Synchronous generators, Construction features, Types of prime movers, Excitation system and brushes excitation, Polyphase distributive winding, Integral slot & Fractional slot winding, emf equation, Generation of harmonics and their elimination.
Factor affecting size of synchronous generators, armature reaction, leakage reactive, synchronous reactance and impedance, Equivalent circuit of alternator, relation between generated voltage and terminal voltage, determination of equivalent circuit parameters, Short circuit ratio and its effect on performance, phasor diagram, Synchronous generator under load, Effect of excitation variation, Regulation curve, Regulation by synchronous impedance method, mmf method, Zpf and ASA method, Effect of AVR power and Torque relation.
Salient pole machine, Two reaction theory equivalent circuit model and phasor diagram, Determination of Xd and Xq by slip test, regulation of salient pole alternator, Power angle equation and characteristic Synchronizing of alternator with infinite busbar, Synchronizing power, Parallel operation and load sharing operation on infinite bus bar, Effect of varying excitation and mechanical torque, Effect of synchronizing current, Hunting of alternator, synchroncopes and phase sequence indicator.
Synchronous motors, Construction, Starting and Stopping of synchronous motor, Pull in torque, Motor under load power and torque, reluctance torque, Effect of excitation Effect of armature reaction, Power factor adjustment V curves, inverted V curves, synchronous motors as power factor correcting device, synchronous motors as frequency changer, Super synchronous motors, Hunting & damper winding efficiency and losses. Analysis under sudden short circuit, Transient parameters of synchronous machine, Various transient & sub transient reactances, Time constants, expression of transient and sub transient reactance in terms of self & mutual inductances of various winding, Analysis of three phase short circuit oscillograph and determination of transient parameters from oscillogram.
Generalized theory of electrical Machines, Basic for development of generalized approach for analysis of electrical machines, Kron’s Primitive machine, Concept of rotational & Transformer voltage, Pseudo stationery coil, Voltage and flux linkages, equation of electrical machines, based on coupled circuit approach. Expression for Self & Mutual inductance of various windings with respect to rotor position, Park’s and Inverse park’s transformation. Formulation of equations based on generalized approach for various machines,
Single phase and special motors. Permanent magnet motors, P.M.synchronous motors Introduction to shaded pole motors, Repulsion motor, Universal motors, Hysteresis motor, Reluctance motor, Stepper motor, AC-series motor, Linear induction motors, DC & AC servo motors, Magnetic levitation vehicles, Brush less dc motors.
List of Experiments:
1. Determination of equivalent Circuit parameter of a single phase induction motor. Prediction of torque speed characteristic. Verification from load test.
2. V and invested V-curves of a three phase synchronous motor. Comparison with predicted characteristics
3. Regulation of 3 phase alternator by (1) Zero power factor and (2) A.S.A method (3) MMF and (4) Potiers method & results
4. Determination of Xd and Xq of a salient pole synchronous machine.
5. Measurement of phase sequence impedance of a 3 phase alternator.
6. Study of torque step rate characteristics of stepper motor, Discrimination of operating torque.
7. Load characteristics of universal motor. Operating on DC and AC supply, comparison of performance.
8. Synchronization of 3 phase alternator.
9. No loads short circuit test & legend current test on alternator.
10. Standard short circuit test & determination of Xd, Xd' and—Xdand machine time constant.
1. M.G. Say,Performance & design of AC machines, CBS publishers & distributors, Delhi, 3rd edition
2. A.E. Clayton & N.N. Nancock, The Performance & design of DC machines CBS publications & distributors,Delhi, 3rd edition
3. Nagrath I.J.& Kothari D. P., Electric Machines, Tata McGraw Hill , New Delhi, 2nd edition
4. Bharat Heavy Electricals Ltd, Transformers, Tata McGraw Hill
6. A. E. Fitzerald & C. Kingsley & S.D. Umans , Electric Machinery Tata McGraw Hill ,New Delhi ,5th edition
7. P.S. Bhimbra, Generalized theory of Electrical Machines, Khanna publishers, Delhi, 5th edition.
8. Bhimbra. P.S., Electrical Machines, Khanna Pub.
9. Irving L. Kosow, Electric Machinery and Transformers, PHI.
10. Thedore Wildi, Electrical Machines Drives and Power Systems, Pearson Education, Asia.
11. Electrical Machines- Ashfaq Hussain. Dhanpat Rai Publication.
12. Langsdorf, Theory of Alternating Currents Machines, TMH.