PROJECT GUIDEI.Arun Kumar.

TEAM MEMBERS Ch.v.manoja(106K1A0237)S.Ivan (106K1A0232)B.Jyotsnadevi(106K1A0209)M.Harish (106k1A0234)R.Anjaneyulu (116k5A0207)

Induction motors are widely used ac motors in industrial

area. Advanced semi conductor technology and uses of

microcontroller have made the speed control of induction

motor easier. The proposed paper presents variable speed

control application of induction motor using v\f method.

In this system, the speed of induction motor can be

adjusted to user defined speed. Microcontrollers can provide

easy control over induction motor. Microcontroller based

speed control system consist of electronic component,

microcontroller and the LCD. The system is tested and

experimental results are recorded for variable speed under

various load conditions.

Microcontrollers can easily provide control over

induction motor

Voltage and frequency is varied in accordance with

certain ratio, which in turn adjusts directly the motor

speed

v/f ratio is maintained constant so as to keep air gap

flux constant

Speed is displayed according to the difference

between reference or selected speed and measured

speed

MOSFET BRIDGE

DRIVER IC

MICROCONTROLER

POWER SUPPLY

RESET

CRYSTAL OSCILLATOR

SWITCHES

LOAD

LCD

BLOCK DIAGRAM

Motor speed range selection

Load Line voltage at motor terminal(volts)

Frequency(Hz) v/f ratio

Motor speed (rpm)

Motor without load

S3(500rpm) 0 94 17 5 505

S2(1200rpm) 0 144 35 4 1217

S1(1440 rpm)

0 184 45 4 1428

Motor with load

S3(500 rpm) 500 132 36 3 504

S2(1200rpm) 500 162 44 3 1128

S1(1440rpm) 500 164 45 3 1156

Wide range of operation.

Speed is accurate .

Simple control scheme.

The speed is constant which means it will not vary

even by varying the load.

APPLICATIONS

Used in industries for variable speed applications.