Corsi Voltage Control and Protection in Electrical Power Systems

From System Components to Wide-Area Control
1. Auflage 2015
ISBN: 978-1-4471-6636-8
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 579 Seiten

Reihe: Advances in Industrial Control

Based on the author's twenty years of experience, this book shows the practicality of modern, conceptually new, wide area voltage control in transmission and distribution smart grids, in detail. Evidence is given of the great advantages of this approach, as  well as what can be gained by new control functionalities which modern technologies now available can provide. The distinction between solutions of wide area voltage regulation (V-WAR) and wide area voltage protection (V-WAP) are presented, demonstrating the proper synergy between them when they operate on the same power system as well as the simplicity and effectiveness of the protection solution in this case.  The author provides an overview and detailed descriptions of voltage controls, distinguishing between generalities of underdeveloped, on-field operating applications and modern and available automatic control solutions, which are as yet not sufficiently known or perceived for what they are: practical, high-performance and reliable solutions. At the end of this thorough and complex preliminary analysis the reader sees the true benefits and limitations of more traditional voltage control solutions, and gains an understanding and appreciation of the innovative grid voltage control and protection solutions here proposed; solutions aimed at improving the security, efficiency and quality of electrical power system operation around the globe.Voltage Control and Protection in Electrical Power Systems: from System Components to Wide Area Control will help to show engineers working in electrical power companies and system operators the significant advantages of new control solutions and will also interest academic control researchers studying ways of increasing power system stability and efficiency.

Dr. Sandro Corsi, is a senior scientist and project manager at CESI S.p.A.. Formerly, he has been manager and head of the voltage control office at ENEL Research Department. His main interests are in studies, consultancies, specifications, design and applications in real power systems of grid voltage controls, generator controls, power electronics, HVDC systems, substation automation, grid security and protection systems, advanced control and communication methods and technologies. He has a wide experience in field applications, in Italy and further afield, of grid support control systems. His international experience also includes projects related to SCADA/EMS, tailored energy markets and grids integration to UCTE/ETNSO pool. He pioneered the studies and applications of the 'Transmission Network Automatic Voltage Regulation and Wide Area Protection Systems'. On renewable energy, he has a long experience of studies and field applications of special control systems in photovoltaic, wind and fuel cells generators and power stations. Member of: CIGRE, IEEE-PES and CEI WGs and SCs. Member of IREP Board of Directors and IET-GTD; IJRET Editorial Boards. Author of more than 100 technical papers in the main Conferences Proceedings and Reviews on power system stability, control and protection. Reviewer of IEEE-Transactions, and for IET, Elsevier, EPSR , IJRET and International Conference papers.

