Phau ntawv qhia rau Medium Voltage Transformers

 

 

Nruab nrab voltage transformers yog qhov tseem ceeb ntawm cov khoom siv hluav taws xob niaj hnub no. Thaumhigh voltage transformersfeem ntau yog siv rau kev xa hluav taws xob ntau dhau mus ntev - nce lub tshuab hluav taws xob tso zis kom txo qis cov kab poob - nruab nrab voltage transformers ua haujlwm nyob rau hauv lub network faib, hloov hluav taws xob hluav taws xob los ntawm ib theem voltage mus rau lwm qhov hauv nruab nrab. Qhov no ua rau muaj kev nyab xeeb thiab muaj txiaj ntsig xa hluav taws xob thoob plaws hauv kev lag luam, kev lag luam, thiab kev siv hluav taws xob. Kev nkag siab txog cov yam ntxwv, hom, thiab kev xaiv cov txheej txheem ntawm nruab nrab voltage transformers yog li ntawd tseem ceeb rau engineers, chaw tswj, thiab procurement cov tub txawg koom nyob rau hauv hluav taws xob system tsim thiab tu.

 

 

1.1 Kev txhais

Lub tshuab hluav taws xob nruab nrab yog ib qho khoom siv hluav taws xob uas hloov hluav taws xob hluav taws xob nruab nrab ntawm qhov nruab nrab qhov hluav taws xob- feem ntau cov khoom xa tawm hluav taws xob- thiab cov hluav taws xob qis dua tsim nyog rau qhov kawg - siv cov ntawv thov. Hauv cov tswv yim [i] cov ntsiab lus, lub nruab nrab voltage transformer tau txais lub zog ntawm qhov voltages xws li kwv yees li2.4 kV rau 69 kVthiab nqis nws mus rau kev siv hluav taws xob xws li 480 V, 208 V, lossis lwm qib uas xav tau los ntawm kev thauj khoom.

Cov ciam teb voltage sib txawv me ntsis nyob ntawm seb tus qauv twg koj sab laj. Raws li ANSI (American National Standards Institute), nruab nrab voltage transformers tuaj yeem tswj qhov voltages los ntawm2.4 kV txog 69 kV. IEEE txhais cov tshuab hluav taws xob nruab nrab hauv Tebchaws Meskas raws li feem ntau suav nrog5 kV rau 35 kVrau feem ntau daim ntawv thov kev faib tawm, nrog cov khoom siv feem ntau ntsuas ntawm 5 kV lossis 15 kV. Hauv Tebchaws Europe, tus qauv EN 50588-1 txhais tau hais tias nruab nrab lub zog hloov pauv raws li cov khoom siv hluav taws xob ntau tshaj 1.1 kV tab sis tsis tshaj 36 kV.

 

1.2 Lub luag haujlwm hauv Lub Hwj Chim Fais Fab

Txhawm rau kom nkag siab qhov twg qhov nruab nrab voltage transformers haum, nws yuav pab kom pom qhov dav dav lub zog faib hierarchy:

Generation → Kis:Cov chaw tsim hluav taws xob tsim hluav taws xob tsim hluav taws xob ntawm qhov hluav taws xob tsawg, uas tom qab ntawd nce mus rau qhov siab lossis ntxiv -high voltages (115 kV txog 765 kV) kom muaj txiaj ntsig ntev - kis tau tus mob.

Kis → Distribution:Ntawm substations, high voltages yog nqis mus rau nruab nrab voltages (feem ntau 5 kV mus rau 35 kV) rau kev faib los ntawm thawj feeders.

Distribution → Cov neeg siv khoom:Nruab nrab voltage transformers muab qhov kawg voltage transformers, nqis mus rau hauv lub tis voltage mus rau theem siv (xws li, 480 V, 240 V, 120 V) rau kawg - siv cov neeg siv khoom.

Feem ntau, cov khoom siv hluav taws xob xa hluav taws xob mus rau qhov chaw nruab nrab ntawm qhov hluav taws xob nruab nrab, thiab lub chaw muaj thiab ua haujlwm nws tus kheej nruab nrab voltage transformer kom nqis mus rau qhov tsis tshua muaj hluav taws xob. Qhov kev npaj no tso cai rau lub chaw siv kom zoo dua ntawm cov nqi hluav taws xob qis uas cuam tshuam nrog kev pabcuam nruab nrab ntawm qhov hluav taws xob thiab ua rau tus tswv muaj kev tswj hwm lub zog zoo dua.

1.3 Cov qauv tseem ceeb thiab kev ua raws cai

Nruab nrab voltage transformers yog tsim raws li ntau yam kev lag luam qauv, tshwj xeeb tshaj yog los ntawm IEEE thiab IEC. Nyob rau hauv lub tebchaws United States, cov yam ntxwv thiab functionality ntawm feem ntau tis transformers poob nyob rau hauvIEEE Txheem C57.12.00(Standard General Requirements for Liquid-Immersed Distribution, Fais Fab, thiab Regulating Transformers). Txawm li cas los xij, ntau lwm cov qauv siv rau cov hom transformer tshwj xeeb thiab kev siv:

• IEEE C57.12.01:Standard General Requirements for dry-Type Distribution and Fais Fab Transformers
• IEEE C57.12.34:Yuav tsum muaj rau Pad-Mounted, Compartmental-Type, Self-Cooled, Peb-Phase Distribution Transformers
• IEEE C57.12.28/29:Pad-Mounted Equipment Enclosure Integrity
• IEC 60076: Kev qhiaInternational txheem series rau fais fab transformers, nrog rau nruab nrab fais fab transformers
• NEMA TP-1:Phau Ntawv Qhia Txog Kev Txiav Txim Zog rau Kev Tshaj Tawm Transformers
• DOE 10 CFR Tshooj 431:US Department of Energy efficiency cov qauv rau kev faib transformers

Rau kev teeb tsa hauv Tebchaws Meskas, ua raws li covNational Electrical Code (NFPA 70)tseem yuav tsum tau. Hauv Canada, lubCanadian Electrical Code (CEC)siv.

 

 

 

Tsis yog txhua qhov nruab nrab voltage transformers yog tsim sib npaug. Qhov kev xaiv ntawm hom transformer muaj qhov cuam tshuam loj rau tus nqi, kev nyab xeeb, kev xav tau ntawm kev teeb tsa, thiab kev cia siab ntev ntev -.

 

2.1 Liquid-Immersed vs. Qhuav-Hom

Qhov no yog qhov tseem ceeb tshaj qhov txawv ntawm nruab nrab voltage transformers.

Kev lag luam tawm - tawm ntawm ob tsev neeg no yog qhov tseem ceeb:

Yam ntxwv	Kua -Nyob rau hauv	Qhuav -Hom
Hluav taws kub txaus ntshai	Siab dua - yuav tsum muaj kev tiv thaiv hluav taws rau kev siv sab hauv tsev	Tsawg- haum rau kev teeb tsa sab hauv tsev
Txias efficiency	Zoo heev (roj conducts tshav kub zoo)	Nruab nrab (nyob ntawm huab cua ncig)
Kev tu	Yuav tsum tau kuaj xyuas roj thiab pom	Kev saib xyuas tsawg
Lub neej expectancy	30-40 xyoo typical	20-30 xyoo typical
Tej kev siv	Sab nraum zoov substations, kev faib khoom siv hluav taws xob	Kev teeb tsa hauv tsev, cov tsev lag luam
Tus nqi pib	Feem ntau qis dua rau tib qhov ntsuas	Feem ntau siab dua rau tib qhov ntsuas
Environmental txaus ntshai	Cov roj xau tuaj yeem ua paug av	Tsis muaj kua, tsis muaj kev cuam tshuam

 

2.2 Substation Transformers

2.3 Pad-Mounted Transformers

2.4 Ncej-Mounted Transformers

2.5 Cam khwb cia Resin Transformers

 

 

 

Lub cev kev tsim kho ntawm lub transformer lub hauv paus txiav txim siab nws efficiency, poob, thiab kev ua tau zoo yam ntxwv.

3.1 Cov khoom siv tseem ceeb

Cov tub ntxhais ua haujlwm yog txoj hauv kev sib nqus rau lub zog hloov pauv ntawm thawj thiab theem nrab windings. Nws cov khoom siv ncaj qha cuam tshuam tsis muaj -load losses (core poob), efficiency, thiab kub nce.

Grain-oriented silicon steel (GOSS)tseem yog cov khoom siv tseem ceeb tshaj plaws rau nruab nrab voltage transformers. Nws muab siab magnetic permeability thiab tsis tshua muaj eddy tam sim no poob. GOSS yog engineered nrog ib tug nyiam grain orientation uas aligns cov sib nqus domains nrog rau cov kev taw qhia ntawm lub magnetic flux, maximizing efficiency.

Amorphous hlau alloystau tshwm sim los ua lwm txoj hauv kev rau lub zog -cov khoom siv hluav taws xob zoo. Cov ntaub ntawv no muab ultra- tsis tshua muaj hlau poob- feem ntau 70% mus rau 80% qis dua li cov pa roj silicon steel -tab sis ntawm cov khoom siv kim dua. Lawv yog tshwj xeeb tshaj yog txaus nyiam rau transformers uas ua hauj lwm ntawm tsawg loads rau ncua sij hawm.

Nanocrystalline mos magnetic alloysnthuav tawm cov khoom sib nqus zoo heev ntawm cov zaus siab thiab feem ntau yog siv hauv hluav taws xob lossis tshwj xeeb - lub hom phiaj transformers es tsis yog cov pa 50/60 Hz faib units.

 

 

 

Xaiv txoj cai transformer pib nrog kev nkag siab txog nws cov kev ntsuas tseem ceeb.

4.1 Kev ntsuas hluav taws xob

Txhua qhov nruab nrab voltage transformer muaj ob qhov tseem ceeb ntawm qhov ntsuas hluav taws xob: thawj qhov hluav taws xob (sab input) thiab theem nrab voltage (sab tawm). Piv txwv li, transformer ntsuas 13.8 kV / 480 V tau txais 13.8 kV ntawm thawj sab thiab xa 480 V rau sab thib ob.

Transformers kuj tseem muaj theem pib impulse (BIL), uas sawv cev rau qhov siab tshaj qhov hluav taws xob qhov rwb thaiv tsev tuaj yeem tiv taus thaum muaj hluav taws xob los yog hloov hluav taws xob. Rau nruab nrab voltage transformers, BIL ratings ranges ntawm 60 kV mus rau 150 kV los yog siab dua, nyob ntawm seb qhov voltage thiab daim ntawv thov.

