Kuyerekeza Kothandiza kwa Zosintha Zamakono Zoyezera vs Chitetezo

Chitetezo cha CT KulondolaKulondola kwa chitetezo cha CT sikukhudza kubweza mwatsatanetsatane koma kumakhudza magwiridwe antchito panthawi ya vuto. Kulondola kwake kumatanthauzidwa ndi "zolakwika zamagulu" pamachulukidwe ake omwe adavotera. Gulu lachitetezo chodziwika bwino ndi5P10.Kutchulidwa uku kumatheka motere:

• 5: Cholakwika chophatikizika sichidzadutsa 5% pamlingo wolondola.
• P: Kalata iyi imatchula ngati kalasi ya Chitetezo CT.
• 10: Ichi ndi Chiyeso Cholondola Chochepa (ALF). Zikutanthauza kuti CT isunga kulondola kwake mpaka nthawi 10 yomwe idavotera pakali pano.

Mwachidule, 5P10 CT imatsimikizira kuti nthawi yoyamba ikafika nthawi 10, chizindikiro chomwe chimatumizidwa ku relay chikadali mkati mwa 5% yamtengo wapatali, kuwonetsetsa kuti wodutsayo akupanga chisankho choyenera.

Burden ndi VA Rating

Katundundi kuchuluka kwamagetsi komwe kumalumikizidwa ndi ma terminals achiwiri a CT, omwe amayezedwa ndi Volt-Amperes (VA) kapena ohms (Ω). Chida chilichonse ndi waya zolumikizidwa ku CT zimathandizira pazitunduzi. Kupitilira zolemetsa zovoteledwa ndi CT kudzasokoneza kulondola kwake.

Katundu wonse ndichiwerengero cha impedances zonse zigawo zikuluzikulumu chigawo chachiwiri:

• CT's own secondary winding resistance resistance.
• Kukaniza kwa mawaya otsogolera kulumikiza CT ku chipangizocho.
• Kulepheretsa kwamkati kwa chipangizo cholumikizidwa (mita kapena relay).

Kuwerengera Katundu Wonse:Katswiri akhoza kuwerengera kuchuluka kwa katunduyo pogwiritsa ntchito fomula:Total Burden (Ω) = CT Winding R (Ω) + Waya R (Ω) + Chipangizo Z (Ω)Mwachitsanzo, ngati CT yachiwiri yokhotakhota kukana ndi 0.08 Ω, mawaya olumikiza ali ndi 0.3 Ω ya kukana, ndipo relay ili ndi cholepheretsa cha 0.02 Ω, chiwerengero chonse cha dera ndi 0.4 Ω. Mtengowu uyenera kukhala wocheperako poyerekeza ndi zomwe CT idavotera kuti izigwira bwino ntchito.

Ma measurement CTs nthawi zambiri amakhala ndi ma VA otsika (mwachitsanzo, 2.5 VA, 5 VA) chifukwa amalumikizana ndi zida zoyezera kwambiri, zogwiritsa ntchito pang'ono pa mtunda waufupi. Chitetezo cha CTs chimafuna ma VA apamwamba kwambiri (mwachitsanzo, 15 VA, 30 VA) chifukwa ayenera kupereka mphamvu zokwanira kuti agwiritse ntchito makina ochepetsetsa, ogwiritsira ntchito kwambiri a relay yotetezera, nthawi zambiri pa chingwe chachitali kwambiri. Kufananiza molakwika kuchuluka kwa kulemedwa kwa CT ndi katundu weniweni wadera ndizomwe zimachitika nthawi zambiri pamakina a metering ndi chitetezo.

Kumvetsetsa Knee Point Voltage

Knee Point Voltage (KPV) ndi gawo lofunikira lomwe limakhudza chitetezo cha CTs. Imatanthauzira malire apamwamba amtundu wothandiza wa CT musanayambe kukhuta. Mtengo uwu ndi wofunikira kuti uwonetsetse kuti relay yotetezera imalandira chizindikiro chodalirika panthawi ya vuto lalikulu.

Mainjiniya amazindikira KPV kuchokera pamapindikira osangalatsa a CT, omwe amawongolera mphamvu yachiwiri yosangalatsa motsutsana ndi yachiwiri yosangalatsa yapano. "Bondo" ndi mfundo yomwe ili pamapindikira apa pomwe mphamvu za maginito zapakati zimasintha kwambiri.

