Electrical Machinery [Theory, Performance and Applications]

This thoroughly revised and updated Edition presents a rigorous and comprehensive treatment of transformers and more common types of rotating Electrical machines types. Each chapters begins with rudimentary concepts and is so developed, that an average Student can easily comprehend it. The salient features of this Book are :
1. In-depth coverage of transformers, d.c. machines, 3-phase synchronous and induction machines.
2. Highlights that electrical machines operate on the same basic principles.
3. Devotes a chapter on electromechanical-energy-conversion principles and another on d.c./a.c. machine windings.
4. Drive aspects and applications are discussed for each machine type.
5. Clearity of presentation is enhanced by illustrative figures and examples selected from questions-papers of important Universities, IAS, IBS and GATE.
6. Includes numerous problems, conceptual questions and objective-type questions (with answers) to help the reader master the basic concepts.

This edition also includes : electrical machinery overview, energy efficiency and resent advances; 3-phase transformers; 3-phase induction generators; appendices on magnetic circuits, 3-phase circuits and short-answer type questions.

All these features contribute towards making this book an ideal text for undergraduate students of degree classes. Practising engineers, through self-study, will also find this volume useful to them.

Dr. P.S. Bimbhra retired as Professor of Electrical and Electronics Engineering from Thapar Institute of Engineering and Technology (Deemed University), Patiala-147004. He has over 40 years of Teaching and Research experience in Electrical Engineering. He has published several papers in renowned journals and national and international conferences. Dr. Bimbhra is a fellow of I.E. (India), a member of I.E.E. (U.K.) and a life member of I.S.T.E.

Overview of Electrical Machinery

I. TRANSFORMERS :
1. Transformer Construction
2. Principle of Transformer Action
3. Ideal Two-winding Transformer
4. Transformer Phaser Diagrams :
i. Transformer Phasor Diagram at no Load
ii. Transformer Phasor Diagram Under Load
iii. Leakage Flux

5. Rating of Transformers
6. Equivalent Circuit of a Transformer
7. Open-circuit and Short-circuit Tests
8. The Per Unit System
9. Voltage Regulation of a Transformer
10. Transformer Losses and Efficiency :
i. Transformer Losses
ii. Transformer Efficiency
iii. Separation of Hysteresis and Eddy Current Losses

11. Testing of Transformers
12. Auto-transformers
13. Parallel Operation of Single-phase Transformers
14. Tap-Changers on Transformers :
i. No-Load (or Off-load) Tap Changer
ii. On-load Tap-changer

15. Induction Regulators :
i. Single-phase Induction Regulator
ii. Three-phase Induction Regulator

16. Transformer as a Magnetically Coupled Circuit :
i. Co-efficient of Coupling
ii. Methods of Increasing the Coefficient of Coupling

17. Audio-Frequency Transformers
18. Pulse Transformers
19. Three-phase Transformers :
i. Three-phase Transformer Connections

20. Transformer Noise
21. Some Worked Examples
22. Summary

II. ELECTROMECHANICAL ENERGY CONVERSION PRINCIPLES :
1. Principle of Energy Conversion
2. Singly Excited Magnetic Systems
3. Reluctance Motor
4. Doubly-excited Magnetic Systems :
i. Electromagnetic and Reluctance Torques

5. Elementary Synchronous Machines
6. Singly-excited Electric Field Systems
7. Dynamic Equations
8. Some Worked Examples

III. BASIC CONCEPTS OF ROTATING ELECTRICAL MACHINES :
1. Physical Concepts of Torque Production :
i. Electromagnetic (or Interaction) Torque
ii. Reluctance (or Alignment) Torque

2. Constructional Features of Rotating Electrical Machines :
i. Polyphase Induction Machines
ii. Synchronous Machines
iii. Direct Current Machines

3. Concepts of General Terms Pertaining to Rotating Machines
4. Generated emfs :
i. Generated e.m.f. in a Full-Pitched Coil
ii. Generated e.m.f. in a Short-pitched Coil
iii. A.C. Machines
iv. Generated e.m.f. in d.c. Machines

5. E.m.f. Polygon:
i. Distribution, Breadth or Belt Factor
ii. Pitch (or Coil-span) Factor
iii. Elimination of Harmonics from Alternator emf Waveforms

6. M.m.f. Produced by Distributed Windings :
i. M.m.f. of a Coil
ii. M.m.f. of Distributed Windings
iii. Current-sheet Concept
iv. M.m.f. Waveform of Commutator Machines

7. Rotating Magnetic Field
8. Production of Torque in Non-Salient Pole Machines :
i. Alternative Derivation for Torque

9. Losses and Efficiency
10. Machine Ratings :
i. Choice of Power of Electric Machines

11. Cooling (Loss Dissipation)
12. Machine Applications

IV. D.C. MACHINES :
1. Action of Commutator
2. E.m.f. Generated in the Armature
3. Torque in D.C. Machines
4. Circuit Model of DC Machines
5. Methods of Excitation
6. M.m.f. and Flux Density Waveforms in d.c. Machines :
i. Armature Reaction
ii. Methods of Limiting the Effects of Armature Reaction

