Kutchinga komwe kumagwiritsidwa ntchito muzinthu zamawaya ndi zingwe kumakhala ndi malingaliro awiri osiyana: kutchingira kwamagetsi ndi kutchingira kumunda wamagetsi. Electromagnetic shielding idapangidwa kuti iteteze zingwe zotumiza ma siginecha apamwamba kwambiri (monga zingwe za RF ndi zingwe zamagetsi) kuti zisasokoneze kusokoneza kwakunja kapena kutsekereza mafunde akunja amagetsi kuti asasokoneze zingwe zomwe zimatumiza mafunde ofooka (monga ma siginecha kapena zingwe zoyezera), komanso kuchepetsa kulumikizana pakati pa mawaya. Kutchinga kumunda kwamagetsi kumapangidwa kuti kukhale kolinganiza malo amagetsi amphamvu pamtunda wa kondakita kapena malo otchingira a zingwe zamagetsi zapakatikati ndi zamphamvu kwambiri.
1. Mapangidwe ndi Zofunikira za Magetsi Oteteza Zamagetsi
Kuteteza kwa zingwe zamagetsi kumaphatikizapo kutchingira kwa conductor, kutchingira kutchingira, ndi kutchingira kwachitsulo. Malinga ndi miyezo yoyenera, zingwe zokhala ndi ma voliyumu ovotera kuposa 0.6/1kV ziyenera kukhala ndi zitsulo zotchingira zotchingira, zomwe zitha kuyikidwa pachimake chilichonse kapena pachimake cha chingwe chamitundu yambiri. Kwa zingwe za XLPE zokhala ndi ma voliyumu ovotera osachepera 3.6/6kV ndi zingwe za EPR zopyapyala zokhala ndi voteji yosachepera 3.6/6kV (kapena zingwe zokhuthala zokhala ndi ma voltage ovotera osachepera 6/10kV), zida zotchingira zamkati ndi zakunja za semi-conductive zimafunikanso.
(1) Conductor Shielding ndi Insulation Shielding
Kutchinga kwa conductor (chitetezo chamkati cha semi-conductive) kuyenera kukhala kopanda chitsulo, kokhala ndi zinthu zotulutsa semi-conductive kapena tepi ya semi-conductive yomwe imakulungidwa mozungulira kondakitala ndikutsatiridwa ndi wosanjikiza wa semi-conductive wotuluka.
Chotchinga chotchinga (chotchinga chakunja cha semi-conductive) ndi chosanjikiza chopanda chitsulo chokhala ndi semi-conductive chomwe chimatuluka molunjika pamwamba pa phata lililonse lotsekeredwa, lomwe limatha kumangirizidwa mwamphamvu kapena kusungunuka kuchokera pakusungunula. Zigawo zotuluka mkati ndi kunja kwa semi-conductive ziyenera kulumikizidwa mwamphamvu ndi zotchingira, zolumikizana zosalala, zopanda zingwe zowoneka bwino, zopanda nsonga zakuthwa, tinthu tating'ono, zipsera, kapena zokanda. The resistivity pamaso ndi pambuyo ukalamba sayenera upambana 1000 Ω · m kwa kondakitala kutchinga wosanjikiza ndi 500 Ω · m kwa kutchinjiriza wosanjikiza zotchinga.
Zida zotetezera mkati ndi kunja kwa semi-conductive shielding zimapangidwa mwa kusakaniza zipangizo zotetezera zofanana (monga polyethylene yolumikizira mtanda, mphira wa ethylene-propylene, etc.) ndi carbon black, antioxidants, ethylene-vinyl acetate copolymer, ndi zina zowonjezera. The mpweya wakuda particles ayenera uniformly omwazika mkati polima, popanda agglomeration kapena osauka kubalalitsidwa.
Kuchuluka kwa zigawo zamkati ndi kunja kwa semi-conductive shielding kumawonjezeka ndi mlingo wa voteji. Chifukwa mphamvu yamagetsi pazigawo zotsekera ndi yokwera mkati ndi kutsika kunja, makulidwe a magawo otchinga a semi-conductive ayeneranso kukhala akulu mkati kuposa kunja. M'mbuyomu, chishango chakunja cha semi-conductive chinkakhala chokhuthala pang'ono kuposa chamkati kuti chiteteze kukwapula chifukwa cha kusakhazikika bwino kapena kubowola chifukwa cha matepi amkuwa olimba kwambiri. Tsopano, ndikuwunika kwapaintaneti kokhazikika komanso matepi ofewa amkuwa, chotchinga chamkati cha semi-conductive chikuyenera kukulitsidwa pang'ono kapena chofanana ndi chakunja. Pazingwe za 6–10–35 kV, makulidwe a mkati mwake nthawi zambiri amakhala 0.5–0.6–0.8 mm.
(2) Kuteteza Chitsulo
Zingwe zokhala ndi voteji wamkulu kuposa 0.6/1kV ziyenera kukhala ndi zitsulo zotchingira. Chotchinga chotchinga chachitsulo chiyenera kuyikidwa pachimake chilichonse kapena pachimake cha chingwe. Chotchinga chachitsulo chiyenera kukhala ndi tepi imodzi kapena zingapo zachitsulo, zomangira zitsulo, mawaya achitsulo osakanikirana, kapena kuphatikiza mawaya achitsulo ndi matepi achitsulo.
