Vlf Hipot Test yog dab tsi?

VLF Hipot Testing (Qhov Kev Ntsuas Tsawg Heev Muaj Peev Xwm Muaj Peev Xwm Zoo) yog qhov tsis yog-kev ntsuas hluav taws xob puas siv los ntsuas qhov kev nyab xeeb ntawm cov khoom siv hluav taws xob thiab cov khoom siv. Hauv qab no yog cov ncauj lus kom ntxaws txog nws qhov tseem ceeb, lub hom phiaj, txheej txheem, thiab kev siv:

1. Core txhais

VLF: "Very Low Frequency" yog hais txog qhov ntsuas voltage zaus, feem ntau 0.1 Hz txog 0.01 Hz (deb qis dua tus qauv 50/60 Hz fais fab zaus).

Hipot: Luv luv rau "High Potential," txhais tau tias qhov kev sim siv qhov hluav taws xob ntau dua li cov khoom siv ua haujlwm ib txwm muaj zog kom ntxhov siab rau cov rwb thaiv tsev.

Lub hom phiaj: txheeb xyuas qhov tsis muaj zog ntawm rwb thaiv tsev (piv txwv li, tawg, ya raws, paug, lossis kev tsim khoom tsis zoo) uas tuaj yeem ua rau tawg thaum lub sijhawm ua haujlwm ib txwm muaj- yam tsis muaj kev puas tsuaj rau cov rwb thaiv tsev zoo.

2. Vim li cas thiaj siv VLF hloov lub zog zaus?

Traditional hipot xeem ntawm 50/60 Hz yuav tsum tau loj, hnyav transformers los tsim high voltage (impractical rau siv teb). VLF daws qhov no los ntawm:

Txo Cov Khoom Siv Loj: Tsawg zaus txhais tau tias me me, sib zog ntsuas cov teeb (tseem ceeb rau ntawm - qhov chaw sim ntawm cov cuab tam loj xws li cables lossis transformers).

Mimicking DC Kev Nyuaj Siab Zoo: VLF voltage coj zoo li "quasi-DC" (them thim rov qab polarity), uas ua kom pom qhov tsis xws luag ntawm rwb thaiv tsev (xws li, noo noo ingress) uas tej zaum yuav plam los ntawm kev kuaj AC. Tsis zoo li kev kuaj DC ntshiab, VLF tsis txhob them lub rwb thaiv tsev (uas tuaj yeem ua rau muaj kev puas tsuaj lossis xav tau lub sijhawm tso tawm ntev).

Ua raws li Cov Qauv: Ua raws li cov qauv thoob ntiaj teb (xws li IEEE 400, IEC 60502) rau kev sim siab -voltage rwb thaiv tsev hauv cables, motors, thiab transformers.

3. Kev kuaj VLF Hipot ua haujlwm li cas

Kev xeem ua raws cov kauj ruam tseem ceeb no:

Kauj Ruam 1: Kev Npaj

Cais cov cuab yeej los ntawm lub zog hluav taws xob thiab hauv av uas tsis yog - cov khoom kuaj.

Xyuas kom cov rwb thaiv tsev huv si thiab qhuav (cov dej noo tuaj yeem ua rau pom kev).

Kauj Ruam 2: Kev siv hluav taws xob

Lub tshuab hluav taws xob VLF siv lub sinusoidal lossis square-wave voltage (feem ntau 2–5x cov khoom siv ntsuas hluav taws xob) rau lub rwb thaiv tsev rau lub sijhawm teev tseg (xws li 15–60 feeb rau cables).

Piv txwv: Rau 11 kV cable, qhov ntsuas hluav taws xob yuav yog 25-35 kV (VLF).

Kauj Ruam 3: Kev Saib Xyuas & Kev Ntsuas

Ntsuas ob qhov tseem ceeb rau kev ntsuas kev tiv thaiv kev noj qab haus huv:

Leakage Current: Cov tam sim no me me uas ntws los ntawm / nyob ib puag ncig lub rwb thaiv tsev thaum kuaj. Qhov tshwm sim tam sim ntawd los yog qhov txawv txav siab tam sim no qhia tau hais tias muaj qhov tsis xws luag (xws li pinhole hauv cov rwb thaiv tsev).

