Frequency Characteristics 6

1.3.1 Influence of the Frequency Variation on the Actuation Motors 6 1.3.2 Capacitor Bank and Harmonie Filters 7 1.3.3 Transformers and Coils in the Power Network 7

1.4 Influence of Frequency on Users' Equipment 8 1.4.1 Influence of Frequency Variations on Asynchronous Motors 8 1.4.2 Influence of Frequency Variations on Parallel-Connected

Condensers and Coils 11 1.4.3 Influence of Frequency Variations on Series-Connected

Condensers and Coils 12 1.5 Governing of Turbine Speed 12 1.6 Frequency Control in Power Systems 16

1.6.1 Composite Load 17 1.6.2 The Generation Characteristic 19 1.6.3 The System Properties and Control Basics 20 1.6.4 Frequency Control in an Islanding System and

in Interconnected Systems 22 1.6.5 Frequency Control: Primary, Secondary and Tertiary 23 1.6.6 Technical and Organizational Aspects of

Load-Frequency Control 28 Bibliography 29

CONTENTS

Continuity of Supply 31 Krish Gomatom and Tom Short

2.1 Distribution Reliability 31 2.1.1 Customer-Based Indices 32 2.1.2 Load-Based Indices 34 2.1.3 Variation in the Utility Indices 35

2.2 Quality of Supply 36 2.2.1 Customer Service 36 2.2.2 Continuity of Supply 37 2.2.3 Voltage Quality 37

2.3 Factors Affecting Reliability Performance 40 2.3.1 Reliability Indices Reporting 41 2.3.2 Differences Based on Type of Supply 42

2.4 Improving Reliability 44 2.4.1 Utility-Side Improvement Options 44 2.4.2 Custom Power Devices 46

2.5 Costs, Markets and Value for Reliability 49 2.5.1 Size of the End-User Load and Duration Affect Cost 49 2.5.2 Market for Reliability 50 2.5.3 Value of Reliability: a Macro View 51 2.5.4 Impact of Reliability Events on End-User Productivity 53 2.5.5 Mapping Reliability to End-User Facility Operating Hours 54

Bibliography 57

Voltage Control in Distribution Systems 59 Andrzej Kanicki \

3.1 Description of the Phenomena 60 3.2 Disturbance Sources 61 3.3 Disturbance Effects 62

3.3.1 Load Models 62 3.3.2 Voltage Drop 63 3.3.3 Voltage Stability 64

3.4 Methods of Effect Elimination 68 3.4.1 Generator Excitation Control 68 3.4.2 Transformer Ratio Control 70 3.4.3 Voltage Control by Means of Reactive Power Flow Change 72 3.4.4 Voltage Control by Means of Network Impedance Change 74 3.4.5 Node Voltage Optimization 76

3.5 Standards 76 3.5.1 Voltage Standards in Grid Normal Operating Conditions 76 3.5.2 Voltage Standards in Grid Disturbed Operating Conditions 76

CONTENTS

3.5.3 Voltage Standards in Middle- and Low-Voltage Distribution Networks 77

Bibliography 77

4 Voltage Dips and Short Supply Interruptions 79 Zbigniew Hanzelka

4.1 Description of the Phenomena 79 4.2 Parameters 82

4.2.1 Voltage Dip Duration 82 4.2.2 Magnitude of a Voltage Dip 83

4.3 Sources 87 4.3.1 Sources of Voltage Dips 87 4.3.2 Sources of Short Supply Interruptions 89

4.4 Effects 89 4.4.1 IT Equipment and Control Systems 90 4.4.2 Contactors and Relays 92 4.4.3 Induction Motors 92 4.4.4 Syncfhronous Motors 93 4.4.5 Variable Speed Drives 93 4.4.6 High-Pressure Discharge Lamps 94

4.5 Mitigation 94 4.5.1 Reduction of the Number of Faults 95 4.5.2 Reduction of the Fault Clearance Time 95 4.5.3 Modification of the Supply System Configuration 96 4.5.4 Voltage Stabilizers 97 4.5.5 Improvement in Equipment Immunity 98

4.6 Measurement 100 4.6.1 Principles of Measurement 100 4.6.2 Statistical Methods of Analysis 112 4.6.3 Area of Vulnerability 114

