Dynamics and Control of Electric Transmission and Microgrids
1st Edition
Published on 15. February 2019
Book
Hardback
504 pages
978-1-119-17338-0 (ISBN)
Description
A guide to the latest developments in grid dynamics and control and highlights the role of transmission and distribution grids
Dynamics and Control of Electric Transmission and Microgrids offers a concise and comprehensive review of the most recent developments and research in grid dynamics and control. In addition, the authors present a new style of presentation that highlights the role of transmission and distribution grids that ensure the reliability and quality of electric power supply.
The authors - noted experts in the field - offer an introduction to the topic and explore the basic characteristics and operations of the grid. The text also reviews a wealth of vital topics such as FACTS and HVDC Converter controllers, the stability and security issues of the bulk power system, loads which can be viewed as negative generation, the power limits and energy availability when distributed storage is used and much more. This important resource:
Puts the focus on the role of transmission and distribution grids that ensure the reliability and quality of electric power supply
Includes modeling and control of wind and solar energy generation for secure energy transfer
Presents timely coverage of on-line detection of loss of synchronism, wide area measurements and applications, wide-area feedback control systems for power swing damping and microgrids-operation and control
Written for students of power system dynamics and control/electrical power industry professionals, Dynamics and Control of Electric Transmission and Microgrids is a comprehensive guide to the recent developments in grid dynamics and control and highlights the role of transmission and distribution grids that ensure the reliability and quality of electric power supply.
Dynamics and Control of Electric Transmission and Microgrids offers a concise and comprehensive review of the most recent developments and research in grid dynamics and control. In addition, the authors present a new style of presentation that highlights the role of transmission and distribution grids that ensure the reliability and quality of electric power supply.
The authors - noted experts in the field - offer an introduction to the topic and explore the basic characteristics and operations of the grid. The text also reviews a wealth of vital topics such as FACTS and HVDC Converter controllers, the stability and security issues of the bulk power system, loads which can be viewed as negative generation, the power limits and energy availability when distributed storage is used and much more. This important resource:
Puts the focus on the role of transmission and distribution grids that ensure the reliability and quality of electric power supply
Includes modeling and control of wind and solar energy generation for secure energy transfer
Presents timely coverage of on-line detection of loss of synchronism, wide area measurements and applications, wide-area feedback control systems for power swing damping and microgrids-operation and control
Written for students of power system dynamics and control/electrical power industry professionals, Dynamics and Control of Electric Transmission and Microgrids is a comprehensive guide to the recent developments in grid dynamics and control and highlights the role of transmission and distribution grids that ensure the reliability and quality of electric power supply.
Reviews / Votes
This textbook is one of the first on Power System Dynamics, Control and Stability to integrate in a straightforward and illustrative way the recently introduced modern power system components, such as Renewable Energy Sources (RES), converter interfaced generating sources, FACTS, energy storage devices, and wide area measurement systems (WAMS), in the same, common and well defined framework with the more conventional component, such as Synchronous Generators. - C. Vournas, NTUA, Athens, GreeceMore details
Series
Language
English
Place of publication
United States
Publishing group
John Wiley & Sons Inc
Target group
Professional and scholarly
Product notice
sewn/stitched
Cloth over boards
Dimensions
Height: 244 mm
Width: 175 mm
Thickness: 30 mm
Weight
885 gr
ISBN-13
978-1-119-17338-0 (9781119173380)
Copyright in bibliographic data and cover images is held by Nielsen Book Services Limited or by the publishers or by their respective licensors: all rights reserved.
Schweitzer Classification
Other editions
Additional editions
K. R. Padiyar | Anil M. Kulkarni
Dynamics and Control of Electric Transmission and Microgrids
E-Book
12/2018
1st Edition
Wiley
€84.99
Available for download
K. R. Padiyar | Anil M. Kulkarni
Dynamics and Control of Electric Transmission and Microgrids
E-Book
12/2018
1st Edition
Wiley
€84.99
Available for download
Persons
K. R. PADIYAR is Professor Emeritus, Indian Institute of Science, Bangalore, India.
ANIL M. KULKARNI is Professor of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai, India.
ANIL M. KULKARNI is Professor of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai, India.