Dielectric Discharge (Partial Discharges): Cov hluav taws xob me me hauv qhov hluav taws xob tsis zoo. Kev ntsuam xyuas VLF tuaj yeem kuaj pom cov paug tawm no, uas yog qhov ua ntej rau kev rwb thaiv tsev tsis ua haujlwm.

Yog tias cov dej xau tam sim no tseem nyob ruaj khov thiab tsis pom muaj qhov paug tawm, qhov rwb thaiv tsev yog pom tau.

4. Cov ntawv thov tseem ceeb

VLF Hipot Testing yog dav siv rau high-voltage (HV) thiab nruab nrab-voltage (MV) cov cuab yeej uas qhov kev ntseeg tau ntawm rwb thaiv tsev yog qhov tseem ceeb:

Fais fab Cables: Underground, submarine, los yog MV / HV tis cables (qhov feem ntau daim ntawv thov).

Transformers: Fais fab thiab faib transformers (kom kuaj winding rwb thaiv tsev).

Motors & Generators: Loj AC / DC motors thiab generators (stator winding rwb thaiv tsev).

Switchgear: MV / HV Circuit Court breakers, bushings, thiab insulated conductors.

5. Qhov zoo thiab qhov txwv

Qhov zoo:

Tsis yog -Kev puas tsuaj: Kev ntxhov siab rwb thaiv tsev yam tsis muaj kev puas tsuaj rau cov khoom noj qab haus huv.

Portable: Compact test sets enables on -site (field) testing.

rhiab heev rau qhov tsis xws luag: Tshawb xyuas cov dej noo, tawg, thiab kev sib kis zoo dua li qee qhov kev ntsuam xyuas AC / DC.

Nqis -Zoo: Tsis txhob raug nqi ntau los ntawm kev txheeb xyuas cov teeb meem ntxov.

Kev txwv:

Tsis yog rau Low-Voltage Equipment: Overkill for low-voltage (LV) devices (piv txwv li, cov khoom siv hauv tsev).

Lub Sijhawm Xeem Ntev: Qee daim ntawv thov (piv txwv li, cov cables ntev) xav tau 30+ feeb ntawm kev sim.

Yuav tsum Muaj Cov Khoom Siv Tshwj Xeeb: VLF generators yog kim dua li cov hipot testers.

6. Cov qauv & Cov kev coj ua zoo tshaj plaws

IEEE 400: Phau Ntawv Qhia rau Kev Tshawb Fawb thiab Kev Ntsuam Xyuas Kev Ruaj Ntseg ntawm Cov Hluav Taws Xob Hluav Taws Xob Cable.

IEC 60502: Fais fab Cables nrog Extruded rwb thaiv tsev thiab lawv cov khoom siv.

ANSI / NETA MTS-2023: Tus Qauv rau Kev Ntsuas Kev Ntsuas Kev Ntsuas rau Cov Khoom Siv Hluav Taws Xob.

Cov kev coj ua zoo tshaj plaws suav nrog:

Calibrating cov cuab yeej ntsuas tsis tu ncua.

Ua raws li cov lus qhia voltage / sijhawm rau cov khoom siv tshwj xeeb.

Sib piv cov txiaj ntsig rau cov ntaub ntawv hauv paus (los ntawm cov cuab yeej tshiab lossis cov cuab yeej kuaj yav dhau los) rau kev tsom xam.

Hauv cov ntsiab lus, VLF Hipot Testing yog ib qho cuab yeej tseem ceeb rau kev ua kom muaj kev nyab xeeb thiab kev ntseeg siab ntawm siab -voltage hluav taws xob systems. Los ntawm kev siv tsawg- zaus, siab- qhov muaj peev xwm voltage, nws txheeb xyuas qhov cuam tshuam ntawm rwb thaiv tsev uas tuaj yeem ua rau muaj kev puas tsuaj loj heev- ua rau nws tseem ceeb rau cov khoom siv hluav taws xob, chaw tsim khoom, thiab pab pawg tu hluav taws xob.