ASSESSMENT OF STRESSES ON INDUCTION MOTOR UNDER DIFFERENT FAULT CONDITIONS

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1 Jounal of Theoetcal and Appled Infoaton Technology JATIT. All ght eeved. ASSESSMENT OF STESSES ON INDUCTION MOTO UNDE DIFFEENT FAUT CONDITIONS 1 B.AUNA KUMAI, 2 K.NAGA SUJATHA, 3 K.VAISAKH * 1 M.E. Student, Dept. of Electcal Engneeng, Andha Unvety, Vakhapatna , AP, Inda 2 Aoc. Pof., Dept. of Electcal Engneeng, Andha Unvety, Vakhapatna , AP, Inda 3 Pofeo, Dept. of Electcal Engneeng Andha Unvety, Vakhapatna , AP, Inda * Coepondng autho, E-al: ABSTACT Th pape peent an aeent of tee poduced n an nducton oto when the oto allowed to un unde open-ccut and hot-ccut condton. A genealzed dynac odel of a thee-phae quel cage nducton oto ha been developed ung d and q vaable n a ynchonouly otatng efeence fae. Th odel can pedct pefoance of the oto dung open-ccut and hot-ccut condton. The ulaton eult ae obtaned fo two quel cage nducton oto, zed 3 hp and 2250 hp. Keywod: Modelng, Inducton oto (IM), open-ccut (OC), hot-ccut (SC) 1. INTODUCTION Inducton achne odelng ha contnuouly attacted the attenton of eeache not only becaue uch achne ae ade and ued n laget nube but alo due to the vaed ode of opeaton both unde teady and dynac tate. In an electc dve yte the achne a pat of the contol yte eleent. To be able to contol the dynac of the dve yte, dynac behavo of the achne need to be condeed. The dynac behavo of IM can be decbed ung dynac odel of IM. The dynac odel conde the ntantaneou effect of vayng voltage/cuent, tato fequency and toque dtubance. In th pape the dynac odel of IM deved by ung d and q vaable n a ynchonouly otatng efeence fae and alo the dynac pefoance of IM unde open ccut and hot ccut fault condton fo both low and hgh powe achne. Inducton oto ae coonly contolled by contacto, whch ae electoagnetc wtche that ae hghly entve to voltage depeon and oentay evce nteupton. Voltage depeon ae huge poble fo any ndute, and t pobably the ot peng powe qualty poble today. The Voltage depeon caued by fault on the yte affect the pefoance of nducton oto, n te of the poducton of both tanent cuent and tanent toque. It often deable to nze the effect of the voltage dp on both the nducton oto and oe potantly on the poce whee the oto ued. age toque peak ay caue daage to the haft o equpent connected to the haft. Soe coon eaon fo voltage depeon ae lghtnng tke n powe lne, equpent falue, accdental contact powe lne, and electcal achne tat. Depte beng a hot duaton between 10 llecond to 1 econd event dung whch a educton n the MS voltage agntude take place, a all educton n the yte voltage can caue eou conequence [6]. 2. MODEING OF INDUCTION MOTO In th pape the atheatcal odel of the nducton oto odeled ung atlab / ulnk poga baed on efeence [1] to [5]. Th odel decbed n pace vecto foulaton n ynchonouly otatng abtay d-q efeence fae aocated wth the fequency w of the tato exctaton (ung pe unt decpton). Th odel obtaned condeng the nducton 772

