DQ Modeling Of Induction Motor With Broken Rotor Bars In MATLAB Simulink

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1 DQ Moeling Of Inuction Moto With Boken Roto Bas In MATLAB Simulink Pincy P 1 an Gayathi Vijayachanan 2 1,2 Depatment. Of Electical an Electonics, See Buha College of Engineeing, Keala Abstact To analyze the pefomance of electical machines, theoy of efeence have been effectively use. This pape pesents the q moel of inuction moto in synchonous efeence fame. Hee a step by step implementation of stato an oto voltage equations is clealy shown. The moel is ceate using the cuent an voltage equations fo a healthy inuction moto an inuction moto with boken oto ba is also applie to see the vaiation in cuent spee an toque wavefoms an compae with a healthy moto. The moel escibe in the pape can be use in analyzing both tansient an steay state conition of the moto. Keywos inuction moto, tansient, boken otos, q moeling, steay state. I. INTRODUCTION Inuction machines play a vey impotant ole in the fiel of electomechanical enegy convesion. They ae wiely use in vaiety of ivese inusties pouct line, pocess manufactuing, automation applications, heating an ai conitioning, tanspotation, aeospace an maine populsion application to the health cae inusty. Even though the inuction motos ae well esigne thee may be possibilities of incipient failue which may amages the entie machine opeation. Fault iagnosis on inuction moto is one of the impotant concens in the electic ives inusty as 8% of the electic ives inusty is woking on Inuction motos [1]. The tansient an steay state behavio of an inuction machine can be escibe fom its ynamic moel. The ynamic moel of inuction moto, which is fequently use in moto ynamic stuies like moto contol, ive specifications, moto potection, stating high inetia loas, fast an lage loa changing, successive stating, locke oto, etc is expesse by the six iffeent equations of thee- phase instantaneous toque, spee, voltage an cuent equations. The machine is moele in such a way that it gives clea iea about the equations an the subsystems ae clealy shown using MATLAB Simulink. In aition to this, a faulty moto that is boken oto is also moele an compae the vaiations in toque an cuent wavefoms. Boken oto bas ae one of the most sevee inuction moto faults. It can be cause by themal stesses ue to themal oveloa an unbalance, hot spots o excessive losses, spaking (mainly fabicate otos), magnetic stesses cause by electomagnetic foces, unbalance magnetic pull, electomagnetic noise an vibation, esiual stesses ue to manufactuing poblems, ynamic stesses aising fom shaft toques, centifugal foces an cyclic stesses, envionmental stesses cause by contamination an abasion of oto mateial ue to chemicals o moistue, mechanical stesses ue to lose laminations, fatigue pats, beaing failue, etc [2]. The main goal of this pape is to simulate the mathematical moel of inuction moto in MATLAB Simulink with an without boken otos an its effect on toque, spee an cuent wavefoms. II. INDUCTION MOTOR MODELING Dynamic moel inclues thee pefee spees o efeence fames as follows: they ae (i) the stationay efeence fame when the q axes o not otate. (ii) the oto efeence fame when the q axes otate at oto spee. (iii) Synchonously otating efeence fame when the q axes otate at synchonous spee. Using any of the thee efeence fame, the tansient natue of the machine All ights Reseve 22

2 Intenational Jounal of Moen Tens in Engineeing an Reseach (IJMTER) be analyze. Hee, synchonous efeence fame is use since the stat an oto voltages ae balance. The inuction machine is highly symmetical. Figue 1. Dynamic - q equivalent cicuits of machine (a) q-axes, (b) axes cicuit Duing the stating as well as uing the othe tansient opeations the inuction motos aw lage cuent which esults in voltage ips, oscillatoy toques an even geneate the hamonics in the powe systems. The q axis moel is moe eliable an accuate to investigate such of these poblems. The ynamic moel is eive by using two-phase moto in iect an quaatue. This appoach is useful because of the conceptual simplicity obtaine with two set of winings one is on the stato an othe is on the oto. [3]. The voltage balance equation fo the q coil in abitay efeence fame is: vqs Rs pls sls plm slm iqs v s sls Rs pls slm pl m i s v plm ( s ) Lm R pl ( s ) L i v ( s ) Lm plm ( s ) L R pl i whee p= /t. In synchonous fame, the spee of efeence fame inuction moto in synchonous efeence is shown below: s = (1) e. The mathematical moel of vqs Rs pls els plm elm iqs v s els Rs pls elm pl m i s v plm ( e ) Lm R pl ( e ) L i v ( e ) Lm plm ( e ) L R pl i (2) Flux linkage as vaiables can be use in ynamic equations of the inuction moto in any efeence fame. This involves the euction of a numbe of vaiables in the ynamic equations. If the voltages an cuents ae iscontinuous then also the flux linkages ae continuous. The flux linkages of the stato an oto can be escibe as: L i L i Eqn. (3) qs s qs m L i L i Eqn. (4) s s s All ights Reseve 23

