4EX1-ELECTRICAL MACHINES-I |
Units: I-ELECTROMECHANICAL ENERGY CONVERSION: |
Basic principles of
Electromechanical energy conversion. Basic aspects and physical phenomena involved in
energy conversion. Energy balance.
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Units: II-DC GENERATORS: |
Construction, Types of DC generators, emf equation, lap & wave
windings, equalizing connections, armature reaction, commutation, methods of improving
commutations, demagnetizing and cross magnetizing mmf, interpoles, characteristics, parallel
operation. Rosenberg generator. |
Units: III-DC MOTORS: |
Principle, back emf, types, production of torque, armature reaction &
interpoles, characteristics of shunt, series & compound motor, DC motor starting. Speed
Control of DC Motor: Armature voltage and field current control methods, Ward Leonard
method. Braking, losses and efficiency, direct & indirect test, Swinburne’s test, Hopkinsion
test, field & retardation test, single-phase series motor.
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Units: IV-TRANSFORMERS: |
Construction, types, emf equation. No load and load conditions.
Equivalent circuits, Vector diagrams, OC and SC tests, Sumpner’s back-to-back test,
efficiency. Voltage regulation, effect of frequency, parallel operation, autotransformers,
switching currents in transformers, separation of losses.
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Units: V-POLYPHASE TRANSFORMERS: |
Single unit or bank of single-phase units, polyphase
connections, Open delta and V connections, Phase conversion: 3 to 6 phase and 3 to 2 phase
conversions, Effect of 3-phase winding connections on harmonics, 3-phase winding
transformers, tertiary winding.
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