Autoren/Hrsg.

Corsi, Sandro

Inhaltsverzeichnis

1;Series Editors’ Foreword;7
2;Preface;9
3;Acknowledgements;12
4;Contents;14
5;Abbreviations and Acronyms;20
6;Introduction;22
6.1;References;26
7;Part I;28
7.1;Voltage Control Resources;28
7.1.1;Chapter-1;29
7.1.1.1;Relationship Between Voltage and Active and Reactive Powers;29
7.1.1.1.1;1.1 Grid Short Lines;29
7.1.1.1.1.1;1.1.1 Reactive Power Transfer;31
7.1.1.1.1.2;1.1.2 Losses;32
7.1.1.1.2;1.2 Reactive Loads;33
7.1.1.1.3;1.3 Grid Medium-Long Length Lines;34
7.1.1.1.4;1.4 Grid as a Combination of Loads and Lines;36
7.1.1.1.5;References;37
7.1.2;Chapter-2;38
7.1.2.1;Equipment for Voltage and Reactive Power Control;38
7.1.2.1.1;2.1 Introduction;38
7.1.2.1.2;2.2 Reactive Power Compensation Devices;39
7.1.2.1.2.1;2.2.1 Shunt Capacitors;39
7.1.2.1.2.2;2.2.2 Mechanically Switched Capacitors (MSC);40
7.1.2.1.2.3;2.2.3 Shunt Reactors;41
7.1.2.1.2.4;2.2.4 Mechanically Switched Reactors (MSR);42
7.1.2.1.2.5;2.2.5 Multiple Compensation Device Operating Point;43
7.1.2.1.3;2.3 Voltage and Reactive Power Continuous Control Devices;45
7.1.2.1.3.1;2.3.1 Synchronous Generators;45
7.1.2.1.3.1.1;ECS with Exciting Dynamo;46
7.1.2.1.3.1.2;ECS with Alternator and Rotating Diodes;47
7.1.2.1.3.1.3;ECS with Static Exciter;48
7.1.2.1.3.1.4;ECS Model Parameters;49
7.1.2.1.3.1.5;Synchronous Generator as Reactive Power Source;49
7.1.2.1.3.2;2.3.2 Synchronous Compensators;55
7.1.2.1.3.3;2.3.3 SVG: Static VAR Generators;57
7.1.2.1.3.3.1;Thyristor-Controlled Reactor (TCR);58
7.1.2.1.3.3.2;Thyristor-Switched Capacitor (TSC);59
7.1.2.1.3.3.3;Fixed Capacitor and Thyristor Controlled Reactor (FC-TCR);61
7.1.2.1.3.3.4;Thyristor-Switched Capacitor, Thyristor-Controlled Reactor (TSC-TCR);63
7.1.2.1.3.4;2.3.4 Static VAR Compensators (SVCs);66
7.1.2.1.3.4.1;SVC Voltage Control Requirements;67
7.1.2.1.3.4.2;SVC Regulation Slope;68
7.1.2.1.3.5;2.3.5 Static Compensators (STATCOMs);69
7.1.2.1.3.5.1;STATCOM Voltage Control Requirements;72
7.1.2.1.3.5.2;STATCOM Regulation Slope;74
7.1.2.1.3.6;2.3.6 Unified Power Flow Control (UPFC);74
7.1.2.1.3.6.1;Fundamentals of the Shunt Voltage Source Converter;76
7.1.2.1.3.6.2;Fundamentals of the Series Voltage Source Converter;77
7.1.2.1.3.6.3;Fundamentals of the UPFC;80
7.1.2.1.3.6.4;UPFC Voltage Control Requirements;85
7.1.2.1.4;2.4 Voltage and Reactive Power Discrete Control Devices: On-load Tap-changing Transformers;87
7.1.2.1.4.1;2.4.1 Generalities;87
7.1.2.1.4.2;2.4.2 Output Voltage Dependence on Current Turns Ratio;88
7.1.2.1.4.3;2.4.3 Static Characteristic of the Transformer;90
7.1.2.1.4.4;2.4.4 Link of Voltage, Reactive Power and Turns Ratio in OLTC Transformer Applications;95
7.1.2.1.4.4.1;Combined Use of OLTC and Reactive Power Injections in Transmission Networks;95
7.1.2.1.4.4.2;Radial Transmission/Distribution System with Two Cascaded OLTC Transformers;99
7.1.2.1.4.5;2.4.5 Regulating Transformers;101
7.1.2.1.4.5.1;In-Phase Regulating Transformer (IPRT);101
7.1.2.1.4.5.2;Phase-Shifting Transformers (PSTs);101
7.1.2.1.5;2.5 Conclusion;103
7.1.2.1.6;References;104
7.1.3;Chapter-3;106
7.1.3.1;Grid Voltage and Reactive Power Control;106
7.1.3.1.1;3.1 General Considerations;106
7.1.3.1.2;3.2 Voltage-Reactive Power Manual Control;110