4.7 Contract 114 4.7.1 Duration of Measurements 116 4.7.2 Reference Voltage Value 116 4.7.3 Location and Method of Connection of Measuring Instrument 117 4.7.4 Technical Specifications for Measuring Instrumentation 118 4.7.5 Threshold Values for Disturbance Detection 118 4.7.6 Techniques of Reporting the Measurement Results 119 4.7.7 Methods for Aggregation of Measurement Results 119

4.8 Standards 124 4.9 Alternative Voltage Dip Indices 126

4.9.1 Indices Based on the Voltage Change 126 4.9.2 Energy-Related Indices 127 4.9.3 Others 129

CONTE

Acknowledgement 131 Bibliography 131

Voltage Fluctuations and Flicker 135 Araceli Hernändez Bayo

5.1 Description of the Phenomenon 135 5.1.1 Voltage Changes, Voltage Fluctuations and Flicker 135 5.1.2 Physiology of Flicker Perception 137

5.2 Parameters 138 5.3 Measurement 139

5.3.1 The IEC Flickermeter 139 5.3.2 Use of the Flickermeter 146 5.3.3 Simplified Methods for Pst Assessment 148

5.4 Sources 151 5.4.1 Industrial Loads 152 5.4.2 Electrical Appliances Supplied from LV Networks 155 5.4.3 Wind Turbine Generation Systems 155

5.5 Effects 156 5.6 Mitigation Strategies 156

5.6.1 Devices Based on Decreasing Reactive Power Variations 157 5.6.2 Methods Oriented to Increase the Short-Circuit Power 160 5.6.3 Other Solutions for Flicker Mitigation 161

Bibliography 161

Voltage and Current Unbalance 163 Irena Wasiak /

6.1 Description of the Phenomena 163 6.2 Symmetrical Components of Currents and Voltages 165 6.3 Parameters 170 6.4 Measurements 171 6.5 Sources 173 6.6 Effects 174

6.6.1 Asynchronous Motors 174 6.6.2 Synchronous Generators 174 6.6.3 Converters 175 6.6.4 Other Loads 175

6.7 Mitigation 175 6.7.1 Principle of Balancing 176 6.7.2 Static Compensators 178

6.8 Standards 181 6.8.1 Limits 181 6.8.2 Principles of Assessment 183

Bibliography 184

CONTENTS

7 Voltage and Current Harmonics 187 Angelo Baggini and Zbigniew Hanzelka

7.1 Description of the Phenomena 187 188 189 190 190

192 194 195 200 200 202 202 204 204

208 209 213 214

217 218 221 223 226 227 228 229 230 232 234 236 236 236 237

Load and Harmonie Source 252 7.7.4 Reduction of Load Sensitivity to

Disturbances 252 7.8 Standards 257 Bibliography 259

7.2 7.3 7.4

7.5 7.6

7.7

7.1.1 7.1.2 7.1.3 7.1.4 7.1.5

Composition of Distorted Waveform Decomposition of Distorted Waveform Harmonics and Symmetrical Components Classification of Distortion Components Quantities Describing Voltage and Current Distortion

Parameters Measurements Sources of Current Harmonics 7.4.1 7.4.2 7.4.3 7.4.4 7.4.5 7.4.6

Transformers Motors and Generators Are Furnaces Fluorescent Lighting Electronic and Power Electronic Equipment Harmonie Current Values/Magnitudes for Selected Loads

Voltage and Current Harmonics Effects 7.6.1 7.6.2

7.6.3 7.6.4 7.6.5 7.6.6 7.6.7 7.6.8 7.6.9 7.6.10 7.6.11 7.6.12 7.6.13 Mitigat 7.7.1 7.7.2 7.7.3

Power Factor Overheatingi of Phase and Neutral Conductors Skin Effect Motors and Generators Transformers Capacitors Light Sources Nuisance Tripping of Circuit-Breakers Earth-Fault Currents Converters and Electronic Equipment Measuring Instruments Relay and Contactor Protective Systems Telecommunications Interference

ion Methods of Voltage Distortion Reduction Reduction of Harmonie Emission Reduction of the Coupling Between Sensitiv

CONTENTS

Overvoltages 263 Franco Bua, Francesco Buratti and Alan Ascolari

8.1 Description of the Phenomena 264 8.1.1 Continuous (Power Frequency) Voltage 264 8.1.2 Temporary Overvoltage 264 8.1.3 Transient Overvoltage 265 8.1.4 Combined Overvoltage 265 8.1.5 Overvoltage Propagation 267