TheIEEE C57.13 muyezoamapereka tanthauzo lenileni la mfundo imeneyi. Kwa CT yopanda malire, nsonga ya bondo ndi pamene tangent yokhotakhota imapanga ngodya ya 45-degree ndi yopingasa. Kwa CT pachimake chosiyana, ngodya iyi ndi madigiri 30. Mfundo yeniyeni iyi ndi chiyambi cha machulukitsidwe.

Pamene CT imagwira ntchito pansi pa mawondo ake, chigawo chake chimakhala mumtundu wa maginito. Izi zimalola kuti ibweretsenso molondola vuto lamakono la relay yolumikizidwa. Komabe, mphamvu yachiwiri ikadutsa KPV, pachimake chimalowa m'machulukidwe. Kuchulukitsitsa, komwe nthawi zambiri kumayendetsedwa ndi mafunde akulu a AC ndi ma DC kuchotsedwa pakalakwitsa, kumayambitsa CTmagnetizing impedance kutsika kwambiri. Transformer sangathenso kuwonetsera mokhulupirika zamakono zamakono kumbali yake yachiwiri.

Ubale pakati pa KPV ndi kudalirika kwachitetezo ndiwolunjika komanso wofunikira:

• Pansi pa mfundo ya bondo:CT Core imagwira ntchito mozungulira. Amapereka chiwonetsero cholondola cha vuto lapano ku relay yoteteza.
• Pamwamba pa bondo:Pakatikati amakhuta. Izi zimabweretsa kuwonjezeka kwakukulu kwa ntchito ya magnetizing panopa komanso yopanda mzere, kutanthauza kuti CT siwonetseranso molondola cholakwika chenichenicho.
• Kugwiritsa ntchito Relay:Ma relay oteteza amafunika chizindikiro cholondola kuti agwire bwino ntchito. Ngati CT imadzaza chiwongolerocho chisanapange chisankho, relay ikhoza kulephera kuzindikira kukula kwenikweni kwa vutolo, zomwe zimayambitsa ulendo wochedwa kapena kulephera kwathunthu kugwira ntchito.
• Chitetezo Padongosolo:Chifukwa chake, voliyumu ya mawondo a CT iyenera kukhala yokwera mokwanira kuposa mphamvu yachiwiri yachiwiri yomwe ikuyembekezeka pakalakwitsa. Izi zimatsimikizira kuti relay imalandira chizindikiro chodalirika kuti chiteteze zipangizo zamtengo wapatali.

Mainjiniya amawerengera KPV yofunikira kuti awonetsetse kuti CT imakhalabe yopanda mphamvu pazovuta kwambiri. Njira yosavuta yowerengera izi ndi:

KPV yofunikira ≥ Ngati × (Rct + Rb)

Kumene:

• If= Kuwonongeka kwachiwiri kwachiwiri (Amps)
• Rct= CT yachiwiri yokhotakhota kukana (Ohms)
• Rb= Katundu wonse wa ma relay, ma waya, ndi maulumikizidwe (Ohms)

Pamapeto pake, Knee Point Voltage imakhala chizindikiro chachikulu cha chitetezo cha CT kuti chigwire ntchito yake yachitetezo pansi pa kupsinjika kwakukulu kwa magetsi.

Kumasulira Matchulidwe Amakono a Transformer Nameplate

Current Transformer nameplate ili ndi code yophatikizika yomwe imatanthawuza momwe imagwirira ntchito. Mawu a zilembo ndi manambalawa ndi chiyankhulo chachidule cha mainjiniya, chosonyeza kulondola kwa gawo, kagwiritsidwe ntchito, ndi malire a kagwiritsidwe ntchito. Kumvetsetsa manambalawa ndikofunikira pakusankha chida choyenera.

Kutanthauzira Makalasi a CT Measurement (mwachitsanzo, 0.2, 0.5S, 1)

Makalasi a Measurement CT amatanthauzidwa ndi nambala yomwe imayimira cholakwika chachikulu chovomerezeka pamlingo wapano. Nambala yocheperako imasonyeza kulondola kwambiri.

