ishitvtech.inishitvtech.in/pdf/j3.docx · web viewlabview includes a set of express vis to help for...

South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23

ISSN No: 2454-9614

PERFORMANCE ANALYSIS OF AC MOTOR BY LabVIEWSushmitha.s.v Sobica.S,

Revathi.P(Assistant Professor)Department of electronics and instrumentation Engineering,

kongu engineering college, perunduraiTamilnadu, India.

*Corresponding Author: Sushmitha.S.V

Phone: +91-9942722339E-mail: [email protected],

Received: 6/11/2017, Revised: 30/12/2017 and Accepted: 4/2/2018

Abstract

This project deals with the estimation of current, voltage and speed of the ac induction motor. Here the estimation of the current

is made by the current transformer , the speed with the help of infrared sensor and voltage measurement is by potential

transformer. Finally the value from these sensors are acquired and displayed in laptop using DAQ in LabVIEW. Laboratory

Virtual Instrument and Engineering Workbench (LabVIEW) software is used for modelling the induction motor and helps in

analyzing the performance characteristics of a machine .The three phase stator currents (ir iy and ib) and the corresponding

speed and voltage of induction motor under various load conditions are measured by LabVIEW. The data are acquired by

interfacing the DAQ with induction motor.

Keywords: Data acquisition system, Real-time, LabVIEW, sensors

1. IntroductionAlmost 70% of industry use induction motor. Induction motor plays an important role in industrial as well as

commercial purpose due to low cost, ruggedness, low maintaince and construction. As the ac power is used in

generation, transmission and distribution , induction motors occupied significant place in industrial drive applications

and out rule the dc motors which were earlier used for industrial application. Three phase induction motors will have

self starting torque unlike synchronous motor. However, single phase induction motors does not have self starting

torque and are made to rotate using some auxiliaries.

II. BLOCK DIAGRAM DESCRIPTIONThis project deals with the measuring of speed, current and voltage by using sensor. It is connected with

current and potential transformer in order to obtain analog low value .The analog output is given to ADC in

order to get the discrete value. For the speed measurement infrared sensor is used. Finally the output from these

sensors are given to DAQ . The DAQ is used to acquire values and it is displayed using LabVIEW software.

14

Procedia, 06/19/15,

SAJET office will update with volume, Issue and page numbers

mailto:[email protected]


Figure 1 Block diagram for estimation of speed ,voltage, current of induction motor

III. THREE PHASE MOTORThe three phase motor whose current , voltage and speed is to be estimated in a squirrel cage induction motor with

the following specifications:

Voltage : 415 V

Current : 7.5 A

Speed : 1470 rpm

Figure 2 Circuit diagram of induction motor IV. DATA ACQUISTION USING LabVIEWIn NI-DAQmx, a task is a collection of one or more channels, timing, triggering and other properties that apply to the

task itself. Conceptually, a task represents a measurement or generation to be performed. For example, a task can be

created to measure temperature from one or more channels on a DAQ device. LabVIEW includes a set of express VIs

to help for analysing signals.

V. ACQUIRING SPEED SIGNAL IN LabVIEW Arduino can be used as a DAQ by making it communicate serially. This serial communication using NI visa. NI visa is just

used to receive data from the sensor. Initially it is set with the baud rate of 9600 and its connected port. The data received is

15


checked for its error. After checking if the data is received correctly, then the data is read from the read buffer. For further

process if the data is not read properly, it will indicate an error. The data read is indicated as an rpm of the motor. The motor

rpm is read using IR sensor which send pulse and receives this pulse digitally and counts the time between the pulse and the

rpm iscalculated.

Figure Block diagram for acquiring speed signalV1. ACQUIRING VOLTAGE SIGNAL IN LabVIEWThe output from the DAQ is acquired as voltage and it is connected to the analog input and ground. The signal is

acquired from the DAQ . The output value is multiplied with the constant value and again multiplied with the constant

value to obtain the voltage value.

Figure 4 Block diagram for acquiring voltage signalVII. ACQUIRING CURRENT SIGNAL IN LabVIEWThe voltage value from the current transformer is acquired by the DAQ and it is acquired in the analog input . The

output signal from the DAQ is converted to current value in LabVIEW. The division , subtraction , multiplication numeric

palette are taken from function palette and placed in the block diagram panel and it is converted into a current value.

And it is finally displayed in the indicator .

