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U n i t - 1
3-phase induction motors
Construction details of squirrel cage and slip ring induction motors – Production of rotating magnetic field –
Principle of operation – Equivalent circuit – Phasor diagram – Slip speed-rotor emf and rotor frequency – Rotor
current and pf at standstill and during running conditions – Rotor power input, rotor copper loss and mechanical
power developed and their interrelationship.
U n i t - 2
characteristics and testing methods of induction motors
Torque equation – Expressions for maximum torque and starting torque – Torque slip characteristic – Double
cage and deep bar rotors – Crawling and cogging – Speed control of induction motor with V/F control method
– No load and blocked rotor tests – Circle diagram for predetermination of performance – Induction generator
operation (Qualitative treatment Only).
U n i t - 3
starting methods of 3-phase induction motors
Methods of starting of three phase induction motors: DOL, Auto transformer, Star-Delta and rotor resistance
methods.
single phase induction motors
Constructional features - Equivalent circuit - Problem of starting - Double revolving field theory - Methods of
starting, AC series motors.
U n i t - 4
construction, operation, voltage regulation and parallel operation of
synchronous generator
Constructional features of non-salient and salient pole machine – types of armature windings – Distribution,
pitch and winding factors – E.M.F equation – Improvements of waveform and armature reaction – Phasor
diagrams - Voltage regulation by synchronous impedance method – MMF method and Potier triangle method
– Two reaction analysis of salient pole machines and phasor diagram.
Parallel operation with infinite bus and other alternators – Synchronizing power – Load sharing – Control of real
and reactive power – Numerical problems.
U n i t - 5
synchronous motor – operation, starting and performance
Synchronous motor principle and theory of operation – Phasor diagram – Starting torque – Variation of current
and power factor with excitation – Capability curves – Synchronous condenser – Mathematical analysis for
power developed – Hunting and its suppression – Methods of starting – Applications.