This presentation contains the details about Types of single phase induction motor and equivalent circuit

1. TYPES OF SINGLE-PHASE INDUCTION MOTOR
AND EQUIVALENT CIRCUIT
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit
Contents:
Split phase resistance start motor
Split phase capacitor start motor
Capacitor start – capacitor run motor
Shaded pole method
Equivalent circuit of single phase induction motor
No load and Blocked rotor test
Comparison of single phase induction motor Vs Three
phase induction motor
References

2. SPLIT-PHASE RESISTANCE START MOTOR
This method of starting is mostly used in motor
with low inertia load or continuous operating
load.
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

3. SPLIT-PHASE CAPACITOR START MOTOR
In this type of motor, an
electrolytic capacitor is
connected in series with the
auxiliary winding. Due to the
presence of the capacitor, the
auxiliary winding current will
now lead the applied voltage
and the main winding current
will lag the applied voltage.
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

4. CAPACITOR-START – CAPACITOR-RUN
INDUCTION MOTOR
These motors are used
for such applications
where large starting
torque and quiet
operations are required.
These motors produce
constant torque and
have better efficiency
and power factor.
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

5. SHADED POLE METHOD
A part of each pole is wrapped with low
resistance copper bands, which form a closed
loop (These copper bands are called shading
bands or shaded poles).
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

6. SHADED POLE METHOD
• When a single-phase AC supply is given to
the stator of an induction motor, alternating flux
will set up a current in the shading bands.
• The flux in the shaded poles will lag the stator
flux. The result is similar to a rotating field
moving from un-shaded to shaded portion of
the pole. This will produce the starting torque.
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

7. EQUIVALENT CIRCUIT OF A SINGLE-
PHASE INDUCTION MOTOR
Equivalent circuit at stand still based on double-
field revolving theory
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

8. EQUIVALENT CIRCUIT OF A SINGLE-
PHASE INDUCTION MOTOR
Equivalent circuit at any
slipKongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

9. BLOCK ROTOR TEST
 Blocked rotor test is conducted on an induction
motor. It is also known as short circuit test or
locked rotor test or stalled torque test.
 From this test short-circuit current at normal
voltage, power factor on short-circuit, total leakage
reactance, starting torque of the motor can be
found.
 The test is conducted at low voltage because if
the applied voltage was normal voltage then the
current flowing through the stator windings were
high enough to over heat the winding and damage
them.
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

10. NO-LOAD TEST
 In this test, the rotor is made to rotate freely
without any load.
 Under this condition, the slip due to forward
rotating field will reach zero and the slip due
to backward rotating field will be 2.

11. COMPARISON OF SINGLE-PHASE AND THREE-PHASE
INDUCTION MOTOR
 Single-phase induction motors are simple in
construction, reliable and economical for small
power rating as compared to three-phase induction
motors.
 The electrical power factor of single-phase induction
motors is low as compared to three-phase induction
motors.
 For the same size, single-phase induction motors
develop about 50% of the output as that of three-
phase induction motors.
 The starting torque is low for asynchronous motors.
 The efficiency of single-phase induction motors is
less as compared to that of three-phase induction
motors.Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit

12. REFERENCES
S.No Book s / Web Sources
1
A.E. Fitzgerald, Charles Kingsley, Stephen. D. Umans, ‘Electric Machinery’, Tata Mc Graw Hill publishing
Company Ltd, 2003.
2 D.P. Kothari and I.J. Nagrath, ‘Electric Machines’, Tata McGraw Hill Publishing Company Ltd, 2002.
3 P.S. Bhimbhra, ‘Electrical Machinery’, Khanna Publishers, 2003.
4 M.N.Bandyopadhyay, Electrical Machines Theory and Practice, PHI Learning PVT LTD., New Delhi, 2009.
5 K. Murugesh Kumar, ‘Electric Machines’, Vikas Publishing House Pvt. Ltd, 2002.
6
Syed A. Nasar, Electric Machines and Power Systems: Volume I, Mcgraw -Hill College; International ed
Edition, January 1995.
7 J. Ganavadivel, ‘Electrical Machines II’, Anuradha publications, Fourth edition, 2015.
8 U.A.Bakshi &M.V.Bakshi, ”Electrical Machines II,” Technical Publications, Second revised edition, 2016.
9 Google and Wikipedia
Kongunadu college of Engineering & Technology Types Single phase Induction Motor &
Equivalent Circuit