16


Figure 5 Block diagram for acquiring current signalVIII. INDUCTION MOTOR WITH HALL EFFECT SENSORThe induction motor is connected with hall effect sensor there are five pins in which the +ip is connected to auto

transformer and –ip is connected to the motor.The remaining three pins such as Vdd , Gnd, Vout are connected to RPS

and the remaining one pin is connected DAQ . The output from the current sensor is high and it cannot be given to DAQ

as it accept only maximum of 200mA current and 5V . In this method the output cannot be given to DAQ . As the

values obtained from the current sensor is above 1A it cannot be accepted in DAQ. As the DAQ accepts only 200mA of

current it is not feasible and hence we use current transformer.

Figure 7 Circuit diagram of motor with hall effect

sensor

IX. INDUCTION MOTOR WITH CURRENT TRANSFORMERThe current transformer is connected to the motor with and its is made one winding around the primary side and in

the secondary side resistance of 1K Ohm is connected across the two sides . As the output from the secondary side is AC

inorder give the output to DAQ the AC signal is converted to DC signal. The AC signal is converted to DC by the

rectifier and it is given to capacitor and voltage divider circuit . The output from the voltage divider is given to

analog input and the ground of DAQ . In that DAQ the signal is acquired as voltage and it is given as the

continuous samples . By creating the loop the value is continuously is obtained from the motor by changing the value

in the auto transformer.

17


Figure 8 Circuit diagram of motor with current transformerX. INDUCTION MOTOR WITH POTENTIAL TRANSFORMERIn the voltage measurement circuit the 230V supply is given to the step down transformer of 230V – 12V and then

from the 12V it is given to the rectifier to convert the AC signal into DC signal . The DC signal is then given to

the voltage divider bias circuit . The output from the voltage divider circuit is given to the zener diode to reduce the

voltage to 2.8V as the DAQ accepts the voltage range 0 to 5V. The output across the diode is given to the DAQ.

The following conversion to voltage is performed in the LabVIEW .The voltage obtained as the output is 2.8V.

TX1R 1

1k

V 11V a c23 0 V

D 4

D 1 N 40 0 1

R 2

20 0

D 2

D 1 N 40 0 1

D 1

12

<D oc > <R ev C o d e>

<Tit le >

A

1 1Th u rs d ay , J u ly 2 0 , 2 01 7

Tit le

S ize D o c u m e n t N um b er R e v

D a t e : S he e t o f

D 5

D 1 N 40 0 1

C 1

10 0 m ic ro

D 3

D 1 N 40 0 1

Figure 1.9 Circuit diagram of motor with potential transformerXI. INDUCTION MOTOR WITH INFRARED SENSORThe infrared sensor is placed nearer to the motor as it senses the speed of the motor according to the rotation of

the wheel. The sensor give the output pulse for one rotation of motor .The output pulse is given to the DAQ and the

pulse is acquired and it is programmed in LabVIEW and the speed of the motor is acquired and displayed in the

indicator as the rpm.

XII. RESULTS AND DISCUSION

18


In this project performance of ac induction has been analysed from current sensor, current transformer, potential transformer,

infrared sensor .The list of measured values are given below,

TABLE No. 1. MEASURED VALUES FROM CURRENT SENSOR

S.NO PHASES WITH

VOLTAGE OF 360V

AMMETER

(A)

MULTIMETER

(V)

CURRENT

SENSOR

VALUE IN

(MV)

CURRENT

SENSOR

VALUE IN (A)

1 R 1.6 2.65 300 1.15

2 Y 1.7 2.65 300 1.15

3 B 1.95 2.78 430 1.6

19


Figure 1.10 Induction motor with hall effect sensorAccording to the datasheet value,

In the current sensor 1A = 260 mV

The values obtained from the sensor is in volt which is converted by the following conversion.

Input voltage (Vdd) : 4.7V

Step 1:

Vdd / 2 = 4.7/2 = 2.35

Step 2:

Output from current sensor : 2.65V

V = 2.65-2.35

= 0.3V

Step 3:

Volt is converted into Mv

V = 0.3*1000

= 300mV

Step 4:

1A = 260 mV

The current value is 1.15A

As the values obtained from the current sensor is above 1A it cannot be accepted in DAQ. As the DAQ accepts only 200mA

of current it is not feasible and hence we use current transformer.