Content
Preface xiii
Acknowledgements xv
1 Introduction 1
1.1 Present Status of Grid Operation 1
1.1.1 General 1
1.1.2 HVDC Transmission 4
1.1.3 Reliability of Electricity Supply 4
1.2 Overview of System Dynamics and Control 4
1.2.1 Power System Stability 4
1.2.2 Mathematical Preliminaries 6
Stability of Equilibrium Point 6
Steady-State Behavior 8
1.2.3 Power System Security 8
1.3 Monitoring and Enhancing System Security 10
1.4 Emergency Control and System Protection 11
1.5 Recent Developments 12
1.5.1 Power System Protection 12
1.5.2 Development of Smart Grids 13
1.5.3 Microgrids 14
1.5.4 Role of System Dynamics and Control 14
1.6 Outline of Chapters 14
References 17
2 Grid Characteristics and Operation 19
2.1 Description of Electric Grids 19
2.2 Detailed Modeling of Three-Phase AC Lines 21
2.3 Circuit Models of Symmetric Networks 22
2.4 Network Equations in DQo and ????o Components 23
2.4.1 Transformation to Park (dqo) Components 24
2.4.2 Steady-State Equations 25
2.4.3 D-Q Transformation using ??-?? Variables 26
2.5 Frequency and Power Control 28
2.5.1 Tie-Line Bias Frequency Control 31
2.6 Dynamic Characteristics of AC Grids 33
2.6.1 Grid Response to Frequency Modulation 33
2.6.2 Grid Response to Injection of Reactive Current 35
2.7 Control of Power Flow in AC Grids 38
2.7.1 Power Transfer Capability of a Line 38
2.7.2 Power Flow in a Line connected to an AC Transmission Grid 41
2.8 Analysis of Electromagnetic Transients 42
2.8.1 Modeling of Lumped Parameter Components 42
2.8.2 Modeling of a Single-Phase Line 43
2.8.3 Approximation of Series Resistance of Line 44
2.8.4 Modeling of Lossless Multiphase Line 45
2.8.5 Modeling of Multiphase Networks with Lumped Parameters 46
2.9 Transmission Expansion Planning 47
2.10 Reliability in Distribution Systems 48
2.11 Reliable Power Flows in a Transmission Network 48
2.12 Reliability Analysis of Transmission Networks 50
2.A Analysis of a Distributed Parameter Single-Phase Line in Steady State 51
2.A.1 Expressions for a Lossless Line 53
2.A.2 Performance of a Symmetrical Line 54
2.B Computation of Electrical Torque 55
References 57
3 Modeling and Simulation of Synchronous Generator Dynamics 59
3.1 Introduction 59
3.2 Detailed Model of a Synchronous Machine 59
3.2.1 Flux Linkage Equations 60
3.2.2 Voltage equations 61
3.3 Park's Transformation 62
3.4 Per-Unit Quantities 69
3.5 Equivalent Circuits of a Synchronous Machine 72
3.6 Synchronous Machine Models for Stability Analysis 76
3.6.1 Application of Model (2.1) 80
3.6.2 Application of Model (1.1) 80
3.6.3 Modeling of Saturation 82
3.7 An Exact Circuit Model of a Synchronous Machine for Electromagnetic Transient Analysis 82
3.7.1 Derivation of the Circuit Model 83
3.7.2 Transformation of the Circuit Model 87
3.7.3 Modeling of a Synchronous Generator in the Simulation of Electromagnetic Transients 91
3.7.4 Treatment of Dynamic Saliency 92
3.8 Excitation and Prime Mover Controllers 93
3.8.1 Excitation Systems 93
3.8.2 Modeling of Prime-Mover Control Systems 98
3.9 Transient Instability due to Loss of Synchronism 101
3.10 Extended Equal Area Criterion 103
3.11 Dynamics of a Synchronous Generator 104
Network Equations 104
Calculation of Initial Conditions 106
System Simulation 108
3.A Derivation of Electrical Torque 110
References 112
4 Modeling and Simulation of Wind Power Generators 115
4.1 Introduction 115
4.2 Power Extraction byWind Turbines 116
4.2.1 Wind Speed Characteristics 117
4.2.2 Control of Power Extraction 118
4.3 Generator and Power Electronic Configurations 120
4.3.1 Wind Farm Configurations 122
4.4 Modeling of the Rotating System 122
4.5 Induction Generator Model 124
4.5.1 Rotor Speed Instability 127