4.2 kVA ntsuas

Qhov ntsuas kVA (kilovolt-ampere) ntawm lub tshuab hloov pauv qhia tias nws lub zog muaj peev xwm pom tseeb - tam sim no nws tuaj yeem nqa tau yam tsis muaj cua sov. Txheem peb-theem nruab nrab voltage transformer kVA qhov ntau thiab tsawg suav nrog:30, 45, 75, 112.5, 150, 225, 300, 500, 750, 1,000, 1,500, 2,000, thiab 2,500 kVA.

Xaiv qhov raug kVA ntsuas yog qhov tseem ceeb. Lub transformer uas yog undersized yuav overheat, txo cov rwb thaiv tsev lub neej thiab tej zaum yuav ua rau tsis ua hauj lwm ntxov ntxov. Ib qho kev hloov pauv loj loj tuaj yeem ua rau tus nqi pib thiab tuaj yeem ua haujlwm tsis muaj txiaj ntsig ntawm lub teeb, vim qhov poob tseem muaj nyob tsis hais txog kev thauj khoom.

4.3 Chav ntsuas kub thiab rwb thaiv tsev

Transformers tau teev nrog qhov ntsuas kub nce siab -feem ntau yog 80℃, 115℃, lossis 150℃- uas qhia tias qhov ntsuas kub ntawm lub transformer yuav nce siab npaum li cas ntawm qhov kub thiab txias nyob rau hauv tag nrho load. Lub tshuab hluav taws xob nrog 80℃nce siab ua haujlwm txias dua li ib qho ntsuas rau 150℃nce, uas tuaj yeem txhais tau ntev dua lub neej rwb thaiv tsev thiab kev ua haujlwm zoo dua, tab sis kuj tseem muaj nqi pib dua.

Rwb thaiv tsev chav kawm (Class A ntawm 105 degree, Chav B ntawm 130 degree, Chav F ntawm 155 degree, Chav H ntawm 180 degree) txhais tau qhov siab tshaj plaws ua haujlwm kub uas cov ntaub ntawv rwb thaiv tsev tuaj yeem tiv taus yam tsis muaj kev puas tsuaj loj.

 

 

 

Txoj kev sib txuas ntawm transformer windings txiav txim siab nws qhov kev ua tau zoo nrog cov khoom tsis sib npaug, kev sib haum xeeb, thiab kev ua txhaum hauv av.

5.1 Hom kev sib txuas yooj yim

Muaj peb yam tseem ceebwinding kev twb kev txuasschemes:

Lub hnub qub (Wye) kev sib txuas (Y):Ib qho kawg ntawm txhua theem winding yog txuas ua ke ntawm ib qho chaw (qhov nruab nrab). Lub hnub qub kev sib txuas muab qhov nruab nrab nruab nrab uas tuaj yeem ua rau hauv av.

Delta kev twb kev txuas (D):Cov theem txuas nrog hauv lub voj kaw, tsis muaj qhov nruab nrab. Kev sib txuas ntawm Delta yog qhov sib npaug thiab muab txoj hauv kev rau xoom- ntu ntu tam sim no.

Zigzag kev twb kev txuas (Z):Ib qho kev sib txuas tshwj xeeb siv feem ntau rau hauv av transformers lossis transformers nrog cov nqi zog me me. Zigzag kev sib txuas feem ntau tsuas yog siv rau sab thib ob.

 

5.2 Vector Group Cov Lus Cim

Pawg vector ntawm lub transformer piav qhia txog lub winding configuration thiab theem kev sib raug zoo ntawm thawj thiab theem nrab voltages. Cov ntawv sau ua raws li tus qauv qauv:

Thawj tsab ntawv (tus ntawv loj) qhia txog thawj qhov kev sib txuas: D rau delta, Y rau lub hnub qub, Z rau zigzag.

Tsab ntawv thib ob (tus lej qis) qhia txog kev sib txuas thib ob.

Ib qho "n" qhia tias cov ntsiab lus nruab nrab raug coj tawm.

Tus lej qhia txog theem hloov pauv hauv moos - teev teev (ntau ntxiv los ntawm 30℃kom tau txais qib ntawm lag).

5.3 Sib piv Dyn11 thiab Yyn0

Ob pawg vector tswj hwm kev faib khoom siv:Dyn 11thiabYyn 0.

Dyn 11nta delta- txuas thawj (D) thiab lub hnub qub- txuas theem nrab nrog nruab nrab (yn), nrog rau theem hloov ntawm 330℃(11 ntawm lub moos). Lub hauv paus delta muab ib txoj hauv kev rau xoom- ntu ntu ntu thiab ntxiab triplen harmonics (3rd, 9th, thiab lwm yam), tiv thaiv lawv los ntawm kev xav rov qab mus rau hauv daim phiaj xa khoom. Dyn11 kuj tseem ua haujlwm tsis zoo ntawm cov khoom thauj tshwj xeeb, ua rau nws qhov kev xaiv zoo tshaj plaws rau kev faib khoom niaj hnub nrog cov khoom tsis muaj - linear loads xws li khoos phis tawj, LED teeb pom kev zoo, thiab cov tsav tsheb sib txawv.

