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Unit1.
INTRODUCTION: General equation of inducted emf, AC armature windings:
concentric and distributed winding, chording, skewing, effect on induced
emf. Armature and field mmf, effect of power factor and current on
armature mmf, harmonics. Rotating fields.
Unit2. INDUCTION MOTORS: Construction of squirrel cage & slip ring
induction motor, basic principles, flux and mmf waves, induction motor as
a transformer. Equivalent circuits, torque equation, torque-slip curves,
no load & block rotor tests, circle diagram, performance calculation.
Effect of rotor resistance. Cogging, Crawling. Double cage squirrel cage
induction motor, induction generator, induction regulator.
Unit3. STARTING & SPEED CONTROL OF INDUCTION MOTORS: Various
methods of starting & speed control of squirrel cage & slip ring motor,
cascade connection, braking. Single-Phase Induction Motor: Revolving field
theory, starting methods, equivalent circuits.
Unit4. SYNCHRONOUS GENERATOR: Construction, types, excitation
systems, principles. Equation of induced emf, flux and emf waves, theory
of cylindrical rotor and salient pole machines, two-reactance theory,
phasor diagrams, power developed, voltage regulation, OC & SC tests, zero
power factor characteristics, potier triangle and ASA method of finding
voltage regulation, synchronization, parallel operation, hunting and its
prevention.
Unit5. SYNCHRONOUS MOTORS: types, construction, principle, phasor
diagrams, speed torque characteristics, power factor control, V-curves,
starting methods, performance calculations, applications, synchronous
condenser, synchronous induction motor.
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