speed control of single phase induction motor” by using triac_ppt

8/14/2019 SPEED CONTROL OF SINGLE PHASE INDUCTION MOTOR” BY USING TRIAC_ppt

http://slidepdf.com/reader/full/speed-control-of-single-phase-induction-motor-by-using-triacppt 1/30

SS P E E DP E E D CC O N T R O LO N T R O L

OO FF SS I N G L EI N G L EPP H A S EH A S E

II N D U C T O NN D U C T O NMM O T O RO T O R UU S I N GS I N G AATT R I A CR I A C



SUBMITTED BY:

GROUP NO: 13CHAITANYA KRISHNA A 08241A0205

KARTHIK K 08241A0216

SIDDHARTHA S 08241A0245

SHANKER M 09245A0213



Single phase induction motor are small motors having awide field of usefulness where a poly phase supply is not

available. They are generally used in fans, blowers,washing machines, refrigerators, etc.

The speed of the induction motor can be varied in anarrow range by varying the voltage applied to the stator

winding.

This method of speed control is suitable for suchapplications, where the load varies approximately as the

square of speed, such as centrifugal pump drives, fanload.



The terminal voltage across the stator winding of themotor can be varied for obtaining the desired speedcontrol by controlling the firing angle of thesemiconductor power devices(TRIAC in our project)

For any firing angle α the average output voltage

across a TRIAC is given byV = (2V’cosα/

) ;

V’ is the max voltage provided.



In our project the following are works to be done :

I. Simulation of schematic circuit in multisimsoftware.

II. PCB design in Eagle software.

III. After getting the actual PCB soldering ofcomponents on PCB.

IV. And finally connecting all along with ACmotor and performing the experiment ofspeed control.



S.no. Name of the component Rating Quantity Name ofIC

1. Transformer 220/15V-1amp 1

2. Potentiometer 20kΩ and10kΩ

11

3. Resistors 10 kΩ,2kΩ and1kΩ

113

4. Capacitor 100uf10uf

12

5. 555 timer LM555CM 1

6. Rectifier 1amp 2 MIC

DB1077. Op-Amp 1 LM741

8. AND gate 1 7408N

9. DC regulated Powersupply

5V ,12V

12



SCHEMATICCIRCIUT

DIAGRAM



The functioning of the entire triggering circuitcan be studied in five parts:

1. TRANSFORMER

2. RECTIFIER

3. COMPARATOR

4. 555 TIMER

5. AND GATE



TRANSFORMER

The transformer in our circuit is a stepdown transformer

This transforms the 220V input to 15Vat 1 amp.

It acts as an isolation device betweenthe ac mains and the electronic circuit.



RECTIFIER

There are two bridge rectifiers used in the circuit to

rectify the 15V ac . The output from one of the rectifier is filtered using

the appropriate capacitors and is used as a input topositive terminal of the comparator.

The output of the remaining rectifier acts as thereference to the comparator.

The rectifiers used in the circuit are MIC DB107



COMPARATOR

The comparator used in the circuit is LM741

The comparator compares the rectified voltage at thepositive terminal with the filtered input voltage atthe negative terminal which acts as a reference and

hence generates a square wave. The magnitude of the square wave is equal to the

saturation value, and its magnitude is positive whenthe input voltage is greater than the reference

voltage and vice versa. The resultant output wave forms the input to the

AND gate



555 TIMER

The 555 timer used in the circuit is in the astable

mode. The resistors R1 and R2 help in varying the

frequency of the output from the comparator ,

This helps in generating a pulse train used to trigger

the gate of the triac used. The biasing voltage used in the circuit is 5V.

Frequency of generated pulse

(f) = 1/[(R1+2R2)*C*ln(2)] The thus generated pulse train is fed to an AND

gate.



AND-GATE

The AND gate used in the circuit is 7408N.

The input of the gate is derived from the output ofthe comparator and of the 555 timer.

The AND gate is used to eliminate the negative

pulse train.



D92N5444

V2

230 V

50 Hz

0Deg

6

0

54

TRIGERRINGCIRCIUT

IM

POTENTI-OMETER



The simulation of the schematic circuit in themultisim software have been done.



THANK YOU

speed control of single phase induction motor” by using triac_ppt

Documents