4.5.2 Modeling Issues 130
4.5.3 Frequency Conversion Using Voltage Source Converters 132
4.6 Control of Type IIIWTG System 133
4.6.1 Rotor-Side Converter Control 133
4.6.2 Grid-Side Converter Control 136
4.6.3 Overall Control Scheme for a Type III WTG system 137
4.6.4 Simplified Modeling of the Controllers for Slow Transient Studies 141
4.7 Control of Type IVWTG System 142
References 143
5 Modeling and Analysis of FACTS and HVDC Controllers 145
5.1 Introduction 145
5.2 FACTS Controllers 146
5.2.1 Description 146
5.2.2 A General Equivalent Circuit for FACTS Controllers 147
5.2.3 Benefits of the Application of FACTS Controllers 148
5.2.4 Application of FACTS Controllers in Distribution Systems 150
5.3 Reactive Power Control 150
Control Characteristics 153
5.4 Thyristor-Controlled Series Capacitor 153
5.4.1 Basic Concepts of Controlled Series Compensation 155
5.4.2 Operation of a TCSC 157
5.4.3 Analysis of a TCSC 158
5.4.4 Computation of the TCSC Reactance (XTCSC) 159
5.4.5 Control of the TCSC 161
5.5 Static Synchronous Compensator 166
5.5.1 General 166
5.5.2 Two-Level (Graetz Bridge) Voltage Source Converter 168
5.5.3 Pulse0020Width Modulation 169
5.5.4 Analysis of a Voltage Source Converter 171
5.5.5 Control of VSC 175
5.6 HVDC Power Transmission 177
5.6.1 Application of DC Transmission 178
5.6.2 Description of HVDC Transmission Systems 178
5.6.3 Analysis of a Line Commutated Converter 180
5.6.4 Introduction of VSC-HVDC Transmission 186
5.A Case Study of a VSC-HVDC Link 190
References 193
6 Damping of Power Swings 195
6.1 Introduction 195
6.2 Origin of Power Swings 196
6.3 SMIB Model with Field Flux Dynamics and AVR 199
6.3.1 Small-Signal Model and Eigenvalue Analysis 201
6.4 Damping and Synchronizing Torque Analysis 205
6.5 Analysis of Multi-Machine Systems 210
6.5.1 Electro-Mechanical Modes in a Multi-Machine System 210
6.5.2 Analysis with Detailed Models 216
6.6 Principles of Damping Controller Design 225
6.6.1 Actuator Location and Choice of Feedback Signals 229
6.6.2 Components of a PSDC 230
6.6.3 PSDCs based on Generator Excitation Systems: Power System Stabilizers 231
6.6.4 Adverse Torsional Interactions with the Speed/Slip Signal 237
6.6.5 Damping of Swings using Grid-Connected Power Electronic Systems 237
6.7 Concluding Remarks 241
6.A Eigenvalues of the Stiffness matrix K of Section 6.5.1 242
6.B Three-Machine Data 244
References 244
7 Analysis and Control of Loss of Synchronism 247
7.1 Introduction 247
7.2 Effect of LoS 247
7.3 Understanding the LoS Phenomenon 249
7.4 Criteria for Assessment of Stability 251
7.5 Power System Modeling and Simulation for Analysis of LoS 252
7.5.1 Effect of System Model 254
7.5.2 Effect of Changing Operating Conditions 255
7.6 Loss of Synchronism in Multi-Machine Systems 256
7.6.1 Effect of Disturbance Location on Mode of Separation: 258
7.6.2 Effect of the Load Model 258
7.6.3 Effect of Series Compensation in a Critical Line 260
7.6.4 Effect of a Change in the Pre-fault Generation Schedule 261
7.6.5 Voltage Phase Angular Differences across Critical Lines/Apparent Impedance seen by Relays 261
7.7 Measures to Avoid LoS 263
7.7.1 System Planning and Design 263
7.7.2 Preventive Control During Actual Operation 264
7.7.3 Emergency Control 264
7.8 Assessment and Control of LoS Using Energy Functions 265
7.8.1 Energy Function Method Applied to an SMIB System 266
7.8.2 Energy Function Method Applied to Multi-Machine Systems/Detailed Models 270
7.8.3 Evaluation of Critical Energy in a Multi-Machine System 274
7.9 Generation Rescheduling Using Energy Margin Sensitivities 274
7.9.1 Case Study: Generation Rescheduling 276
7.A Simulation Methods for Transient Stability Studies 276
