Reactive Power Compensation A Practical Guide

by Hofmann, Wolfgang; Schlabbach, Jü; rgen; Just, Wolfgang

• ISBN13: 9780470977187
• ISBN10: 0470977183
• Edition: 1st
• Format: Hardcover
• Copyright: 2012-04-23
• Publisher: Wiley

Summary

The only practical guide to cover reactive power compensation in detail, presenting the design, application and operation of reactive power equipment and installations Written by experts in the field, this book is roughly (i.e. 20%) based on their successful German title Blindstrom-Kompensation in der Betriebspraxis (Reactive Compensation in Operational Practice). It first gives an overview of reactive power consumers and reactive power. The next chapters discuss the effects of reactive power on generation, transmission and distribution, and in reactive power energy contracts. Methods for determination of the reactive power and power factor are looked at, and then the improvement of power factor. The book then goes on to look at the design, arrangement and power of LV-capacitors and the determination of the required power of capacitors. The compensation of existing installations is covered in detail, as is the control and de-loading of reactive power. This unique book analyses the de-loading and the protection of capacitors and compensation, before covering the switching of capacitors in detail. There is a chapter devoted to installation, maintenance and disturbances, also a separate chapter on reactive power compensation of generation and unit special considerations. Finally, the book presents compensation and power converters. Presents a concise overview as well as deep specific knowledge on the Segment Power Factor Regulation and Network Quality The theory of reactive power compensation is coupled with typical application examples such as car manufacturing, metal rolling and chemical works Includes chapter summaries with charts explaining how to put the theory into practice Covers the economical aspects of this technology, including the efficient use of energy and the reduction of CO2

Author Biography

Wolfgang Hofmann, Reactive Power Engineering, Munich, Germany Jrgen Schlabbach, University of Applied Sciences, Bielefeld, Germany Wolfgang Just, Engineering Consultant, Dorsten, Germany