2 Jounal of Theoetcal and Appled Infoaton Technology oto a 6 agnetcally coupled ccut. Unde balanced condton, the u of tato cuent a well a oto cuent zeo. The nducton oto ae odeled n d-q vaable. The d-q odel ue two wndng fo each tato and oto of the nducton oto. Only fou ndependent vaable ae needed to odel the nducton oto. A tanfoaton of vaable can be ued. The powe nvaant two-axe tanfoaton ued and defned a: JATIT. All ght eeved. () 3-phae to 2-phae (abc-dq) conveon: To convet 3-phae voltage to voltage n the 2- phae ynchonouly otatng fae, they ae ft λ conveted to 2-phae tatonay fae ( α β ) o n the oveent wth an abtay peed ung (1) and then fo the tatonay fae to the ynchonouly otatng fae (dq) ung (2). In place of voltage thee ay be cuent o flux lnkage. 1 1 Va V 1 α 2 = 2 2 Vb Vβ V c 2 2 (1) Vd co γ n γ Vα = Vq n γ co γ Vβ (2) Whee γ the tanfoaton angle. ω () 2-phae to 3-phae (dq-abc) conveon: Th conveon doe the oppote of the abc-dq conveon fo the cuent vaable ung (3) and (4) epectvely by followng the ae pleentaton technque a befoe. α co γ n γ d = β n γ co γ q (3) 1 0 a 1 3 α = b 2 2 β c (4) The dynac equaton n abtay efeence fae whch otatng at peed ω n the decton of oto otaton. 1. When ω equal to zeo, the efeence fae fxed n the tato (q-d ef. fae). 2. When ω equal to ωe, the efeence fae fxed on the ynchonouly otatng efeence fae. 3. When ω equal to ω, the efeence fae fxed n the oto. That, the efeence fae otatng at peed of ω. The dynac equaton ued ae: Electcal yte equaton: V = V = 1 dλ + ω + em (p / 2) [5] ω b dt 1 dλ + + ( ωe ω) M(p / 2) λ [6] ωb dt λ d = ; = ; λ q Flux lnkage-cuent elaton: λ = + [7.a] λ = + [7.b] Whee = + l and = + l Mechancal yte equaton: dωec T e = 2H + Bωec + T dt [8] Whee T = λ = M λ and e (p / 2) 2 ec = ω p 3. SIMUINK MODE OF INDUCTION MOTO The odel of the nducton oto n d-q vaable epeented by (5), (6), (7) and (8). Cuent o flux lnkage can be ued a tate vaable. In th pape the flux lnkage ae choen a tate vaable and t wa vefed n the Matlab/Sulnk oftwae envonent. The block daga of a thee-phae nducton oto uppled by a thee-phae powe upply hown n Fg. 1. The vaable = ω λ ω epeent the peed of the coon efeence fae ued. Th peed an abtay peed. It cont of fve ajo block: the 3-phae voltage, abc-dq conveon, dq-abc conveon, nducton achne d-q odel (I_dq_odel) and the echancal yte (ech y) block. (a) 3-phae voltage A thee-phae voltage and fequency ae epeented n th block. (b) abc-dq Tanfoaton The abc-dq block ealze the tanfoaton of vaable defned by (1) and (2). 773

3 Jounal of Theoetcal and Appled Infoaton Technology JATIT. All ght eeved. Fg.1 Block daga of nducton oto odel n the abtay fae Fg.3 Flux Cuent elaton Block Fg. 2 DQ odel of the nducton achne n abtay efeence fae (I_dq_odel) (c) IM _dq_odel Th block epeent the nducton oto ung d-q vaable n an abtay efeence fae and hown n fg.(2). The d-q odel of the nducton oto epeented ung equaton 5 and 6 wth flux-cuent elaton block. The ub-block daga of flux-cuent elaton ung equaton 7.a and 7.b hown n Fg.3. It ued to copute the fou dq cuent ung the fou flux lnkage and the nvee nductance Fg. 4 ech y block atx. (d) dq-abc Tanfoaton The dq-abc block ealze the tanfoaton of vaable defned by equaton (3) and (4). (e) ech y The echancal yte (ech y) block detene the electoagnetc toque ung equaton (8) and hown n fg. (4) 774

