Distribution System Modeling and Analysis, Third Edition

by Kersting; William H.

• ISBN13: 9781439856222
• ISBN10: 1439856222
• Edition: 3rd
• Format: Hardcover
• Copyright: 2012-01-24
• Publisher: CRC Press

Summary

First introduced in 2001, Kersting's Distribution System Modeling and Analysisis the only textbook on computational modeling for electric power distribution systems. Computer models are only as good as their input, and this intuitive work clearly explains the principles and mathematics behind these models and provides approximation methods that help students recognize when a result is not what it should be. Using the same authoritative yet accessible approach, this second edition was updated to reflect the changes and advances in the field since the first edition appeared.Nearly every chapter of this book has been updated according to new trends and areas of interest, new technologies, and the increasing spread of distributed generation. Most notably, this edition features a new chapter on the center-tapped transformer for providing three-wire service to single-phase customers. New discussions consider the effects of mutual coupling between overhead and underground lines running parallel for long distances, expand on the discussion of induction machines to consider the rotor circuit, and examine the effects of distributed generation technologies such as windmills on feeders.Illustrated with numerous figures, examples, and exercises, Distribution System Modeling and Analysis, Second Editionremains the definitive textbook for teaching students to understand and model all aspects of modern distribution systems.

Table of Contents

Preface	p. ix
Acknowledgments	p. xiii
Author	p. xv
Introduction to Distribution Systems	p. 1
Distribution System	p. 2
Distribution Substations	p. 2
Radial Feeders	p. 5
Distribution Feeder Map	p. 6
Distribution Feeder Electrical Characteristics	p. 8
Summary	p. 9
Nature of Loads	p. 11
Definitions	p. 11
Individual Customer Load	p. 13
Demand	p. 13
Maximum Demand	p. 13
Average Demand	p. 14
Load Factor	p. 14
Distribution Transformer Loading	p. 15
Diversified Demand	p. 16
Maximum Diversified Demand	p. 16
Load Duration Curve	p. 17
Maximum Noncoincident Demand	p. 18
Diversity Factor	p. 18
Demand Factor	p. 19
Utilization Factor	p. 20
Load Diversity	p. 20
Feeder Load	p. 20
Load Allocation	p. 20
Application of Diversity Factors	p. 21
Load Survey	p. 21
Transformer Load Management	p. 25
Metered Feeder Maximum Demand	p. 26
What Method to Use?	p. 27
Voltage Drop Calculations Using Allocated Loads	p. 28
Application of Diversity Factors	p. 28
Load Allocation Based upon Transformer Ratings	p. 32
Summary	p. 33
Problems	p. 34
Approximate Method of Analysis	p. 39
Voltage Drop	p. 39
Line Impedance	p. 41
"K" Factors	p. 42
Kdrop Factor	p. 42
Krise Factor	p. 45
Uniformly Distributed Loads	p. 47
Voltage Drop	p. 47
Power Loss	p. 49
Exact Lumped Load Model	p. 51
Lumping Loads in Geometric Configurations	p. 54
Rectangle	p. 54
Triangle	p. 58
Trapezoid	p. 63
Summary	p. 68
Problems	p. 69
Reference	p. 73
Series Impedance of Overhead and Underground Lines	p. 75
Series Impedance of Overhead Lines	p. 75
Transposed Three-Phase Lines	p. 76
Untransposed Distribution Lines	p. 77
Carson's Equations	p. 79
Modified Carson's Equations	p. 81
Primitive Impedance Matrix for Overhead Lines	p. 84
Phase Impedance Matrix for Overhead Lines	p. 85
Sequence Impedances	p. 88
Parallel Overhead Distribution Lines	p. 95
Series Impedance of Underground Lines	p. 98
Concentric Neutral Cable	p. 99
Tape-Shielded Cables	p. 105
Parallel Underground Distribution Lines	p. 108
Summary	p. 112
Problems	p. 112
Windmil Assignment	p. 117
References	p. 117
Shunt Admittance of Overhead and Underground Lines	p. 119
General Voltage Drop Equation	p. 119
Overhead Lines	p. 120
Shunt Admittance of Overhead Parallel Lines	p. 125
Concentric Neutral Cable Underground Lines	p. 128
