Power and distribution transformers : practical design guide / K.R.M. Nair.

Format:

Book

Author/Creator:

Nair, K. R. M., author.

Language:

English

Subjects (All):

Electric power distribution.

Electric power systems--Design and construction.

Electric power systems.

Physical Description:

1 online resource (xxiii, 473 pages)

Edition:

1st ed.

Place of Publication:

Boca Raton, Florida : CRC Press, [2021]

Summary:

This book is based on the author's50+ years experience in the power and distribution transformer industry. The first few chapters of the bookprovide astep-by-step procedures of transformer design. Engineers without prior knowledge or exposure to design can follow the procedures and calculation methods to acquire reasonable proficiency necessary to designing a transformer. Although thetransformer is a mature product, engineers working in the industry need to understandits fundamentals oand design to enable them to offer products to meet the challenging demandsof the power system and the customer. This book can function as a useful guide for practicing engineers to undertake new designs, cost optimization, design automation etc., without the need for external help or consultancy. The book extensively covers the design processes with necessary data and calculationsfrom a wide variety of transformers, including dry-type cast resin transformers, amorphous core transformers, earthing transformers, rectifier transformers, auto transformers, transformers for explosive atmospheres, andsolid-state transformers. The other subjects covered include, carbon footprint salculation of transformers, condition monitoring of transformers and design optimization techniques. In addition to being useful for the transformer industry, this book can serve as a reference for power utility engineers, consultants, research scholars, and teaching faculty at universities.

Contents:

Cover

Half Title

Title Page

Copyright Page

Table of Contents

Preface

Acknowledgments

Author

Chapter 1 Transformer Design

1.1 Introduction

1.2 Definition of Transformer

1.3 Design Objectives

1.4 Basic Theory of Transformer

1.4.1 Electromagnetic Terms and Concepts

1.4.2 Charges, Electric Field and Magnetic Field

1.4.3 Maxwell's Equations

1.5 Power Transfer Capacity of Transformer

Chapter 2 Brief History of Transformers and the Emerging Trends

2.1 Brief History of the Transformer

2.2 Development of Materials for Transformer production

2.2.1 Conducting Material

2.2.2 Cooling Medium

2.2.3 Magnetic Material (Electrical Steel)

2.2.4 New and Emerging Technologies

2.2.5 New Technologies in Commercial Use

2.2.5.1 Amorphous Core Transformers

2.2.5.2 Symmetrical Wound Core (3D Core) Transformer

2.2.5.3 Biodegradable Oil-Filled Transformer

2.2.5.4 Gas-Insulated Transformers

2.2.6 Application of Emerging Technologies to Transformer Design and Manufacture ??

2.2.6.1 Transformers Using High-Temperature Superconductors

2.2.6.2 Intelligent Transformer for Smart Grid

2.3 Replacement of Copper/Aluminium by Carbon Nanotube

2.4 Use of Artificial Intelligence (AI) for Transformer Design and Diagnostics

2.5 Use of Additive Manufacturing (3D Printing) for Transformer Production

Chapter 3 Design Procedures

3.1 Design Input Data

3.2 Design Flow Chart [For Design with LV Parallel Conductors and HV Layer Windings]

Chapter 4 Core Design: Core Area Calculation

4.1 Calculation of Core Diameter and Core Area

4.1.1 Selection of Core Circle

4.1.2 Selection of Core Step Widths

4.1.2.1 Optimum Width of Core Steps to Get Maximum Core Area

4.1.3 Calculation of Gross Area and Net Area of Core

Chapter 5 Winding Design

5.1 Calculation of Volts per Turn.

5.2 Calculation of Phase Volts and Phase Currents

5.3 Calculation of Number of Turns

5.3.1 Calculation of Voltage and Turns of Extended Delta Winding

5.3.2 Calculation of Tap Turns

5.3.2.1 Categories of Voltage Variation

5.4 Calculation of the Cross Section Area of Conductor

5.5 Selection of Current Density

5.6 Selection of Conductor Sizes

5.7 Selection of Types of Windings

5.8 Tap CHANGERS and Tap Changer Connections

5.8.1 Off-Circuit Tap Changer

5.8.2 Off-Load Tap Changer

5.8.3 On-Load Tap Changer

5.9 Calculation of Axial Height of Winding

5.9.1 Spiral Winding

5.9.2 Foil Winding

5.9.3 Crossover Coils

5.9.4 Disc Winding

5.10 Electrical Clearances of Oil-Filled Three-Phase Transformers

5.11 Calculation of Electrical Stresses for Different Configurations

5.11.1 Two Bare Uniform Electrodes (Parallel Electrodes) (One Dielectric) ?

5.11.2 Multidielectric (Parallel Electrodes)

5.11.3 Concentric Cylindrical Electrodes (One Dielectric)

5.11.4 Concentric Cylindrical Electrodes with Multiple Dielectrics

5.11.5 Cylindrical Conductor to Plane Electrode

5.11.6 Insulated Cylindrical Conductor to Plane Electrode

5.11.7 Factors Affecting Insulation Strength

5.12 Insulation between Layers

5.13 Calculation of Winding Diameter and Radial Depth

5.14 Weight of Bare Conductor, Covered Conductor and Resistance of Winding

Chapter 6 Calculation of Load Loss

6.1 Calculation of I 2R Loss

6.2 Calculation of Eddy Current Losses and Stray Losses

6.2.1 Eddy Current Loss in Winding

6.2.2 Stray Loss in Bushing plate

6.2.3 Stray Losses in Flitch Plate (Tie Plate)

6.2.4 Circulating Current Loss in Continuous Disc Winding

6.2.5 Empirical Formula for Tank Loss Calculation

6.2.6 Loss on Transformer Tank Due to High-Current Busbars.

6.2.7 Empirical Formula for Calculating Total Stray Loss

6.3 Calculation of Load Loss

Chapter 7 Calculation of Reactance

7.1 Reactance Calculation of Two-Winding Transformer

7.1.1 Alternate Formula for Reactance Calculation

7.2 Reactance Calculation of Zigzag Connected two-winding Transformers

7.2.1 Effective Reactance of Zigzag Connected Transformers

7.3 Reactance Calculation with Different Ampere-Turn Distributions

7.3.1 LV-HV-LV Arrangement or Similar

7.3.2 Winding with Ducts inside or Windings Made in Two Separate Layers with Gaps

7.3.3 Reactance of Layer Winding with Reduced Layer Height towards Outer Layers

7.4 Reactance Calculations Based on Total Inductance

7.5 Reactance Calculation of Extended Winding

7.6 Zero Sequence Impedance of Zigzag Earthing Transformer

7.7 Reactance Calculation of Neutral Earthing Transformer with Auxiliary Winding

7.8 Reactance of Autotransformer with Tertiary Winding

7.9 Effective Reactance of Windings in Series (Autotransformer)

7.10 Reactance Calculation of Split Winding

