Power Distribution System Reliability: Practical Methods and Applications (IEEE Press Series on Power Engineering)

POWER DISTRIBUTION SYSTEM RELIABILITY......Page 4
CONTENTS......Page 10
Preface......Page 22
ACKNOWLEDGMENTS......Page 23
1.1 Introduction......Page 26
1.2.1 Generation System Reliability Assessment......Page 27
1.2.2 Transmission System Reliability Assessment......Page 28
1.2.3 Distribution System Reliability Assessment......Page 29
1.3 Organization of the Chapters......Page 30
1.4 Conclusions......Page 35
References......Page 36
2.1.1 Introduction......Page 38
2.2 Important Parameters of Frequency Distribution......Page 40
2.2.4 Standard Deviation......Page 41
2.3.1 Concept......Page 42
2.3.2 Probability Laws and Theorems......Page 43
2.4.1 Random Variable......Page 44
2.4.2 Probability Density Function......Page 45
2.4.3 Parameters of Probability Distributions......Page 46
2.4.4 The Binomial Distribution......Page 47
2.4.5 The Poisson Distribution......Page 50
2.4.6 The Exponential Distribution......Page 51
2.4.7 The Normal Distribution......Page 52
2.5.3 Sampling Distributions......Page 54
2.5.5 Estimation of Population Statistic......Page 57
2.5.6 Computation of Sample Size......Page 59
2.6 Statistical Decision Making......Page 61
2.6.2 Types of Error......Page 62
References......Page 67
3.1.1 Concept and Model......Page 70
3.1.2 Concept of Bathtub Curve......Page 71
3.2.1 Theory of First Principles......Page 72
3.2.2 Reliability Model......Page 75
3.2.3 The Poisson Probability Distribution......Page 77
3.2.4 Reliability of Equal Time Steps......Page 78
3.3 Mean Time to Failures......Page 79
3.4.1 Series Systems......Page 80
3.4.2 Parallel Systems......Page 81
3.4.3 Partially Redundant Systems......Page 83
3.4.4 Bayes' Theorem......Page 85
3.5.2 Spares for One Unit......Page 87
3.5.3 Spares for Multiple Interchangeable Units......Page 88
3.6.1 Mean Time to Repair......Page 90
3.6.3 Markov Model......Page 91
3.6.4 Concept of Dependability......Page 92
3.7.1 Concept......Page 93
3.7.3 Confidence Limit of Failure Rate......Page 94
3.7.4 Chi-Square Distribution......Page 95
References......Page 102
4.1.1 Introduction......Page 104
4.1.3 Failure Rate Computation......Page 105
4.2.1 Availability Considerations and Requirements......Page 106
4.2.2 Availability Model......Page 107
4.2.3 Long-Run Availability......Page 108
4.3.2 Study Methods......Page 110
4.4 Distribution Pole Maintenance Practices......Page 111
4.6.2 Inspection Program for Insulators......Page 112
4.6.3 Voltage Surges On Lines......Page 113
4.6.4 Critical Flashover......Page 114
4.6.5 Number of Insulators in a String......Page 116
4.7.2 Popular Distribution Reliability Indices......Page 118
4.7.3 Reliability Criteria......Page 119
4.8 Conclusions......Page 120
References......Page 121
5.1 Introduction......Page 122
5.4 Formulas for Computing Interest......Page 123
5.5.1 Concept of Annual Cost......Page 126
5.5.2 Alternatives with Different Life Times......Page 127
5.6 Present Value (PV) Concept......Page 128
5.7 Theory of Rate of Return......Page 130
5.8 Cost–Benefit Analysis Approach......Page 131
5.9.2 Principles......Page 132
5.10 Conclusions......Page 133
References......Page 134
6.1 Introduction......Page 136
6.2.1 Basic Assumptions: Criteria for System Success—Power is Delivered to All Loads......Page 137
6.3 Network Reduction Methods......Page 140
6.3.1 Path Enumeration Methods: Minimum Tie Set......Page 141
6.3.2 Path Enumeration Methods: Minimum Cut Set......Page 146
6.4 Bayes' Theorem in Reliability......Page 154
6.5 Construction of Fault Tree Diagram......Page 164
6.5.1 Basic Rules for Combining the Probability of Independent Input Failure Events to Evaluate the Probability of a Single-Output Failure Event......Page 165
6.6 The Application of Conditional Probability Theory to System Operating Configurations......Page 171
References......Page 176
7.1 Introduction......Page 178
7.2 Example 1: Simple Radial Distribution System......Page 179
7.2.3 Conclusions: Simple Radial System Example 1......Page 180
7.3 Example 2: Reliability Analysis of a Primary Selective System to the 13.8 kV Utility Supply......Page 181
7.3.1 Description: Primary Selective System to the 13.8 kV Utility Supply......Page 182
7.3.2 Results: A Primary Selective System to the 13.8 kV Utility Supply......Page 183
7.3.3 Conclusions: Primary Selective System to 13.8 kV Utility Supply......Page 184
7.4.1 Description of a Primary Selective System to the Load Side of a 13.8 kV Circuit Breaker......Page 186
7.4.2 Results: Primary Selective System to Load Side of 13.8 kV Circuit Breaker......Page 187