7.A.1 Simultaneous Implicit Method 277
7.A.2 Partitioned Explicit Method 277
7.B Ten-Machine System Data 279
References 281
8 Analysis of Voltage Stability and Control 283
8.1 Introduction 283
8.2 Definitions of Voltage Stability 284
8.3 Comparison of Angle and Voltage Stability 286
8.3.1 Analysis of the SMLB System 287
8.4 Mathematical Preliminaries 290
8.5 Factors Affecting Instability and Collapse 292
8.5.1 Induction Motor Loads 292
8.5.2 HVDC Converter 293
8.5.3 Overexcitation Limiters 294
8.5.4 OLTC Transformers 295
8.5.5 A Nonlinear Dynamic Load Model 296
8.6 Dynamics of Load Restoration 296
8.7 Analysis of Voltage Stability and Collapse 298
8.7.1 Simulation 298
8.7.2 Small Signal (Linear) Analysis 298
8.8 Integrated Analysis of Voltage and Angle Stability 301
8.9 Analysis of Small Signal Voltage Instability Decoupled from Angle Instability 303
8.9.1 Decoupling of Angle and Voltage Variables 304
8.9.2 Incremental RCFN 305
8.9.3 Nonlinear Reactive Loads 306
8.9.4 Generator Model 306
Discussion 307
8.10 Control of Voltage Instability 308
References 308
9 Wide-AreaMeasurements and Applications 311
9.1 Introduction 311
9.2 Technology and Standards 311
9.2.1 Synchrophasor Definition 313
9.2.2 Reporting Rates 314
9.2.3 Latency and Data Loss 315
9.3 Modeling ofWAMS in Angular Stability Programs 315
9.4 Online Monitoring of Power Swing Damping 316
9.4.1 Modal Estimation based on Ringdown Analysis 317
9.4.2 Modal Estimation based on Probing Signals 319
9.4.3 Modal Estimation based on Ambient Data Analysis 323
9.5 WAMS Applications in Power Swing Damping Controllers 327
9.6 WAMS Applications in Emergency Control 330
9.7 Generator Parameter Estimation 335
9.8 Electro-MechanicalWave Propagation and Other Observations in Large Grids 335
References 338
10 Analysis of Subsynchronous Resonance 341
10.1 Introduction 341
10.2 Analysis of Electrical Network Dynamics 342
10.2.1 Equations in DQo Variables 344
10.2.2 Interfacing a DQ Network Model with a Generator Model 346
10.3 Torsional Dynamics of a Generator-Turbine System 353
10.3.1 Damping of Torsional Oscillations 359
10.3.2 Sensitivity of the Torsional Modes to the External Electrical System 360
10.4 Generator-Turbine and Network Interactions: Subsynchronous Resonance 362
10.4.1 Torsional Modes in Multi-Generator Systems 368
10.4.2 Adverse Interactions with Turbine-Generator Controllers 371
10.4.3 Detection of SSR/Torsional Monitoring 373
10.4.4 Countermeasures for Subsynchronous Resonance and Subsynchronous Torsional Interactions 374
10.4.5 Case Study: TCSC-Based SSDC 377
10.5 Time-InvariantModels of Grid-Connected Power Electronic Systems 378
10.5.1 Discrete-Time DynamicModels using the PoincareMapping Technique 380
10.5.2 Dynamic Phasor-Based Modeling 380
10.5.3 Numerical Derivation of PES Models: A Frequency Scanning Approach 383
10.A Transfer Function Representation of the Network 385
References 386
11 Solar Power Generation and Energy Storage 391
11.1 Introduction 391
11.2 Solar Thermal Power Generation 392
11.3 Solar PV Power Generation 392
11.3.1 Solar Module I-V Characteristics 393
11.3.2 Solar PV Connections and Power Extraction Strategies 393
11.3.3 Power Electronic Converters for Solar PV Applications 395
11.3.4 Maximum Power Point Tracking Algorithms 397
11.3.5 Control of Grid-Connected Solar PV Plants 398
11.3.6 Low-Voltage Ride Through and Voltage Support Capability 400
11.4 Energy Storage 403
11.4.1 Attributes of Energy Storage Devices 404
11.4.2 Energy Storage Technologies 404
11.4.3 Mapping to Applications 406
11.4.4 Battery Modeling 410
References 412
12 Microgrids: Operation and Control 415
12.1 Introduction 415