Yyn 0nta lub hnub qub- txuas thawj (Y) thiab lub hnub qub- txuas nrog nruab nrab (yn), nrog xoom theem hloov chaw. Lub hnub qub tseem ceeb tsis muaj txoj hauv kev rov qab los rau xoom- ntu ntu tam sim no. Yog li ntawd, triplen harmonics tuaj yeem tshwm sim ntawm thawj qhov hluav taws xob, thiab cov khoom tsis sib npaug tuaj yeem ua rau tsis muaj kev hloov pauv, ua rau theem voltage imbalances. Yyn0 feem ntau txwv rau cov ntawv thov nrog cov ntsiab lus sib haum xeeb tsawg thiab cov khoom sib npaug. Muaj ib qho kev txwv ntxiv: hauv Yyn0 transformers, cov kab nruab nrab tam sim no yuav tsum tsis pub tshaj 25% ntawm qhov thib ob winding ntsuas tam sim no, whereas Dyn11 tuaj yeem tuav txog 75%.

Hauv luv luv, rau cov ntawv thov niaj hnub no feem ntau-tshwj xeeb tshaj yog cov uas tsis yog- cov khoom thauj khoom, cov chaw khaws ntaub ntawv, cov chaw tsim khoom, lossis ib qho chaw uas muaj ib qho tseem ceeb -theem loads-Dyn11 yog pawg vector xaiv.

 

Kev ntsuas qhov ntsuas kom zoo yog ib qho kev txiav txim siab tseem ceeb tshaj plaws hauv kev tsim hluav taws xob. Kev ua yuam kev nyob rau theem no tuaj yeem ua rau xyoo tsis muaj peev xwm lossis ua tsis tiav ntxov.

6.1 Kauj Ruam -los ntawm - Kauj Ruam Sizing

Kauj ruam 1: xam tag nrho cov load zog.Sau cov khoom muag ntawm tag nrho cov loads txuas nrog downstream ntawm transformer - motors, teeb pom kev zoo, HVAC, chaw ua hauj lwm khoom, thiab ntau lawm machinery.

Kauj Ruam 2: Siv cov txheej txheem simultaneity.Tsis yog txhua qhov kev thauj khoom ua haujlwm ntawm lub peev xwm ib txhij. Ib qho kev sib txawv (feem ntau yog 0.7 txog 0.9) suav rau qhov tseeb.

Kauj ruam 3: Tus account rau lub cev muaj zog pib tam sim no.Inductive loads zoo li cov motors kos 3 mus rau 7 npaug ntawm lawv cov kev khiav hauj lwm tam sim no thaum pib. Lub transformer yuav tsum muaj peev xwm txaus los tswj cov inrush tam sim no yam tsis muaj hluav taws xob ntau dhau.

Kauj Ruam 4: Siv cov npoo kev nyab xeeb.Ntxiv 20% mus rau 30% muaj peev xwm ntxiv kom haum rau kev hloov pauv ntawm kev thauj khoom thiab kev nthuav dav yav tom ntej.

Kauj Ruam 5: xam cov peev txheej transformer.Siv tus qauv:

Transformer Peev Xwm (kVA)=Tag Nrho Lub Hwjchim (kW) ÷ Lub Hwjchim Loj × Kev Nyab Xeeb Margin

Cov khoom siv hluav taws xob zoo li ntawm 0.8 txog 0.95 rau feem ntau cov khoom lag luam thiab kev lag luam.

Kauj ruam 6: Xaiv tus qauv loj tom ntej.Hloov mus rau qhov ze tshaj plaws tus qauv kVA ntsuas los ntawm cov npe hauv Tshooj 4.2.

 

6.2 Kev txiav txim siab ntawm ib puag ncig thiab kev thov

Kev xam qhov loj me yog qhov pib xwb. Ob peb lwm yam yuav cuam tshuam koj qhov kev xaiv zaum kawg:

• Kub kub ib puag ncig:Rau kev txhim kho nyob rau hauv siab ambient kub los yog siab tshaj 1,000 meters altitude, txo lub rated peev xwm los ntawm 5% mus rau 20% vim txo qis cua txias thiab rwb thaiv tsev efficiency.
• Harmonic cov ntsiab lus:Cov kab ke uas muaj ntau yam tsis yog- cov kab khiav tawm (qhov sib txawv zaus tsav, UPS systems, LED teeb pom kev zoo, khoos phis tawj) yuav xav tau lub tshuab hloov pauv nrogK-factor ratinglos tuav harmonic cua sov tsis derating.
• Installation ib puag ncig:Qhuav- hom transformers feem ntau nyiam rau kev teeb tsa sab hauv tsev uas muaj kev nyab xeeb hluav taws kub ntxhov. Cov kua dej - cov chav nyob rau hauv dej yog tus nqi ntau dua - siv tau rau kev teeb tsa sab nraum zoov nrog qhov chaw txaus thiab ntim khoom.
• Shock loads:Rau cov khoom siv xws li vuam lossis compressors uas ua rau muaj kev xav tau tam sim no, ua kom muaj peev xwm ntawm 10% mus rau 30%.

