# 2K6EE 504 : ELECTRICAL MACHINES II￼

**Module I (12 hours)**

Synchronous generators: Construction – principle of operation – type and selection- EMF developed in a winding – Distribution factor- Chording factor – armature reaction – voltage regulation – automatic voltage regulator – predetermination of voltage regulation – EMF method – MMF method – Potier method – ASA method – phasor diagrams – short circuit ratio- two reaction theory – modified phasor diagram – analysis by two reaction theory – slip test – sudden short circuit – current waveforms – transient and subtransient reactances – DC excitation – static excitation – brush less excitation .**Module II (14 hours)**

Analysis of synchronous machines – Power angle characteristics of cylindrical rotor and salient pole machines -active and reactive power control – alternator connected to infinite bus -synchronizing power and torque- effect of armature reactance- load sharing upon parallel operation – power frequency characteristics – locus of generated voltage for constant real power and variable excitation – V curves – inverted V curves Synchronous motor – Principle of operation – different starting methods -equivalent circuit – phasor diagram- effect of load changes on synchronous motor – mechanical load diagram – torque and power relations- synchronous condenser- hunting – periodicity of hunting – suppression- applications.**Module III (14 hours)**

Theory of induction machines: 3 phase induction motors – construction – principle of operation – rotor MMF and production of torque – slip and frequency of rotor current – phasor diagram – equivalent circuit – mechanical power developed – maximum torque – torque slip characteristics – losses and power flow – single phasing – no-load and blocked rotor tests – the circle diagram – double cage rotors – effects of air gap flux harmonics – cogging and crawling – line excited and self excited induction generators – applications of induction motors.**Module IV (12 hours)**

Starting and speed control of induction motors: starting methods for three phase induction motors – direct on line starting – auto transformer starting – star delta starting – rotor resistance starting – speed control – basic methods – voltage control – frequency control – rotor resistance control – pole changing – slip power recovery schemeSingle phase induction motor – double field revolving theory – equivalent circuit- starting methods-capacitor based starting and running.

Text book and References

1. Langsdorf A.S., Theory of A.C Machinery, McGraw Hill.

2. Dr PS Bimbhra, Electrical Machinery, Khanna Publishers

3. Nagrath I.J. & Kothari D.P., Electric Machines, Tata McGraw Hill

4. Fitzgerald A.E. & Kingsley, Electrical Machinery, McGraw Hill

5. Say M.G., Performance and Design of AC Machines, Pitman, ELBS.

6. Stephen J Chapman, Electric Machinery Fundamentals, McGraw Hill.

7. Vincent Del Toro, Electrical Machines and Power Systems, Prentice Hall

8. Ashfaq Hussain, Electric machines, Dhanpat Rai & co.

9. Theodore Wildi, Electrical Machines, Drives and Power systems, Pearson

10. Smarajit Ghosh, Electrical Machines, Pearson

11 JB Gupta, Theory and Performance of Electrical Machines, SK Kataria & Sons