ELECTRICAL MACHINE - I SYLLABUS

UNIT – I
Review of transformer theory, Auto-transformer equivalent circuit and phasor diagram,
three-phase transformers, core and shell type transformer, three-phase tank, three-phase
unit, different connections and vector groups, three winding transformer connections,
parameters of three winding transformer, coupled circuit view point.

UNIT – II
Parallel operation of single-phase and three-phase transformer, Scott connection, opendelta,
back-to-back test, separation of losses, excitation phenomenon in transformers.

UNIT – III
Electromagnetic principle of DC machine, constructional details, production of voltage
and torque, BLV and BLI concepts, classification of DC machine, conditions of self
excitation, armature reaction and its effect, flux and mmf waves, effect of brush shift,
commutation, methods of improving commutation, Operating characteristics of DC
generator, parallel operation.

UNIT – IV
DC machine as motor, armature reaction, its effect on motor working, electrical and
mechanical characteristics of DC motor, starting and speed control of DC motors, losses
in DC machines, Testing of DC machines, Swinburne’s test, regenerative and retardation
test.

UNIT – V
Cross-field machines, armature winding, transformer cooling, wide band transformer,
pulse transformer, audio frequency transformer.

Text Books:
1. Electrical Machines by Smarajit Ghosh, Pearson Education
2. Performance & Design of A.C. Machines by M.G. Say, C.B.S. Publishers

Reference Books:
1. Performance & Design of D.C. Machines by A.E. Clayton & Hancock, C.B.S.
Pbs.
2. Electric Machines by Nagrath & Kothari, TMH Pbs.
3. Electric Machines by P.K. Mukherjee & S.Chakravarti, Dhanpat Rai
4. Electrical machines by B. R, Gupta, New age International.