 

6.3 Efficiency thiab Energy Standards

Zog efficiencytau dhau los ua qhov kev txiav txim siab tseem ceeb hauv kev xaiv transformer, uas tau tsav los ntawm ob qho tib si cov nqi khiav lag luam thiab cov kev cai tswj hwm.

Hauv Tebchaws Meskas, lubDepartment of Zog (DOE)tsim kom muaj cov qauv kev ua tau zoo rau kev faib khoom siv hluav taws xob, pib lub Ib Hlis 1, 2016, nyob rau hauv 10 CFR Part 431. Cov qauv no, uas siv rau txhua qhov kev faib hluav taws xob hloov hluav taws xob tsim los lossis tom qab hnub ntawd thiab muag hauv ib lub xeev Asmeskas, yog raws li kev ntsuas kev ua haujlwm ntawm35% load-xav txog kev tshawb fawb qhia tias feem ntau cov khoom siv hluav taws xob faib ua haujlwm ntawm kwv yees li 35% ntawm cov peev txheej ntsuas qhov nruab nrab.

Rau cov ntawv thov xav tau kev ua haujlwm siab tshaj plaws,NEMA hwmefficiency transformers muaj kwv yees li 30% qis dua qhov DOE 2016 yuav tsum. Thaum tus nqi pib tus nqi tuaj yeem yog qhov tseem ceeb, lub sijhawm them rov qab los ntawm kev txo lub zog poob yog feem ntau txaus nyiam rau cov hloov pauv tsis tu ncua.

 

6.4 impedance

Transformer impedance(qhia raws li feem pua) txiav txim siab npaum li cas lub transformer txwv tsis pub tam sim no thiab ntau npaum li cas voltage poob tshwm sim nyob rau hauv load. Standard faib transformers feem ntau muaj impedances li ntawm 2% mus rau 8%. Cov impedance siab dua txo qhov txhaum tam sim no thiab tiv thaiv cov khoom siv qis tab sis ua rau kom muaj zog poob.

 

 

 

Kev txhim kho kom zoo yog qhov tseem ceeb rau kev nyab xeeb ntawm transformer, kev ua tau zoo, thiab kev ua haujlwm ntev. Kev teeb tsa uas tsis ua raws li cov cai yuav ua rau muaj kev kub ntxhov, hluav taws xob muaj teeb meem, kev soj ntsuam tsis ua tiav, thiab muaj peev xwm lav tau.

7.1 Kev Tshem Tawm thiab Chaw Ua Haujlwm

Txoj Cai Hluav Taws Xob Hauv Tebchaws (NEC) xav kom muaj chaw ua haujlwm txaus nyob ib puag ncig cov khoom siv hluav taws xob kom tso cai rau kev npaj thiab kev nyab xeeb, kev saib xyuas, thiab tshuaj xyuas. Cov ntsiab lus tseem ceeb suav nrog:

• Yam tsawg kawg nkaus qhov chaw ua haujlwm qhov siab:2.0 m (6.5 ft)
• Yam tsawg kawg nkaus qhov chaw ua haujlwm dav dav:914 hli (3 ft)
• Pem hauv ntej clearance:Yam tsawg kawg 3 ko taw (0.9 m) nyob rau hauv pem hauv ntej ntawm transformer enclosures rau kev soj ntsuam thiab tu
• Ventilation clearance:Feem ntau 150 mus rau 300 mm (6 mus rau 12 ntiv tes) nyob ib ncig ntawm qhov chaw ua pa kom qhuav - hom hloov pauv kom tso cai rau huab cua tsis muaj zog

Rau ncoo-mounted transformers, tshwj xeeb clearance yuav tsum nyob ntawm lub installation. NEC tsis yog ib txwm sau tseg rau sab laug, sab xis, thiab rov qab tshem tawm hauv cov ntsiab lus meej, tab sis cov lej hauv zos thiab cov lus qhia cov chaw tsim khoom yuav tsum ua raws. FM Ntiaj teb no, piv txwv li, yuav tsum tau 25 ko taw ntawm cov roj ntxhia- cov khoom hloov pauv, txawm hais tias qhov kev xav tau no poob rau xoom rau cov transformers siv tsawg dua - cov kua hluav taws xob.

7.2 Kev sib cais ntawm cov khoom sib cais

Rau nruab nrab voltage installation, qhov nruab nrab voltage thiab tsawg voltage compartments yuav tsum tau sib cais nrog ib tug steel barrier uas txuas rau tag nrho qhov siab thiab qhov tob ntawm compartments. Ob qhov chaw yuav tsum tau tsim los ntawm cov ntawv hlau ua tau raws li ANSI cov cai.

7.3 Kev sib tw

Kev cog av kom zoo yog qhov tseem ceeb rau kev nyab xeeb thiab kev tiv thaiv cov khoom siv. Grounding resistance feem ntau yuav tsum tau khaws cia ntawmTsawg dua los yog sib npaug li 10 ohms. Lub transformer nruab nrab (yog tias tam sim no) yuav tsum tau grounded kom zoo raws li qhov system tsim thiab siv cov cai. Cov kev cai hauv av tau piav qhia hauv NEC Tshooj 250.

