Title Power Transformers - Principles and Applications 2.0 MB 286
Power Transformers Principles and Applications
Power Transformers Principles and Applications
Preface
Contents
Series Introduction
Chapter 01: Basic Transformer Theory
1.1 Definition Of A Transformer
1.2 Magnetic Units And Conversion Factors
1.3 Currents And Magnetic Fields
1.4 Magnetic Induction
1.5 Constructing A Simple Transformer
1.6 The Magnetic Circuit
1.7 The B-h Curve
1.8 The B-h Curve And Hysteresis
1.9 Magnetizing Currents And Harmonics
1.10 Transformer Core Design And Construction
1.11 Magnetostriction
1.12 Completing The Transformer By Adding A Second Winding
1.13 Placement Of The Windings
References
Chapter 02: Two-winding Transformer Connections
2.1 Introduction
2.2 The Y-y Connection In Three- Phase Systems
2.3 Advantages Of The Y-y Connection
2.4 Disadvantages Of The Y-y Connection
2.5 The Y-.connection And The .-y-connection
2.6 Phase Angle Displacement And Phase Rotation
2.7 The Y-. Grounding Bank
2.8 The Zigzag Connection
2.9 Comparisons Of Economy Of The Different Winding Configurations
2.10 Trade-off Between Steel And Copper In The Design Of A Transformer
2.11 Connecting Three-phase Banks Using Single- Phase Transformers
2.12 Transforming Three-phase Voltages Into Two- Phase Voltages
2.13 The Scott Transformer Connection
2.14 Three-phase Transformer Designs
2.15 Standard Terminal Markings For Transformers
References
Chapter 03: Transformer Impedance And Losses
3.1 Leakage Flux And Leakage Reactance
3.2 Conductor Losses
3.4 Magnetizing Reactance
3.5 Equivalent Circuit Of A Two- Winding Transformer
3.6 A Brief Tutorial On Symmetrical Components
3.7 Transformer Equivalent Circuits Modeled In Zero Phase Sequence Networks
3.8 Series Impedance And Regulation
3.9 Matching Transformers For Parallel And Bank Operations
3.10 Impedance Mismatch In Threephase Transformer Banks
3.11 Temperature Rise And The Thermal Capability
3.12 Interpreting Transformer Test Reports
3.13 Calculating The Hot-spot Temperature Using The Ieee Method
3.14 Calculating The Loss Of Life
References
Chapter 04: Autotransformers And Three- Winding Transformers
4.1 Autotransformer Connections
4.2 Impedance Of An Autotransformer
4.3 Limitations Of The Autotransformer Connection
4.4 Autotransformer Voltages With Short Circuits Applied
4.5 Impulse Voltages Applied To Autotransformers
4.6 Autotransformer Core And Coil Designs And Terminal Configurations
4.8 Three-winding Transformers
4.9 Modification Of Transformer Laws With Three Windings
4.10 Equivalent Circuit Of A Threewinding Transformer
4.11 Core And Coil Construction Of Three- Winding Transformers
4.12 Thermal Capability Of Threewinding Transformers
4.13 The Stabilizing Effect of A . Tertiary Winding
Reference
Chapter 05: Short Circuits, Inrush Currents, And Other Phenomena
5.1 Effects Of Short Circuits On Transformers
5.2 Comparisons Of Short-circuit Currents For Various Faults
5.3 Mechanical Forces In Transformers
5.4 Forces Between Transformer Windings
5.5 Short-circuit Forces In Threewinding Transformers
5.6 Exciting Current Inrush
5.7 Tank Overheating From Zero- Sequence Currents
5.8 Primary Fuse Misoperations
5.9 Ferroresonance
5.10 Voltage Surges
References
Chapter 06: Ancillary Equipment
6.1 Bushings
6.2 Oil Preservation Systems
6.3 Cooling Equipment
6.4 Temperature, Oil Level, And Pressure Gauges
6.5 Tap-changing Equipment
6.7 Voltage Regulating Transformers
6.8 Tap Changer Automatic Controls
6.9 Variable Phase Shifting Transformers
Reference
Chapter 07: Reading And Applying Nameplate Information
7.1 Minimum Nameplate Requirements
7.2 Manufacturer’s Information
7.3 Cooling Class, Number Of Phases, And Operating Frequency
7.4 Voltage Ratings
7.5 KVA Or MVA Ratings
7.6 Winding Connection Diagram
7.7 Phasor Or Vector Diagram
7.8 Weights And Oil Capacity
7.9 Operating Pressure Range
7.10 Impedance
7.11 Basic Insulation Level
7.12 Nameplate Layout
References
Chapter 08: Maintenance, Testing, Troubleshooting, And Reliability
8.1 Good Utility Practices
8.1.1 Scope
8.1.2 Schedule For Tests, Inspections
8.1.3 Receiving New Or Rebuilt Transformers
8.1.4 Handling And Shipping
8.1.5 Storage
8.1.6 Acceptance For Service
8.1.7 Safety Precautions
8.1.8 Internal Inspection Precautions
8.1.9 Test Procedures
8.1.10 Vacuum Oil Filling
8.1.11 Maintenance Of Spare Transformers
8.2 Preventative Maintenance Versus Predictive Maintenance
8.3 Factory Tests
8.4 Ratio Test
8.5 Other Factory Tests
8.6 Field Tests
8.7 Gas-in-oil Analysis
8.8 Water-in-oil Analysis
8.9 Drying Transformers
8.10 Oil Dielectric Test
8.11 Reliability Calculations
8.12 The Chi-squared Distribution
8.13 The Poisson Distribution
8.14 Statistical Economics
References