This document summarizes a seminar presentation on speed control of single phase induction motors using integral cycle switching. The presentation discusses various speed control methods for single phase induction motors and focuses on integral cycle control. It provides an overview of the working principle, block diagram, and advantages of integral cycle control. Specifically, it controls speed by varying the on/off ratio of the applied voltage through thyristor switching. Integral cycle control eliminates harmonics, provides proportional speed variation over a wide range, and reduces electromagnetic interference compared to phase control methods.

1. SEMINAR
ON
“SPEED CONTROL OF SINGLE PHASE INDUCTION
MOTOR BY INTEGRAL CYCLE SWITCHING”
Presentation by:
Pavan S. kolte
Third Year Electrical Engineering
Department of electrical
engineering

2. INTRODUCTION
 Single phase induction motor is widely used in many
application such as washing machine, watch industry
so the variation of speed is necessary this can be done
by various method such as
 By changing applied voltage
 By V/f Method
 Pole Changing Method
 Stator frequency control

3.  To improve the performance of single phase induction
motor, electronic means have been employed
increasingly to achieve adjustable speed operation in
recent year.
 This can be achieved by two ways namely phase
control method and integral cycle control method.
 Integral cycle control is a new technique for speed
control of single phase induction motor

4.  It is also known as ‘Burst Firing’ or ‘On-Off Control’ in
which ratio of on time to total (On + Off) time is
varied
 Thus we can eliminate several number of input voltage
cycles. This controlled voltage is applied to induction
motor and thus speed control is obtained.

5. INTEGRAL CYCLE CONTROL

6. Working Principle
 The basic principle of on-off control technique is
explained with reference to a single phase full wave ac
voltage controller circuit shown.
 The thyristor switches are turned on by applying
appropriate gate trigger pulses to connect the input ac
supply to the load for ‘n’ number of input cycles during
the time interval .
 The thyristor switches are turned off by blocking the
gate trigger pulses for ‘m’ number of input cycles
during the time interval .

7. Waveforms
Vs
Vo
io
ig1
ig2
wt
wt
wt
wt
Gate pulse of T1
Gate pulse of T2
n m

8.  If the input ac supply is connected to load for ‘n’
number of input cycles and disconnected for ‘m’
number of input cycles, then
Where, T= 1/f = time period
To=Output Time Period=(n*T + m*T)

9. BLOCK DIAGRAM OF SPEED CONTROL OF SPIM
BY INTEGRAL CYCLE CONTROL

10.  By using the software instruction we are generating
integral cycle in the microcontroller.
 Then the integral cycle is given to driver circuit.
 The driver circuit contains with MOSFET.
 The induction motor interface with MOSFET and
speed sensor .
 MOSFET driver circuit is used to control the ON/ OFF
time of MOSFET.
 In this project four set of MOSFET are used.
 Through the driver circuit switching time between the
MOSFET‘s is varied.

11.  At the time of high portion in the integral cycle two
MOSFET is switched ON and remaining OFF.
 At the time of low portion of integral cycle another
two MOSFET is switched ON, before two MOSFET is
switched OFF.
 Through this wave circuit AC voltage is generated
 This voltage and given to motor.
 The speed we can set through keypad.

12. Conclusion
 A speed control is proposed for single phase induction
motor by integral-cycle control.
 The voltage hence speed is controlled in step by
variation of ON/OFF ratio, while fine voltage control is
achieved by increasing OFF time.
 Abnormal behavior of the motor e.g. large pulsation in
speed and torque, locking rotor, unproportional speed
variation etc. are reduced due to integral-cycle
switching.

13.  . Although the harmonics introduced by phase control
method is eliminated by integral cycle control
method.
 The major advantages of this system are it eliminates
the radio frequency electromagnetic interferences and
gives better power factor at low speed.
 Integral cycle switching is a voltage and frequency
control method.
 Internal cycle switching is applied to only main
winding. It reduces harmonics and proportional speed
variation over wide range is obtained.

14. Reference
 “Smooth Speed Control Of Single-Phase Induction Motor
By Integral-Cycle Switching “,By M .Syed Jamil Asghar
,member, IEEE.
 “Dynamic Model of an Integral-Cycle Controlled Single-
phase Induction Machine”, By Longya Xu, Member, IEEE.
 “Low cost speed control for single phase induction motors -
comparing different approaches with regard to efficiency
”,By Klaus Krischan, Guenther Dannerer, Oliver Koenig,
Roland R. Seebacher.
 “Alternating Current Machines”, By M. G. Say 5th Edition.
 “Fundamental of electric drives”, G. K. Dubey.
 “Power Electronics”, By Hari Babu.
 “Power Electronics”, By M.D.Singh and Khanchandani.

15. THANK YOU