7.4 Tiv thaiv hluav taws

Rau cov roj- cov tshuab hloov pauv tau nruab rau hauv tsev lossis nyob ze rau cov tsev, yuav tsum tau ntsuas kev tiv thaiv hluav taws. Cov no tuaj yeem suav nrog:

• Hluav taws kub- ntsuas phab ntsa lossis thaiv
• Tsis siv neeg tua hluav taws tua tshuab
• Cov roj ntim (spill container bass or oil-containment pits)
• Tsis siv neeg dej deluge systems rau kev teeb tsa loj dua

Hom kua dej siv hauv transformer kuj cuam tshuam rau kev tiv thaiv hluav taws. Cov tshuab hloov pauv uas muaj tsawg dua - cov kua hluav taws xob los yog biodegradable tuaj yeem tsim nyog rau kev txo qis thiab kev tiv thaiv hluav taws yooj yim.

 

 

 

Tiv thaiv lub nruab nrab voltage transformer yuav tsum muaj kev sib koom ua ke uas hais txog ob qho tib si sab hauv thiab kev cuam tshuam sab nraud.

8.1 Kev tiv thaiv overcurrent

NEC cov cai rau transformer overcurrent tiv thaiv nyob ntawm transformer impedance. Rau cov transformers nrog 6% impedance lossis tsawg dua, NEC yuav tsum muaj kev tiv thaiv thawj thiab theem nrab. Thawj fuse yuav tsum tsis pub tshaj 300% ntawm thawj qhov puv -load tam sim no (FLA), thiab cov khoom siv hluav taws xob thib ob ntawm 480 V yuav tsum tsis pub tshaj 125% ntawm FLA thib ob.

8.2 Fuses vs. Circuit Breakers

Kev xaiv ntawm fuses thiab Circuit Court breakers rau kev tiv thaiv transformer muaj kev lag luam -offs:

Hauv ntau lub network faib, kev sib xyaw ua ke yog siv: fuses ntawm thawj sab rau luv luv - tiv thaiv Circuit Court, ua ke nrog qis -voltage main breaker uas muab kev tiv thaiv overload.

 

 

 

 

 

Txawm tias qhov kev ntseeg siab tshaj plaws transformer xav tau kev saib xyuas tsis tu ncua kom ua tiav nws lub neej kev pabcuam tag nrho. Ib qhov zoo-tsim kho qhov kev pab cuam tuaj yeem txuas lub neej hloov pauv los ntawm 20-30 xyoo mus rau 40 xyoo lossis ntau dua.

9.1 Predictive Maintenance

Kev saib xyuas kwv yees siv cov cuab yeej kuaj mob txhawm rau txheeb xyuas cov teeb meem ua ntej lawv ua tsis tiav.

• Dissolved Gas Analysis (DGA):Cov cuab yeej muaj zog tshaj plaws rau kev ntsuas kev noj qab haus huv ntawm cov roj -immersed transformers. Los ntawm kev txheeb xyuas cov roj hluav taws xob yaj hauv cov roj insulating-hydrogen, methane, acetylene, ethylene- cov kws kho mob tuaj yeem txheeb xyuas cov teeb meem xws li overheating, arcing, thiab rwb thaiv tsev tawg. DGA tsis tu ncua muab kev ceeb toom ntxov ntawm kev txhim kho kev ua txhaum thiab pab saib xyuas kev ua haujlwm tseem ceeb.
• Infrared Thermography (IR scanning):Thermal imaging detects hotspots uas qhia tau tias kev sib txuas xoob, siab -cov pob qij txha tiv taus, overloading, los yog tsis muaj rwb thaiv tsev. Rau qhov chaw- hom hloov pauv, IR qee zaum tuaj yeem kuaj xyuas cov cua kub txawv txav ntawm cov kev sib cuag tsis zoo lossis lwm yam ua haujlwm tsis zoo uas ua rau kub nce ntawm qhov chaw sab nraud.
• Kev Tso Tawm Ib Feem (PD) Kev Saib Xyuas:Kev tso tawm ib nrab yog qhov taw qhia thaum ntxov ntawm rwb thaiv tsev deterioration. Kev saib xyuas PD siv cov sensors los kuaj xyuas cov hluav taws xob tawm hauv lub tshuab hluav taws xob qhov hluav taws xob ua ntej lawv nce mus rau qhov tsis ua tiav.

9.2 Kev Tiv Thaiv Kev Tiv Thaiv

Kev tiv thaiv kev saib xyuas ua raws li lub sijhawm teem tseg los daws qhov hnav thiab tsim kua muag.

• Tsis tu ncua roj sampling thiab kuaj:Kev ntsuas hluav taws xob tawg ntsuas cov roj insulating lub zog; qis BDV qhia tias muaj kab mob los yog ya raws. Cov ntsiab lus noo noo yuav tsum tau ntsuas siv Karl Fischer titration thiab khaws cia nyob rau hauv kev txwv.
• Kev tshuaj xyuas Bushing:Kev soj ntsuam pom kev tawg, av nkos, thiab kev puas tsuaj. Capacitance thiab tan delta tests ntsuas qhov xwm txheej ntawm bushing rwb thaiv tsev.
• Kais changer kev kho:Rau cov transformers nrog rau ntawm -load kais hloov pauv (OLTCs), cov roj qib yuav tsum tau kuaj xyuas, cov neeg raug kuaj xyuas cov pa roj carbon deposits thiab ntxuav, thiab cov roj hloov yog tias muaj paug.
• Tightness check thiab leak detection:Cov roj xau yuav tsum raug txheeb xyuas thiab kho tam sim kom muaj kev ruaj ntseg ntawm rwb thaiv tsev thiab tiv thaiv ib puag ncig.