7.1.3.1.2.1;3.2.1 Manual Voltage Control by Reactive Power Flow;111
7.1.3.1.2.2;3.2.2 Manual Voltage Control by Network Topology Modification;111
7.1.3.1.3;3.3 Voltage-Reactive Power Automatic Control;111
7.1.3.1.3.1;3.3.1 Automatic Voltage Control by OLTC Transformer;112
7.1.3.1.3.2;3.3.2 Automatic Voltage Control (AVR) of Generator Stator Edges;115
7.1.3.1.3.2.1;Linear Analysis of Generator Voltage Control Loop;117
7.1.3.1.3.3;3.3.3 Automatic Voltage Control by Generator Line Drop Compensation (Compounding);124
7.1.3.1.3.3.1;Objective of Compounding;124
7.1.3.1.3.3.2;Link Between Voltage and Reactive Power;125
7.1.3.1.3.3.3;Line Drop Compensation (Compounding);126
7.1.3.1.3.3.4;Line Drop Compensation and Stability;128
7.1.3.1.3.3.5;Line Drop Compensation Simplified Feedback;130
7.1.3.1.3.4;3.3.4 Generalities on Automatic High Side Voltage Control at a Substation;131
7.1.3.1.3.4.1;Voltage Control at a Substation;132
7.1.3.1.3.5;3.3.5 Automatic High Side Voltage Control at a Power Plant;133
7.1.3.1.3.5.1;Principal Scheme;133
7.1.3.1.3.5.2;Model of the Power Plant;133
7.1.3.1.3.5.3;High Side Voltage Regulator;137
7.1.3.1.3.6;3.3.6 Automatic Voltage-Reactive Power Control by SVC;143
7.1.3.1.3.6.1;SVC Voltage Regulation;143
7.1.3.1.3.6.2;SVC Voltage Control Drop;146
7.1.3.1.3.6.3;Dynamic Behaviour of SVC;149
7.1.3.1.3.6.4;Dynamic Behaviour of SVC Reactive Power Control;153
7.1.3.1.3.7;3.3.7 Automatic Voltage-Reactive Power Control by STATCOM;158
7.1.3.1.3.7.1;STATCOM Grid Voltage Regulation;159
7.1.3.1.3.7.2;STATCOM Voltage Control Drop;161
7.1.3.1.3.7.3;Dynamic Behaviour of the STATCOM;165
7.1.3.1.3.7.4;Dynamic Behaviour of the STATCOM Reactive Power Control;168
7.1.3.1.3.8;3.3.8 Automatic Voltage-Reactive Power Control by UPFC;173
7.1.3.1.3.8.1;UPFC Control Schemes;173
7.1.3.1.3.8.2;UPFC Shunt Converter Control;174
7.1.3.1.3.8.3;UPFC Series Converter Control;174
7.1.3.1.3.8.4;UPFC Dynamic Behaviour;176
7.1.3.1.4;3.4 Conclusion;181
7.1.3.1.5;References;182
8;Part II;184
8.1;Wide Area Voltage Control;184
8.1.1;Introduction to Part II;184
8.1.1.1;Chapter-4;185
8.1.1.1.1;Grid Hierarchical Voltage Regulation;185
8.1.1.1.1.1;4.1 Structure of the Hierarchy;185
8.1.1.1.1.1.1;4.1.1 Generalities;185
8.1.1.1.1.1.2;4.1.2 Basic SVR and TVR Concepts;189
8.1.1.1.1.1.3;4.1.3 Primary Voltage Regulation;190
8.1.1.1.1.1.4;4.1.4 Secondary Voltage Regulation: Architecture and Modelling;194
8.1.1.1.1.1.4.1;Principle of Secondary Voltage Regulation;194
8.1.1.1.1.1.4.2;Dynamic Model of Secondary Voltage Control System;197
8.1.1.1.1.1.4.3;SVR Control Structure;200
8.1.1.1.1.1.4.4;Reference Transients;206
8.1.1.1.1.1.5;4.1.5 Tertiary Voltage Regulation;210
8.1.1.1.1.2;4.2 SVR Control Areas;214
8.1.1.1.1.2.1;4.2.1 Procedure to Select Pilot Nodes and Define Control Areas;214
8.1.1.1.1.2.1.1;Analytical Procedure for Selecting Pilot Nodes;214
8.1.1.1.1.2.2;4.2.2 Procedure to Select Control Generators;217
8.1.1.1.1.2.2.1;Analytical Procedure for Selecting Control Generators;218
8.1.1.1.1.2.3;4.2.3 Power Flow and Optimal Power Flow Computation in the Presence of Secondary Voltage Regulation;219
8.1.1.1.1.2.4;4.2.4 Examples of Pilot Node and Control Power Station Selection;220
8.1.1.1.1.2.4.1;Pilot Nodes and Control Power Stations in Italy;221
8.1.1.1.1.2.4.2;Pilot Nodes and Control Power Stations in the Taiwan Grid;223
