LESSON 11: TRANSFORMER NAME PLATE DATA AND CONNECTIONS

Transcription

1 ET 332 Motors, Geertors d Power Systems LESSON 11: TRNSFORMER NME PLTE DT ND ONNETIONS 1 LERNING OJETIVES fter this presettio you will e le to: Idetify trsformer polrity usig dot d ovetiol lelig. Expli d iterpret iformtio foud o trsformer me pltes. ompre d otrst the performe of three phse trsformer oetios. Idetify the shemti symols of potetil d urret trsformer. List hrteristis o these devies d expli how they relte to performe. 2 1

2 TRNSFORMER MRKINGS ND POLRITY Dot Nottio - Termils mrked with dot re osidered istteously positive I 1 I 2 E degree shift D N 1 N 2 ove Termils d re positive t the sme time Phsor Digrm E 0 degrees E D 3 TRNSFORMER MRKINGS ND POLRITY - I 2 E degree shift D ove Termils d D re positive t the sme time Phsor Digrm E E D 180 degrees 4 2

3 TRNSFORMER MRKINGS ND POLRITY ovetiol Lelig H = high voltge side X = low voltge side X phse shift X2 Termil more positive th. O seodry side X1 more positive th X2 5 TRNSFORMER MRKINGS ND POLRITY ovetiol Lelig H = high voltge side X = low voltge side - X2 180 phse shift - X1 Note: Polrity of seodry is reversed retig 180 degree phse shift ross trsformer 6 3

4 TRNSFORMER NMEPLTE DT Voltge rtigs high side d low side vlues (o-lod vlues) dditiol Voltge Mrkigs Dsh (-) = Idites voltges from differet widigs Slt (/) = voltges from sme widig ross(x) = voltges otied y series or prllel oetio of two prt widigs Wye (Y) = wye-oeted widigs 7 TRNSFORMER VOLTGE RTINGS Sigle Phse Exmples 240/ 240x 240- Three Phse Exmple Y-277 V 240 V widig with eter tp Two prt widig tht e oeted i series for 240 V d prllel for V 240 V d seprte V widig Two widig trsformer. Wye oeted seodry with 277V d 480 V ville 8 4

5 OTHER NME PLTE DT Frequey kv Rted frequey of trsformer Rted ppret power of trsformer ppret power rtig determied y ostrutio d oolig- oil ooled. Oil lso provides isultio Power rtigs O rtig - turl ovetio ir d oil. F rtig - turl ovetio of oil d fored ir FO rtig - fored ir d oil irultio 9 TRNSFORMER POWER RTINGS Typil rtigs 30/40/50 MV O/F/FO Dry Type Isulted trsformers (o oil) Typil t voltges of 15 kv d elow lsses - dry type, self-ooled, turl ovetio of ir F - Dry type, fored-ir oolig /F Dry type self-ooled/fored ir ooled Fored oil y irultig pumps Fored ir y rditors d fs Dul rtig tht requires fs 10 5

6 OTHER NME PLTE DT Peret Impede Temperture Rise Impede mesured t idited temperture. se S d V vlues re the rtigs of the trsformer Mximum llowle temperture rise Het effets the isultio Exessive hetig redues life of trsformer lss Isultig medium d oolig ( see previous slide) 11 SI IMPULSE LEVEL IL (si Impulse Level) Mesures the mximum voltge stresses tht the trsformer hdle Impulse tests used to simulte the effets of lightig over-voltges Voltge surges i exess of the IL use isultio filures 12 6

7 THREE PHSE TRNSFORMER ONNETIONS Trsformers irese voltge, deresig urret i power systems. Lower I mes less power loss due to I 2 R losses i lies, les, trsformers, et Step up trsformer I V Step dow trsformer V I Geertor Three phse trsformers 3 sigle-phse uits form 3-phse k or Sigle three-phse trsformer (3 seprte ores i sigle tk) Step up/dow trsformers re differet oetios of 1-f uits or oils sed o wye-delt ofigurtios 13 THREE PHSE TRNSFORMER ONNETIONS Exmples from the field Three-Phse Trsformer Sigle Uit, Susttio Type Three Phse k Three idividul Trsformers 14 7