9.3 Kev soj ntsuam zaus

Txawm hais tias cov zaus tshwj xeeb nyob ntawm qhov cuam tshuam ntawm kev hloov pauv thiab kev ua haujlwm ib puag ncig, cov lus qhia dav dav suav nrog:

• Kev kuaj pom pom:Txhua hli mus rau peb lub hlis twg, tsom mus rau qib roj, cov dej xau, suab nrov txawv txawv, thiab cov xwm txheej dav dav
• Infrared Thermography:Txhua xyoo, los yog ntau zaus rau cov transformers tseem ceeb
• Roj sampling thiab DGA:Txhua xyoo rau cov qauv kev teeb tsa; semi-ib xyoos rau cov transformers tseem ceeb lossis hnyav hnyav
• Kev ntsuam xyuas hluav taws xob (kev tiv thaiv kev tiv thaiv, kev hloov pauv, kev ua haujlwm winding):Txhua xyoo 2 txog 5 xyoos
• Comprehensive overhaul:Txhua 10 mus rau 15 xyoo rau lub zog loj transformers

 

 

 

Nruab nrab voltage transformers ua hauj lwm zoo kawg li ntau yam kev siv.

10.1 Industrial Facilities

Hauv kev tsim cov chaw tsim khoom thiab cov chaw tsim khoom, qhov nruab nrab voltage transformers muab lub zog rau cov motors loj, tshuab, thiab cov khoom siv uas xav tau ntau dua voltage rau kev ua haujlwm zoo. Kev lag luam xws li tsheb, tshuaj ua haujlwm, mining, thiab steel manufacturing feem ntau ua haujlwm rau lawv tus kheej nruab nrab voltage tis systems, nrog transformers nqis nqis nqi hluav taws xob rau cog tis voltage, thiab ntxiv transformers ntxiv nqis mus rau lub tshuab siv theem.

10.2 Cov Tsev Ua Lag Luam

Chaw ua hauj lwm complexes, khw malls, tsev kho mob, tsev so, thiab lwm yam lag luam chaw cia siab rau nruab nrab voltage transformers rau teeb pom kev zoo, HVAC, elevator, thiab lwm yam tseem ceeb hluav taws xob loads. Cov tsev lag luam loj feem ntau tau txais kev pabcuam thawj zaug ntawm qhov nruab nrab voltage (feem ntau 13.8 kV lossis 4.16 kV), nqis mus rau 480 V rau kev faib thoob plaws hauv lub tsev, nrog rau qis dua -voltage transformers pab 120/208 V loads.

10.3 Utility Substations

Cov khoom siv hluav taws xob siv hluav taws xob nruab nrab ntawm cov hluav taws xob hloov hluav taws xob kom txo qis qhov hluav taws xob los ntawm cov kab sib txuas mus rau qis qis tsim nyog rau kev faib rau cov neeg siv khoom hauv tsev thiab kev lag luam. Cov khoom siv hluav taws xob no - muaj cov transformers tsim cov caj qaum ntawm cov kab ke.

10.4 Kev Siv Hluav Taws Xob Hluav Taws Xob

Hnub ci thiab cua ua liaj ua teb suav nrog qhov nruab nrab voltage transformers los txuas cov hluav taws xob tsim hluav taws xob rau hauv daim phiaj. Raws li kev siv hluav taws xob txuas ntxiv txuas ntxiv mus ntxiv, qhov kev thov rau nruab nrab voltage transformers tsim tshwj xeeb rau cov ntawv thov no- suav nrog cov qauv tsim uas tswj cov hluav taws xob bidirectional ntws thiab qhov sib txawv ntawm qhov dav voltage - tau nce ntau heev.

10.5 Data Centers

Cov chaw zov me nyuam yog ib qho ntawm cov kev thov xav tau tshaj plaws rau nruab nrab voltage transformers. Lawv xav tau kev ntseeg siab heev (feem ntau N+1 lossis 2N redundancy), lub zog zoo, thiab kev ua haujlwm siab vim kev ua haujlwm tsis tu ncua. Feem ntau cov chaw zov me nyuam siv cov kev pabcuam nruab nrab voltage (feem ntau 13.8 kV lossis 15 kV) nqis mus rau 480 V, nrog cov hloov pauv hloov pauv hloov pauv UPS cov tshuab thiab cov khoom siv hluav taws xob.

10.6 Cov Chaw Kho Mob

Cov tsev kho mob thiab cov chaw kho mob siv cov khoom siv hluav taws xob nruab nrab los pub ntau yam tsawg-voltage switchboards, nrog rau cov hloov hluav taws xob sib cais ua haujlwm rau cov ceg tseem ceeb, ceg kev nyab xeeb lub neej, thiab cov ceg hluav taws xob ib txwm ua kom ntseeg tau tias cov tshuab tseem ceeb tseem ua haujlwm nyob rau hauv txhua qhov xwm txheej tsis ua haujlwm.