4 Jounal of Theoetcal and Appled Infoaton Technology JATIT. All ght eeved INDUCTION MOTO UNDE SHOT CICUIT CONDITIONS When a thee phae hot ccut fault occu electcally cloe to the oto no electcal enegy can ente o leave the oto. It obvou that cuent can tll flow n both the tato and oto wndng, thu toque can be poduced. The enegy toed n the agnetc feld can theefoe be dpated ethe a echancal enegy o a heat due to coppe loe n the oto. A the fault appled, thee a lage negatve toque tanent aocated wth the tanent cuent of a typcal agntude of 9 p.u. It not uncoon fo oto to have a axu evee toque pule of up to 15 p.u [12 13]. Th toque pule eache t axu wthn few cycle, but decay apdly. Snce the flux decay apdly, cleang of the fault and the ubequent eetablhent of the upply voltage poduce tanent of the ae ode a at tatup. Howeve f any oto ae left connected to the yte the cobned effect could lead to a voltage depeon due to lage cuent, and all the oto ght not be able to acceleate back to full peed. 4. INDUCTION MOTO UNDE OPEN CICUIT CONDITIONS When the oto open-ccuted the oto wndng cay the cuent to antan the f and hence the flux n the oto. Once the fault ha been cleaed, the oto can be econnected to the upply. If the oto tenal ae dconnected fo the upply, once agan no enegy can ente o leave the agnetc feld va the electcal tenal. Futhe a thee no cuent n the tato, toque cannot be poduced, thu enegy cannot be tanfeed to the echancal load. At that ntant when the tato cuent nteupted, the net f n the oto ut ean contant. Th f balance acheved by an ntantaneou nceae n the cuent n the oto wndng whch eult n enegy decay due to the etance n the oto. 6. SIMUATION ESUTS Th pape peent the odelng of the IM and t pefoance unde dffeent fault condton fo vaou atng of the achne. The effect of electcal toque, peed, cuent due to udden change n appled voltage fo both 3 hp and 2250 hp nducton achne ae analyzed. Th analy caed though atlab/ulnk oftwae envonent. Dynac pefoance of Inducton achne: Fo a 3-hp and 2250 hp nducton achne, the paaete ae fo [9] and ae gven n Appendx. Typcal ulaton eult ae gven n fgue 5 to 12 n [p.u]. Fg.5 and fg.6 how the fee acceleaton chaactetc of a 3-hp and 2250-hp nducton oto and alo the toque veu peed chaactetc ae hown n fgue 7 and 8 epectvely. Fo all thee ulaton the ntal condton ae zeo. Intally the achne tatng fo et wth ated voltage and no echancal load. Becaue fcton and wndage loe ae not epeented, the achne acceleate to ynchonou peed; unde th condton the tatng cuent lage. Due to the applcaton of tato voltage, the ntantaneou toque vae at 60-Hz about an aveage potve value. Th decayng, 60-Hz vaaton n the ntantaneou toque due to the tanent n the tato cuent. Even though the tato cuent depend upon the value of ouce voltage at the te of applcaton, the ntantaneou toque ndependent of the balanced ouce voltage becaue the achne yetcal. Thee ocllaton n the toque take place untl fnal opeatng pont eached. Fo the fg.7 and 8 we can obeve the oto peed hghly daped n the cae of 3-hp achne and the fnal opeatng condton attaned wthout ocllaton. Whee a n the cae of 2250-hp achne an ocllatoy anne. Dynac pefoance of Inducton achne dung a 3-phae hot-ccut fault: The dynac pefoance of the 3-hp and 2250 hp nducton achne hown, epectvely n fg 9 and 10 dung a hot-ccut (SC) fault at the tenal. Intally the oto unnng at teady tate condton wth a contant load toque. The SC fault at the tenal ulated by ettng the tato voltage to zeo at te t=1 ec. At that ntant, the voltage pae though zeo gong potve. Afte 10 cycle.e at t=2 ec the tato voltage ae eappled. Fgue 9 and 10 how that teppng the upply voltage to zeo volt caue a negatve toque peak of appoxately 9 te the ated teady tate toque. It not uncoon fo oto to have a axu evee toque pule of up to 15 p.u. 775