8 3/2/2018 DELT-DELT (D-D) ONNETION primry seodry Prllel oils re prt of sme trsformer or ore Phse digrm dvtges: sors ule of lod. Ule I irultes i delt. Lose oe trsformer d still operte Disdvtges: No turl eutrl 15 WYE-WYE ONNETION N Three phse, four-wire, grouded wye primry dvtges: Two voltge levels ville Grded High voltge isultio Esy lig etwee 1-f d 3-f lods Disdvtges: / Three / V trsformers Primry V = V = V = 7200 V H 1 - H 2 V LL = V Seodry V = V = V = V X 1 - X 2 V LL = V Sigle phse short iruit urrets pssed. Zero sequee (3rd Hrmois pssed) Totl k power: S 1 S 2 S 3 = S T 16 8

9 3/2/2018 DELT-DELT (180 O SHIFT) Three phse, three-wire, delt primry dvtges Idel for motor lods, 3-wire. tolerte sigle lie shorts with o iterruptio. Trps 3rd hrmoi urrets //240 3 Trsformers / V primry V = V = V = 7200 V V LL = 7200 V Seodry V = V = V = 240 V V LL = 240 V Disdvtges Full isultio required o H.V. Widigs. T1 must e lrger KV whe Servig 1-f lod with 3-f. No turl groud poit Uled oetio whe servig 1-f d 3-f lods together k power S 1 S 2 S 3 = S T 180 o phse shift H 1 -H 2 to X 1 -X 3 17 EXMPLE FROM FIELD kv Lie-tolie primry Smller size idites lower power rtig Seodry oetios Three-Phse k Uequl Trsformer Power Rtigs 18 9

10 DELT-WYE ONNETION- 30 PHSE SHIFT Three phse, three-wire, delt primry dvtges: Sigle phse lod esy to le. New eutrl poit is estlished. Two voltge levels. Trps 3rd hrmois / Disdvtges: Full isultio required o H.V. widig of trsformers k Power S 1 S 2 S 3 = S T 3 Trsformers / V Primry V LL = V p = 7200 V Seodry V =V = V = V V = V 30 o phse shift V to V lg is stdrd 19 OPEN DELT-OPEN DELT Three phse, three-wire, delt primry Two trsformers supply led 3 phse voltges d urrets. oetio itself is uled k Power // If S 1 = S 2 S T S S S S 2 T trsformers / V Primry V p = V LL = 7200 V Seodry V LL = V p = 240 V Trsformers exhge retive power to provide led voltges d urrets to 3-phse lods 20 10

11 INSTRUMENT TRNSFORMERS High power mesuremet requires highly urte trsformers to redue the levels or voltge d urret to sfe rge. Meter oil rtigs Voltge oils for voltmeters, power meters d wtthour meters V urret oils for mmeters, power meters d wtthour meters (100% overlod llowed) (short time) I power systems, voltge levels 100 s of kv d thousds of mps Istrumet Trsformers overt high voltges d urrets to mesuremet levels Potetil trsformers (PTs) urret trsformers (Ts) 21 URRENT TRNSFORMERS (TS) Sigle tur primry - usully the odutor with the urret to e mesured Multi-tur seodry - side oeted to low power istrumets Shemti Symols ushig type T Stdrd type T urret trsformer rtios 200/5 200 mps iput gives 5 mps output (40/1) 600/5 600 mps iput gives 5 mps output (/1) overlod rted vlues % otiuously 22 11

12 POTENTIL TRNSFORMERS (PT S) High ury trsformers with miimum power loss d very smll voltge drop. ssume ide opertio of oth Ts d PTs Potetil trsformers redues high voltges to 110- V rge Potetil Trsformer Shemti Symol Shemti symols should idite polrity mrk Typil potetil trsformer rtios 39, V V exeed V i rtigs y pproximtely ±10% 23 PT S ND T S HRTERISTIS Power Rtigs (urde) V rtig of ll istrumets oeted ot exeed this vlue or ury of trsformers will suffer Phse Shift Typilly less th 1 degree of phse shift or less through trsformer Voltge d urret Mgitude Mgitude ury: Pel meterig d protetio < 0.5% Reveue meterig < 0.1% 24 12

13 PT/T SFETY ONSIDERTIONS PTs - lwys groud seodry. pitive ouplig use dgerously high voltge to develop o low voltge widigs Ts - NEVER OPEN LOD ON T IRUIT. LWYS SHORT T SEONDRY TERMINLS EFORE REMOVING LOD. idue 2-6 kv o ope seodry leds 2-6 kv 25 ET 332 Motors, Geertors d Power Systems END LESSON 11: TRNSFORMER NME PLTE DT ND ONNETIONS 26 13