Yog tias koj puas tau xav paub yog vim li cas ob lub me me -tam sim no qhov chaw ua txhaum hauv av zoo tib yam rau sab nraud tab sis txawv los ntawm ib qho ntawm ob tus nqi, cov lus teb feem ntau yog muab zais rau hauv qhov piv txwv pem hauv ntej kawg. Cov CTs, analog -rau- digital converter, lub moos uas synchronizes txhua yam - yog qhov uas tus nqi tiag tiag thiab qhov ua tau zoo tiag tiag nyob. Nyob rau hauv ib qho system nrog ib qho tsis muaj av los yog resonant - grounded nruab nrab, qhov txhaum tam sim no ntawm faulty feeder yog me me heev. Ob peb amps nyob rau hauv cov xwm txheej ib txwm muaj, thiab thaum qhov kev ua txhaum tsis raug siab, nws tuaj yeem poob mus rau kaum tawm milliamps. Nyob rau theem ntawd, lub cuab yeej tsis yog ntsuas lub teeb liab xwb; nws tab tom sim rub ib lub ntxhi tawm ntawm chav tsis nrov. Thiab qhov zoo ntawm qhov rub tawm yog nyob ntawm qhov tseeb ntawm cov qauv.
Thawj qhov kom nkag siab yog qhov koj tab tom sim ntes. Thaum ib zaug ib zaug -theem- rau- qhov ua txhaum hauv av tshwm sim, qhov hloov pauv xoom- ntu ntu tam sim no yog tus ntiv tes siv tau zoo tshaj plaws. Nws nce siab, oscillates rau ob peb milliseconds, thiab tom qab ntawd nyob rau hauv ib qho chaw ruaj khov uas me dua. Lub oscillation zaus feem ntau yog ntau pua hertz mus rau ob peb kilohertz. Qhov kev tawg tam sim no yog qhov uas cov khoom noj tsis zoo cais nws tus kheej ntawm cov noj qab haus huv. Yog tias koj tus lej ntsuas qis dhau, koj tsis pom qhov ncov. Koj tsis pom lub suab nrov. Koj tau txais ib qho smoothed - dhau version uas zoo li ntau yam uas cov neeg noj qab haus huv pom. Nyob rau hauv 10 kV network nrog tsib feeders, piv txwv li, thaum lub grounding kuj nce mus txog 1 kΩ, koj xav tau ib tug sampling tus nqi tsawg kawg yog 6 kHz kom lub sij hawm kaw qhov yuam kev nyob rau hauv 10%. Muab tso rau hauv qab no, thiab lub waveform koj tab tom txheeb xyuas tsis yog lub waveform uas tau tshwm sim lawm.
Amplitude qhov tseeb yog qhov teeb meem tom ntej. Feem ntau xoom-ib ntu tam sim no transformers yog tsim los kom raug ntawm qhov ntsuas tam sim no, uas tej zaum yuav yog 5 A lossis ntau dua. Tab sis ntawm 0.5 A, ntau ntawm lawv pom qhov ua yuam kev ntawm 20% mus rau 80% thiab theem yuam kev ntawm 10℃txog 50 degree. Qhov ntawd tsis yog qhov sib txawv me me. Yog tias koj txoj kev xaiv muab piv rau qhov amplitude ntawm xoom- ntu ntu ntawm cov feeders, 20% yuam kev tuaj yeem hloov pauv tau yooj yim. Lub feeder uas yuav tsum tau flagged li faulty dheev zoo li noj qab nyob zoo, thiab noj qab haus huv feeder yuav liam. Txawm hais tias CT zoo meej, ADC qhia txog nws tus kheej cov teeb meem. Ib tug 12-ntsis converter nrog kev tsim tsis zoo cov tswv yim scaling tuaj yeem poob cov ntsiab lus qis-amplitude. Quantization nrov tuaj yeem faus lub teeb liab heev uas koj xav tau thaum qhov kev ua txhaum loj heev.
