This textbook provides an introduction to power transformers, rotating ac machines, and photovoltaic power systems. An introduction to power electronic converters is covered, with applications to variable speed drives for AC motors and generators.

Electromechanical Machinery Theory and Performance presents a detailed explanation of electromagnetic machines, giving specific focus on transformers and AC rotating machines that can be used in the generation, transmission and utilization preservation and transference of electrical energy and power. This book is developed for students at both graduate and undergraduate level, and can be used by practicing engineers as well.

Electromechanics combines processes and procedures drawn from electrical engineering and mechanical engineering. Electromechanics focuses on the interaction of electrical and mechanical systems as a whole and how the two systems interact with each other. This process is especially prominent in systems such as those of DC or AC rotating electrical machines which can be designed and operated to generate power from the mechanical process or used to power mechanical motors. Electrical engineering, in this context, also encompasses electronics engineering.

Key Features:

• Covers the basics of AC machine performance
• Focuses on applications of these machines in practical systems
• Discusses machine rating and limitations
• Includes practical examples and homework exercises
• Includes material on permanent magnet machines

Preface

Acknowledgements

Author biography

1 Energy and power

1.1 Energy

1.1.1 Energy sources

1.1.2 Electrical energy

1.2 Power—single phase

1.2.1 Power in sinusoidal single-phase electrical circuits

1.2.2 Reactive power and apparent power

1.3 Three-phase power

1.3.1 A balanced wye-connected power system

1.3.2 Per phase equivalent circuit

1.3.3 Delta-connected loads

1.4 Summary

1.4.1 Questions

1.4.2 Problems

References

2 Magnetic circuits

2.1 Rectangular core magnetic circuit

2.2 Magnetic circuits with small air gap

2.3 Three-legged core

2.4 Properties of magnetic materials

2.4.1 Questions

2.4.2 Problems

3 Single phase transformers

3.1 Single-phase two-winding transformer

3.2 The ideal transformer

3.3 The real transformer

3.3.1 Core magnetization and core loss

3.3.2 Winding resistance and leakage reactance

3.3.3 The full transformer equivalent circuit

3.3.4 Simplified equivalent circuits

3.4 Transformer ratings

3.5 Determining equivalent circuit parameters by test

3.6 Power transformer thermal model

3.7 Frequency response of signal transformers

3.7.1 Questions

3.7.2 Problems

Reference

4 Three-phase transformer banks

4.1 Three-phase transformer cores

4.2 Three-phase transformer windings

4.2.1 Wye winding

4.2.2 Delta connection

4.3 Wye–wye transformers

4.4 Delta–wye transformers

4.5 Delta–delta transformers

4.6 Per-phase analysis of three-phase transformers

4.6.1 Questions

4.6.2 Problems

5 Rotating AC machine basics

5.1 The two-pole one-phase machine

5.2 Machines with higher pole numbers

5.3 Three-phase machines

5.4 Stator current and flux

5.5 Synchronous-generator per-phase equivalent circuit

5.5.1 Generator convention and motor convention

5.6 Mechanical power and torque—generator convention

5.7 Distributed windings and salient pole designs

5.7.1 Distributed windings in round-rotor machines

5.7.2 Salient pole machines

5.7.3 Permanent magnet machines

5.8 Salient pole machines

5.9 Summary

5.9.1 Questions

5.9.2 Problems

**6 Synchronous generator performance **

6.1 Synchronous generators

6.2 Determining synchronous machine parameters by test

6.3 Synchronous generator operation

6.4 Grid connected operation

6.4.1 Questions

6.4.2 Problems

7 Induction machines

7.1 Overview

7.2 Theory

7.3 Stator and rotor rotating flux waves

7.4 Torque and power

7.5 Squirrel cage machines

7.6 Induction motor operation

7.7 Squirrel cage motor performance

7.8 Direct connection motor starting

7.9 Induction generator

7.9.1 Questions

7.9.2 Problems

8 Power electronic converters and speed control of AC machines

8.1 Pulse width modulated converters: the full bridge converter

8.1.1 DC to DC PWM converter

8.1.2 DC-to-single phase AC PWM converter

8.2 Three-phase PWM converter

8.2.1 8-10

8.3 Converter connected synchronous machines

8.4 The ideal DC drive

8.5 Variable speed control of round-rotor permanent-magnet synchronous motors

8.6 Variable-speed induction motor drives

8.7 AC motor drive performance and control

8.7.1 Questions

8.7.2 Problems

9 Grid-connected photovoltaic farms

9.1 Photovoltaic cell basics

9.2 Photovoltaic modules

9.3 Solar insolation

9.4 PV arrays

9.5 PV farm performance

9.6 PV farm capacity factor

9.7 Summary

9.7.1 Questions

9.7.2 Problems

References