12.2 Microgrid Concept 416
12.2.1 Definition of a Microgrid 416
12.2.2 Control System 417
12.3 Microgrid Architecture 419
12.4 Distribution Automation and Control 420
12.5 Operation and Control of Microgrids 421
12.5.1 DER Units 421
12.5.2 Microgrid Loads 423
12.5.3 DER Controls 423
12.5.4 Control Strategies under Grid-Connected Operation 425
12.5.5 Control Strategy for an Islanded Microgrid 427
12.6 Energy Management System 428
12.6.1 Microgrid Supervisory Control 429
12.6.2 Decentralized Microgrid Control based on a Multi-Agent System 430
12.6.3 IndustrialMicrogrid Controllers 431
12.7 Adaptive Network Protection in Microgrids 432
12.7.1 Protection Issues 433
12.7.2 Adaptive Protection 434
12.8 Dynamic Modeling of Distributed Energy Resources 435
12.8.1 Photovoltaic Array with MPP Tracker 435
12.8.2 Fuel Cells 437
12.8.3 Natural Gas Generator Set 438
12.8.4 Fixed-SpeedWind Turbine Driving SCIG 439
12.9 Some Operating Problems in Microgirds 442
12.10 Integration of DG and DS in a Microgrid 444
12.11 DC Microgrids 444
12.12 Future Trends and Conclusions 445
12.A A Three-Phase Model of an Induction Machine 448
References 452
A Equal Area Criterion 455
An Interesting Network Analogy 456
References 458
B Grid Synchronization and Current Regulation 459
Choice of Reference Frames 459
References 462
C Fryze-Buchbolz-Depenbrock Method for Load Compensation 463
C.1 Introduction 463
C.2 Description of FBDTheory 463
C.3 Power Theory in Multiconductor Circuits 466
Virtual Star Point 466
Collective Quantities 467
C.4 Examples 469
C.5 Load Characterization over a Period 470
C.6 Compensation of Non-Active Currents 471
Discussion 472
References 472
D Symmetrical Components and Per-Unit Representation 473
D.1 Symmetrical Component Representation of Three-Phase Systems 473
D.2 Per-Unit Representation 476
References 478
Index 479
Acknowledgements xv
1 Introduction 1
1.1 Present Status of Grid Operation 1
1.1.1 General 1
1.1.2 HVDC Transmission 4
1.1.3 Reliability of Electricity Supply 4
1.2 Overview of System Dynamics and Control 4
1.2.1 Power System Stability 4
1.2.2 Mathematical Preliminaries 6
Stability of Equilibrium Point 6
Steady-State Behavior 8
1.2.3 Power System Security 8
1.3 Monitoring and Enhancing System Security 10
1.4 Emergency Control and System Protection 11
1.5 Recent Developments 12
1.5.1 Power System Protection 12
1.5.2 Development of Smart Grids 13
1.5.3 Microgrids 14
1.5.4 Role of System Dynamics and Control 14
1.6 Outline of Chapters 14
References 17
2 Grid Characteristics and Operation 19
2.1 Description of Electric Grids 19
2.2 Detailed Modeling of Three-Phase AC Lines 21
2.3 Circuit Models of Symmetric Networks 22
2.4 Network Equations in DQo and ????o Components 23
2.4.1 Transformation to Park (dqo) Components 24
2.4.2 Steady-State Equations 25
2.4.3 D-Q Transformation using ??-?? Variables 26
2.5 Frequency and Power Control 28
2.5.1 Tie-Line Bias Frequency Control 31
2.6 Dynamic Characteristics of AC Grids 33
2.6.1 Grid Response to Frequency Modulation 33
2.6.2 Grid Response to Injection of Reactive Current 35
2.7 Control of Power Flow in AC Grids 38
2.7.1 Power Transfer Capability of a Line 38
2.7.2 Power Flow in a Line connected to an AC Transmission Grid 41
2.8 Analysis of Electromagnetic Transients 42
2.8.1 Modeling of Lumped Parameter Components 42
2.8.2 Modeling of a Single-Phase Line 43
2.8.3 Approximation of Series Resistance of Line 44
2.8.4 Modeling of Lossless Multiphase Line 45
2.8.5 Modeling of Multiphase Networks with Lumped Parameters 46
2.9 Transmission Expansion Planning 47
2.10 Reliability in Distribution Systems 48
2.11 Reliable Power Flows in a Transmission Network 48
