Distribution System Modeling and Analysis

Updated to reflect the latest changes and advances in the field, Distribution System Modeling and Analysis, Third Edition again illustrates methods that will ensure the most accurate possible results in computational modeling for electric power distribution systems. With the same simplified approach of previous editions, this book clearly explains the principles and mathematics behind system models, also discussing the "smart grid" concept and its special benefits.
However, this volume adds a crucial element not found in previous editions. The first two books developed models for all components but focused less on how to actually implement those models on a computer for planning and for real-time analysis. This book includes numerous models of components and several practical examples, to demonstrate how engineers can apply and customize computer programs to help them plan and operate systems.
It also covers approximation methods to help users interpret computer program feedback, so they recognize when a result is not what it should be. Another improvement is the book’s earlier introduction (in chapter 4) of the modified ladder iterative technique. The author explains the need for this method—which is used in most distribution analysis programs—detailing how it is applied and why it is among the most powerful options.
Concluding with a detailed summary of presented topics that readers have come to expect, this edition provides useful problems, references, and assignments that help users apply Mathcad® and WIndmil programs to put their new learning into practice. An invaluable tool for engineering students and professionals worldwide, this book explores cutting-edge advances in modeling, simulation, and analysis of distribution systems that can ensure the continued dispersal of safe, reliable energy.

William H. Kersting received his BSEE from New Mexico State University (NMSU), Las Cruces, and his MSEE from the Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as professor of electrical engineering and director of the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, New Mexico. Professor Kersting is a life fellow of the Institute of Electrical and Electronics Engineers. He received the Edison Electric Institute’s Power Engineering Educator Award in 1979 and the NMSU Westhafter Award for Excellence in Teaching in 1977. Prior to joining NMSU, he was employed as a distribution engineer at El Paso Electric Company. Professor Kersting has been an active member of the IEEE Power Engineering Education Committee and the Distribution System Analysis Subcommittee.

Introduction to Distribution Systems

Distribution System

Distribution Substations

Radial Feeders

Distribution Feeder Map

Distribution Feeder Electrical Characteristics



Nature of Loads

Definitions

Individual Customer Load

Distribution Transformer Loading

Feeder Load



Approximate Method of Analysis

Voltage Drop

Line Impedance

"K" Factors

Uniformly Distributed Loads

Lumping Loads in Geometric Configurations



Series Impedance of Overhead and Underground Lines

Series Impedance of Overhead Lines

Series Impedance of Underground Lines

Windmil Assignment



Shunt Admittance of Overhead and Underground Lines

General Voltage Drop Equation

Overhead Lines

Concentric Neutral Cable Underground Lines

Tape-Shielded Cable Underground Lines

Sequence Admittance

Shunt Admittance of Parallel Underground Lines

Windmil Assignment



Distribution System Line Models

Exact Line Segment Model

Modified Line Model

Approximate Line Segment Model

Modified "Ladder" Iterative Technique

General Matrices for Parallel Lines

Windmil Assignment



Voltage Regulation

Standard Voltage Ratings

Two-Winding Transformer Theory

Two-Winding Autotransformer

Step-Voltage Regulators

Windmil Assignment



Three-Phase Transformer Models

Introduction

Generalized Matrices

Delta-Grounded Wye Step-Down Connection

Delta-Grounded Wye Step-Up Connection

Ungrounded Wye-Delta Step-Down Connection

Ungrounded Wye-Delta Step-Up Connection

Grounded Wye-Delta Step-Down Connection

Open Wye-Open Delta

Grounded Wye-Grounded Wye Connection

Delta-Delta Connection

Open Delta-Open Delta

Thevenin Equivalent Circuit

Windmil Assignment



Load Models

Wye-Connected Loads

Delta-Connected Loads

Two-Phase and Single-Phase Loads

Shunt Capacitors

Three-Phase Induction Machine

Windmil Assignment



Distribution Feeder Analysis

Power-Flow Analysis

Short-Circuit Studies

Windmil Assignment



Center-Tapped Transformers and Secondaries

Center-Tapped Single-Phase Transformer Model

Ungrounded Wye-Delta Transformer Bank with a Center-Tapped Transformer

Leading Open Wye-Open Delta Transformer Connection

Lagging Open Wye-Open Delta Connection

Four-Wire Secondary

Putting It All Together

Windmil Assignment



Appendix A: Conductor Data

Appendix B: Underground Cable Data