3 m qs Intenational Jounal of Moen Tens in Engineeing an Reseach (IJMTER) L i L i Eqn. (5) Li Lmis Eqn. (6) On expaning the equation (2), we get vqs Rsiqs Ls iqs elsis Lm i elmi t t Eqn. (7) vs Rsis Ls is elsiqs Lm i elmi t t Eqn. (8) v Ri L i ( e ) Lmis Lm iqs ( e ) Li t t Eqn. (9) v Ri L i ( e ) Lmiqs Lm is ( e ) Li t t Eqn. (1) Fom eqn.(7)- eqn.(1), fin out the eivative of i qs, i s, i, i an moeling is pefome. Finally, the value of stato cuent is the esultant of i s an i qs is is iqs Eqn. (11) 3 The electomagnetic toque of the inuction moto in synchonous efeence fame can be given as: 3PLm Te isi iqsi 4 Eqn. (12) The electo-mechanical equation is given by: 2 Te TL J Eqn. (13) P t Using all the above eive equations, inuction moto can be moele. Figue 2. Simulink moel of Inuction All ights Reseve 24

4 Intenational Jounal of Moen Tens in Engineeing an Reseach (IJMTER) Figue 3. Subsystem of inuction moto moel Figue 4. Simulink moel fo All ights Reseve 25

5 Intenational Jounal of Moen Tens in Engineeing an Reseach (IJMTER) Figue 5. Simulink moe fo toque equation. III. MODELING OF INDUCTION MOTOR WITH BROKEN ROTORS Boken oto ba faults occue geneally in inuction moto ue to iffeent easons some of them ae themal stess, magnetic tension, beaing failue, ynamic pessue an loa vaiation [4], [5], [6]. Wheneve thee is a boken ba in the moto, it will avesely affect the oto esistance. A boken ba may esult in the incease of the esistance at that paticula ba. As a esult, the cuent flows though the boken ba get ecease an hence moe cuent will flow though the ajacent bas causing amage to the moto. So boken oto conition can be analyze by vaying the oto esistance. Assume that the moto has a total numbe of N oto bas out of which n bas ae boken. A symmetic boken ba conition is consiee in which the magnetic flux in the stato an oto emains symmetic. The conucto of the faulty phase becomes {(N-n)/3} an its esistance is given by 3R R ba b Eqn. (14) N n whee Rb is the esistance of each oto ba. Change in esistance is given by : 3Rba 3Rba R Rb R Eqn. (15) N n N IV. SIMULATION RESULTS The inuction moto chosen fo the simulation stuies has the following paametes: Type: thee-phase, 4-pole, wye-connecte, squiel-cage inuction moto with, Rs =.88 Ω/ph, R = Ω /ph, Ls =.425 Ω /ph, Lm =.4 Ω /ph, L =.425 Ω /ph, J=.4 kg m. The simulation esults of cuent, toque an spee wavefoms obtaine fo inuction moto which is being moele in MATLAB ae shown in Fig. 6 an Fig. 7. Inuction moto with boken bas has also been moele in MATLAB an the toque, cuent wavefoms ae obtaine. Fig8, Fig. 9 an Fig 1 show the spee toque wavefom fo fou an eight numbe of boken oto bas espectively. The effect of boken bas in toque an cuent wavefoms ae clea in these All ights Reseve 26

6 stato cuent (A) toque Toque stato cuent (A) Intenational Jounal of Moen Tens in Engineeing an Reseach (IJMTER) time(sec) Figue 6. Stato cuent fo healthy inuction moto spee Figue 7. Spee Toque wavefom fo healthy inuction moto spee Figue 8. Spee toque wavefoms fo eight boken oto bas time(sec) Figue 9. Stato cuent fo inuction moto with fou bas All ights Reseve 27

7 cuent(a) Intenational Jounal of Moen Tens in Engineeing an Reseach (IJMTER) time(sec) Figue 1. Stato cuent fo inuction moto with eight bas boken V. CONCLUSION This pape pesents the q moeling of inuction moto with an without boken bas in synchonous efeence fame an its effect on stato cuent, toque an spee wavefoms. Moeling is one in MATLAB Simulink using sim powesystem block sets. Satisfactoy esponse has been obtaine fom the simulate esults in tems of toque, spee an cuent chaacteistics. REFERENCES [1] S.M Shashihaa, Taeoff Analysis of Wavelet Tansfom techniques fo the Detection of Boken oto bas in inuction, Intenational Jounal of Avance Reseach in Electical, Electonics an Instumentation,vol.3,ISSN , July 213 [2] Neelam Mehala, Ratna Dahiya, Roto Faults Detection in Inuction Moto by Wavelet Analysis, Intenational Jounal of Engineeing Science an Technology, vol.1 (3),29 [3] R. Kishan, Electic moto ives: Moelling, analysis an contol, Pentice Hall Company, New Jesey, 21 [4] S. A. Tahe an M. Malekpou, A novel technique fo oto ba failue etection in single-cage inuction moto using FEM an MATLAB/ SIMULINK, vol. 211, pp. 1 14, 211. [5] Nani an H. A. Toliyat, Fault iagnosis of electical machines-a eview, in Poc. Int. Electic Machines an Dives Conf, pp , [6] Nani an H. A. Toliyat, Conition monitoing an fault iagnosis of electical machines-a eview, in poc. In. Applicat. Soc., vol. 1, pp , All ights Reseve 28