8.2 Parameters 268 8.2.1 Lightning Impulse Protective Level of a Surge Arrester 269 8.2.2 Switching Impulse Protective Level of a Surge Arrester 270

8.3 Sources 270 8.3.1 Internal Overvoltages 270 8.3.2 External Overvoltages 283

8.4 Effects 285 8.4.1 Breakdown Consequences 285 8.4.2 Reduction of Overvoltage Risk and Level 286

8.5 Mitigation 287 8.5.1 Principles of Protection 287 8.5.2 Insulation Coordination 287 8.5.3 Overvoltage Protective Devices 291

8.6 Standards v 296 8.6.1 Insulation Coordination 296

Bibliography 298

Analysis of Waveforms in Modern Power Systems 299 Johan Rens and Piet Swart

9.1 Frequency Analysis of Non-Sinusoidal Waveforms: Practical Considerations 300

9.2 Analog-to-Digital Conversion 300 9.2.1 Signal-to-Noise Ratio 300 9.2.2 Spectral Leakage and Aliasing 301 9.2.3 Spectral Leakage and Windowing 301 9.2.4 Metrological Features of Measurement System 302 9.2.5 Harmonie Power Measurement in

Non-simultaneous Sampling 302 9.3 Sequence Component Analysis 307

9.3.1 Fortesque Transform Redefined for Non-sinusoidal Circuits 307 9.3.2 Three-Wire Power System Analysis 309 9.3.3 Four-Wire Power System Analysis 316

9.4 EEEE 1459: Power Defmitions for Modern Power Systems 321 9.4.1 Voltage and Current Quantities under Non-sinusoidal

Unbalanced Conditions 321 9.4.2 Apparent Power Defmitions 324

CONTENTS

9.4.3 Arithmetic Apparent Power 324 9.4.4 The Vector Apparent Power 324 9.4.5 The Effective Apparent Power 325 9.4.6 Harmonie Pollution and Unbalance 326 9.4.7 Fundamental Frequency Active and Reactive Power 327 9.4.8 Power Factor Definitions 327

9.5 Localization of Sources of Waveform Distortion in a Modern Power System 328

Bibliography 329

10 Earthing 331 Franco Bua, Francesco Buratti and Antoni Klajn

10.1 Typical Earthing System 331 10.2 Electric Resistivity of Soil 332 10.3 Electrical Properties of the Earth Electrodes 335

10.3.1 Resistance and Impedance to Earth 335 10.3.2 Voltage-to-Earth and Surface Potential Distribution 339 10.3.3 Properties of Earth Electrodes at Lightning Currents 340

10.4 Typical Earth-Electrode Constructions 342 10.4.1 Simple Horizontal Earth Electrodes 343 10.4.2 Simple Rod, Vertical Earth Electrodes 346 10.4.3 Simple, Combined Earth Electrodes 349 10.4.4 Meshed Earth Electrodes 350 10.4.5 Foundation Earth Electrodes 352 10.4.6 Cable with Earthing Effect 354

10.5 Earthing Arrangements in Protection Against Electric Shock 355 10.5.1 Earthing Arrangements as Protection Elements

in LV Networks 357 10.5.2 Earthing Arrangements as Protection Elements

in HV Networks 358 10.6 Role of Earthing in Electronic and Telecommunication Systems 361

10.6.1 Protective and Functional Earthing 362 10.6.2 Combined Earthing System 362 10.6.3 Safety Aspects 363 10.6.4 Functionality Aspects 366 10.6.5 Disturbances and Coupling Mechanisms 367 10.6.6 Low-Noise Equipotential Bonding 369

10.7 Lifetime Aspects of the Earthing Arrangements 370 10.7.1 Chemical Corrosion 370 10.7.2 Corrosion Caused by Stray (Direct) Currents 372 10.7.3 Galvanic (Electrochemical) Corrosion 373

10.8 Measurements of Earthing Arrangements 375 10.8.1 Measurement of Soil Resistivity 376 10.8.2 Measurement of Resistance to Earth of an Earth Electrode 377

Bibliography 380

11 Reliability of Electricity Supply: Structure Angelo Baggini, David Chapman and Francesco Buratti

383

11.1 Basic Schemes of Electrical Grids 384 11.1.1 Simple Radial System 384 11.1.2 RingScheme 385 11.1.3 Double Radial Scheme 387 11.1.4 Meshed Scheme 388 11.1.5 Compound Scheme 388

