Thaum lub sij hawm kev ntsuam xyuas transformer, raws li ib tug engineer fais fab, peb yuav ntsib ntau yam teeb meem thaum lub sij hawm ua hauj lwm. Los ntawm cov lus nug thiab lus teb hauv qab no txog CT PT ntsuas, peb tuaj yeem tau txais kev paub thiab cov ntaub ntawv tseem ceeb heev.
FAQ 1: Ratio yuam kev yog dab tsi, thiab vim li cas 0.2s Chav Kawm CTs nruj heev?
Q: Kev sib piv yuam kev ntawm 0.05%? Vim li cas qhov ntsuas CT yuav tsum muaj tseeb ntau dua li kev tiv thaiv CT?
A: Qhov kev ua yuam kev yog qhov % qhov sib txawv ntawm daim ntawv teev npe thiab ntsuas . 0.2s txhais tau tias "Tshwj xeeb" qhov tseeb mus rau 1% tam sim no. Nws yog hais txog "Honesty" ntawm daim nqi hluav taws xob.
FAQ 2: Polarity - Lub "Veto" hauv kev tiv thaiv txawv
Q: Yuav ua li cas yog tias kuv qhov piv txwv zoo tag nrho tab sis polarity (S1 / S2) thim rov qab?
A: Txoj kev tiv thaiv yuav ua "Kev tua tus kheej." Lub relay yuav pom qhov yuam kev loj heev tam sim no.
Differential Logic (87 Relay):
• Corect Polarity: 100A Hauv - 100A Tawm=0Qhov txawv. ✅
• Rov qab polarity: 100A Hauv - (-100A Tawm)=200Qhov txawv. ❌
• Cov txiaj ntsig: Kev mus ncig tsis tseeb tam sim. Koj tsis tuaj yeem ua kom lub zog ntawm qhov chaw nres tsheb.
FAQ 3: Theem Displacement (Lub kaum ntse ntse yuam kev) thiab daim nqi hluav taws xob
Q: Vim li cas me me "Phase Yuam" (xws li . 15 feeb) tseem ceeb yog tias qhov loj me yog qhov tseeb?
A: Vim Active Power P=V * I * cos(phi). Theem kev hloov pauv hloov lub sijhawm ntawm nthwv dej tam sim no.
Qhov tseeb Trap:
• Meters ntsuas lub kaum sab xis ntawm V thiab I.
• Nyob rau hauv qis- zog-factor loads (xws li cos phi=0.5), 15-min yuam kev ua rau 1% yuam kev hauv lub hwj chim.
FAQ 4: Txoj Kev Ua Qauv - txheeb xyuas 1000A nrog tsuas yog 120V
Q: Cov kev sim tsoos thawb 1000A los ntawm thawj. Yuav ua li cas thiaj li ntsuas tau qhov tseeb yam tsis muaj nws?
A: Nws siv txoj kev "Modeling Method." Nws cais lub cev geometry (tig) los ntawm cov hlau nplaum poob.
Nws ua haujlwm li cas:
❶ Kev sib piv: Siab- qhov tseeb voltage choj ntsuas Ns/Np.
❷ Magnetic Model: Excitation nkhaus captures raws nraim li cas tam sim no cov tub ntxhais hlau "steals."
❸ Kev twv ua lej lej: Khoos phib tawj ua ke Hloov + Poob + Burden los kwv yees 1000A yuam kev.
FAQ 5: Field Reliability - 0.1% raug nyob rau hauv lub substation nrov
Q: Yuav tsis substation cuam tshuam puas 0.1% precision ntsuas?
A: Cov kws tshuaj ntsuam siv nqaim -band Digital Filtering thiab Frequency Shifting kom nyob twj ywm.
Noise Rejection Tactics:
• Frequency Shifting: Txhaj cov cim ntawm 49.7 Hz lossis 50.3 Hz. Tsis quav ntsej 50 Hz tom qab suab nrov.
• Internal Reference: Tus kheej -calibrates tiv thaiv ultra- ruaj khov nyob rau hauv voltage references.
• Kelvin 4-Wire: Tshem tawm qhov tsis kam ntawm koj tus kheej cov kev xeem.