Syllabus Electrical Machines - I - (BE03009021) Total Credits = TH/30 Assessment Pattern and Marks Total Marks Theory Tutorial / Practical ESE (E) PA (M) PA (I) TW/SL(I) ESE (V) 04 70 30 20 30 50 200 Unit No. Content 1. Single Phase Transformer : Review of single phase transformer, E.M.F. equation, Equivalent circuit, phasor diagram for different power factor, Losses, separation of no-load losses, conditions for maximum efficiency, determination of equivalent circuit parameters, calculation of efficiency and voltage regulation using O.C. and S.C. Test, Sumpner’s test. Polarity test, Determination of Efficiency and Voltage regulation by direct load test, Concept of all-day efficiency. Parallel operation of transformers and Load sharing under different operating conditions. Auto transformer, saving of copper and applications. Numerical based on above topics. (Chapters - 1, 2) 2. Three Phase Transformer : Construction, types of connection and their comparative features, Vector groups, Types of Transformers, terminal marking and nomenclature, protective and safety devices fitted on Transformers, Parallel operation of three phase transformers, Magnetizing current, Phase conversion - Scott connection, No-load and on-load tap-changing of transformers, Three-winding transformers. Cooling of transformers. Short Circuit Forces and Mechanical stresses, Application of transformers in various electrical systems. (Chapter - 3) 3. Three Phase Induction Machine : Constructional details, classification, principle of operation, production of rotating magnetic field, Torque equations for starting, full load and maximum operating conditions, condition for maximum - output, slip for maximum-output, Torque-slip characteristics, Effect of parameter variation on torque speed characteristics (variation of rotor and stator resistances, stator voltage, frequency), Effect of Harmonics, Crawling and Cogging of induction motor, Phasor-diagram, equivalent circuit. Losses and efficiency, Tests on Induction Motor : No load and blocked rotor test - determination of equivalent circuit parameters. Predetermination of performance under different operating conditions using circle diagram. Methods of starting and speed control for induction motors with conventional methods and static convertors. Energy Efficient three phase induction motor. Numerical based on above topics. Induction Generator : Principle of operation, equivalent circuit and application. (Chapter - 4) 4. Single Phase AC Motor : Double field revolving theory, Starting & running performance of 1 - phase induction Motor, Equivalent circuit of 1- induction motor, Types of single-phase motors, Principle and operation of split phase, Resistance start, Capacitor start and capacitor start & run induction motor, Shaded pole induction motor, Universal motor. Repulsion motor. Applications of various single phase induction motors (Chapter - 5)
