Modeling and simulation of synchronous machine and its behaviour against voltage sags

IEEE In e na ional Symposium on Indus ial Elec onics (ISlE 2009) Seoul Olympic Pa k el, Seoul, Ko ea July 5-8, 2009 Modeling and Simula ion o Synch onous Machine and i s beha iou agains Vol age Sags Daniel Aguila ', Al a o Luna, Alejand o Rolan, Ge a do Vazquez Elec ical Depa men o Enginee ing Technical Uni e si y o Ca alonia Colom 1- 08222-Te assa, Spain 'Con ac Au ho : [email p o ec ed] Gus a o Ace edo Elec ical Depa men o Enginee ing and Powe Sys ems Fede al Uni e si y o Pe nambuco (UFPE) Reci e, Pe nambuco B azil Abs ac - This pape s udies he e ec s o ol age sags (dips), bo h symme ical and unsymme ical, on he h ee-phase Synch onous Machine (SM). The as majo i y o he elec ical powe gene a ion sys ems in he wo ld is consis o synch onous gene a o s coupled o he elec ical ne wo k hough a ans o me . Vol age sags on SM cause speed a ia ions, cu en and o que peaks and hence may cause ipping and equipmen damage. The consequences o ol age sags in he machine beha iou depends on di e en ac o s such as i s magni ude (o dep h), du a ion and ini ial poin -on-wa e, and also on he pa ame e s o he machine. In his s udy, h ee machines o di e en nominal powe ha e been used o simula e on MATLAB he e ec s o he ol age sags on he machine unde speci ic condi ions. SM is essen ial in o de o ob ain a eliable analysis o s abili y and dynamical pe o mance. The aim o his pape is simula e he SM and analyze i s beha iou agains ol age sags. Sec ion II p esen s he SM model. Sec ion III shows he ol age sags classi ica ion. Finally, based on he simula ions using MATLAB, ol age sags e ec s on SM a e analyzed in Sec ion IV. II. SYNCHRONOUS MACHINE MODEL In his pape he SM gene ic model is used conside ing i s dynamic equa ions in he dq e e ence ame gi en by [6]. Dampe winding exis in bo h dand qaxis: The o que T ) and he load angle J( ) (measu ed om phaso E.s o phaso ~) a e exp essed as: I'(z) = isq(MdFiF +MdDiD)-isd(MqiQ)+ ... ... + (Ld-Lq )isdi sq (4) This is an impo an angle because i is use ul o analyzing he machine s abili y. Th ee SM ha e been simula ed: a high-speed s eam u bine gene a o (835MVA), a low-speed hyd o u bine gene a o (325MVA), bo h ob ained om [6], and a small gene a o , whose a ed pa ame e s a e included in Table I. Fo simplici y pu poses, his model does no include sa u a ion. Ne e heless, i is impo an o emphasize ha some ol age sags may cause sa u a ion; howe e his happens a e he sag e ec , no du ing i . This means ha sa u a ion leads o high cu en . Howe e , sa u a ion akes he machine as e back in o he s eady s a e, which educes he ansien ime a e he ol age sag. Fu he mo e, due o sa u a ion he e is no a big a ia ion on he beha iou o he o que [7]. (3) (5) (1) (2) 1. INTRODUCTION The elec ici y is he main sou ce o ene gy nowadays in ou socie y. I is used o p o ide he ene gy needed o ope a ing a g ea a ie y o indus ial p ocesses, ligh ing and anspo a ion as well as o he in o ma ion and communica ion echnologies [1]. The Synch onous Gene a o (SG) has been widely used o his pu pose a ound he wo ld due o i s capabili y o gene a ing elec ici y in la ge scale powe plan s. In addi ion, small synch onous gene a o s, in he kVA ange, a e o en used as well in an isola ed sys em whe e he gene a o is d i en wi h a small combus ion engine as a p ime-mo e . These can be used as eme gency powe sou ces o hospi als, he mili a y acili ies and in he indus y in case o a blackou . Mo eo e , he i s s wind u bines based