ELECTRICAL MACHINES 2 DIPLOMA EEE
Department of Technical Education
DIPLOMA COURSE IN ELECTRICAL AND
ELECTRONICS ENGINEERING
Fourth Semester
Sub: ELECTRICAL MACHINES – II
Sub Code:
Contact Hrs/Week:
4.
Contact
Hrs/Sem: 64
Chapter
No
Topic
No. of Hours
UNIT I
1 Transformers
22
UNIT II
2 Induction
motors
20
UNIT III
3
Synchronous motors
10
4
Single phase
motors
2
Industrial innovation
6
Tests and
Revision 4
_________
TOTAL 64
CONTENT
1.
TRANSFORMERS
22Hrs
1. Working Principle of
Transformer
4
2. E.M.F.
Equation.
3
3. Operation on No Load & On Load
1
4. Equivalent Circuit
1
5. Regulation & Efficiency
6 Three Phase Transformers 2
7. Cooling of Transformer
2
8. Welding Transformer
1
9. Auto
Transformer
1
10. Parallel Operation
1
2
Induction
motors
20Hrs
1. Working
principle
3
2. Types: Types of induction motor and their construction
details.
1
3. Torque: Torque-slip
curves.
4
4. Equivalent
circuit
1
5. Power output
2
6. Circle diagram: No load and blocked rotor tests-construction of circle
diagram-problems.
3
7. Starting: Necessity & Types, soft
starters.
2
8. Speed Control: Different
methods
2
A] Change of applied voltage
B] Change of
frequency
C] Change of poles
D] Rheostat control
9. Linear induction
motor
1
10. Induction
generator
1
3
Synchronous
motors
10Hrs
1. Working
principle.
2
2, Operation on
load
1
3.
Characteristics
2
4.
Hunting
1
5.Starting
Method:
1
6.
Applications
1
7. Permanent magnet synchronous
motor
2
NEODYMIUM, SAMARIUM, COBALT, FERRITE,
ALNICO.5
4.
Single phase
Motors
2Hrs
Split phase motors and Capacitor motors
SPECIFIC INSTRUCTIONAL OBJECTIVES
1 Transformers
1.1
Working principle, construction and classification
1.1.1 Explain the working principle of
transformers.
1.1.2 Classify the various types of transformers
1.1.2.1 Based on construction
1.1.2.2 Based on
application
1.1.3 Explain briefly the various parts of the transformer and explain the
functions
of each
part.
1.1.4 Name the different insulating material used in
transformer.
1.1.4.1 Write the properties and uses of transformer
oil.
1.1.5 Explain the construction of core type and shell type
transformers.
1.2
Emf Equation
1.2.1 Derive emf equation and explain transformation
ratio.
1.2.2 Solve problem on emf equation.
1.3
Operation
1.3.1 Explain the operation of a transformer on no load and on load with vector
diagrams.
1.3.2 Solve the problem on transformer on no load.
1.4
Equivalent circuit
1.4.1 Define the equivalent resistance of a transformer as refereed to primary
and
secondary
side.
1.4.2 Explain magnetic leakage in a transformer
core.
1.4.3 Explain leakage reactance & calculate equivalent reactance as
referred to
primary and secondary
side.
1.4.4 Write the formula for equivalent impedance.
1) Referred to primary.
2) Referred to
secondary
1.4.5 Draw the equivalent circuit diagram of a transformer.
1.5
Regulation and Efficiency
1.5.1 Explain the various losses in a
transformer.
1.5.2 Explain open circuit and short circuit test on transformer to find no
load and
copper
losses
1.5.3 Define voltage regulation in the
transformer.
1.5.4 Write equation for voltage
regulation.
1.5.5 Calculate the efficiency of transformer at given
loads.
1.5.6 State the condition for maximum
efficiency
1.5.7 Define all day
efficiency.
1.5.8 Solve the problems on the above.
1.6
3 phase transformers
1.6.1 Explain working principle and construction of 3 phase transformers.
1.6.2 Explain star-star, Delta-Delta, star-Delta, Delta-star, open delta and
Scott
connections
1.7 Cooling of transformer
1.7.1 Explain the necessity of cooling of
transformer.
1.7.2 List the various types of cooling of
transformer.
1.7.3 Write the meaning of AN, ON, OFA.
1.8 Welding transformer
1.8.1 Explain the construction and write the applications of
a welding
transformer.