Ku Ulaya ndi maiko ena otukuka, chifukwa chogwiritsa ntchito makina ozungulira ozungulira awiri omwe ali ndi mafunde apamwamba afupikitsa, kutchinga kwa waya wamkuwa kumagwiritsidwa ntchito kwambiri. Opanga ena amayika mawaya amkuwa mu sheath yolekanitsa kapena m'chimake chakunja kuti achepetse kuchuluka kwa chingwe. Ku China, kupatulapo mapulojekiti ena ofunikira omwe amagwiritsa ntchito makina otchinga-ozungulira kawiri, machitidwe ambiri amagwiritsa ntchito magetsi a arc-suppression coil-based single-circuit power powers, omwe amachepetsa nthawi yocheperako, kotero kuti tepi yotchinga yamkuwa ingagwiritsidwe ntchito. Chingwe mafakitale ndondomeko anagula zolimba mkuwa matepi ndi slitting ndi annealing kuti akwaniritse elongation ena ndi kumakoka mphamvu (zolimba kwambiri kukanda kutchinjiriza wosanjikiza, zofewa kwambiri makwinya) pamaso ntchito. Matepi ofewa amkuwa akuyenera kutsatira GB/T11091-2005 Copper Tape for Cables.
Chotchinga chamkuwa chizikhala ndi wosanjikiza umodzi wa tepi yofewa yophimbidwa kapena zigawo ziwiri za tepi yofewa yokhala ndi mipata. Kuchulukana kwapakati pa tepi yamkuwa kuyenera kukhala 15% ya m'lifupi mwake (mtengo wadzina), ndipo kuchuluka kocheperako kuyenera kukhala kosachepera 5%. Kunenepa mwadzina kwa tepi yamkuwa kuyenera kukhala osachepera 0,12 mm pazingwe zapakatikati komanso osachepera 0.10 mm pazingwe zamapakati. Makulidwe ochepa a tepi yamkuwa sayenera kukhala osachepera 90% ya mtengo wadzina. Kutengera kukula kwa kunja kwa chitetezo chotchinga (≤25 mm kapena> 25 mm), m'lifupi mwake tepi yamkuwa nthawi zambiri imakhala 30-35 mm.
Chotchinga chawaya chamkuwa chimapangidwa ndi mawaya ofewa ofewa, otetezedwa ndi mawaya amkuwa kapena matepi amkuwa. Kukaniza kwake kuyenera kukwaniritsa zofunikira za GB/T3956-2008 Conductors of Cables, ndipo dera lake lodziwika bwino liyenera kutsimikiziridwa molingana ndi vuto lomwe lilipo. Chotchinga chamkuwa chitha kuyika mkati mwa zingwe zapakati pazingwe zitatu kapena molunjika pamwamba pa chotchingira, chotchinga chakunja cha semi-conductive, kapena chinsalu chamkati choyenera cha zingwe zapakatikati. Kusiyana kwapakati pakati pa mawaya amkuwa oyandikana nawo sayenera kupitirira 4 mm. Avereji gap G imawerengedwa pogwiritsa ntchito fomula:
kumene:
D - awiri a pachimake chingwe pansi pa mkuwa kutchinga waya, mu mm;
d - awiri a waya wamkuwa, mu mm;
n - chiwerengero cha mawaya amkuwa.
2. Udindo Woteteza Zigawo ndi Ubale Wake ndi Magawo a Voltage
(1) Udindo wa Mkati ndi Wakunja Semi-Conductive Shielding
Ma Cable conductors nthawi zambiri amapangidwa kuchokera ku mawaya angapo. Pakutulutsa kwazitsulo, mipata, ma burrs, ndi zina zosokoneza pamtunda zitha kukhalapo pakati pa kondakitala pamwamba ndi zosanjikiza zotchingira, zomwe zimapangitsa kuti magetsi azizungulira, zomwe zimatsogolera kutulutsa mpweya wam'deralo ndikutulutsa kwamitengo, ndikuchepetsa magwiridwe antchito a dielectric. Potulutsa gawo la semi-conductive material (conductor shielding) pamwamba pa kondakitala, zimatsimikizira kukhudzana kolimba ndi kutchinjiriza. Chifukwa chosanjikiza cha semi-conductive ndi woyendetsa ali ndi kuthekera kofanana, ngakhale pali mipata pakati pawo, sipadzakhala gawo lamagetsi lamagetsi, potero zimalepheretsa kutulutsa pang'ono.
Momwemonso, pali mipata pakati pa kutchingira kwakunja ndi chitsulo chachitsulo (kapena chitsulo chotchinga), ndipo kukweza kwa voteji kumapangitsa kuti mpweya utuluke. Ndi extruding theka-conductive wosanjikiza (kuteteza chitetezo) pa kunja kutchinjiriza pamwamba, ndi akunja equipotential pamwamba aumbike ndi m'chimake zitsulo, kuchotsa minda magetsi mu mipata ndi kupewa kumaliseche pang'ono.
(2) Udindo Woteteza Chitsulo
Ntchito zachitetezo chazitsulo zikuphatikizapo: kunyamula capacitive panopa pansi pazikhalidwe zabwinobwino, kutumikira ngati njira yachidule chamagetsi panthawi yolakwika; kutsekereza gawo lamagetsi mkati mwa kutsekereza (kuchepetsa kusokoneza kwamagetsi akunja) ndikuwonetsetsa kuti pali gawo lamagetsi lofananira; kuchita ngati mzere wosalowerera ndale mu magawo atatu a mawaya anayi kuti azinyamula mopanda malire; ndikupereka chitetezo chotchinga madzi ma radial.
Nthawi yotumiza: Jul-28-2025