• Kalasi 1:Ndikoyenera metering wamba wamba pomwe kulondola kwambiri sikofunikira.
• Gawo 0.5:Amagwiritsidwa ntchito popangira mabilu azamalonda ndi mafakitale.
• Gulu 0.2:Zofunikira pakuwerengera ndalama zolondola kwambiri.

Ena makalasi ndi chilembo 'S'. Matchulidwe a 'S' m'makalasi a CT a kuyeza kwa IEC, monga 0.2S ndi 0.5S, akuwonetsa kulondola kwambiri. Kugawika kumeneku nthawi zambiri kumagwiritsidwa ntchito poyesa tariff pomwe miyeso yolondola ndiyofunikira, makamaka kumapeto kwenikweni kwa mtundu wapano.

Kutanthauzira Makalasi a Chitetezo cha CT (mwachitsanzo, 5P10, 10P20)

Makalasi a chitetezo a CT amagwiritsa ntchito code ya magawo atatu yomwe imafotokozera zomwe amachita pakalakwitsa. Chitsanzo chofala ndi5P10.

Kuphwanya Code 5P10:

• 5: Nambala yoyamba iyi ndiye cholakwika chachikulu chamagulu ambiri (5%) pamlingo wolondola.
• P: Chilembo 'P' mugulu ngati 5P10 chimayimira 'gulu lachitetezo'. Izi zikuwonetsa kuti CT idapangidwa makamaka kuti ikhale yoteteza kutumizirana mauthenga m'malo moyesa molondola.
• 10: Nambala yomalizayi ndi Accuracy Limit Factor (ALF). Zimatanthawuza kuti CT idzasunga kulondola kwake mpaka kulakwitsa komwe kuli nthawi 10 mlingo wake.

Mofananamo, a10P20kalasi ya CT ili ndi malire olakwika a 10% ndi Zolemba Zolondola za20. M'matchulidwe ngati 10P20, nambala '20' imayimira malire olondola. Izi zikuwonetsa kuti cholakwika cha thiransifoma chikhalabe m'malire ovomerezeka pomwe pano ndi nthawi 20 mtengo wake wovotera. Kuthekera kumeneku ndikofunikira pakuwonetsetsa kuti zolumikizirana zoteteza zimagwira ntchito moyenera pakanthawi kochepa kwambiri.

Upangiri Wogwiritsa Ntchito: Kufananiza CT ndi Ntchito

Kusankha Current Transformer yoyenera si nkhani yokonda koma chofunikira cholamulidwa ndi kugwiritsa ntchito. Muyezo wa CT umapereka kulondola kofunikira pazachuma, pomwe chitetezo cha CT chimapereka kudalirika kofunikira pachitetezo cha katundu. Kumvetsetsa komwe mungagwiritse ntchito mtundu uliwonse ndikofunikira pamapangidwe ndi magwiridwe antchito amagetsi.

Nthawi Yomwe Mungagwiritsire Ntchito Measurement CT

Mainjiniya akuyenera kugwiritsa ntchito muyeso wa CT pakugwiritsa ntchito kulikonse komwe cholinga chachikulu ndicho kutsatira mosamalitsa kagwiritsidwe ntchito ka magetsi. Zipangizozi ndizo maziko a zolipira zolondola komanso kasamalidwe ka mphamvu. Mapangidwe awo amaika patsogolo kulondola kwakukulu pansi pamikhalidwe yabwinobwino.

Ntchito zazikulu zoyezera ma CT ndi:

• Revenue & Tariff Metering: Zothandizira zimagwiritsa ntchito ma CT olondola kwambiri (mwachitsanzo, Class 0.2S, 0.5S) polipira makasitomala akunyumba, amalonda, ndi mafakitale. Kulondola kumawonetsetsa kuti ndalama zizichitika mwachilungamo komanso moyenera.
• EMS (Energy Management Systems): Zida zimagwiritsa ntchito ma CTs kuti aziwunika momwe magetsi amagwiritsidwira ntchito m'madipatimenti osiyanasiyana kapena zida zosiyanasiyana. Deta iyi imathandizira kuzindikira zolephera ndikuwongolera kugwiritsa ntchito mphamvu.
• Kusanthula Ubwino Wamphamvu: Zowunikira zamphamvu zamagetsi zimafunikira zolowera zolondola kuti muzindikire zovuta monga ma harmonics ndi ma voltage sags. Pamiyezo iyi, makamaka pamakina apakati pamagetsi, kuyankha pafupipafupi kwa chosinthira chida ndikofunikira. Osanthula amakono angafunike deta yodalirikampaka 9 kHz, amafuna ma frequency-wokometsedwa thiransifoma kuti agwire sipekitiramu yonse ya harmonic.

