induction motor modelling and applications

A Project on

Induction Motor Modeling And Applications

By Deepa Kokati

Sachin SShweta Joshi

Venkanagouda P. C

Department of Electrical and Electronics EngineeringK. L. E. Institute Of Technology, Hubli.

Under the guidance of Prof.Gurunayk C. N.

CONTENTS

• Objectives • Methodology• Simulation Results• Application • Conclusion and future work• Reference

OBJECTIVES • AC motor control is to make the rotor turn at a desired

speed despite load variations by d-q modeling

observer

LITERATURE SURVEY

• The research so far discussed about different modeling based on different reference frame theories.

• Few discussed the application like control of speed, Torque, Flux etc.

• However analysis of effect of temperature on induction motor system is not carried out.

5

Park Transformation: The Park’s transformation is a three-phase to two-phase transformation for machine analysis.

bI

aI

cI

qi

di

cos Base componensin( ) Vertical Component

t

q a

d a

i Ii I

cos(120 ) Base componentsin( (120 )) Vertical Component

d b

q bi Ii I

120 240

cos(240 ) Base componensin( (240 )) Vertical C

tomponent

d

q c

c

i Ii I

qi

di

6

1

2

2 4cos cos cos3 32 4sin sin sin .3 3

d a

q b

o co o o

i ini in

i iK K K

To complete the transformation, it remains to assign values to and 1

2

nn

oK

• Triphase system and its equivalent two-phase system .• Both systems create the same MMF • Thus the relation between three phase current and equivalent two phase current is given by

, dqo abcor i P i

7

1

abc dqoi P i

1 112 2

2 3 30 .3 2 2

1 1 12 2 2

P

•Following matrix is obtained by substituting,

• Thus park transformation preserves amplitude and energy.

0

•The inverse transformation,

Voltage equations

Flux equations

Where,

Synchronous Speed , or Speed of RMFRotor Speed

s

r

[ ] [ ]

[ ] [ ]sdq s sdq sr rdq

rdq r rdq sr sdq

L i M i

L i M i

[ ][ ] [ ]

[ ][ ] [ ]

sabcsabc s sabc

rabcrabc r rabc

dV R i

dtdV R idt

Basic Voltage Equations

( )

( )

sdsd s sd s sq

sqsq s sq s sd

rqrd r rd s r rq

rqrq r rq s r rd

dV R i

dtd

V R idtd

V R idtd

V R idt

1 [ ]

[ ]

( ) [ ]

( )

sd sd rd s sd ssr s sq sr rq

s s s s

sq sq s sq rqsr ss sd sr rd

s s s s

rd rd sr sd s rrrd r rq sr sq

r r r r

rq rq r rq sqsr s r

r r r

di V di R iM L i M idt L L dt L L

di V R i diM L i M idt L L L dt L

di V M diR i L i M idt L L L dt L

di V R i diMdt L L L dt L

[ ]r rd sr sd

r

L i M i

Final equations

3 ( )4em m qs dr ds qrT PL i i i i

2r emP T dtJ

•Torque Equation

•Expression for Rotor Speed Developed

2 rm P

• Effect change in temperature in rotor is considered and

observed

• Similarly efficiency, power factor and slip are calculated

using basic equations and considering all possible losses.

• 20 hp, • 460V, 50Hz, 3 • Induction motor with the following equivalent circuit parameters: Rs = 0.087 Ls = 0.0425 H Rr= 0.187 Lr= 0.043H Lm =0.04H P = 4 We=500 rpm Friction=10Nm/rad Stator copper loss=700w Temperature coefficient=

Motor ratings

33.9 10 /o C

Simulink model for normal operating

Speed

Speed v/s torque

Slip

Slip v/s torque

D-Q currents

Efficiency

Application

• Fault detection and analysis of effect of temperature variation on Induction motor parameters.

Fault detection :• a sudden load is applied for very short duration of time, when Induction motor is at steady state. Then its effect on torque, speed, current, slip, and flux are observed.

Simulink model for fault detection

Speed

Torque

D-Q currents

Simulink model for temperature effect

Power factor

D-Q currents

Fluxes of D-Q axis

Temperature variation

• the effect of change in temperature can be observed immediately on, change in resistance of the windings. This causes change in currents, fluxes, and power factor. Analysis is carried out to investigate the effect of change in temperature on Induction motor parameters

Conclusion And Future Work

• Implementation of Induction motor in simulink model.• Any Induction machine control estimation algorithm can be simulated in the simulink environment with this model, without actually using sensors.

Future work• Controller can be designed to obtain desired speed automatically with change in loading conditions.• Kalman estimator can be designed for accurate estimation applications.•Hardware implementation can be done.

REFERENCES [1] Norman S Nise, “Control Systems Engineering”, Wiley Student Edition, 5th Edition, 2009 [2] Joseph J Distefano III and other, “Feedback and Control Systems”, Schaum’s Outlines, TMH, 2ndEdition, 2007 [3] Ashfaq Hussain, “Electrical Machines”, Dhanpat Rai Publications [4] Katsuhiko Ogata, “Modern Control Engineering”, PHI,5th Edition, 2010 [5] Fouad Giri “AC electric motors control”: advanced design techniques and applications , John Wiley & Sons, Ltd. 2013 [6] Chee-Mun ong , “Dynamic simulation of electric machinary”,using matlab/simulink [7] Krstic M, Kanellakopoulos I, and Kokotovic P (1995) “Nonlinear and Adaptive Control Design”. John Wiley & Sons. Leonard W (2001) “Control of Electrical Drives”. Springer, New York. [8] Novotnak RT, Chiasson J, and Bodson M (1999) High performance mtion control of an induction motor with magnetic saturation, IEEE Transactions on Control Systems Technology, 7, 315–327. [9] Astolfi A, Karagiannis D, and Ortega R (2007) “Nonlinear and Adaptive Control with Applications”. Springer. Besanc¸on G (2007) “Nonlinear Observers and Applications”. Springer [10] Khalil HK and Strangas EG (1996) Robust speed control of induction motors using position and current measurement. IEEE Transactions on Automatic Control, 41, 1216– 1220. [11] Dorf & Bishop- Pearson education, “Modern control systems”, 11th Edition 2008.