ELECTRICAL MACHINES 3.

4 Method of excitation: separately and self excited, Types of DC

EE 554 Generator
Lecture : 3 Year : II 3.5 Characteristics of series, shunt and compound generator
Tutorial : 1 Part : II 3.6 Losses in DC generators
Practical : 3/2 3.7 Efficiency and Voltage Regulation
4. DC Motor (7 hours)
Course Objectives:
4.1 Working principle and Torque equation
To impart knowledge on constructional details, operating principle and performance
4.2 Back EMF
of Transformers, DC Machines, 1-phase and 3-phase Induction Machines, 3-phase
4.3 Method of excitation, Types of DC motor
Synchronous Machines and Fractional Kilowatt Motors
4.4 Performance Characteristics of D.C. motors
1. Magnetic Circuits and Induction (4hours) 4.5 Starting of D.C. Motors: 3 point and 4 point starters
1.1 Magnetic Circuits 4,6 Speed control of D.C. motors: Field Control, Armature Control
1.2 Ohm’s Law for Magnetic Circuits 4.7 Losses and Efficiency
1.3 Series and Parallel magnetic circuits
5. Three Phase Induction Machines (6 hours)
1.4 Core with air gap
5.1 Three Phase Induction Motor
1.5 B-H relationship (Magnetization Characteristics)
5.1.1 Constructional Details and Types
1.6 Hysteresis with DC and AC excitation
5.1.2 Operating Principle, Rotating Magnetic Field, Synchronous Speed, Slip,
1.7 Hysteresis Loss and Eddy Current Loss
Induced EMF, Rotor Current and its frequency, Torque Equation
1.8 Faraday’s Law of Electromagnetic Induction, Statically and
5.1.3 Torque-Slip characteristics
Dynamically Induced EMF
5.2 Three Phase Induction Generator
1.9 Force on Current Carrying Conductor
5.2.1 Working Principle, voltage build up in an Induction Generator
2. Transformer (9 hours) 5.2.2 Power Stages
3.1 Constructional Details, recent trends
6. Three Phase Synchronous Machines (6 hours)
3.2 Working principle and EMF equation
6.1 Three Phase Synchronous Generator
3.3 Ideal Transformer
6.1.1 Constructional Details, Armature Windings, Types of Rotor, Exciter
3.4 No load and load Operation
6.1.2 Working Principle
3.5 Operation of Transformer with load
6.1.3 EMF equation, distribution factor, pitch factor
3.6 Equivalent Circuits and Phasor Diagram
6.1.4 Armature Reaction and its effects
3.7 Tests: Polarity Test, Open Circuit test, Short Circuit test and Equivalent
6.1.5 Alternator with load and its phasor diagram
Circuit Parameters
6.2 Three Phase Synchronous Motor
3.8 Voltage Regulation
6.2.1 Principle of operation
3.9 Losses in a transformer
6.2.2 Starting methods
3.10 Efficiency, condition for maximum efficiency and all day efficiency
6.2.3 No load and Load operation, Phasor Diagram
3.11 Instrument Transformers: Potential Transformer (PT) and Current Transformer
6.2.4 Effect of Excitation and power factor control
(CT)
3.12 Auto transformer: construction, working principle and Cu saving 7. Fractional Kilowatt Motors (7 hours)
3.13 Three phase Transformers 3.14 Single phase Induction Motors: Construction and Characteristics
3.15 Double Field Revolving Theory
3.16 Split phase Induction Motor
3. DC Generator (6 hours)
7.1.1 Capacitors start and run motor
3.1 Constructional Details and Armature Winding
7.1.2 Reluctance start motor
3.2 Working principle and Commutator Action
3.17 Alternating Current Series motor and Universal motor
3.3 EMF equation
3.18 Special Purpose Machines: Stepper motor, Schrage motor and Servo motor
Practical: The questions will cover all the chapters of syllabus. The evaluation scheme will be
1. Magnetic Circuits as indicated in the table below:
- To draw B-H curve for two different sample of Iron Core
- Compare their relative permeability Chapter Topics
Unit Marks
2. Two Winding Transformers
- To perform turn ratio test 1 1&3 all 16
- To perform open circuit (OC) and short circuit (SC) test to determine equivalent 2 2 all 16
circuit parameter of a transformer and hence to determine the regulation and 3 4 all 16
efficiency at full load 4 5&6 all 16
3. DC Generator
- To draw open circuit characteristic (OCC) of a DC shunt generator 5 7 all 16
- To draw load characteristic of shunt generator Total 80
4. DC Motor
- Speed control of DC Shunt motor by (a) armature control method (b) field control
method
- To observe the effect of increasing load on DC shunt motor’s speed, armature
current, and field current.
5. 3-phase Machines
- To draw torque-speed characteristics and to observe the effect of rotor resistance on
torque-speed characteristics of a 3-phase Induction Motor
- To study load characteristics of synchronous generator with (a) resistive load (b)
inductive load and (c) capacitive load

6. Fractional Kilowatt Motors

- To study the effect of a capacitor on the starting and running of a single-phase
induction motor
- Reversing the direction of rotation of a single phase capacitor induct

References:
1 I.J. Nagrath&D.P.Kothari,“Electrical Machines”, Tata McGraw Hill
2 S. K. Bhattacharya, “Electrical Machines”, Tata McGraw Hill
3 B. L. Theraja and A. K. Theraja, “Electrical Technology (Vol-II)”, S. Chand
4 Husain Ashfaq ,” Electrical Machines”, DhanpatRai& Sons
5 A.E. Fitzgerald, C.KingsleyJr and Stephen D. Umans,”Electric Machinery”, Tata
McGraw Hill
6 B.R. Gupta &VandanaSinghal, “Fundamentals of Electrical Machines, New Age
International
7 P. S. Bhimbra, “Electrical Machines”’ Khanna Publishers
8 Irving L.Kosow, “Electric Machine and Tranformers”, Prentice Hall of India.
9 M.G. Say, “The Performance and Design of AC machines”, Pit man & Sons.
10 Bhag S. Guru and Huseyin R. Hizirogulu, “Electric Machinery and Transformers”
Oxford University Press, 2001.

Evaluation Scheme