8.1.1.1.1.2.4.3;Pilot Nodes and Control Power Stations in South Korea;226
8.1.1.1.1.2.4.4;Pilot Nodes and Control Power Stations in South Africa;226
8.1.1.1.1.2.5;4.2.5 Examples of Control Apparatuses Required by SVR;234
8.1.1.1.1.2.5.1;The SQR Apparatus: Functional Design and Technological Issues;234
8.1.1.1.1.2.5.2;RVR Apparatus: Functional Design and Technological Issues;237
8.1.1.1.1.2.5.3;NVR Apparatus: Functional Design and Technological Issues;243
8.1.1.1.1.2.6;4.2.6 SVR Dynamic Performance During Tests in Real Grids;245
8.1.1.1.1.2.6.1;4.2.6.1 Verified Performance and Field Tests;245
8.1.1.1.1.2.7;4.2.7 General Considerations on Practical Issues;252
8.1.1.1.1.3;4.3 Conclusion;253
8.1.1.1.1.4;References;254
8.1.1.2;Chapter-5;257
8.1.1.2.1;Examples of Hierarchical Voltage Control Systems Throughout the World;257
8.1.1.2.1.1;5.1 French Hierarchical Voltage Control System;257
8.1.1.2.1.1.1;5.1.1 General Overview;257
8.1.1.2.1.1.2;5.1.2 Original Secondary Voltage Regulation and Its Limits;258
8.1.1.2.1.1.3;5.1.3 Coordinated Secondary Voltage Control (CSVC);261
8.1.1.2.1.1.4;5.1.4 Performance and Results of Simulations;264
8.1.1.2.1.1.4.1;Voltage Control in Case of Failure and Load Variation;264
8.1.1.2.1.1.5;5.1.5 Final Comments on French Hierarchical Voltage Control Power System;264
8.1.1.2.1.2;5.2 Italian Hierarchical Voltage Control System;266
8.1.1.2.1.2.1;5.2.1 General Overview;266
8.1.1.2.1.2.2;5.2.2 Power System Operation Improvement;268
8.1.1.2.1.2.2.1;Voltage Control System Dynamics;268
8.1.1.2.1.2.2.2;Voltage Stability Limit Increase;269
8.1.1.2.1.2.2.3;Network Loss Reduction;270
8.1.1.2.1.2.3;5.2.3 Final Remarks on Italian Hierarchical Voltage Control System;272
8.1.1.2.1.3;5.3 Brazilian Hierarchical Voltage Control System;272
8.1.1.2.1.3.1;5.3.1 General Overview;272
8.1.1.2.1.3.2;5.3.2 Results of Study Simulations;274
8.1.1.2.1.3.2.1;SVR Step Response;274
8.1.1.2.1.3.2.2;Load Variation;275
8.1.1.2.1.3.2.3;Single Contingency Case;276
8.1.1.2.1.3.2.4;Loading the Light Subsystem;276
8.1.1.2.1.3.3;5.3.3 Conclusions on the Brazilian Voltage Control System;278
8.1.1.2.1.4;5.4 Romanian Hierarchical Voltage Control System;279
8.1.1.2.1.4.1;5.4.1 Characteristics of the Studied System;279
8.1.1.2.1.4.2;5.4.2 SVR Area Selection;279
8.1.1.2.1.4.2.1;Line Outage;281
8.1.1.2.1.4.2.2;Generator Outage;283
8.1.1.2.1.5;5.5 Chinese Hierarchical Voltage Control System;284
8.1.1.2.1.6;References;285
8.1.1.3;Chapter-6;287
8.1.1.3.1;SVR Dynamic Tests with Contingencies;287
8.1.1.3.1.1;6.1 Tests Without Contingencies in Large Power Systems;287
8.1.1.3.1.1.1;6.1.1 Tests on Italian Hierarchical Voltage Control System;288
8.1.1.3.1.1.2;6.1.2 Tests on South Korean Hierarchical Voltage Control System;291
8.1.1.3.1.1.3;6.1.3 Tests on South African Hierarchical Voltage Control System;291
8.1.1.3.1.1.3.1;Test on SVR with Load Variation in One Area Only;294
8.1.1.3.1.1.3.2;Test Like § 6.1.3.1, But with PVR Alone. Load Steps at Pegasus Area;299
8.1.1.3.1.1.3.3;Test on SVR with Step Variation at All the Pilot Nodes Voltage Set-Points;302
8.1.1.3.1.2;6.2 Tests with Contingencies in Large Power Systems;306
8.1.1.3.1.2.1;6.2.1 Tests on Line-Opening;306
8.1.1.3.1.2.1.1;Performance Comparison Between SVR with PVR in South Korean Hierarchical Voltage Control System;306