7. Effect of Brush Shift
8. Commutation Process :
i. Interpoles
ii. Brushes

9. Compensating Windings
10. Basic Performance Equations for D.C. Machines :
i. Magnetisation Curve
ii. Effect of Armature m.m.f. on d.c. Machine Calculations

11. Operating Characteristics of D.C. Generators :
i. Separately-excited Generators
ii. Shunt Generators
iii. Series Generators
iv. Compound Generators
v. Effect of Speed on External Characteristics

12. Operating Characteristics of D.C. Motors :
i. D.C. Shunt Motor
ii. D.C. Series Motor
iii. D.C. Compound Motor

13. D.C. Motor Starting :
i. Shunt and Compound Motor Starters
ii. Series Motor Starters

14. Speed Control of D.C. Motors :
i. Speed Control by Varying the Armature-circuit Resistance
ii. Speed Control by Varying the Field Flux
iii. Speed Control by Varying the Armature Terminal Voltage

15. Efficiency and Testing of d.c. Machines :
i. Efficiency of d.c. Machines
ii. Testing of d.c. Machines

16. Rotating Amplifiers :
i. Cross-field or Metadyne Generators
ii. Amplidyne

17. Permanent Magnet DC (PMDC) Motors
18. D.C. Machine Applications :
i. Generator Applications
ii. Motor Applications

V. POLYPHASE SYNCHRONOUS MACHINES :
1. Excitation Systems for Synchronous Machines
2. Flux and mmf Phasors in Synchronous Machines :
i. Cylindrical-rotor Synchronous Machines
ii. Salient-pole Machines

3. Phasor Diagram of a Cylindrical Rotor Alternator :
i. The open-circuit and Short-circuit Characteristics of Synchronous Machines
ii. Zero Power-factor Characteristic and Potier Triangle

4. Voltage Regulation of an Alternator :
i. The Electromotive Force (emf) Method or Synchronous Impedance Method
ii. The Magnetomotive Force (m.m.f.) Method
iii. Zero Power Factor Method
iv. New A.S.A. (American Standards Association) Method
v. Saturated Synchronous-reactance Method

5. Physical Concepts of Synchronous Machine Operation
6. Synchronous Motor Phaser Diagram
7. Operating Characteristics of Alternators and their Ratings :
i. External Load Characteristics
ii. Alternator Compounding Characteristics
iii. Rating of Alternators

8. Power Flow Through an Inductive Impedance :
i. Maximum Power Conditions
ii. Reactive Power

9. Circle Diagrams of Synchronous Machines :
i. Synchronous Motor Circle Diagrams

10. Power Factor Control of Synchronous Machines :
i. Power-factor Control of Synchronous Motors
ii. Power-factor Control of Alternators

11. Two-reaction Theory of Salient-pole Machines
12. Power-angle Characteristics of Synchronous Machines :
i. Cylindrical-rotor Synchronous Machine
ii. Salient-pole Synchronous Machine

13. Synchronizing Power and Synchronizing Torque :
i. Physical Concepts of Synchronizing Power

14. Synchronous Machine Stability
15. Hunting and Damper Windings :
i. Hunting
ii. Damper Windings

16. Measurement of Xd and Xq
17. Efficiency of Synchronous Machines
18. Operating Limit on Synchronous Generators :
i. Operating Chart
ii. Capability Curves

19. Power Factor Correction by Synchronous Motors :
i. Synchronous Condenser
ii. Dual-purpose Synchronous Motor

20. Starting of Synchronous Motors :
i. Starting of Synchronous Motors Against High Torques

21. Some Worked Examples
22. Synchronous Machine Applications

VI. Polyphase Induction Motors :
1. Induction Motor as a Transformer
2. Principle of Operation
3. Flux and mmf Phasors and Waves in Induction Motors
4. Rotor Frequency
5. Rotor e.m.f., Current and Power
6. Losses and Efficiency
7. Induction Motor Phasor Diagram
8. Equivalent Circuit
9. Analysis of the Equivalent Circuit :
i. Torque-slip Characteristics
ii. Power-slip Characteristics

10. Operating (or Performance) Characteristics of Induction Motors :
i. Induction Motor Stability

11. Determination of Equivalent Circuit Parameters
12. Circle Diagram
13. Power Factor Control of Three Phase Induction Motors :
i. Static Capacitors

14. Starting of Polyphase Induction Motors :
i. Starting of Squirrel-cage Motors
ii. Methods of Starting Wound-rotor Motors

15. Polarity Test
16. Induction Generator :
i. Self-excited or Isolated Induction Generator
ii. Applications of Induction Generators

17. Applications of Polyphase Induction Motors

V. Armature Windings :
1. Closed Windings :
i. Closed-winding Terms

2. Simplex Lap Winding :
i. Split Coils

3. Simplex Wave Winding :
i. Dummy Coils

4. Multiplex Windings
5. Equalizer Rings
6. Open Windings or A.C. Armature Windings
7. Double Layer Windings :
i. Integral Slot Windings

8. Fractional Slot Windings
9. Single-Layer Windings :
i. Concentric Windings
ii. Mush Windings