2.12 Reliability Analysis of Transmission Networks 50
2.A Analysis of a Distributed Parameter Single-Phase Line in Steady State 51
2.A.1 Expressions for a Lossless Line 53
2.A.2 Performance of a Symmetrical Line 54
2.B Computation of Electrical Torque 55
References 57
3 Modeling and Simulation of Synchronous Generator Dynamics 59
3.1 Introduction 59
3.2 Detailed Model of a Synchronous Machine 59
3.2.1 Flux Linkage Equations 60
3.2.2 Voltage equations 61
3.3 Park's Transformation 62
3.4 Per-Unit Quantities 69
3.5 Equivalent Circuits of a Synchronous Machine 72
3.6 Synchronous Machine Models for Stability Analysis 76
3.6.1 Application of Model (2.1) 80
3.6.2 Application of Model (1.1) 80
3.6.3 Modeling of Saturation 82
3.7 An Exact Circuit Model of a Synchronous Machine for Electromagnetic Transient Analysis 82
3.7.1 Derivation of the Circuit Model 83
3.7.2 Transformation of the Circuit Model 87
3.7.3 Modeling of a Synchronous Generator in the Simulation of Electromagnetic Transients 91
3.7.4 Treatment of Dynamic Saliency 92
3.8 Excitation and Prime Mover Controllers 93
3.8.1 Excitation Systems 93
3.8.2 Modeling of Prime-Mover Control Systems 98
3.9 Transient Instability due to Loss of Synchronism 101
3.10 Extended Equal Area Criterion 103
3.11 Dynamics of a Synchronous Generator 104
Network Equations 104
Calculation of Initial Conditions 106
System Simulation 108
3.A Derivation of Electrical Torque 110
References 112
4 Modeling and Simulation of Wind Power Generators 115
4.1 Introduction 115
4.2 Power Extraction byWind Turbines 116
4.2.1 Wind Speed Characteristics 117
4.2.2 Control of Power Extraction 118
4.3 Generator and Power Electronic Configurations 120
4.3.1 Wind Farm Configurations 122
4.4 Modeling of the Rotating System 122
4.5 Induction Generator Model 124
4.5.1 Rotor Speed Instability 127
4.5.2 Modeling Issues 130
4.5.3 Frequency Conversion Using Voltage Source Converters 132
4.6 Control of Type IIIWTG System 133
4.6.1 Rotor-Side Converter Control 133
4.6.2 Grid-Side Converter Control 136
4.6.3 Overall Control Scheme for a Type III WTG system 137
4.6.4 Simplified Modeling of the Controllers for Slow Transient Studies 141
4.7 Control of Type IVWTG System 142
References 143
5 Modeling and Analysis of FACTS and HVDC Controllers 145
5.1 Introduction 145
5.2 FACTS Controllers 146
5.2.1 Description 146
5.2.2 A General Equivalent Circuit for FACTS Controllers 147
5.2.3 Benefits of the Application of FACTS Controllers 148
5.2.4 Application of FACTS Controllers in Distribution Systems 150
5.3 Reactive Power Control 150
Control Characteristics 153
5.4 Thyristor-Controlled Series Capacitor 153
5.4.1 Basic Concepts of Controlled Series Compensation 155
5.4.2 Operation of a TCSC 157
5.4.3 Analysis of a TCSC 158
5.4.4 Computation of the TCSC Reactance (XTCSC) 159
5.4.5 Control of the TCSC 161
5.5 Static Synchronous Compensator 166
5.5.1 General 166
5.5.2 Two-Level (Graetz Bridge) Voltage Source Converter 168
5.5.3 Pulse0020Width Modulation 169
5.5.4 Analysis of a Voltage Source Converter 171
5.5.5 Control of VSC 175
5.6 HVDC Power Transmission 177
5.6.1 Application of DC Transmission 178
5.6.2 Description of HVDC Transmission Systems 178
5.6.3 Analysis of a Line Commutated Converter 180
5.6.4 Introduction of VSC-HVDC Transmission 186
5.A Case Study of a VSC-HVDC Link 190
References 193
6 Damping of Power Swings 195
6.1 Introduction 195
6.2 Origin of Power Swings 196
6.3 SMIB Model with Field Flux Dynamics and AVR 199
6.3.1 Small-Signal Model and Eigenvalue Analysis 201
6.4 Damping and Synchronizing Torque Analysis 205
6.5 Analysis of Multi-Machine Systems 210
6.5.1 Electro-Mechanical Modes in a Multi-Machine System 210