8.1.1.3.1.2.1.2;Performance Comparison Between SVR with PVR in Taiwan Hierarchical Voltage Control System;308
8.1.1.3.1.2.1.3;Performance Comparison Between SVR with PVR in South African Hierarchical Voltage Control System;310
8.1.1.3.1.2.2;6.2.2 Tests on Generator Tripping;314
8.1.1.3.1.2.2.1;Performance Comparison Between SVR with PVR in South African Hierarchical Voltage Control System;314
8.1.1.3.1.2.2.2;Performance Comparison Between SVR with PVR in Taiwan Hierarchical Voltage Control System;318
8.1.1.3.1.3;References;320
8.1.1.4;Chapter-7;321
8.1.1.4.1;Economics of Voltage Ancillary Service;321
8.1.1.4.1.1;7.1 General Overview;321
8.1.1.4.1.2;7.2 Cost/Benefit Analysis of Voltage Service;323
8.1.1.4.1.2.1;7.2.1 Generation Costs;323
8.1.1.4.1.2.1.1;Capital Costs;324
8.1.1.4.1.2.1.2;Operation Costs;324
8.1.1.4.1.2.2;7.2.2 Transmission Costs;325
8.1.1.4.1.2.2.1;Capital Costs;325
8.1.1.4.1.2.2.2;Operation Costs;325
8.1.1.4.1.2.3;7.2.3 Voltage-VAR Control Benefits;326
8.1.1.4.1.2.3.1;Example of Economic Benefits on South African Transmission Grid;327
8.1.1.4.1.2.3.2;Reduction of Switching Manoeuvres by SVR-TVR in South African Grid;328
8.1.1.4.1.2.3.3;Loss Reduction Example Due to SVR benefits in South Korean Grid;329
8.1.1.4.1.2.3.4;Example of economic benefit evaluation for a large power system (50-GW peak load);331
8.1.1.4.1.2.4;7.2.4 SVR-TVR Cost/Benefit Illustrative Case;331
8.1.1.4.1.3;7.3 Economic Performance Recognition of Voltage Service;332
8.1.1.4.1.3.1;7.3.1 Voltage Service with SVR: Role Played by Power Plant Voltage and Reactive Power Regulator (SQR);334
8.1.1.4.1.3.2;7.3.2 Voltage Service Indicators;335
8.1.1.4.1.3.2.1;Index of Generator Available Capability;336
8.1.1.4.1.3.2.2;Index of Generator Available Voltage Field;337
8.1.1.4.1.3.2.3;New Power Plant Meter For Voltage Service;338
8.1.1.4.1.3.3;7.3.3 Simplicity, Correctness and Indubitableness of Proposed Indicators;339
8.1.1.4.1.3.3.1;Final Remarks On New Voltage Service Meter;340
8.1.1.4.1.4;References;340
8.1.1.5;Chapter-8;342
8.1.1.5.1;Voltage Stability;342
8.1.1.5.1.1;8.1 General Overview on Stability;342
8.1.1.5.1.2;8.2 Electrical Power System Stability;344
8.1.1.5.1.2.1;8.2.1 Transient Stability;345
8.1.1.5.1.2.2;8.2.2 Steady-State Stability;349
8.1.1.5.1.2.3;8.2.3 Generator AVR Contribution to Steady-State Stability;351
8.1.1.5.1.2.3.1;Electromechanical Oscillation Damping Through Additional Feedbacks on Generator Voltage Control Loop;353
8.1.1.5.1.2.4;8.2.4 SVR Contribution to Angle Stability;357
8.1.1.5.1.3;8.3 Voltage Stability: Introduction;364
8.1.1.5.1.3.1;8.3.1 Relationship Between Load Power and Network Voltage;366
8.1.1.5.1.3.1.1;V-P Curve Basics;369
8.1.1.5.1.3.1.2;Proposed Equivalent System;373
8.1.1.5.1.3.1.3;Analysis of V-P Curves of the Test System;376
8.1.1.5.1.3.1.4;V-P Curve Analysis for a More Realistic Generic Load Representation;388
8.1.1.5.1.3.1.5;V-P Curve Analysis for The Italian System;389
8.1.1.5.1.3.1.6;Understanding and Modeling Voltage Instability;398
8.1.1.5.1.3.1.7;V-P Curve in Presence of Grid Automatic Voltage Regulation;400
8.1.1.5.1.3.2;8.3.2 Distinguishing Voltage Instability from Voltage Collapse;405
8.1.1.5.1.3.2.1;Further Examples of Voltage Instability and Collapse;408
8.1.1.5.1.3.3;8.3.3 Voltage Instability and Bifurcation Analysis;412
8.1.1.5.1.3.3.1;Equilibrium and Stability of Dynamic Systems;412
