ELECTRICAL DEPARTMENT NOTICE BOARD

MID-SEMESTER TEST SYLLABUS for 

SUBJECT:A C Machines (4Th semester) [ subject code : 2140906]

	Content
1	Poly-phase Induction Motor: Construction, Types of motor, Working principle, Rotating magnetic field. Operating parameters at different load, No-load & blocked rotor test, Equivalent circuit, Phasor diagram, Circle diagram, Efficiency and slip scale with the help of circle diagram, Effect of rotor resistance on performance of motor, Double cage motor and its equivalent circuit, Introduction to machine dynamics. Starters of poly-phase induction motor including soft starter, Methods of speed control of 3- phase motor, Schematic diagram and advantages of Variable Voltage Variable Frequency drive. Electrical transients in induction machine, Magnetic levitation : Principle, advantages and application of linear induction motor. Effect of harmonics, Harmonic torques, Cogging & Crawling, Effect of unbalanced voltages on performance of motor. Performance of motor with variable voltage and frequency. Testing of induction motor as per IS, Energy efficient motors.
2	Synchronous Machines: Construction, Types, Applications, Working principle. Equation of induced emf with and without harmonics in MMF, pitch factor and distribution factor, MMF of distributed windings, Torque equation, Machine efficiency, Armature reaction and its compensation, Short circuit ratio, Effect of change in excitation, Effect of change in torque and speed, Voltage regulation, Determination of voltage regulation by Synchronous impedance method, MMF method, ZPF method and AIEE method, Synchronization : Importance and Methods of synchronization. Operating characteristic, Load angle and Power flow equations, Capability curves, Two reaction model of Salient pole machines, Parallel operation, Load sharing between parallel connected generators, Effect of unequal voltages & unequal percentage impedance, Governor characteristics, Introduction to single phase generators, Slip test for measurement of direct axis and quadrature axis reactance for salient pole machine, Sudden short circuit of Synchronous machine, Hunting of synchronous machines and its prevention