# Transformers And Induction Machines

 Course Code : 10EE46 Author : uLektz University : Visvesvaraya Technological University, Karnataka (VTU) Regulation : 2010 Categories : Electrical & Electronics Format : ePUB3 (DRM Protected) Type : eBook

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Description :Transformers And Induction Machines of 10EE46 covers the latest syllabus prescribed by Visvesvaraya Technological University, Karnataka (VTU) for regulation 2010. Author: uLektz, Published by uLektz Learning Solutions Private Limited.

Note : No printed book. Only ebook. Access eBook using uLektz apps for Android, iOS and Windows Desktop PC.

##### Topics
###### UNIT - I BASIC CONCEPTS

1.1 Principle of operation of transformer, Constructional details of shell type and core type single-phase and three-phase transformers.

1.2 EMF equation, operation of practical power transformer under no load and on load (with phasor diagrams).

1.3 Concept of ideal transformers, current inrush in transformers

###### UNIT - II SINGLE-PHASE TRANSFORMERS

2.1 Equivalent circuit, losses, efficiency, condition for maximum efficiency, all day efficiency.

2.2 Open circuit and Short circuit tests, calculation of parameters of equivalent circuit, Regulation, predetermination of efficiency and regulation

2.3 Polarity test

2.4 Sumpner’s test

###### UNIT - III PARALLEL OPERATIONS

3.1 Parallel operation - need, conditions to be satisfied for parallel operation, Load sharing in case of similar and dissimilar transformers

3.2 Auto-transformers, copper economy

3.3 Brief discussion on constant voltage transformer, constant current transformer

###### UNIT - IV THREE-PHASE TRANSFORMERS

4.1 Introduction, choice between single unit three-phase transformer and bank of single-phase transformers. Transformer connection for three phase operation – star/star, delta/delta, star/delta, zigzag/star and vee/vee, choice of connection

4.2 Phase conversion - Scott connection for three-phase to two-phase conversion. Labeling of three-phase transformer terminals, phase shift between primary and secondary and vector groups.

4.3 Conditions for parallel operation of three-phase transformers,load sharing. Equivalent circuit of three-phase transformer

###### UNIT - V BASIC CONCEPTS OF THREE PHASE INDUCTION MACHINES

5.1 Concept of rotating magnetic field, Principle of operation, construction

5.2 Classification and types - single-phase, three-phase, squirrel-cage, slip-ring.

5.3 Slip, torque, torque-slip characteristic covering motoring, generating and braking regions of operation, Maximum torque

###### UNIT - VI THREE-PHASE INDUCTION MOTOR

6.2 Equivalent circuit, Losses, efficiency, No-load and blocked rotor tests

6.3 Circle diagram and performance evaluation of the motor, Cogging and crawling

###### UNIT - VII HIGH TORQUE ROTORS AND INDUCTION GENERATOR

7.1 High torque rotors-double cage and deep rotor bars, Equivalent circuit and performance evaluation of double cage induction motor.

7.2 Induction generator – externally excited and self excited, Importance of induction generators in windmills

###### UNIT - VIII STARTING AND SPEED CONTROL OF THREE-PHASE INDUCTION MOTORS

8.1 Need for starter, Direct on line (DOL), Star-Delta and autotransformer starting, Rotor resistance starting, Soft(electronic) starters, Soft(electronic) starters.

8.2 Speed control - voltage, frequency, and rotor resistance.