TABLE No. 2. MEASURED VALUES FROM POTENTIAL TRANSFORMER

S.NO SUPPLY VOLTAGE(V) OUTPUT(V)

20


1 230 2.8

Figure 11 Induction motor with potential transformerIn the voltage measurement the output value is 2.8

The voltage divider bias circuit formula is

=Vin(R2/R1+R2)

R1=1000 Ohm R2=200 Ohm

= 8.2 (200/1200)

= 6.83

The voltage is 12*7.14*2.8

= 230V

TABLE No.3. MEASURED VALUES FROM INFRARED SENSOR

S.NO SPEED FROM TACHOMETER

(rpm)

SPEED VALUE FROM SENSOR

(rpm)

1 61 60

2 225 240

3 1480 1500

21


Figure 12 Induction motor with infrared sensorCONVERSION

The formula used to calculate the speed of the motor is,

Rpm = (60 * 1000 / pulsePerRotation)/ (millis() - timeold)* pulses;

Pulses per rotation is according to the speed of the motor such as 1

By assuming the values the speed of motor is

Rpm = 60000/1/(0.2-0.1)*1000

= 600 rpm.

TABLE NO.4 MEASURED VALUE FROM CURRENT TRANSFORMER

S.No VOLTAGE

(V)

VOLTAGE FROM DAQ

(V)

AMMETER

(A)

VOLTAGE

VALUE (V)

1 360 0.32 3.5 0. 315

2 320 0.29 3 0.27

3 280 0.23 2.5 0.225

22


CONVERSION i) Voltage from DAQ = 0.32V

The ammeter value =3.5 *0.09

= 0.315V

ii) voltage from DAQ = 0.29V

The current value = 3 * 0.09

= 0.27V

iii) voltage from DAQ = 0.23V

The current value = 2.5 * 0.09

= 0.225V

XIII. CONCLUSION AND FUTURE SCOPEIn this project, the method of estimating current, voltage and speed by sensors has been used. Since DAQ is unable to sense the

output of these sensors as the output exceeds the limit of DAQ, sensors have been replaced by current transformers. In the

future this project will be used to estimate of speed of motor and this can be done with the help of neural network by varying

the voltage and current . Commercial applications of these technologies generally focus on solving complex signal processing

or pattern recognition problems. Examples of significant commercial applications since 2000 include handwriting recognition

for check processing, speech-to-text transcription, oil-exploration data analysis, weather prediction and facial recognition.

REFERENCES1) R..K. Rajput (1993),“Electrical Machines,” first edition, New York: McGraw- Hill, pp. 352-35.

2) R.. Krishnan(2001),“Electric Motor Drives Modeling, Analysis and Control”, first edition, Prentice-Hall International, Inc.

Upper Saddle River, New Jersey 07458, pp 400 - 415.

3) J. Kudla (2003),“Use of induction motor steady-state characteristics determined by means of the finite element method for

parameter estimation of motor nonlinear circuit model,” in Proceedings of the 11th International Symposium on Applied

Electromagnetics & Mechanics, Versailles, France.

4) RA Jabbar,et al.(2010),“Simulation of Electrical Machines Laboratory using LabVIEW”. International Conference on

Computer, Electrical, and Systems Science, and Engineering, World Academy of Science Engineering and Technology, pp

29-31.

5) Gentian dume (2013),“Synchronous generator model based on LabVIEW software”, WSEAS Transactions on Advances in

Engineering Education vol:10 pp: 101-112.

6) Abdenour Soualhi, Guy Clerc, and Hubert Razik,(2013), “Detection and diagnosis of faults in induction motor using an

improved artificial ANT clustering technique” IEEE Transactions on Industrial Electronics, Vol. 60, pp: 4053 – 4062.

7) M. Aderiano da Silva, J. Richard Povinelli, and A.O Nabeel Demerdash (2013),“Rotor bar fault monitoring method based

on analysis of air-gap torques of induction Motors”, IEEE Transactions on Industrial Informatics, Vol. 9, pp: 2274 – 2283.

8) E.Ramprasath, P.Manojkumar (2015) “Modelling and Analysis of Induction Motor using LabVIEW”, International Journal

of Power Electronics and Drive System (IJPEDS) ,Vol. 5,

23

ishitvtech.inishitvtech.in/pdf/j3.docx · web viewlabview includes a set of express vis to help for...

Documents