11.2 General Criteria for the Study and Choice of the Schemes 389 11.2.1 Parameters and Basic Conditions 389 11.2.2 Scheme of the Grid as a Link Between

Supplies and Loads 389 11.2.3 Characteristics of the Installation 390 11.2.4 The System Supply Section and End Section 400 11.2.5 The Standard and Preferential Functions 400

Bibliography 401

12 Reliability of Electricity Supply: Appliances and Equipment 403 Roberto Villafäfila-Robles and Joan Bergas-Jane

404 405 406 407 410 411 413 414 415 416 417 420 421 425 425 425 426 427 429 429 429 432 433

12.1 12.2 12.3

12.4

12.5

12.6

Power Quality, Reliability and Availability General Aspects of Reliability Appliances Power System Protection Alternatives 12.3.1 Power Conditioners Emergency and Standby Power Systems 12.4.1 12.4.2 12.4.3 12.4.4 12.4.5 12.4.6 12.4.7 12.4.8

Engine-Driven Generators Microturbine-Driven Generators Uninterruptible Power Systems Dynamic UPS Static UPS Hybrid Static/Dynamic UPS D.C. Power Supply Systems Technological Comparison

Dynamic UPS Systems 12.5.1 12.5.2 12.5.3 12.5.4 12.5.5

Modern Flywheels Components Classification Application Future Developments and Applications

Static UPS System 12.6.1 12.6.2 12.6.3

Components Classification UPS Technology

CONTENTS

12.6.4 Application 438 12.6.5 Future Developments and Applications 440

12.7 Good Engineering Practice 442 Bibliography 443

13 Monitoring Power Quality 445 Andreas Sumper and Samuel Galceran-Arellano

13.1 Monitoring Objectives 445 13.1.1 Benefits of Power Quality Monitoring 446

13.2 Measurement Issues 447 13.2.1 Measurement Chain 447 13.2.2 R.M.S. Measurement 448 13.2.3 Transients Measurement 448 13.2.4 Sampling Rate 449 13.2.5 Bandwidth Amplitude/Frequency 449 13.2.6 Accuracy 449 13.2.7 Precision 449 13.2.8 Resolution 450 13.2.9 Measurement Aggregation Algorithm 450

13.3 Selection of Monitoring Instruments 451 13.3.1 General Features of Monitoring Instruments 452 13.3.2 Signal Input/Output 453 13.3.3 Functions 454

13.4 Successful Power Quality Monitoring 454 13.4.1 Power Quality Program 454 13.4.2 Managing Monitoring Projects 456 13.4.3 Immunization Program 458

13.5 Postprocessing Monitoring Results 460 13.5.1 Interpreting Monitoring Results 460 13.5.2 Data Collection and Monitoring Systems 460 13.5.3 Software and Data Analysis Tools 460 13.5.4 Power Quality Data Interchange Format (PQDIF) 461

Bibliography 461

14 Static Converters and Power Quality 463 Mircea Chindris and Antoni Sudriä-Andreu

14.1 Impact of Static Converters on the Supply Network 464 14.1.1 Industrial Equipment 464 14.1.2 Control and Informatics Equipment 469 14.1.3 Solutions 470 14.1.4 Electromagnetic Compatibility Issues 477 14.1.5 Impact on Loads Supplied by Power Converters 481

14.2 Impact of Supply Network Disturbances on Static Converters 487 14.2.1 Impact of Voltage Disturbances on Static Converters 487 14.2.2 Voltage Sag Susceptibility 490 14.2.3 Immunization Techniques 490

Bibliography 494

15 Compensation of Reactive Power 499 Stefan Fassbinder and Alan Ascolari

15.1 Basics 500 15.1.1 Characteristics of Inductances and Capacitances 500 15.1.2 Reactive Power 502 15.1.3 Wattless current 503 15.1.4 Reactive Power Compensator 505

15.2 Power Factor Correction 506 15.2.1 Control and Regulation of Reactive Power 506 15.2.2 Centrally and Dispersed Compensation 508 15.2.3 Detuning 510

15.3 Passive Filters 513 15.3.1 Dedicated Filtenng Circuits for Individual Frequencies 514 15.3.2 Central and Dispersed Solution 515 15.3.3 L/C Ratio 516 15.3.4 Sound Frequency Signals 518