Phase raug yog ib yam tseem ceeb, thiab nws yog feem ntau overlooked. Ntau lub algorithms cia siab rau qhov tseeb tias qhov tsis zoo ntawm tus feeder qhov xoom- cov kab ke tam sim no yog qhov sib txawv nyob rau theem rau cov khoom noj noj qab haus huv '. Raws li txoj cai, qhov no yog 180℃sib txawv. Tab sis yog tias koj CT qhia txog 15℃theem hloov, thiab koj lub moos ADC ntxiv 5 degree, koj tau compressed qhov txawv. Tam sim no lub feeder noj qab nyob zoo thiab faulty feeder tsuas yog txawv ntawm 140℃lossis 150 degree, uas yog qhov nyuaj rau kev ntxub ntxaug, tshwj xeeb tshaj yog thaum koj muaj ntau lub feeders nrog ntev ntev thiab load profiles. Qhov teeb meem loj zuj zus nyob rau hauv cov chaw nres tsheb digital, qhov twg xoom- ntu ntu tam sim no tau tsim los ntawm peb theem tam sim no. Txhua qhov kev tsis sib haum xeeb hauv qhov raug lossis kev sib koom ua ke ntawm peb cov channel txuas ncaj qha mus rau xoom- tus nqi sib npaug. Peb tau pom cov xwm txheej uas 2℃theem tsis sib haum ntawm cov theem tsim 15% yuam kev hauv kev sib xyaw xoom- ntu ntu tam sim no- txaus los ua kom tsis meej pem qhov kev xaiv logic.
Tom qab ntawd muaj tus lej piv txwv thiab synchronization. Rau kev hloov pauv -raws li txoj hauv kev, Nyquist cov txheej txheem tsuas yog qhov pib. Koj xav tau cov ntsiab lus txaus rau ib lub voj voog kom ntes cov duab ntawm lub sijhawm, tsis yog nws lub neej. Yog hais tias qhov tseem ceeb zaus zaus yog 1.5 kHz, 4 kHz sampling tus nqi muab rau koj tsawg dua peb lub ntsiab lus ib lub voj voog. Qhov ntawd yog qhov txaus ntshai nyob ze rau ntawm ntug, thiab ib qho kev tiv thaiv -aliasing lim nrog maj mam yob- tawm yuav ua rau muaj kev cuam tshuam ntau zaus uas muaj qhov yuam kev kos npe. Cov nqi piv txwv siab dua pab, tab sis lawv kuj xav tau ntau lub zog ua haujlwm thiab tsim cov ntaub ntawv ntau dua. Hauv ntau-feeder system, synchronization ntawm cov channel ua qhov tseem ceeb. Lub sij hawm skew ntawm ob peb microseconds ntawm cov channel txhais mus rau theem yuam kev. Qhov kev ua yuam kev theem ntawd tuaj yeem ua raws li qhov ua txhaum tiag tiag, ua rau muaj kev xaiv tsis raug lossis ploj lawm qhov txhaum tiag.
Yog li qhov no txhais li cas thaum koj xaiv lub cuab yeej? Nws txhais tau tias koj tsis tuaj yeem kho qhov tseeb qhov tseeb raws li qhov tshwj xeeb thib ob. Nws tsis yog ib yam dab tsi los pauv mus rau tus nqi qis dua lossis ib qho chaw me me. Lub algorithm-txawm nws yog wavelet-raws li, kev sib raug zoo-raws li, lossis lwm yam- tuaj yeem ua haujlwm nrog cov ntaub ntawv nws tau txais. Yog hais tias cov ntaub ntawv yog distorted, tsis muaj npaum li cas ntawm ntse lej yuav rov qab tau qhov tseeb. Thaum koj ntsuas qhov chaw ua txhaum cai rau kev lag luam xa tawm, nug txog CT qhov tseeb hauv chav kawm ntawm qhov qis tam sim no, tsis yog ntawm qhov ntsuas tam sim no. Nug txog ADC qhov kev daws teeb meem thiab tus lej ntsuas tus lej ntawm ib qho channel. Nug txog channel-rau-channel synchronization. Ib qho khoom siv nrog 0.5% qhov tseeb tam sim no thiab 10 kHz sampling yuav ua tau zoo dua chav tsev pheej yig dua nrog 2% qhov tseeb thiab 4 kHz sampling hauv txhua qhov tiag tiag -lub ntiaj teb qhov xwm txheej, tshwj xeeb tshaj yog nyob rau hauv cov tshuab uas muaj siab - tsis kam grounding lossis ntev cable khiav qhov twg lub teeb liab tsis muaj zog tshaj.
Thaum kawg, kev ntsuas qhov tseeb yog lub hauv paus. Tau txais nws txoj cai, thiab kev xaiv ua haujlwm ntseeg tau. Tau txais nws yuam kev, thiab koj tab tom txhim kho lub cuab yeej uas zoo nkaus li zoo ntawm daim ntawv tab sis ua tsis tiav thaum nws tseem ceeb tshaj plaws.