 

 

 

Ua hauj lwm nrog nruab nrab voltage transformers xav tau nruj ua raws li txoj cai kev nyab xeeb. Cov cuab yeej no muaj cov hluav taws xob siab thiab ua rau muaj teeb meem hluav taws xob tseem ceeb:

• Tsuas yog cov neeg ua haujlwm tsim nyogyuav tsum tuav lossis ua haujlwm ntawm nruab nrab voltage transformers.
• Ib txwm de-energizelub transformer thiab txheeb xyuas xoom voltage ua ntej mus txog.
• Hauv av transformertom qab de- zog thiab ua ntej ua haujlwm.
• Tuav qhov kev ncua deb kom tsim nyograws li qib voltage.
• Siv cov cuab yeej tiv thaiv tus kheej kom raug (PPE)ntsuas rau qhov muaj txhaum tam sim no.
• Ua raws li cov txheej txheem lockout/tagout (LOTO).raws li OSHA cov cai.

 

 

 

Tus nqi tag nrho ntawm kev ua tswv cuab rau lub nruab nrab voltage transformer txuas mus deb tshaj li tus nqi pib yuav khoom.

Thawj tus nqi yuav khoomNws txawv ntawm hom: qhuav- hom transformers feem ntau raug nqi ntau dua li cov kua-immersed units ntawm tib qhov kev ntsuam xyuas, thaum tus nqi hwm -cov khoom siv tau zoo muaj tus nqi siab dua tus qauv- cov qauv ua tau zoo.

Cov nqi installationsuav nrog kev npaj ntawm qhov chaw, pob zeb pob zeb lossis lub hauv paus, kev sib txuas hluav taws xob, hauv av, kev tiv thaiv hluav taws (yog tias xav tau), thiab kev txiav txim siab tshem tawm rau yav tom ntej.

Zog poobsawv cev tus nqi tseem ceeb tshaj plaws uas ua haujlwm tsis tu ncua. Tsis muaj- thauj khoom poob (cov ntsiab lus poob) muaj 24 teev hauv ib hnub, 365 hnub hauv ib xyoos, tsis hais txog kev thauj khoom. Load losses (tooj liab poob) sib txawv nrog cov square ntawm lub load tam sim no. Rau lub tshuab hloov hluav taws xob uas ua haujlwm tsis tu ncua ntawm cov khoom nruab nrab, lub zog poob ntau dua 30-xyoo lub neej tuaj yeem tshaj li tus nqi pib yuav khoom. Kev nqis peev nyob rau hauv lub tshuab hluav taws xob ntau dua nrog kev poob qis feem ntau xa cov nyiaj rov qab zoo nkauj.

Cov nqi kho mobnyob ntawm hom transformer (kua-immersed yuav tsum tsis tu ncua kev sim roj, qhuav- hom xav tau tsawg), qhov chaw teeb tsa, thiab qhov tseem ceeb rau kev ua haujlwm.

Xaus- ntawm- cov nqi pov tseg lossis rov ua dua tshiabtuaj yeem ua tau ntau yam rau cov roj-immersed transformers, tshwj xeeb tshaj yog cov uas muaj cov roj paug los yog polychlorinated biphenyls (PCBs) hauv cov laus dua.

 

 

 

Qhov nruab nrab voltage transformers yog ib qho kev siv thev naus laus zis- dhau ib puas xyoo dhau los, tseem pheej hloov zuj zus mus kom tau raws li qhov xav tau tshiab rau kev ua tau zoo, kev ntseeg tau, thiab kev ua haujlwm ib puag ncig. Lawv yog cov kev sib txuas ntawm high -voltage transmission grid thiab low-voltage systems that power our world.

Xaiv, txhim kho, thiab tswj cov tshuab hloov pauv no yog kev ua haujlwm ntau yam uas yuav tsum tau nkag siab txog cov qauv hluav taws xob, cov lej kev nyab xeeb, kev xav txog kev siv tshuab, thiab kev lag luam kev lag luam -offs. Ib qhov zoo- xaiv, ntsia tau zoo, thiab mob siab rau khaws cia nruab nrab voltage transformer yuav muab ntau xyoo ntawm kev pabcuam txhim khu kev qha. Ib chav tsev tsis zoo, siv tsis raug, lossis tsis saib xyuas tuaj yeem dhau los ua qhov teeb meem tsis tu ncua, ua rau muaj nqi zog, cuam tshuam kev ua haujlwm, thiab tsim kev nyab xeeb.

Txawm hais tias koj tab tom tsim lub chaw tshiab, hloov cov khoom qub, lossis tsuas yog nrhiav kom nkag siab zoo dua cov transformers hauv koj qhov system uas twb muaj lawm, cov ntsiab lus tau teev tseg hauv phau ntawv qhia no muab lub hauv paus rau kev txiav txim siab zoo. Ua tib zoo saib xyuas cov ntsiab lus- qhov ntsuas qhov ntsuas hluav taws xob, pawg vector, chav tsev rwb thaiv tsev, kev tshem tawm, kev saib xyuas lub sijhawm-thiab koj lub tshuab hloov hluav taws xob nruab nrab yuav muab nqi zog rau koj nrog kev nyob ntsiag to, muaj txiaj ntsig, kev pabcuam ntev -.