on SG a e di ec ly coupled o he g id ( ixed speed gene a ion sys ems), al hough he p og ess in he s a ic con e e echnology, has ans o med his gene a ion sys ems hough a iable speed ope a ion, allowing he op imum powe e icien o a wide wind speed ange [2]. Du ing he las yea s, he powe quali y has gained a g ea impo ance in bo h indus y and in esea ch. The g id may p esen many ypes o dis u bances, being he ol age sags he mos common ones. A ol age sag is a sho -du a ion ( om hal cycle o 1 minu e) d op be ween 10% and 90% in he magni ude o he ms ol age. The in e es in s udying his kind o dis u bances is mainly due o he p oblems ha hey cause in he elec ical equipmen s [3]. The simula ion o he SM's beha iou unde ol age sags pe mi s de ining di e en c i e ia o p o ec ing and p e en ing po en ial damages in such machines, as well as he e ec s on he powe supply in e up ions [4, 5]. Hence, a alid model o 978-1-4244-4349-9/09/$25.00 ©2009 IEEE 729 RAT ED DATAOF5KVASY NCHRO NO US MA CHI NE RAT ED DATA OF 325MVA SYN CHRO NO US MA CHI NE TABLE I RAT ED DATA OF 835MVA SYN CHRO NO US MA CHI NE SN=835MVA N=60Hz Spe ed = 3600 lmin SN=325MVA N=60Hz Speed = 112.5 lmin SN=5kVA N=60Hz Speed = 3600 lmin UN= 26kV H=5 .6s 1 pole pai UN=20kV H= 7.5s 32 pole pai s UN=437V H=3 .55s 1 pole pai cos qJN=0 .85 J=65.8x l O!Js2 cos p N= 0.85 J=35 .1x1(JJJs2 cos p N=0.85(j) J=0.2498 Kg m2 V Fmax =6.6901V 5kVA SM. This machine has winding dampe s on he dand q axes, which educe he e ec s o hese dis u bances, hus he machine synch onism is no los . Ne e heless, in lage machines, such as he 325MVA, winding dampe s canno a oid he synch onism los o dep hs (o du a ions) sag de e mined. On he o he hand, when unsymme ical sag is applied o he SM, he machine beha iou is di e en o each six unsymme ical sag ypes. On he whole, he ansien wa e shape caused by ol age sag depends on di e en ac o s such as i s dep h, du a ion, ini ial poin -on-wa e and machine pa ame e s [8]. A b ie desc ip ion o hese ac o s is gi en below. Type A Type B TABL E" SAGS TYPESINE QU ATI ON FORM (OBTAI NED FROM BOLLE N[4]) III. SAG CLASSIFICATION AND CHARACTERIZATION Vol age sags can be ei he symme ical o unsymme ical, depending on he causes. I he indi idual phase ol ages a e equal and he phase ela ionship is 120°, he sag is symme ical. O he wise, he sag is unsymme ical [8]. Acco ding o [3] ol age sags can be g ouped in o se en ypes, deno ed as A, B, C, 0, E, F and G. Table II shows hei exp essions (whe e his he sag dep h) and Fig. 1 shows hei phaso diag ams. The mos common causes o ol age sags a e aul s, la ge ans o me ene gizing and la ge mo o s a ing. Fig. I. Vol age sags ypes: Symme ical ( ype A) and unsymme ical ( ype B - G). All sags ha e a dep h o 50%. (Ob ain ed om [4]) In o de o simula e he beha iou o SM, in his pape i has been conside ed ha he sag shape is ec angula , no phase jump occu s and he sag ype does no change when he aul is clea ed. Hence, he ol age sags will be de ined by hei dep h h(0.1 S hS 0.9), hei du a ion S ,and hei ini ial poin -on- wa e l li [8]. IV. VOL TAGE SAGS EFFECTS The mos ele an ol age sags e ec s on he SM beha iou a e speed a ia ions, wi h possible loss o he synch onism, cu en and o que peaks. The machine beha iou is di e en when symme ical and unsymme ical sags a e p oduced in he ne wo k. When symme ical sag is applied o he SM he mos se e e peaks occu a he beginning and a he end o he sags. Fig. 2 shows he ansien e ec s caused by symme ical sag on he =hV - G I J3 ~b =- - hV - j-hV 2 2 I J3 ~b =- - hV + j-hV 2 2 Type C =hV -G I J3 ~b =- - V- j - hV 2 2 1 J3 ~b =- - V+ j - hV 2 2 Type E =V -G I J3 ~b = --hV - j-hV 2 2 I J3 ~b = --hV + j-hV 2 2 Type G = .!..