5 Jounal of Theoetcal and Appled Infoaton Technology Snce the oto peed and fequency alo deceae once the upply voltage eoved. The agntude of the wot toque peak and the nteupton duaton at whch t occu ae a functon of the oto and load neta. age yte neta caue the oto peed to deceae oe lowly..e lowe the agntude of the negatve toque pule hghe the load neta. In the cae of 3-hp achne, both the tato and oto tanent ae hghly daped and ubde befoe the fault eoved and the voltage ae eappled. A n the cae of 2250 hp achne, whch ha hghe leakage eactance to etance ato than the 3-hp achne, the tato and oto tanent ae tll peent even though the fault eoved and the voltage ae eappled. When the voltage ae eappled the tanent agan occu n the tato cuent. Dynac pefoance of Inducton achne dung an open-ccut fault: JATIT. All ght eeved. The dynac pefoance of the 3-hp and 2250 hp nducton achne hown, epectvely n fg 11 and 12 dung a open-ccut (OC) fault at the tenal. In th cae, the nducton oto dconnected fo the upply at te (t=1ec), and then econnected at a te ( t=2 ec). Fg.11 and 12 how the decay n the flux n the achne and alo the electoagnetc toque of the oto becoe zeo at the oent of dconnecton,.e thee no toque pule. Howeve, when the healthy upply etoed thee a lage negatve toque pule. In the cae of 3-hp achne, both the tato and oto tanent ae hghly daped and ubde befoe the fault eoved and the voltage ae eappled. A n the cae of 2250 hp achne, whch ha hghe leakage eactance to etance ato than the 3-hp achne, the tato and oto tanent ae tll peent even though the fault eoved and the voltage ae eappled. When the voltage ae eappled the tanent agan occu n the tato cuent. Fg.5 Machne vaable dung fee acceleaton of a 3-hp nducton oto [p.u]. Fg.6 Machne vaable dung fee acceleaton of a 2250-hp nducton oto [p.u] 776

6 Jounal of Theoetcal and Appled Infoaton Technology JATIT. All ght eeved toque-peed chaactetc hp nducton achne 2 toque peed Fg.7 Toque-Speed chaactetc dung fee acceleaton: 3-hp nducton oto [p.u] 600 toque-peed chaactetc 2250 hp nducton achne toque peed Fg.8 Toque-Speed chaactetc dung fee acceleaton: 2250-hp nducton oto [p.u] Fg.10 Dynac pefoance of 2250-hp nducton achne dung a hot-ccut fault [p.u] Fg.9 Dynac pefoance of 3- hp nducton achne dung a hot- ccut fault [p.u] Fg.11 Dynac pefoance of 3-hp nducton achne dung a Open-ccut fault [p.u] 777

7 Jounal of Theoetcal and Appled Infoaton Technology JATIT. All ght eeved. condton, t how that the SC fault condton can caue oe evee echancal tee than the OC fault condton. 8. EFEENCES Fg.12 Dynac pefoance of 2250-hp nducton achne dung a Open-ccut fault [p.u] 7. CONCUSIONS In th pape the dynac odel of nducton oto ha been analyzed by ung d and q vaable n a ynchonouly otatng efeence fae and alo the pefoance of IM dung a hot-ccut and openccut fault fo both 3-hp and 2250-hp powe achne. In both cae, thee decay n flux n the achne. It potant to note that the decay n OC fault vey uch lowe than fo the SC fault and alo the peak cuent alot double the tatng cuent. Howeve t ut be noted that the tanent of hot duaton and hence wll not have a eou effect n te of heatng, but t can caue evee echancal tee on the wndng of the achne. By copang wth OC and SC fault [1] G. J. ette, Matx and Space-phao theoy of electcal Machne,Akadéa Kadó, Budapet, [2] D. O Kelly and Son, Intoducton to Genealed Electcal Machne Theoy, McGaw-Hll, [3] Mohan, N. Advanced Electc Dve. Analy, Contol and Modelng ung Sulnk, MNPEE, [4] Adkn, B. The