armature winding design

Introduction to AC Machines Dr. Suad Ibrahim Shahl
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ELECTRICAL MACHINES II
Lecturer: Dr. Suad Ibrahim Shahl
Syllabus
I. Introduction to AC Machine
II. Synchronous Generators
III. Synchronous Motors
IV. Three-Phase Induction Machines
V. Three-Phase Induction Motors
VI. Induction Generators
VII. Induction Regulators
Recommended Textbook :
1) M.G.Say
Alternating Current Machines
Pitman Pub.
2) A.S. Langsdorf
Theory of AC Machinery
McGRAW-HILL Pub.
Introduction to AC Machines Dr. Suad Ibrahim Shahl
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I. Introduction to AC Machines
Classification of AC Rotating Machines
•Synchronous Machines:
•Synchronous Generators: A primary source of electrical energy.
•Synchronous Motors: Used as motors as well as power factor compensators (synchronous condensers).
•Asynchronous (Induction) Machines:
•Induction Motors: Most widely used electrical motors in both domestic and industrial applications.
•Induction Generators: Due to lack of a separate field excitation, these machines are rarely used as generators.
• Generators convert mechanical energy to electric energy.
Energy Conversion
• Motors convert electric energy to mechanical energy.
• The construction of motors and generators are similar.
• Every generator can operate as a motor and vice versa.
• The energy or power balance is :
– Generator: Mechanical power = electric power + losses
– Motor: Electric Power = Mechanical Power + losses.
Introduction to AC Machines Dr. Suad Ibrahim Shahl
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AC winding design
The windings used in rotating electrical machines can be classified as
 Concentrated Windings
• All the winding turns are wound together in series to form one multi-turn coil
• All the turns have the same magnetic axis
• Examples of concentrated winding are
– field windings for salient-pole synchronous machines
– D.C. machines
– Primary and secondary windings of a transformer
 Distributed Windings
• All the winding turns are