6.5.2 Analysis with Detailed Models 216
6.6 Principles of Damping Controller Design 225
6.6.1 Actuator Location and Choice of Feedback Signals 229
6.6.2 Components of a PSDC 230
6.6.3 PSDCs based on Generator Excitation Systems: Power System Stabilizers 231
6.6.4 Adverse Torsional Interactions with the Speed/Slip Signal 237
6.6.5 Damping of Swings using Grid-Connected Power Electronic Systems 237
6.7 Concluding Remarks 241
6.A Eigenvalues of the Stiffness matrix K of Section 6.5.1 242
6.B Three-Machine Data 244
References 244
7 Analysis and Control of Loss of Synchronism 247
7.1 Introduction 247
7.2 Effect of LoS 247
7.3 Understanding the LoS Phenomenon 249
7.4 Criteria for Assessment of Stability 251
7.5 Power System Modeling and Simulation for Analysis of LoS 252
7.5.1 Effect of System Model 254
7.5.2 Effect of Changing Operating Conditions 255
7.6 Loss of Synchronism in Multi-Machine Systems 256
7.6.1 Effect of Disturbance Location on Mode of Separation: 258
7.6.2 Effect of the Load Model 258
7.6.3 Effect of Series Compensation in a Critical Line 260
7.6.4 Effect of a Change in the Pre-fault Generation Schedule 261
7.6.5 Voltage Phase Angular Differences across Critical Lines/Apparent Impedance seen by Relays 261
7.7 Measures to Avoid LoS 263
7.7.1 System Planning and Design 263
7.7.2 Preventive Control During Actual Operation 264
7.7.3 Emergency Control 264
7.8 Assessment and Control of LoS Using Energy Functions 265
7.8.1 Energy Function Method Applied to an SMIB System 266
7.8.2 Energy Function Method Applied to Multi-Machine Systems/Detailed Models 270
7.8.3 Evaluation of Critical Energy in a Multi-Machine System 274
7.9 Generation Rescheduling Using Energy Margin Sensitivities 274
7.9.1 Case Study: Generation Rescheduling 276
7.A Simulation Methods for Transient Stability Studies 276
7.A.1 Simultaneous Implicit Method 277
7.A.2 Partitioned Explicit Method 277
7.B Ten-Machine System Data 279
References 281
8 Analysis of Voltage Stability and Control 283
8.1 Introduction 283
8.2 Definitions of Voltage Stability 284
8.3 Comparison of Angle and Voltage Stability 286
8.3.1 Analysis of the SMLB System 287
8.4 Mathematical Preliminaries 290
8.5 Factors Affecting Instability and Collapse 292
8.5.1 Induction Motor Loads 292
8.5.2 HVDC Converter 293
8.5.3 Overexcitation Limiters 294
8.5.4 OLTC Transformers 295
8.5.5 A Nonlinear Dynamic Load Model 296
8.6 Dynamics of Load Restoration 296
8.7 Analysis of Voltage Stability and Collapse 298
8.7.1 Simulation 298
8.7.2 Small Signal (Linear) Analysis 298
8.8 Integrated Analysis of Voltage and Angle Stability 301
8.9 Analysis of Small Signal Voltage Instability Decoupled from Angle Instability 303
8.9.1 Decoupling of Angle and Voltage Variables 304
8.9.2 Incremental RCFN 305
8.9.3 Nonlinear Reactive Loads 306
8.9.4 Generator Model 306
Discussion 307
8.10 Control of Voltage Instability 308
References 308
9 Wide-AreaMeasurements and Applications 311
9.1 Introduction 311
9.2 Technology and Standards 311
9.2.1 Synchrophasor Definition 313
9.2.2 Reporting Rates 314
9.2.3 Latency and Data Loss 315
9.3 Modeling ofWAMS in Angular Stability Programs 315
9.4 Online Monitoring of Power Swing Damping 316
9.4.1 Modal Estimation based on Ringdown Analysis 317
9.4.2 Modal Estimation based on Probing Signals 319
9.4.3 Modal Estimation based on Ambient Data Analysis 323
9.5 WAMS Applications in Power Swing Damping Controllers 327
9.6 WAMS Applications in Emergency Control 330
9.7 Generator Parameter Estimation 335
9.8 Electro-MechanicalWave Propagation and Other Observations in Large Grids 335
References 338
10 Analysis of Subsynchronous Resonance 341