Chidziwitso pa Kusankha:Posankha CT ya mita yamagetsi kapena analyzer, pali zinthu zingapo zofunika.

• Linanena bungwe Kugwirizana: Zotulutsa za CT (mwachitsanzo, 333mV, 5A) ziyenera kugwirizana ndi zofunikira za mita.
• Katundu Kukula: Mtundu wa amperage wa CT uyenera kugwirizana ndi katundu woyembekezeka kuti ukhale wolondola.
• Physical Fit: CT iyenera kukwanira mozungulira wokonda. Ma flexible Rogowski coils ndi yankho lothandiza pamabasi akulu kapena malo olimba.
• Kulondola: Pakulipiritsa, kulondola kwa 0.5% kapena bwinoko ndikokhazikika. Pakuwunika kwanthawi zonse, 1% ikhoza kukhala yokwanira.

Nthawi Yomwe Mungagwiritsire Ntchito Chitetezo cha CT

Mainjiniya ayenera kugwiritsa ntchito chitetezo cha CT kulikonse komwe cholinga chachikulu ndikuteteza ogwira ntchito ndi zida kuti zisawonongeke ndi zolakwika. Ma CT awa amapangidwa kuti azikhalabe akugwira ntchito panthawi yamagetsi owopsa, kupereka chizindikiro chodalirika ku relay yoteteza.

Ntchito zodziwika bwino zachitetezo cha CTs ndi:

• Overcurrent ndi Earth Fault Protection: Ma CTs awa amadyetsa ma sigino ku ma relay (monga ANSI Chipangizo 50/51) omwe amazindikira zolakwika za gawo kapena pansi. Kenako mawotchiwo amayendetsa chodutsa kuti alekanitse cholakwikacho. Mu medium-voltage switchgear, pogwiritsa ntchito odziperekazero-sequence CTchifukwa pansi-zolakwa chitetezo nthawi zambiri akulimbikitsidwa pa yotsalira kugwirizanamagawo atatu CTs. Kulumikizana kotsalira kungayambitse maulendo abodza chifukwa cha kuchulukitsitsa kosagwirizana pakuyambika kwa injini kapena kuwonongeka kwa gawo.
• Chitetezo Chosiyanasiyana: Dongosololi limateteza zinthu zazikulu monga ma transfoma ndi ma jenereta pofanizira mafunde omwe amalowa ndikutuluka m'dera lotetezedwa. Imafunikira ma seti ofananira achitetezo a CT.Ma relay amakono a digitoikhoza kulipira ma CT osiyanasiyana (Wye kapena Delta) ndi kusintha kwa magawo kupyolera mu mapulogalamu a mapulogalamu, kupereka kusinthasintha kwakukulu muzinthu zovutazi.
• Kutetezedwa Kutali: Amagwiritsidwa ntchito pamizere yopatsirana, chiwembuchi chimadalira chitetezo cha CTs kuyeza kulephera kwa cholakwika. Machulukidwe a CT amatha kusokoneza muyesowu, kupangitsa kuti wotumizirana asamaganize molakwika malo omwe alakwitsa. Chifukwa chake, CT iyenera kupangidwa kuti ipewe kuchuluka kwa nthawi yoyezera.

Malinga ndi ANSI C57.13, CT yodzitchinjiriza yokhazikika iyenera kupirira mpaka20 nthawimayendedwe ake pa nthawi ya vuto. Izi zimawonetsetsa kuti imatha kupereka chikwangwani chogwiritsidwa ntchito pamayendedwe akafunika kwambiri.

Mtengo Wapamwamba Wosankha Molakwika

Kugwiritsa ntchito mtundu wolakwika wa CT ndi vuto lalikulu lomwe lili ndi zotsatira zoyipa. Kusiyana kwa ntchito pakati pa kuyeza ndi kuteteza CTs sikumasintha, ndipo kusagwirizana kungayambitse zotsatira zoopsa komanso zodula.

