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ELECTRICAL ENGINEERING – Vol. III - Direct Current Machines - Edward Spooner

DIRECT CURRENT MACHINES
Edward Spooner
The University Of New South Wales, Australia.
Keywords: Electric machines, dc motor, electromagnetic induction, Faraday 's Law, commutator. Contents

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1. Introduction
2. Magnetism and Electromagnetic principles
2.1. Permanent Magnets
2.2. Magnetic Field around Conductors
2.3. Magnetic Field around a Coil
2.4. Electromagnets
2.5. Magnetic Strength of Electromagnets
2.6. Electromagnetic Induction
3. Current Carrying Wires and Coils
3.1. Force on a Wire in a Magnetic Field
3.2. Force and Torque on a Coil in a Magnetic Field
4. Basic Motor Principles
4.1. The Commutator and Motor Action
4.2. Simplified Version of the dc Motor
4.3. Sizes of Machines (related to Torque)
4.4. Construction of Motors
4.5. The Stator of a dc Machine
4.6. Rotor
4.7. The Commutator
4.8. Electromotive Force (EMF) in dc Machines
5. Machine equations and circuits
5.1. Basic Equivalent Circuit of a dc Motor.
5.2. Direct current Motor Operation & Torque generation
5.3 DC Machine Torque Equations
5.4. DC Machine Equations and Speed Regulation
5.5. Machine Power and Losses
6. Types of dc Machine
6.1. Permanent Magnet
6.2 Shunt Wound
6.3 Separately Excited
6.4. Series Connected
6.5. Compound Connected Motor
7. Stepper Motors
7.1. General
7.2. Permanent Magnet Stepper Motors
7.3. Reluctance Stepper Motors
7.4. Torque – Step Rate
8. Conclusions

©Encyclopedia of Life Support Systems (EOLSS)

ELECTRICAL ENGINEERING – Vol. III - Direct Current Machines - Edward Spooner

Glossary
Bibliography
Biographical Sketch
Summary
This chapter gives a background to the principles behind the operation of dc motors and stepper motors. Permanent magnet, shunt, separately excited, series and compound wound dc motor connections are described. A description of the equations behind the
basic

Bibliography: Edwards J.D. (1991) “Electrical machines and drives : an introduction to principles and characteristics.” Basingstoke : Macmillan Fitzgerald A.E., Kinglsey C. Jr., (1961) “Electric Machinery” 2nd Edition, McGraw Hill. [Comprehensive text on electric machines.] Guru B.S., Hiziroglu H.R., (2001) “Electric Machinery and Transformers” 3rd Edition, New York, Oxford University Press Say M.G. (1983). Alternating Current Machines, 5th Edition, London: Pitman. [This covers the more advanced theory of electrical machines]