(2 + h)V -G 3 ~b = - ~ ( 2 + h)V -j ~ hV ~b = - ~ ( 2 + h)V +j ~ hV =hV - G I J3 ~b =- - V- j - V 2 2 I J3 ~ b =- - V+ j - V 2 2 Typ eD =hV -G 1 ./3 ~b =- - hV - j-V 2 2 I ./3 ~ b =- - hV + j-V 2 2 Type F =hV - G Wh e e: h=0.1 ... 0 .9 sag dep h V=UD /./3 phas e- o-g ound ac ol age 730 A. Dep h In luence The beha iou o he machine is a ec ed by he sag dep h. Asudden d op in he ol age supply p oduces acu en peak a beginning o sag and ano he peak cu en when he aul is clea ed and he ol age is es o ed. A e eaching he i s peak alue, an oscilla ion is p oduced wi h cons an equency (o he g id) and dec easing ampli ude. Bo h cu en peaks a e mo e se e e i he sag is deepe . Fo all dep hs analyzed, he same beha iou is obse ed. To que and ac i e powe ha e he same beha iou . imo /1OCOOdJ T/2+kT T/2+kT T/2+kT lJli 0° 90° A C,E B,D,F Sag ype TABL E III MOST UNFAVORABLE SAG DURA nO N AND INITIAL POINT-ON- WAVE FOR SYNCHRONOUS M ACHINE B. Ini ial poin -on-wa e in luence Ini ial poin -an-wa e is also impo an in he s udy o he sag e ec s. Consequen ly,di e en aul angles cause di e en e ec s on he beha iou o he SM. Fig. 5 show he o que peaks e sus he ini ial poin -one-wa e on he s eam u bine SM o sags ypes A, B, C, D, E and F. Fo all simula ions, dep h sag is 10% and du a ion sag is h ee cycles. The cu en peaks ha e a e y simila beha iou . As can be deduced om his igu e, he wo s peaks occu nea he ini ial-poin -wa e o 90 deg ee o he sags ype B, D and F, and o he sags ype C and E he mos un a ou able peaks a e a ound 0deg ees. In addi ion, igu es show ha i he sag is symme ical ( ype A), he ini ial poin -an-wa e has no in luence on he powe and o que peaks. Bo h he cu en and o que highes alues a e ob ained when sag du a ion is hal ape iod plus any numbe o ull pe iods (A =TI2 +kT whe e kis a in ege k=0,1,2 ... ). Hence, he mos se e e cu en and o que peaks a e p oduced by he speci ic ini ial poin -an-wa e and sag du a ion o Table III. Fig. 3. Dep h in luence: 835MVA SM o que agains asymme ical ol age sag: ype A, h= 0.1 o 0.9, /),./ = lOOms(6 cycles), '/1 ,= 15° _hi"/ nm./_0 IdJ FigA. Dep h in luence : 5kVA SM o que agains a symme ical ol age sag: ypeA ,h =O.1 o 0.9,/),./= lOOms , '/1 ,= 15° 400 00 ". ~ 200 , .Q a ". ~ ';:;.. m-200 V -400a0.05 0.1 0.15 Time [seconds] ~~ I E I a0.05 0.1 0.15 0.2 0.25 Time [seconds] Fig. 2. 5kVA Synch onous Machine beha iou o a symme ical ol age sag: ype A, h=OA, /),./ = lOOms,'/I' = 15° Fig. 3 shows o que o hyd o u bine gene a o agains symme ical ol age sag whose dep h ange is om 10% o 90%. Sag du a ion is ixed on lOOms (six cycles) o all simula ions done and he ini ial-pain -wa e is 15°. I is clea as he impac on o que is mo e se e e i he sag is deepe . The s eam u bine gene a o has a e y simila beha iou . Ne e heless, as a as 5kYA machine is conce ned,cu en , o que and ac i e powe oscilla ions a e a enua ed by winding dampe s, as shown in Fig. 4, whose simula ions ha e been made se ing he sag du a ion on lOOms and he ini ial pain - on-wa e on 15°. Bo h igu es a e he esul o ecu si e simula ions unde speci ic condi ions men ioned abo e in o de o analyze each ac o sepa a ely. :, ' E . : a0.05 0.1 0.15 0.2 0.25 Time [seconds] , :: ~ . ~ ' ~ .:» -100 -200a0.05 0.1 0.15 0.2 0.25 Time [seconds] 731 20 40 60 80 100 120 140 160 180 poin -an-wa e [de ee] impac on cu en s s a o is mo e se e e i he sag is longe , when he ol age is es o ed. Figs. 6 and 7 shows he ansien o he angle Job ained o ecu si e simula ions keeping dep h sag on 10% and ini ial poin -on wa e on 15 deg ees. il===: .