7.5.1 Description of a Primary Selective System to the Primary of the Transformer......Page 188
7.6.1 Description of a Secondary Selective System......Page 189
7.6.3 Conclusions: A Secondary Selective System......Page 190
7.7.1 Description of a Simple Radial System with Spares......Page 191
7.7.3 Conclusions: Simple Radial System with Spares......Page 192
7.8.2 Results: Simple Radial System with Cogeneration......Page 193
7.8.3 Conclusions: A Simple Radial System with Cogeneration......Page 194
7.9 Reliability Evaluation of Miscellaneous System Configurations......Page 195
References......Page 213
8.1 Introduction......Page 216
8.2 Zone Branch Concepts......Page 217
8.3 Industrial System Study......Page 221
8.4 Application of Zone Branch Methodology: Case Studies......Page 226
8.4.1 Case 1: Design "A"—Simple Radial Substation Configuration......Page 227
8.4.2 Case 2: Design "B"—Dual Supply Radial—Single Bus......Page 233
8.4.3 Case 3: Design "C"—Dual Supply Radial with Tiebreaker......Page 240
8.4.4 Case 4: Design "D"—Dual Supply Loop with Tiebreaker......Page 244
8.4.5 Case 5: Design "E"—Dual Supply Primary Selective......Page 250
8.4.6 Case 6: Design "F"—Double Bus/Double Breaker Radial......Page 257
8.4.7 Case 7: Design "G"—Double Bus/Double Breaker Loop......Page 260
8.4.8 Case 8: Design "H"—Double Bus/Breaker Primary Selective......Page 267
8.5 Conclusions......Page 276
References......Page 277
9.1 Introduction......Page 280
9.2 Interruption Data Collection Scheme......Page 281
9.3 Typical Distribution Equipment Outage Statistics......Page 284
References......Page 290
10.1 Introduction......Page 292
10.2 Automatic Outage Management System......Page 293
10.2.2 Customer-Oriented Indices......Page 294
10.2.3 Classification of Interruption as to Causes......Page 295
10.3 Historical Assessment......Page 296
10.3.1 A Utility Corporate Level Analysis......Page 297
10.3.2 Utility Region-Level Analysis......Page 304
10.5 Development of a Composite Index for Reliability Performance Analysis at the Circuit Level......Page 307
References......Page 308
11.1 Introduction......Page 310
11.2 Current Distribution Planning and Design Criteria......Page 311
11.2.2 Reliability Indices......Page 312
11.2.4 Examples of Distribution Reliability Standards in a Deregulated Market......Page 313
11.3 Reliability Cost Versus Reliability Benefit Trade-Offs in Distribution System Planning......Page 315
11.4 Alternative Feed Requirements for Overhead Distribution Systems......Page 318
11.5.1 Reliability of Supply to 25 kV Buses......Page 319
11.6 Value-Based Alternative Feeder Requirements Planning......Page 320
11.6.1 Customer Interruption Cost Data......Page 322
11.6.2 An Illustrative Example for Justification of an Alternate Feed to a Major City......Page 323
References......Page 324
12.1 Introduction......Page 326
12.2 Relevant Issues and Factors in Establishing Distribution Reliability Standards......Page 329
12.2.1 Data Pool......Page 330
12.2.2 Definitions of Terms......Page 332
12.2.4 Outage Data Collection Systems......Page 333
12.3 Performance Indices at Different System Levels of a Utility......Page 334
12.5 Conclusions......Page 339
References......Page 340
13.1 Introduction......Page 342
13.2 Cost of Service Regulation versus Performance-Based Regulation......Page 343
13.3 A Reward/Penalty Structure in the Performance-Based Rates......Page 344
13.4 Historical SAIFI and SAIDI Data and their Distributions......Page 347
13.5 Computation of System Risks Based on Historical Reliability Indices......Page 348
13.6 Cause Contributions to SAIFI and SAIDI Indices......Page 354
13.7 Conclusions......Page 359
References......Page 360
14.1 Introduction......Page 362
14.2 Customer Interruption Cost......Page 363
14.3 Series and Parallel System Model Equations......Page 364
14.4 Dedicated Distribution Radial Feeder Configuration......Page 365
14.5 Distribution Radial Feeder Configuration Serving Multiple Customers......Page 366
14.6 Distribution Radial Feeder Configuration Serving Multiple Customers with Manual Sectionalizing......Page 367
14.7 Distribution Radial Feeder Configuration Serving Multiple Customers with Automatic Sectionalizing......Page 370
14.8.2 Feeder Characteristics: Looped Radial Feeders—Manual Sectionalizing......Page 372
References......Page 380
15.1 Introduction......Page 382
15.2 Value-Based Reliability Planning......Page 383
15.3 Distribution System Configuration Characteristics......Page 385
15.4 Case Studies......Page 387
15.5 Illustrative Example System Problem and Its Reliability Calculations......Page 393
15.5.1 Operating Procedures......Page 394
15.6 Conclusions......Page 398
References......Page 399
16.1 Introduction......Page 400