Table of Contents

Foreword and Acknowledgements	p. xiii
Basics of Reactive Power	p. 1
Chapter Overview	p. 1
Phasors and Vector Diagrams	p. 1
Definition of Different Types of Power	p. 4
Definition of Power for Non-Sinusoidal Currents and Voltages	p. 6
Equivalent Mechanical Model for Inductance	p. 9
Equivalent Mechanical Model for Capacitance	p. 11
Ohmic and Reactive Current	p. 12
Summary	p. 13
References	p. 13
Reactive Power Consumers	p. 15
Chapter Overview	p. 15
Reactive Energy Demand	p. 15
Simplified Model: Series Reactive Power Consumer	p. 16
Realistic Model: Mixed Parallel and Series Reactive Power	p. 16
Reactive Power Demand of Consumers	p. 17
Asynchronous Motors	p. 17
Transformers	p. 18
Control Gear (Ballast) for Gas Discharge Lamps	p. 18
Summary	p. 21
Effect of Reactive Power on Electricity Generation, Transmission and Distribution	p. 23
Chapter Overview	p. 23
Loading of Generators and Equipment	p. 23
Power System Losses	p. 24
Generators	p. 27
Voltage Drop	p. 28
General	p. 28
Transferable Power of Lines and Voltage Drop	p. 29
Transformer Voltage Drop	p. 32
Available Power of Transformers	p. 34
Summary	p. 35
Reactive Power in Standard Energy Contracts	p. 37
Chapter Overview	p. 37
Introduction	p. 37
Reactive Energy to be Considered in Standardized Contracts of Suppliers	p. 38
Pricing Dependent on Consumed Reactive Energy (kvarh)	p. 38
Pricing Dependent on Consumed Apparent Energy (kVAh)	p. 40
importance of Reactive Power in Determining the Costs of Connection	p. 42
Summary	p. 42
Reference	p. 42
Methods for the Determination of Reactive Power and Power Factor	p. 43
Chapter Overview	p. 43
Methods	p. 43
Determination of Power Factor in Single-Phase Grids	p. 43
Direct Indication of Power Factor by Means of Brueger's Device	p. 44
Determination of Power Factor in Three-Phase System	p. 44
Determination of Power Factor Using Portable Measuring Equipment	p. 46
Determination of Power (Factor) via Recorded Data	p. 48
Determination of Power Factor by Means of an Active Energy Meter	p. 48
Determination of Power Factor by Means of an Active and Reactive Energy Meter	p. 49
Determination of Power Factor via the Energy Bill	p. 50
Summary	p. 51
Improvement of Power Factor	p. 53
Chapter Overview	p. 53
Basics of Reactive Power Compensation	p. 53
Limitation of Reactive Power without Phase Shifting	p. 55
Compensation of Reactive Power by Rotational Phase-Shifting Machines	p. 55
Compensation of Reactive Power by Means of Capacitors	p. 56
Summary	p. 58
Design, Arrangement and Power of Capacitors	p. 61
Chapter Overview	p. 61
Basics of Capacitors	p. 61
Reactive Power of Capacitors	p. 64
Different Technologies in Manufacturing Capacitors	p. 65
Capacitors with Paper Insulation	p. 65
Capacitors with Metallized Paper (MP Capacitor)	p. 65
Capacitors with Metallized Plastic Foils	p. 66
Arrangements and Reactive Power of Capacitors	p. 66
Capacitors Connected in Parallel	p. 67
Capacitors Connected in Series	p. 67
Star and Delta Connection of Power Capacitors	p. 68
Design of MV Capacitors	p. 69
Long-Term Stability and Ageing of Capacitor Installations	p. 69
General	p. 69
Influence of Operating Voltage	p. 70
Ageing in the Case of Detuned Capacitors	p. 72
Ageing due to Switching Operations	p. 73
Summary	p. 73
References	p. 73
Determination of Required Power of Capacitors	p. 75
Chapter Overview	p. 75
Basics of Calculation	p. 75
Determination of Compensation at New Projected Plants	p. 79
Summary	p. 85
Reference	p. 85
Types of Reactive Power Compensation	p. 87
Chapter Overview	p. 87
Single-Type Compensation	p. 87
Single-Type Compensation in Asynchronous Motors	p. 88
Single-Type Compensation of Transformers	p. 97
Single-Type Compensation of Reactive Power for Welding Transformers	p. 99
Single-Type Compensation of Fluorescent Lamps	p. 103
Bulk-Type Compensation	p. 108
Central-Type Compensation	p. 111
Mixed Compensation	p. 112
Advantages and Disadvantages of Different Types of Compensations	p. 113
Summary	p. 115
Reference	p. 115
Compensation of Existing Installations	p. 117
Chapter Overview	p. 117
Methods of Determining the Reactive Power for Extension	p. 117
Calculation of the Extension Unit by Means of Energy Invoices	p. 118
Summary	p. 121
Control of Reactive Power	p. 123
Chapter Overview	p. 123
General	p. 123
Reactive Power Compensation Units	p. 124
Control of Reactive Power by Automatic Reactive Power Controllers	p. 124
General	p. 124
Number of Steps and Reactive Power of the Capacitor Steps	p. 125
Threshold Level C/k Value	p. 131
Reverse Control Scheme (cos ¿d Line)	p. 133
Automatic Reactive Power Control	p. 135
No-Volt Release Function	p. 137
How to Wire a Power Factor Relay	p. 137
Reactive Power Control by 'Mixed Measurement'	p. 138
Reactive Power Control with Multiple Feed-ins	p. 140
Measuring by Means of Summation Current Transformer	p. 140