7.11 Calculation of Reactance of Individual Windings

7.12 Calculation of Reactance by Finite Element Method

7.13 Zero Sequence Impedance of Three-Phase Transformers

7.14 Zero Sequence Impedance Calculation

Chapter 8 Calculation of Core Frame Size, Core Losses, Efficiency and Regulation

8.1 Core Frame Size and Core Weight Calculation

8.2 Core Loss Calculation

8.2.1 Loss Calculation Based on Average Building Factor

8.2.2 Loss Calculation by Adding of Losses Across the Grain and Along the Grain

8.3 Specific Losses of Different Grades of CRGO Materials

8.4 Core Losses of Symmetrical Core Transformers

8.4.1 Advantages of Symmetrical Wound Core

8.4.2 Manufacturing Process of Symmetrical Wound Core

8.4.3 Symmetrical Wound Core Designs.

8.5 Calculation of No-Load Current (Excitation Current)

8.6 Suggested Changes of Design Parameters to Get Desired Losses

8.7 Calculation of Efficiency and Regulation

8.7.1 Calculation of Efficiency

8.7.1.1 Calculation of Efficiency as per ANSI Standard

8.7.1.2 IEC 60076 Standard and ANSI C57.12 Standard

8.7.1.3 Calculation of Efficiency as per IEC 60076 and ANSI C57.12

8.7.2 Calculation of Regulation

8.8 Calculation of Equivalent Circuit Parameters of Transformer

Chapter 9 Lightning and Switching Surges on Transformers

9.1 Introduction

9.2 Effect of Surges on Transformer Winding

9.3 Capacitive Equivalent Circuit of Transformer

9.4 Calculation of Capacitances

9.5 Calculation of Initial Voltage Distribution of a Capacitive Ladder Circuit

9.6 Impulse and Switching Surge Waves as per IEC 60076-4

9.7 Simulation of Waveform for Analytical Calculations

9.8 Design Techniques to Reduce Non-linear Impulse Voltage Distribution

9.9 Power Frequency Breakdown and Impulse Breakdown

9.10 Selection of Surge Arrester for Transformer

9.10.1 Surge Arresters Parameters

9.10.2 Calculation of Arrester Rating of Solidly Grounded three-Wire System

Chapter 10 Inrush Current in Transformers

10.1 Introduction

10.2 Problems of Transformer Inrush Current

10.2.1 Mechanical Stresses

10.2.2 Overvoltage Due to Harmonic Resonance

10.2.3 Nuisance Tripping of Transformer

10.2.4 Temporary Voltage Dip

10.2.5 Sympathetic Inrush

10.3 Calculation of Inrush Current

10.3.1 Approximate Value of the First Peak of Inrush Current

10.3.2 First Peak of Inrush Current Considering Switching Angle and Circuit Resistance

10.3.3 Estimation of Initial Few Peaks of Inrush Current

10.3.4 Calculation Example

10.4 Frequency Range of Inrush Current and Other Transients.

10.5 Influence of Design on Inrush Current

10.6 Methods for Reduction of Inrush Current

10.7 Effect of System and Switching Parameters on Inrush Current

10.7.1 Source Resistance

10.7.2 Switching Angle

10.7.3 Effect of Remnant Flux on the First Cycle Peak Current

Chapter 11 Calculation of Core and Coil Assembly Dimensions, Tank Size and Tank Weight

11.1 Calculation of the Dimensions of Core and Coil Assembly (CCA)

11.2 Calculation of Dimensions of Tank

11.3 Calculation of the Size of Wooden Beam (Core Clamp)

11.4 Calculation of Weight of Tank [Radiator-Type Tank]

11.4.1 Weight of Top Cover

11.4.2 Weight of Sidewalls

11.4.3 Bottom Plate

11.4.4 Tank Curb

11.4.5 Horizontal Stiffeners

11.4.6 Vertical Stiffeners

11.4.7 Base Channel

11.5 Design of Conservator

11.5.1 Size of the Conservator

11.6 Air Cell for Conservator

11.7 Dehydrating Breathers for Transformers

11.7.1 Regeneration of Saturated Silica Gel

11.7.2 Design Parameters of Breather

11.7.3 Calculation of Quantity of Silica Gel Required

11.7.4 Self-Dehydrating Breather

11.7.5 Calculation of Desiccant in Breather Alternate Method

Chapter 12 Calculation of Winding Gradient, Heat Dissipation Area and Oil Quantity

12.1 Radiation and Convection from Surface

12.2 Heat Dissipation Data for Radiator

12.3 Calculation of Winding Gradient

12.4 Calculation of Winding Gradient: Alternate Method

12.5 Calculation of Mean Oil Temperature Rise

12.6 Calculation of Weight of Radiator Panels

12.7 Calculation of Weight of Corrugated Fins

12.8 Effect of Ambient Temperature on the Top Oil Temperature Rise

12.9 Heat Dissipation by Forced Air Cooling

12.10 Reference Ambient as per IEC

12.11 Calculation of Weighted Average Ambient Temperature

12.12 Calculation of Oil Quantity.

Chapter 13 Calculation of Pressure Rise, Stresses and Strength of Tank.

Notes:

OCLC-licensed vendor bibliographic record.

Description based on print version record.

ISBN:

1-00-308857-0

1-003-08857-0

1-000-34228-X

1-000-34236-0

9781003088578

OCLC:

1232140601