1.9 Auto
transformer
1.9.1 Explain briefly an auto
transformer.
1.9.2 Compare auto transformer with two winding
transformer.
1.9.3 List the application of auto transformer.
1.10 Parallel
operation
1.10.1 Explain the necessity and conditions for parallel
operation.
1.10.2 Explain with neat sketches parallel operation of
single phase
transformers with their load sharing.
2 Induction motor
2.1
Working principle
2.1.1 Explain the working principle of induction
motor.
2.1.2 Compare with it a
transformer.
2.1.3 Explain how the rotating magnetic field is produced by
poly phase supply.
2.1.4 Define the terms slip, frequency of rotor current.
2.2
Types
2.2.1 Describe the construction of stator, squirrel cage
rotor and phase wound
rotor.
2.3
Torque
2.3.2 Derive an expression for starting
torque.
2.3.3 Compare the starting torques of squirrel cage and slip
ring induction motor.
2.3.4 State the condition for max starting
torque.
2.3.5 Explain the effect of change in supply voltage on
starting torque.
2.3.6 State equation for torque under running
conditions.
2.3.7 Draw torque - slip
curves.
2.3.8 State relationship
between
1. Full load torque and maximum
torque.
2. Starting torque and maximum
torque.
2.4
Equivalent circuit
2.4.1 Draw the equivalent circuit of an induction motor.
2.5
Power
output
2.5.1 State the relationship between rotor power input, rotor
copper loss, and mechanical
power developed and slip.
2.5.2 Solve problems on the
above.
2.6
Circle diagrams
2.6.1 Construct the circle diagram for the given 3 induction
motor using the no-load and
blocked rotor test results.
2.6.2 Calculate slip rotor stator copper losses, power factor,
efficiency, speed regulation for
Full load conditions from above
circle
diagram.
2.6.3 Solve problems on the above.
2.7
Starting
2.7.1 Explain the necessity of starters for 3 induction
motors and list the various types of
starters.
2.7.2 Explain the construction and working
of
1. D.O.L.
Starter
2. Soft Starter
3. Star-Delta Starter
2.8
Speed
control
2.8.1 With neat circuit diagram. Explain the speed control of
3 induction motor.
1. Change of applied
voltage
2. Change of frequency(Variable voltage and variable
frequency)
3. Change of
poles
4. Rheostat control.
2.8.2. Explain the principle of working & application of linear
induction motor.
2.8.3 Explain Induction Generators and its
applications.
3.Synchronous motors
3.1
Working principle
3.1.1 Describe the general principle of operation of
synchronous
motor.
3.1.2 Compare the synchronous motor with induction motor
3.2
Operation on load
3.2.1 Explain the effect of change in excitation at constant
load
3.3
Characteristics
3.3.1 Explain the effect of excitation on armature current
& power factor.
3.3.2 Define V-curves & inverted V-curves & draw the
same.
3.4
Hunting
3.4.1 Explain hunting and its prevention.
3.5
Starting
3.5.1 Explain the methods of starting synchronous
motor.
3.6
Applications
3.6.1 Explain the applications of synchronous motors.
3.7
Permanent Magnet Synchronous motor
3.7.1 Explain permanent magnet Synchronous
motor.
3.7.2 State the characteristics of permanent
magnet.
3.7.3 List the properties of NEODYMIUM, SAMARIUM, COBALT,
FERRITE,
ALNICO.5.
4 Single phase
motors
4.1
Split phase induction
motor
4.1.1 State the principle of working of single phase
induction motor.
4.1.2 Name different types of single phase induction
motor.
4.1.3 Explain the construction, principle of operation,
characteristics &applications of
a) Single phase capacitor start capacitor run I.M b) Single phase
capacitor start
induction run I.M
REFERENCES: ELECTRICAL MACHINES
2 Book
1. Electrical Technology volume 2 –
by BL Theraja & A.K.Theraja S.Chand publication
2. Principles of Electrical Machines
by V.K.Mehtha.S.Chand publication
3. Electrical Machines by
Bhattacharya. Tata McGraw Hill Co.
4. Electrical Machines – by
J.B.Guptha Kataria & Sons Publications.
5. Generation of Electrical Energy
by BR Gupta. S.Chand Publication.
6. Fundamentals of elecrical drives
– by G.K. Dubey Narosa publications.
7.
Electrical Machines – by Deshpande.
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