Parallel Operation of Compensation Banks for Each Incoming Supply	p. 142
Performances of Automatic Compensation Banks	p. 144
Summary	p. 146
Discharging Devices for Power Capacitors	p. 147
Chapter Overview	p. 147
Basis at LV Applications	p. 147
Rapid Discharging with Additional Resistances Switched in	p. 150
Discharging Capacitors by Means of Reactors	p. 150
Discharging Devices in MV Capacitors	p. 152
MV Capacitors to be Discharged by Resistances	p. 152
MV Capacitors to be Discharged by Reactors	p. 154
Calculation of the Electric Charge to be Stored on an MV Capacitor	p. 154
Summary	p. 156
Protection of Capacitors and Compensations	p. 157
Chapter Overview	p. 157
Protection against Overcurrent and Short Circuit	p. 157
Overvoltage Protection	p. 158
Protection against Overtemperatures	p. 158
Protection against Internal Faults	p. 158
Protection against Voltage Flashover	p. 159
Self-healing Technology	p. 159
Protection against Overheating and Internal Overpressure	p. 159
Protection by Balance Observation at Single-Phase MV Capacitors	p. 162
Summary	p. 163
Reference	p. 163
Switching of Capacitors	p. 165
Chapter Overview	p. 165
General	p. 165
Selection of Switchgear	p. 167
Air Contactors	p. 168
Circuit Breakers	p. 169
Switch Fuses and Magnetic Trips	p. 169
Switching by Semiconductors (Thyristor Modules)	p. 169
General	p. 169
Static Contactors for Switching Capacitors up to 415 V	p. 171
Static Contactors for Switching Capacitors of Rated Voltage Higher than 500 V	p. 173
Power Factor Relays for Static Contactors	p. 173
Dynamic Reactive Power Compensation (Ready to Install)	p. 174
Summary	p. 175
Reference	p. 175
Installation, Disturbances and Maintenance	p. 177
Chapter Overview	p. 177
Installation of Automatically Controlled Compensation Banks	p. 177
Automatic Compensation Banks: Setting into Operation	p. 178
Selection of Current Transformer (CT) and Determination of the CT Cable	p. 178
Preset Switching Time Delay per Capacitor Step	p. 183
Disturbances and How to Solve Them	p. 184
Working and Maintenance	p. 185
Summary	p. 187
References	p. 187
Reactive Power Compensation in Electrical Plants with Generators	p. 189
Chapter Overview	p. 189
General	p. 189
Automatic Control of Reactive Power within Four Quadrants	p. 190
Technical Considerations	p. 190
Bargaining Considerations	p. 192
Summary	p. 193
References	p. 194
Effects of Perturbation Considering Especially the Impact of Harmonics on Power Factor Correction Capacitors	p. 195
Chapter Overview	p. 195
Perturbations and Improved Power Quality for Business Customers	p. 196
Measuring and Analysis	p. 198
Summary	p. 203
References	p. 204
Resonances in Electrical Power Systems	p. 205
Chapter Overview	p. 205
Parallel Resonance Circuit	p. 205
Series Resonance Circuit	p. 208
Typical Resonances in Power Systems	p. 208
Resonance due to Reactive Power Compensation in 6 kV System	p. 208
Parallel Resonance in a 30 kV Industrial System	p. 210
Impedance in Urban 10 kV System	p. 212
Summary	p. 212
Reference	p. 212
Reactor-Protected Capacitors and Filter Circuits	p. 213
Chapter Overview	p. 213
Effect of Reactor-Protected Systems and System Configuration	p. 214
Effect of Reactor-Protected Systems	p. 214
System Configuration of Reactor-Protected Capacitor Banks	p. 217
Notes on the Selection of Reactors	p. 220
Influence of the Reactor Rate on the Capacitor's Lifetime	p. 222
Filter Effect with Detuned Filters	p. 223
Filter Circuits	p. 225
General	p. 225
Active Filters	p. 227
Passive Filters	p. 229
Comparison of Active and Passive Filters	p. 233
Neutral Line Harmonic Filtering	p. 233
General	p. 233
Special Features of the Third Harmonic	p. 234
Network Relief by the Neutral Line Harmonic Filter	p. 235
Summary	p. 238
References	p. 239
Dynamic Reactive Power Compensation Systems	p. 241
Chapter Overview	p. 241
Improvement of Power Quality via Dynamic Reactive Power Compensation Systems	p. 242
Motor Startup Compensation	p. 245
Flicker Compensation	p. 245
Evaluation of Power Factor Correction Solutions as Seen by the Distribution System Operator (Power Utility)	p. 251
Summary	p. 252
References	p. 252
Compensation Effects at Rectifiers	p. 253
Chapter Overview	p. 253
General	p. 253
Compensation Bank at a Six-Pulse Rectifier	p. 254
Time Courses of Voltage and Current at a Three-Phase Bridge-Connected Rectifier	p. 256
How Compensation Banks Affect Three-Phase Bridge-Connected Rectifiers	p. 257
Characteristic Behaviour of Reactive Power Controllers at Rectifiers	p. 260
Summary	p. 261
References	p. 261
Environmental and Climate Protection Using Capacitors	p. 263
Chapter Overview	p. 263
PCB-Filled Capacitors	p. 263
Climate Change and Energy Efficiency through Power Factor Correction	p. 264
Summary	p. 267
References	p. 267
Symbols and Abbreviations	p. 269
Index	p. 273
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