8.1.1.5.1.3.3.2;Equilibrium Points and Trajectories with Saddle-Node Bifurcation;417
8.1.1.5.1.4;References;422
8.1.1.6;Chapter-9;424
8.1.1.6.1;Voltage Instability Indicators;424
8.1.1.6.1.1;9.1 Introduction;425
8.1.1.6.1.2;9.2 Off-line Voltage Instability Indicators;427
8.1.1.6.1.2.1;9.2.1 Basics of Off-line Indices Based on Jacobian Singular Values;429
8.1.1.6.1.2.2;9.2.2 Basics of Off-line Indices Based on Load Margin;432
8.1.1.6.1.2.3;9.2.3 Final Comment;433
8.1.1.6.1.3;9.3 Real-time PMU-based Voltage Instability Indicators;434
8.1.1.6.1.3.1;9.3.1 Introduction;434
8.1.1.6.1.3.2;9.3.2 Thevenin Equivalent Identification Algorithm;436
8.1.1.6.1.3.3;9.3.3 Description of Proposed Real-time Identification Algorithm;441
8.1.1.6.1.3.4;9.3.4 Sensitivity Analysis of the Identification Method;444
8.1.1.6.1.3.5;9.3.5 Algorithm Application to Dynamic Thevenin Equivalent;449
8.1.1.6.1.3.6;9.3.6 Algorithm Application to the Italian 380/20-kV Network;453
8.1.1.6.1.4;9.4 Real-time Voltage Instability Indicators V-WAR–based;462
8.1.1.6.1.4.1;9.4.1 The Real-time and On-line Index;463
8.1.1.6.1.4.2;9.4.2 Voltage Stability Index Definition;464
8.1.1.6.1.4.3;9.4.3 Voltage Stability Index Computation and Meaning;464
8.1.1.6.1.4.4;9.4.4 Crucial Role Played by Tertiary Voltage Regulation;465
8.1.1.6.1.4.5;9.4.5 Voltage Stability Index Control Function;466
8.1.1.6.1.4.6;9.4.6 Functional Performances;466
8.1.1.6.1.4.7;9.4.7 Comparison with Off-line Voltage Stability Indices;471
8.1.1.6.1.5;9.5 Real-time Voltage Instability Indicators Based on Grid Area Reactive Power Injection;473
8.1.1.6.1.6;9.6 A Variety of Real-time Voltage Instability Indicators Based on Phasor Measurements Units Data;474
8.1.1.6.1.6.1;9.6.1 Real-time Indices Based on the Thevenin Equivalent Identification Method;475
8.1.1.6.1.6.2;9.6.2 Index Performance in Front of Load Increase;478
8.1.1.6.1.6.3;9.6.3 Index Performance in Front of Large Perturbations;482
8.1.1.6.1.7;9.7 Final Remarks;485
8.1.1.6.1.8;References;486
8.1.1.7;Chapter-10;488
8.1.1.7.1;Voltage Control on Distribution Smart Grids;488
8.1.1.7.1.1;10.1 Introduction;488
8.1.1.7.1.1.1;10.1.1 Generalities;489
8.1.1.7.1.1.1.1;Generality of PC Voltage Regulation;489
8.1.1.7.1.1.1.2;Generality of PC Frequency Regulation;489
8.1.1.7.1.1.1.3;Generality of PC Power Flow Regulation at the HV Bus Bar;490
8.1.1.7.1.1.1.4;Generality of PC Back-Up Feeding by Neighbouring MV Network;490
8.1.1.7.1.1.2;10.1.2 Chapter Objective;490
8.1.1.7.1.2;10.2 Generalities on Medium Voltage Grid and Primary Cabin Schemes;491
8.1.1.7.1.3;10.3 Generalities of Primary Cabin Voltage Control;493
8.1.1.7.1.4;10.4 PCVR Basic Control Schemes;496
8.1.1.7.1.4.1;10.4.1 OLTC Operation in Presence of PCVR;496
8.1.1.7.1.4.2;10.4.2 Islanded Grid Voltage Regulation;498
8.1.1.7.1.4.3;10.4.3 Automatic Voltage Regulation of HV or MV PC Bus Bars;498
8.1.1.7.1.4.4;10.4.4 Block Diagrams of PCVR Control Functions;500
8.1.1.7.1.5;10.5 Automatic Reactive Power Flow Regulation on the PC HV Bus Bar;502
8.1.1.7.1.6;10.6 Analysis of PCVR and PCQR Control Logicsand Results;504
8.1.1.7.1.6.1;10.6.1 Case of Reactive Power Flow Entering Feederby HV Bus Bar;507
8.1.1.7.1.6.2;10.6.2 Case of Reactive Power Flow Sent by Feeder into PC HV Bus Bar;510
8.1.1.7.1.6.3;10.6.3 OLTC Tap Control by PC-CC Operating as PCVR;512
8.1.1.7.1.6.3.1;Low Voltage in the Feeder with VMV