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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: Sushmi1912@gmail.com,
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.
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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 .
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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.
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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)
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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
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South Asian Journal of Engineering and Technology Vol.4, No.1 (2018) 14–23
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.
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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,
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