Bibliography 519

16 Distributed Generation and Power Quality 521 Vu Van Thong and Johan Driesen

16.1 Distribution Network Modeling 522 16.1.1 Steady-State Modeling 522 16.1.2 Dynamic Modeling 523

16.2 Power Quality and DG 524 16.2.1 Voltage Rise 524 16.2.2 Voltage Dips 524 16.2.3 Voltage Fluctuations and Flicker 524 16.2.4 Harmonics 525 16.2.5 Unbalance 526 16.2.6 Direct Current 526

Bibliography 526

17 Electricity Market 529 Pieter Vermeyen and Johan Driesen

17.1 Market Players 529 17.1.1 Electricity Producers 530 17.1.2 Grid Operators 530

CONTENTS

17.1.3 Electricity Retailers 531 17.1.4 Regulators 531

17.2 Contract Types 531 17.2.1 Residential Customers 532 17.2.2 Small Businesses 532 17.2.3 Small and Medium-Sized Companies 533 17.2.4 Large Companies 533

17.3 Load Management in the Electricity Market 534 17.3.1 Reason for Load Management 534 17.3.2 Multiple Electricity Tariff 535 17.3.3 Real-Time Pricing 535 17.3.4 Contracts for Reducing Consumption 536 17.3.5 Intelligent Energy Meter 536 17.3.6 Other Techniques 537

17.4 Power Quality in the Electricity Market 537 17.4.1 Power Quality Contracts 538 17.4.2 Power Quality Market 542

Bibliography 543

18 Cost of Poor Power Quality 545 Roman Targosz and Jonathan Manson

18.1 Exploring PQ Cost 547 18.1.1 StaffCost 547 18.1.2 Work in Progress 547 18.1.3 Equipment Malfunctioning 548 18.1.4 Equipment Damage 548 18.1.5 Other Costs 548 18.1.6 Specific Costs 548 18.1.7 Savings 549

18.2 Studies on Cost of Poor PQ 549 18.3 Long Interruptions 552 18.4 Short Interruptions 556 18.5 Voltage Dips 556 18.6 Harmonics 558 18.7 Other Disturbances 559 18.8 Profiles by Sector 561 18.9 Cost Per Event of PQ Disturbances 570 18.10 PQ Solutions 574 18.11 nvestment Analysis to Mitigate Costs of PQ 582

8.11.1 Investment Analysis 582 8.11.2 Capital Budgeting 583 8.11.3 Project Classifications 583 8.11.4 Cost of Capital 584 8.11.5 The Time Value of Money 584 8.11.6 Future Value of a Single Cash Flow 585

18.11.7 Present Value of a Single Cash Flow and of a Cash Flow Stream 586

18.11.8 Deterministic Approach to PQ Investment Analysis 586 18.11.9 Discounted Cash Flow Methods 587 18.11.10 Non Discounted Cash Flow Methods 590 18.11.11 Break-even Analysis 591

Bibliography 592

19 Power Quality and Rational Use of Energy 593 Pieter Vermeyen and Johan Driesen

19.1 Reasons for Rational Use of Energy 594 19.1.1 Sustainable Development 594 19.1.2 Economic Considerations 594 19.1.3 Electricity Industry 595

19.2 Techniques for Rational use of Energy 595 19.2.1 Adapted Use of Electrical Systems 595 19.2.2 Efficient Loads 596 19.2.3 Variable Tariffs 598

19.3 Impact on Power Quality 598 19.3.1 Emission of Harmonie Distortion by Fluorescent Lamps 598 19.3.2 Emission of Harmonie Distortion by VSDs 601 19.3.3 Immunity of Fluorescent Lamps 603 19.3.4 Immunity of VSDs 603

Bibliography 605

20 Perceived Power Quality 607 Maurizio Caciotta

20.1 Customer Definition 607 20.2 Customer Requirements 608 20.3 Analysis Process of the Customer with Respect to the

Requirements Concerning the Product 608 20.4 Multiplicity of Goods: Active Categories in the Territory

of Rome 609 Bibliography 611

Index 613

Case Studies and Annexes Accessible on the Companion Website

Annex 1 Angelo Baggini and Alan Ascolari

CONTENTS

Annex 2 Angelo Baggini and Zbigniew Hanzelka

Annex 3 Power Theory with Non-sinusoidal Waveforms Andrzej Firlit

Annex 4 Series and Parallel Resonance Zbigniew Hanzelka