• Kugwiritsa ntchito Measurement CT kwa Chitetezo: Uku ndiye kulakwitsa koopsa kwambiri. Muyeso wa CT wapangidwa kuti ukhale wodzaza ndi ma overcurrents otsika kuti ateteze mita. Pakulakwitsa kwakukulu, imakhuta pafupifupi nthawi yomweyo. CT yodzaza idzalephera kuberekanso vuto lalikulu lamakono, ndipo relay yotetezera sidzawona kukula kwenikweni kwa chochitikacho. Izi zingayambitse ulendo wochedwa kapena kulephera kwathunthu kugwira ntchito, zomwe zingayambitse kuwonongeka kwa zipangizo, moto, ndi chiopsezo kwa ogwira ntchito. Mwachitsanzo, machulukitsidwe a CT angayambitse kufalikira kwa chitetezo cha transformermaloperate, zomwe zimatsogolera ku ulendo wosafunikira panthawi ya vuto lakunja.
• Kugwiritsa ntchito Chitetezo cha CT poyezera: Kusankha kumeneku kumabweretsa kusalondola kwachuma. Chitetezo cha CT sichinapangidwe kuti chikhale cholondola pamayendedwe abwinobwino. Kalasi yake yolondola (mwachitsanzo, 5P10) imatsimikizira kuti imagwira ntchito pamachulukitsidwe ake ambiri, osati kumapeto kwa sikelo yomwe machitidwe ambiri amagwira. Kuigwiritsa ntchito polipira kuli ngati kuyeza mchenga ndi ndodo. Mabilu amagetsi omwe amabwera chifukwa cha mphamvuyo amakhala osalondola, zomwe zimapangitsa kuti ndalama ziwonongeke kapena kuchulukitsa kwa ogula.

Kulephera Kwambiri:M'machitidwe oteteza mtunda, kuchuluka kwa CT kumapangitsa kuti kubwezeredwa kuyeza aapamwamba impedancekuposa mtengo weniweni. Izi zimafupikitsa kufikira kwa chitetezo cha relay. Cholakwa chomwe chiyenera kuthetsedwa nthawi yomweyo chikhoza kuwonedwa ngati cholakwa chakutali, kuchititsa ulendo wochedwa. Kuchedwa kumeneku kumatalikitsa kupsinjika pamagetsi amagetsi ndikuwonjezera kuthekera kwa kuwonongeka kofala.

Pamapeto pake, mtengo wa kusankha kolakwika kwa CT umapitilira mtengo wa gawolo. Imawonekera pakuwonongeka kwa zida, kutha kwa ntchito, mbiri yolakwika yazachuma, komanso kusokoneza chitetezo.

Kodi CT Imodzi Ingatumikire Zonse Zoyezera ndi Chitetezo?

Ngakhale ma CT a muyeso ndi chitetezo ali ndi mapangidwe ake, mainjiniya nthawi zina amafuna chida chimodzi kuti chigwire ntchito zonse ziwiri. Kufunika kumeneku kunapangitsa kuti pakhale ma transfoma apadera omwe ali ndi zolinga ziwiri, koma amabwera ndi malonda enaake.

Cholinga Chapawiri (Kalasi X) CT

Gulu lapadera, lotchedwaKalasi X kapena PS Class Current Transformer, imatha kugwira ntchito zoyezera komanso chitetezo. Zida izi sizimatanthauzidwa ndi makalasi olondola monga 5P10. M'malo mwake, machitidwe awo amatchulidwa ndi magawo ofunikira omwe injiniya amagwiritsa ntchito kutsimikizira kuyenerera kwawo pachitetezo china chake.

Malinga ndi miyezo ya IEC, machitidwe a Class X CT amatanthauzidwa ndi:

• Zovoteledwa poyambirira
• Amatembenuza chiŵerengero
• Magetsi a Knee point (KPV)
• Magnetizing panopa pa voteji wotchulidwa
• Kulimbana ndi mafunde achiwiri pa 75 ° C

Makhalidwewa amalola kuti chipangizochi chizipereka kulondola kwakukulu kwa metering pansi pazikhalidwe zokhazikika komanso kupereka mphamvu yodziŵika bwino ya bondo kuti igwire ntchito yodalirika yopatsirana panthawi ya zolakwika. Amagwiritsidwa ntchito nthawi zambiri pamakina oteteza kusiyanasiyana komwe kumayenera kudziwika bwino.

