EE 401-Electrical Machines-I |
Direct Current machines: |
Review of construction, types of armature winding, physical concepts of winding pitches, derivation of
EMF equation & types of excitation.
Armature reaction and its effect on the performance, methods adopted for compensation of armature
reaction. . Characteristics of DC generator: separately excited, shunt, series and compound generators.
Compensating winding, Commutation and function of commutators. Improvement of commutation: Brush
shift and interpoles.
|
Direct Current motors: |
Review of types of DC motors. Torque equation, speed torque characteristics: shunt, series and compound
motors.
Starting & speed control of DC motors. 3- point starter & its step calculation. Speed control by controlling
armature resistance, field excitation and armature voltage . Ward- Leonard method of speed control.
Losses & efficiency of DC machines, Hopkinson’s & Swinburne’s test. |
3 phase Transformers: |
Determination of polarity and connections ;( Star/star, star/delta, delta/star,
star/zigzag, delta/zigzag, open delta), phasor groups. Effects of unbalanced loading, production of
harmonic in transformers and their suppression.3- phase to 2- phase transformation, Scott connection, 3-
phase to six phase connections: double star & double delta.
3-winding transformers: parameter estimation. Applications. Parallel operation of transformers,
autotransformers. Introduction to tap changers and their functions.
|
3 phase Induction machines: |
Types, construction, rotating magnetic field, principle of operation, slip,
development of equivalent circuit. Performance equations, torque slip characteristics & power slip
characteristics. Parameter estimation. Starting and speed control of Induction motors. Single phase and
three phase induction regulators.
|
Text Books: |
1. Electrical Machinery, P.S. Bhimra, 6/e, Khanna Publishers.
2. Electric Machines, I.J. Nagrath & D.P. Kothari, 3/e, TMH
3. Electrical Machines, P K Mukherjee & S Chakrabarty, Dhanpat Rai Pub.
|
Reference Books: |
1. Electrical Machnery, S.K.Sen, Khanna Publishers.
2. Electric Machinery & Transformers, Bhag S.Guru & H. R. Hiziroglu, Oxford
3. Electrical Machines: Theory & Practice, M.N. Bandoyopadhyay, PHI
4. Electric Machinery & Transformer, Irving L Koskow, 2/e, PHI
|
|