The document provides an overview of single-phase induction motors, detailing their construction, operation, and starting methods. It describes the motor's similarity to three-phase induction motors and outlines the stator's design and functioning principles, including its need for external starting assistance. Various starting methods and split-phase techniques for single-phase motors are also mentioned, along with references for further reading.

1. SINGLE-PHASE INDUCTION MOTOR
Kongunadu college of Engineering & Technology Single phase Induction Motor
Contents:
Introduction
Construction
Double field revolving theory
Cross field theory
Starting of Single phase induction motor
Split phase methods
References

2.  A single-phase induction motor is structurally
similar to a three-phase induction motor; the
difference is only in the stator winding
arrangements.
 The stator windings of a single-phase
induction motor are distributed, pitched and
skewed to produce a sinusoidal m.m.f. in
space.
Kongunadu college of Engineering & Technology Single phase Induction Motor

3.  The construction of a single-phase induction
motor is similar to that of a three-phase
induction motor.
 The single-phase motor stator has a laminated
iron core with two windings arranged
perpendicularly – one is the main and the other
is the auxiliary winding or starting winding.
 The motor uses a squirrel-cage rotor, which has a
laminated iron core with slots in it. Single-phase
induction motor is not self-starting and requires
some mechanism to assist it in the starting
process.
Kongunadu college of Engineering & Technology Single phase Induction Motor

4. According to this theory, a pulsating field
of a single-phase motor can be resolved into
two rotating field of half its amplitude
rotating in opposite direction at synchronous
speed.
Kongunadu college of Engineering & Technology Single phase Induction Motor

5. Kongunadu college of Engineering & Technology Single phase Induction Motor

6.  The torque–slip curve is shown below
Kongunadu college of Engineering & Technology Single phase Induction Motor

7.  When a single-phase supply is given to the
stator of a single-phase induction motor, an
alternating flux is produced in the stator.
 This alternating flux will produce an induced
e.m.f. in the rotor windings, which is initially
at standstill.
 No torque will be produced in the rotor
Kongunadu college of Engineering & Technology Single phase Induction Motor

8. If the rotor is rotated by giving some
external force, an e.m.f. will be induced in
the rotor and thus a current will flow
through the rotor. This current will be
displaced by 90 degree (electrical) from the
stator axis.
Kongunadu college of Engineering & Technology Single phase Induction Motor

9. Some of the starting methods are,
i) Split-phase method
ii) Shaded-pole method
iii) Reluctance-start method
Kongunadu college of Engineering & Technology Single phase Induction Motor

10. The different split-phase techniques are:
i) Split-phase resistance-start motor.
ii) Split-phase capacitor-start motor.
iii) Capacitor-start – capacitor-run induction
motor
iv) Permanent single capacitor induction
motor.
Kongunadu college of Engineering & Technology Single phase Induction Motor

11. 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 Single phase Induction Motor