~ o 20 40 60 80 100 120 140 160 180 poin -an-wa e [de ee] ! l ~ === 2 - 1 o 20 40 60 80 100 120 140 160 180 poin -an-wa e [de ee] !T=== =: • =:=1 o 20 40 60 80 100 120 140 160 180 poin -an-wa e [de ee] i': ~ 1 o m ~ 00 00 100 1m 1~ 1M 100 poin -an-wa e [deg ee] ! 1 ; ~ == : : ===:1 o m ~ 00 00 100 1m 1 ~ 1M 100 poin -an-wa e [deg ee] i': ~ - ' 1 o 20 40 60 80 100 120 140 160 180 poin -an-wa e [deg ee] Fig.5. Ini ial poin -an-wa e in luence: 325MVA SM o que peaks o sags ypes A, B, C, D, E and F o di e en ini ial poin -an-wa e. Du a ion is h ee cycles and dep h is 10%: (alI sag ypes, h=0.1, !J.{ = 50ms ,l Ii =0 ° o 180°) C. Du a ion In luence The angle Jis in luenced by he sag du a ion. An inc ease in he sag du a ion leads an inc ease in he peak alue eached in he oscilla ion ha occu s a e ol age eco e ing. I his peak alue is e y la ge, Jis unable o e u n o i s s eady s a e alue and hen he synch onism is los . In e ms o o que and powe , simula ion esul s sugges ha in sho es ol age sag, peak alues a e highe a he beginning ha a e he ol age is es o ed. Simila ly, compa ing he ansien s o di e en du a ion leng hs i can be seen ha he Time{ 'ocond/ Fig. 6. Du a ion in luence: 325MVA SM <5 agains ansymme ical ol age sag: ype A, h=0.1 , !!J. =0 - 200ms, Ij j = 15° Time ,ocond/ Fig. 7. Du a ion in luence: 5kVA SM <5 agains an symme ical ol age sag: ype A, h=0.1 ,!!J. =0 - 200ms, Ij j = 15° V. CO NCLUSIONS Synch onous machines play a e y impo an ole in he s abili y o powe sys ems, since he as majo i y o he elec ical powe gene a ion sys ems in he wo ld using his machine. Symme ical and unsymme ical ol age sag e ec s on h ee-phase SM ha e been quali a i ely analyzed on h ee SM o di e en nominal powe . The simula ion o SM allows us o unde s and i s pe o mance and o deduc i s beha iou agains dis u bances in he powe supply. Vol age sags e ec s on equipmen depend on di e en elemen s such as sag cha ac e is ics (dep h, du a ion, poin -on- wa e and ype o sag), equipmen and g id. Pa icula ly, he mos ele an ol age sags e ec s on he SM a e cu en and o que peaks and possible loss o synch onism. The e we e no signi ican di e ences in he simula ion o he SM ope a ing as mo o o gene a o . The SM will con inue ha ing a wide applica ion in indus ial p ocesses and powe gene a ion, o hei excellen ea u es. 732 ACKNOWLEDGMENT This esea ch wo k was suppo ed by he p ojec ENE2008- 06588-C04-03-ALT om he Spanish Minis y o Educa ion and Science. REFERENCES [1] 1.G. Sloo weg, Wind Powe : Modelling and Impac on Powe Sys ems Dynamics, Technical Uni e si y o Del , 2003. [2] E ich Hau, Wind Tu bines: Fundamen als, Technologies, Applica ion, Economics, 2nd edi ion, Sp inge [3] M. H.J. Bollen, Unde s anding Powe Quali y P oblems, IEEE P ess, New Yo k, 1999 [4] 1. C. Das, E ec s o Momen a y Vol age Dips on he Ope a ion o Induc ion and Synch onous Mo o s, IEEE, T ans. Indus y Applica ion, Vol 26, No.4, July/Augus 1990. [5] F. Ca lsson, 1. Engs om, C. Sada angani, To que a ia ion Tu ing and a e Vol age Sags o a Synch onous Machine, EPE 2001. [6] P. C. K ause, Analysis o Elec ic Machine y, McG aw-Hill, New Yo k, 1986. [7] F. Ca lsson, Sa u a ion in Synch nous Machines due o Vol age Sags, IEEE 2003. [8] L. Guasch, F. C6 coles and 1. Ped a, E ec s o Symme ical and Unsymme ical Vol age Sags on Induc ion Machines, IEEE, T ans. Powe Deli e y, ol. 19, No.2, Ap il 2004. 733