10.1 Introduction 341
10.2 Analysis of Electrical Network Dynamics 342
10.2.1 Equations in DQo Variables 344
10.2.2 Interfacing a DQ Network Model with a Generator Model 346
10.3 Torsional Dynamics of a Generator-Turbine System 353
10.3.1 Damping of Torsional Oscillations 359
10.3.2 Sensitivity of the Torsional Modes to the External Electrical System 360
10.4 Generator-Turbine and Network Interactions: Subsynchronous Resonance 362
10.4.1 Torsional Modes in Multi-Generator Systems 368
10.4.2 Adverse Interactions with Turbine-Generator Controllers 371
10.4.3 Detection of SSR/Torsional Monitoring 373
10.4.4 Countermeasures for Subsynchronous Resonance and Subsynchronous Torsional Interactions 374
10.4.5 Case Study: TCSC-Based SSDC 377
10.5 Time-InvariantModels of Grid-Connected Power Electronic Systems 378
10.5.1 Discrete-Time DynamicModels using the PoincareMapping Technique 380
10.5.2 Dynamic Phasor-Based Modeling 380
10.5.3 Numerical Derivation of PES Models: A Frequency Scanning Approach 383
10.A Transfer Function Representation of the Network 385
References 386
11 Solar Power Generation and Energy Storage 391
11.1 Introduction 391
11.2 Solar Thermal Power Generation 392
11.3 Solar PV Power Generation 392
11.3.1 Solar Module I-V Characteristics 393
11.3.2 Solar PV Connections and Power Extraction Strategies 393
11.3.3 Power Electronic Converters for Solar PV Applications 395
11.3.4 Maximum Power Point Tracking Algorithms 397
11.3.5 Control of Grid-Connected Solar PV Plants 398
11.3.6 Low-Voltage Ride Through and Voltage Support Capability 400
11.4 Energy Storage 403
11.4.1 Attributes of Energy Storage Devices 404
11.4.2 Energy Storage Technologies 404
11.4.3 Mapping to Applications 406
11.4.4 Battery Modeling 410
References 412
12 Microgrids: Operation and Control 415
12.1 Introduction 415
12.2 Microgrid Concept 416
12.2.1 Definition of a Microgrid 416
12.2.2 Control System 417
12.3 Microgrid Architecture 419
12.4 Distribution Automation and Control 420
12.5 Operation and Control of Microgrids 421
12.5.1 DER Units 421
12.5.2 Microgrid Loads 423
12.5.3 DER Controls 423
12.5.4 Control Strategies under Grid-Connected Operation 425
12.5.5 Control Strategy for an Islanded Microgrid 427
12.6 Energy Management System 428
12.6.1 Microgrid Supervisory Control 429
12.6.2 Decentralized Microgrid Control based on a Multi-Agent System 430
12.6.3 IndustrialMicrogrid Controllers 431
12.7 Adaptive Network Protection in Microgrids 432
12.7.1 Protection Issues 433
12.7.2 Adaptive Protection 434
12.8 Dynamic Modeling of Distributed Energy Resources 435
12.8.1 Photovoltaic Array with MPP Tracker 435
12.8.2 Fuel Cells 437
12.8.3 Natural Gas Generator Set 438
12.8.4 Fixed-SpeedWind Turbine Driving SCIG 439
12.9 Some Operating Problems in Microgirds 442
12.10 Integration of DG and DS in a Microgrid 444
12.11 DC Microgrids 444
12.12 Future Trends and Conclusions 445
12.A A Three-Phase Model of an Induction Machine 448
References 452
A Equal Area Criterion 455
An Interesting Network Analogy 456
References 458
B Grid Synchronization and Current Regulation 459
Choice of Reference Frames 459
References 462
C Fryze-Buchbolz-Depenbrock Method for Load Compensation 463
C.1 Introduction 463
C.2 Description of FBDTheory 463
C.3 Power Theory in Multiconductor Circuits 466
Virtual Star Point 466
Collective Quantities 467
C.4 Examples 469
C.5 Load Characterization over a Period 470
C.6 Compensation of Non-Active Currents 471
Discussion 472
References 472
D Symmetrical Components and Per-Unit Representation 473
D.1 Symmetrical Component Representation of Three-Phase Systems 473
D.2 Per-Unit Representation 476
References 478
Index 479