B. Tech II Year II Semester
18EEE107
INDUCTION AND SYNCHRONOUS MACHINES
Course Prerequisite: 18EEE101, 18PHY102
L T P C
3 0 0 3
Course Description:
This course is designed to obtain thorough knowledge on AC machinery fundamentals, machine
parts, operation of Single phase and Three phase AC machines. The course also equips students with
ability to understand and analyse the phasor diagrams and equivalent circuits of AC Induction and
Synchronous Machines. Course covers Theory, performance, testing, applications and control of
electromechanical energy converters like Induction machines, synchronous machines. To have
hands-on experience by testing Single phase, three phase Induction motor and synchronous machines
to evaluate their performance.
Course Objectives:
1. To emphasize the basic concepts of AC rotating machines.
2. To deal with the detailed analysis of Synchronous generators and motors.
3. To introduce the concept of parallel operation of synchronous generators.
4. To deal with the detailed analysis of polyphase induction motors.
5. To understand operation, construction and types of single phase motors and their applications in
house hold appliances and control systems.
UNIT I: FUNDAMENTALS OF AC MACHINE WINDINGS
Physical arrangement of windings in stator and cylindrical rotor; slots for windings; single turn coil active portion and overhang; full-pitch coils, concentrated winding, distributed winding, winding
axis, Rotating Magnetic field: Windings spatially shifted by 90 degrees, Addition of pulsating
magnetic fields, three windings spatially shifted by 120 degrees (carrying three-phase balanced
currents), revolving magnetic field.
(9)
UNIT II: SYNCHRONOUS GENERATOR
EMF equation, equivalent circuit and phasor diagram, armature reaction, synchronous impedance,
voltage regulation by synchronous impedance method, M.M.F. method, Parallel operation of
alternators - synchronization and load division, control of P and Q outputs - operating chart for
synchronous machine. Salient pole machine - two reaction theory, Synchronous Condenser.
(9)
UNIT III: SYNCHRONOUS MOTOR
Principle of operation - different starting methods- equivalent circuit - effect of load changes on
synchronous motor - mechanical load diagram - armature current as function of power developed and
excitation - V curves - inverted V curves - transition of a machine from generator mode to motor
mode - phasor diagram - torque and power relations - hunting - periodicity of hunting - suppression.
(9)
UNIT IV: INDUCTION MOTORS
Construction, Types (squirrel cage and slip-ring), Torque Slip Characteristics, Starting and
Maximum Torque. Equivalent circuit, Circle diagram, Phasor Diagram, Losses and Efficiency. Effect
of parameter variation on torque speed characteristics (variation of rotor and stator resistances, stator
voltage, frequency). Methods of starting, braking and speed control for induction motors. Induction
Generator operation.
(9)
UNIT V: FRACTIONAL HORSE POWER MACHINES
Constructional features, double revolving field theory, equivalent circuit, determination of
parameters. Split-phase starting methods and applications, Introduction to BLDC, SRM, Stepper
Motors.
(9)
Course Outcomes:
At the end of this course, students will demonstrate the ability to
1. Understand the operating principles of different ac machines.
2. Understand the design of stator and rotor of ac machines.
3. Demonstrate practical testing of different ac machines.
4. Inference the theory of single phase induction motor.
5. Evaluate the performance of Three phase, Single phase Induction motor and synchronous motor.
Text Books:
1. E. Fitzgerald and C. Kingsley, "Electric Machinery”, McGraw Hill Education, 2013.
2. M. G. Say, “Performance and design of AC machines”, CBS Publishers, 2002.
3. P. S. Bimbhra, “Electrical Machinery”, Khanna Publishers, 2011.
4. I. J. Nagrath and D. P. Kothari, “Electric Machines”, McGraw Hill Education, 2010.
References:
1. S. Langsdorf, “Alternating current machines”, McGraw Hill Education, 1984.
2. P. C. Sen, “Principles of Electric Machines and Power Electronics”, John Wiley & Sons, 2007.
3. E.G. Janardanan, ‘Special electrical machines’, PHI learning Private Limited, Delhi, 2014.
4. K. Venkataratnam, ‘Special Electrical Machines’, Universities Press (India) Private Limited,
2008.
Mode of Evaluation: Assignment, Written Examination