Tape-Shielded Cable Underground Lines	p. 132
Sequence Admittance	p. 133
Shunt Admittance of Parallel Underground Lines	p. 134
Summary	p. 135
Problems	p. 136
Windmil Assignment	p. 137
References	p. 137
Distribution System Line Models	p. 139
Exact Line Segment Model	p. 139
Modified Line Model	p. 147
Three-Wire Delta Line	p. 148
Computation of Neutral and Ground Currents	p. 149
Approximate Line Segment Model	p. 152
Modified "Ladder" Iterative Technique	p. 156
General Matrices for Parallel Lines	p. 158
Physically Parallel Lines	p. 162
Electrically Parallel Lines	p. 167
Summary	p. 172
Problems	p. 173
Windmil Assignment	p. 177
References	p. 178
Voltage Regulation	p. 179
Standard Voltage Ratings	p. 179
Two-Winding Transformer Theory	p. 181
Two-Winding Autotransformer	p. 185
Autotransformer Ratings	p. 190
Per-Unit Impedance	p. 193
Step-Voltage Regulators	p. 196
Single-Phase Step-Voltage Regulators	p. 198
Type A Step-Voltage Regulator	p. 198
Type B Step-Voltage Regulator	p. 199
Generalized Constants	p. 202
Line Drop Compensator	p. 203
Three-Phase Step-Voltage Regulators	p. 209
Wye-Connected Regulators	p. 209
Closed Delta-Connected Regulators	p. 219
Open Delta-Connected Regulators	p. 222
Summary	p. 233
Problems	p. 234
Windrnil Assignment	p. 239
References	p. 239
Three-Phase Transformer Models	p. 241
Introduction	p. 241
Generalized Matrices	p. 242
Delta-Grounded Wye Step-Down Connection	p. 243
Voltages	p. 243
Currents	p. 248
Delta-Grounded Wye Step-Up Connection	p. 258
Ungrounded Wye-Delta Step-Down Connection	p. 260
Ungrounded Wye-Delta Step-Up Connection	p. 272
Grounded Wye-Delta Step-Down Connection	p. 274
Open Wye-Open Delta	p. 280
Grounded Wye-Grounded Wye Connection	p. 285
Delta-Delta Connection	p. 288
Open Delta-Open Delta	p. 298
Thevenin Equivalent Circuit	p. 303
Summary	p. 306
Problems	p. 307
Windmil Assignment	p. 311
Load Models	p. 313
Wye-Connected Loads	p. 313
Constant Real and Reactive Power Loads	p. 314
Constant Impedance Loads	p. 315
Constant Current Loads	p. 315
Combination Loads	p. 316
Delta-Connected Loads	p. 318
Constant Real and Reactive Power Loads	p. 319
Constant Impedance Loads	p. 319
Constant Current Loads	p. 320
Combination Loads	p. 320
Line Currents Serving a Delta-Connected Load	p. 320
Two-Phase and Single-Phase Loads	p. 321
Shunt Capacitors	p. 321
Wye-Connected Capacitor Bank	p. 321
Delta-Connected Capacitor Bank	p. 322
Three-Phase Induction Machine	p. 323
Induction Machine Model	p. 323
Equivalent T Circuit	p. 328
Computation of Slip	p. 335
Induction Generator	p. 338
Summary	p. 339
Problems	p. 339
Windmil Assignment	p. 342
References	p. 342
Distribution Feeder Analysis	p. 343
Power-Flow Analysis	p. 343
Ladder Iterative Technique	p. 344
Linear Network	p. 344
Nonlinear Network	p. 345
General Feeder	p. 348
Unbalanced Three-Phase Distribution Feeder	p. 349
Shunt Components	p. 350
Applying the Modified Ladder Iterative Technique	p. 351
Let's Put It All Together	p. 352
Load Allocation	p. 360
Summary of Power-Flow Studies	p. 360
Short-Circuit Studies	p. 361
General Theory	p. 361
Specific Short Circuits	p. 365
Summary	p. 370
Problems	p. 371
Windmil Assignment	p. 374
References	p. 378
Center-Tapped Transformers and Secondaries	p. 379
Center-Tapped Single-Phase Transformer Model	p. 379
Matrix Equations	p. 381
Center-Tapped Transformer Serving Loads through a Triplex Secondary	p. 387
Ungrounded Wye-Delta Transformer Bank with a Center-Tapped Transformer	p. 392
Backward Sweep Equations	p. 392
Forward Sweep Equations	p. 397
Leading Open Wye-Open Delta Transformer Connection	p. 405
Lagging Open Wye-Open Delta Connection	p. 408
Four-Wire Secondary	p. 411
Putting it All Together	p. 415
Computation of Line-to-Neutral Transformer Voltages	p. 415
Summary	p. 423
Problems	p. 423
Windmil Assignment	p. 425
References	p. 426
Conductor Data	p. 427
Underground Cable Data	p. 431
Index	p. 433
Table of Contents provided by Ingram. All Rights Reserved.