Zochepa Zothandiza ndi Kusinthanitsa

Ngakhale kukhalapo kwa Class X CTs, kugwiritsa ntchito chipangizo chimodzi poyezera komanso chitetezo nthawi zambiri kumapewa. Ntchito ziwirizi zili ndi zofunikira zotsutsana.

Muyeso wa CT udapangidwa kuti ukhale wodzaza msanga kuti uteteze mamita ozindikira. Achitetezo CT idapangidwakukana machulukitsidwe kuwonetsetsa kuti wodutsa amatha kuzindikira cholakwika. CT ya zolinga ziwiri iyenera kunyengerera pakati pa zolinga ziwiri zotsutsanazi.

Kunyengerera uku kumatanthauza kuti CT ya zolinga ziwiri sizingagwire ntchito iliyonse komanso gawo lodzipereka. Mapangidwewo amakhala ovuta komanso okwera mtengo. Pazinthu zambiri, kukhazikitsa ma CT awiri osiyana, apadera - imodzi ya metering ndi imodzi yotetezera - ndiyo njira yodalirika komanso yotsika mtengo. Njira iyi imatsimikizira kuti onse awirindondomeko yolipirandi chitetezo dongosolo ntchito popanda kunyengerera.

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Kusankha pakatikuyeza ndi chitetezo CTsndi chigamulo chomveka bwino chozikidwa pa ntchito yofunika kwambiri. Imodzi imapereka kulondola kwa kulipira, pamene ina imatsimikizira kudalirika pakalakwa. Kusankha mtundu wolondola sikungakambirane pachitetezo chadongosolo, kulondola kwachuma, komanso moyo wautali wa zida. Mainjiniya nthawi zonse amayenera kulumikizana ndi ma CT ndi zosowa za chipangizo cholumikizidwa.

Amndandanda womaliza wotsimikizirazikuphatikizapo:

1. Tsimikizirani Zoyambira Panopa: Fananizani chiŵerengero cha CT ndi katundu wambiri.
2. Werengetsani Katundu: Kuwerengera kuchuluka kwa zigawo zonse zolumikizidwa.
3. Tsimikizirani Kalasi Yolondola: Sankhani kalasi yoyenera ya mita kapena chitetezo.

FAQ

Kodi chimachitika ndi chiyani ngati gawo lachiwiri la CT lasiyidwa lotseguka?

Dera lachiwiri lotseguka limapanga voteji yowopsa. Yoyamba panopa imakhala magnetizing panopa, kukhutitsa pachimake. Mkhalidwewu ukhoza kuwononga CT ndipo umabweretsa chiopsezo chachikulu.

Chitetezo Choyamba:Nthawi zonse chepetsani ma terminals achiwiri musanadutse chida chilichonse pagawo.

Kodi mainjiniya amasankha bwanji chiŵerengero choyenera cha CT?

Akatswiri amasankha chiyerekezo chomwe chiwongolero chanthawi zonse chadongosolo chimakhala pafupi ndi mavoti oyambira a CT. Kusankha uku kumatsimikizira kuti CT ikugwira ntchito mkati mwazolondola kwambiri. Mwachitsanzo, katundu wa 90A amagwira ntchito bwino ndi 100:5A CT.

Chifukwa chiyani muyeso wa CT ndi wosatetezeka ku chitetezo?

Muyeso wa CT umadzaza mwachangu pakalakwitsa. Sichingathe kufotokoza vuto lenileni kwa njira yotetezera. Relay ndiye amalephera kuyendetsa wosweka, zomwe zimatsogolera ku kuwonongeka kwa zida komanso zoopsa zachitetezo.

Kodi CT imodzi ingagwire ntchito yoyezera komanso chitetezo?

Ma Special Class X CTs amatha kugwira ntchito zonse ziwiri, koma mapangidwe awo ndi kunyengerera. Kuti pakhale chitetezo chokwanira komanso cholondola, mainjiniya nthawi zambiri amaika ma CT awiri osiyana, odzipatulira - imodzi yowerengera ndi imodzi yoteteza.