16.2 Distribution System Characteristics......Page 403
16.2.1 Distribution Load Transfer Characteristics......Page 404
16.2.3 Feeder Circuit Reliability Data......Page 405
16.3.1 Case Study 1......Page 406
16.3.2 Case Study 2......Page 409
16.3.3 Case Study 3......Page 413
16.4 Major Substation Outages......Page 414
16.5 Summary of Load Point Interruption Costs......Page 416
16.6 Conclusions......Page 417
References......Page 418
17.1 Introduction......Page 420
17.2 Value-Based Reliability Assessment in a Deregulated Environment......Page 421
17.3 The Characteristics of the Illustrative Urban Distribution System......Page 422
17.4 Discussion of Results......Page 425
17.5 Feeder and Transformer Loading Levels......Page 426
17.6.1 Tie Costs and Descriptions......Page 427
17.7.2 Conductor Sizing......Page 428
17.9 Feeder Tie Placement......Page 429
17.10 Finding Optimum Section Length......Page 431
17.10.1 Definition of Terms......Page 432
17.11 Feeder and Transformer Loading......Page 433
17.12 Feeder Tie Cost Calculation......Page 434
17.13 Effects of Tie Maintenance......Page 435
17.14 Additional Ties for Feeders with Three-Phase Branches......Page 436
17.14.1 Definition of Terms......Page 437
References......Page 438
18.1 Introduction......Page 440
18.2 Predictive Feeder Reliability Analysis......Page 441
18.3 Reliability Data and Assumptions......Page 443
18.4.2 Circuit Tie 47-2......Page 444
18.4.3 Circuit Tie 46-1......Page 445
18.4.6 Base Case Reliability......Page 446
18.5.1 Incremental Improvement Alternative 1: Add Distribution Automation Switch......Page 447
18.5.2 Incremental Improvement Alternative 2: Add Sectionalizing Switch......Page 448
18.5.3 Incremental Alternative 3: Relocate Recloser 255......Page 449
18.6 Summary of the Illustrative Feeder Reliability Performance Improvement Alternatives......Page 450
References......Page 451
19.1 Introduction......Page 452
19.2 Problem Definition......Page 453
19.3 Illustrative Distribution System Configuration Characteristics......Page 455
19.4 Reliability Assessment Model......Page 457
19.5 Discussion of Results......Page 458
19.5.1 Equivalent Distributed Generation Reinforcement Alternative......Page 459
References......Page 463
20.1 Introduction......Page 466
20.2.1 Reliability Criterion Model for Determining the Optimal Number of Transformer Spares......Page 467
20.2.2 Mean Time Between Failures (MTBF(u)) Criterion Model for Determining the Optimal Number of Transformer Spares......Page 468
20.2.3 Determination of Optimal Transformer Spares Based on the Model of Statistical Economics......Page 469
20.3 Optimal Transformer Spares for Illustrative 72 kV Distribution Transformer Systems......Page 470
20.3.1 Determination of Optimal Transformer Spares Based on the Minimum Reliability Criterion......Page 471
20.3.2 Determination of Optimal Transformer Spares Based on the Minimum MTBF(u) Criterion......Page 472
20.3.3 Determination of Optimal Transformer Spares Based on the Criterion of Statistical Economics......Page 473
20.4 Conclusions......Page 475
References......Page 476
21.1 Introduction......Page 478
21.2.2 Typical Design Goals of Power Conscious Computer Manufacturers (Often Called the CBEMA Curve)......Page 479
21.3.1 Background......Page 480
21.3.2 Case Study: Radial Distribution System......Page 484
21.4 Frequency of Voltage Sags......Page 486
21.4.1 Industrial Customer Group......Page 487
21.4.2 Commercial Customer Group......Page 488
21.5.1 Utility Distribution Systems......Page 489
21.5.2 Industrial Distribution System......Page 495
21.6.1 Background......Page 497
21.6.2 Voltage Sags and Surges (Time of Day)......Page 498
21.6.3 Voltage Sags and Surges (Day of Week)......Page 500
21.6.4 Frequency of Disturbances Monitored on Primary and Secondary Sides of Industrial Sites......Page 503
21.8 Scatter Plots of Voltage Surge Levels as a Function of Duration......Page 504
21.9 Primary and Secondary Voltage Sages Statistical Characteristics......Page 505
21.10 Primary and Secondary Voltage Surges Statistical Characteristics......Page 506
References......Page 511
Problem Set for Chapters 2 and 3......Page 514
Answers to Problem Set for Chapters 2 and 3......Page 518
Problem Set for Chapter 4......Page 519
Answers to Problem Set for Chapter 4......Page 521
Answers to Problem Set for Chapter 5......Page 522
Problem Set for Chapter 6......Page 523
Answers to Problem Set for Chapter 6......Page 529
Problem Set for Chapter 7......Page 530
Answers to Problem Set for Chapter 7......Page 534
Problem Set for Chapter 8......Page 535
Problem Set for Chapter 21......Page 537
Answers to Problem Set for Chapter 21......Page 541
Index......Page 544