Geneal Theoy of Electcal Machne Chapan & Hall td,1962. [5] Kaue, Analy of Electc Machney, McGaw-Hll, [6] IEEE Induty Applcaton Magazne, Befoe anddung Voltageag,avalable at [7] Mulukutla S S, Gulachenk E M, A ctcal uvey of condeaton n antanng poce contnuty dung voltage dp whle potectng oto wth eclong and butanfe pactce, IEEE, 1991 [8] Swtchgea Manual 8 th edton ABB [9] J.J Cathey,.K.Calvn, III, and A.K.Ayoub, Tanent load odel of an nducton achne, IEEE Tanacton on Powe Appaatu and Syte, vol.92, July/Augut 1973, pp [10] J.. nde, "Effect of Powe Supply Vaaton on AC Moto Chaactetc", IEEE Tanacton on Induty Applcaton, vol. IA-8, no. 4, July/Augut 1972, pp [11] I.. Sth, S. Shaan, "Inducton Moto ewtchng Tanent", Poc. IEEE, Vol.114, No. 4, Apl 1967, pp [12] F.P. Flynn,.D. Slate, W.S. Wood, "Tanent Negatve Toque n Inducton Moto due to apd econnecton of the Supply", Poc. IEE, vol. 116, no.12, Decebe 1969, pp [13].H. Daughety, "Analy of Tanent Electcal Toque and Shaft Toque n Inducton Moto a a eult of Powe Supply Dtubance", IEEE Tanacton on Powe Appaatu and Syte, vol. PAS-101, no. 8 Augut 1982, pp

8 Jounal of Theoetcal and Appled Infoaton Technology JATIT. All ght eeved. APPENDIX Each achne a 4-pole, 60 Hz, 3-phae nducton oto.the paaete ae expeed n oh ung the 60-Hz value of the eactance. Paaete of the 3HP nducton achne p=4; V =220; V =0; ω =2*p*60; d =0.435; = ; q = 0.816; =26.13; J=0.089;.= ( ); Paaete of the 2250HP nducton achne p= 4; V d =2300; V q =0; ω =2*p*60; =.029; =0.022; = ( ); = ; =13.04; J=63.87; NOMENCATUE V the voltage pace vecto, the cuent pace vecto, λ the flux lnkage pace vecto, M the π/2 0 1 otatonal atx, M p / 2 = 1 0 the etance, the nductance, V, V, V phae voltage n abc fae. a ω ω ω λ e b c oto fae feq. dq fae feq. ynchonou fae feq.; (ad/ec) tato flux, λ oto flux, tato and oto etance V, V tato and oto voltage, tato and oto cuent, tato and oto nductance l agnetzng nductance tato leakage nductance l oto leakage nductance T electoagnetc toque e T load toque B vcou fcton coeffcent. d, q dect and quadatue ax p nube of pole H neta contant J neta of the oto. V α ; V β tato and oto voltage n αβ fae α ; β tato and oto cuent n αβ fae Opeato: =co poduct; =dot Poduct. BIOGAPHY B. Auna Kua eceved the B.E degee n electcal & electonc engneeng fo MVG College of Engg, AP, Inda n Cuently he puung M.E degee n the depatent of electcal engneeng, AU College of engneeng, Andha Unvety, Vakhapatna, AP, Inda.. He nteet ae nducton oto dve, and powe yte opeaton and contol. K. Naga Sujatha eceved the B.E degee n electcal engneeng fo Oana Unvety, Hydeabad, Inda n 1995, M.Tech degee fo JNT Unvety, Hydeabad, Inda n She puung PhD n the depatent electcal engneeng, AU College of engneeng, Andha Unvety whee he cuently wokng a Aocate Pofeo. He eeach nteet nclude powe electonc, powe electonc dve, optal contol, fuzzy logc, adaptve neuo-fuzzy yte, paaete etaton, and dgtal gnal poceng. D. K.Vaakh eceved the B.E. degee n electcal engneeng fo Oana Unvety, Hydeabad, Inda n 1994, M.Tech degee fo JNT Unvety, Hydeabad, Inda n 1999, and Ph.D. degee n electcal engneeng fo the Indan Inttute of Scence, Bangaloe,Inda n the yea Cuently, he wokng a pofeo n the depatent of electcal engneeng, AU College of engneeng, Andha Unvety, Vakhapatna, AP, Inda. H eeach nteet nclude optal opeaton of powe yte, voltage tablty, FACTS, powe electonc dve and powe yte dynac. 779