Ukusasazwa koxinzelelo lwentsimi yombane kwiintambo ze-AC kuyafana, kwaye ingqwalasela yezinto zokwambathisa intambo ikwi-dielectric constant, engachatshazelwa bubushushu. Ngokwahlukileyo koko, ukusasazwa koxinzelelo kwiintambo ze-DC kuphezulu kumaleko angaphakathi kwe-insulation kwaye kuchaphazeleka kukumelana kwezinto zokwambathisa. Izinto zokwambathisa zibonisa i-coefficient yobushushu engalunganga, oko kuthetha ukuba njengoko ubushushu busanda, ukumelana kuyancipha.
Xa intambo isebenza, ilahleko ezingundoqo zibangela ukuba ubushushu bunyuke, nto leyo ekhokelela kutshintsho ekuchaseni kwezinto zokukhusela. Oku, kubangela ukuba uxinzelelo lwentsimi yombane ngaphakathi komaleko wokukhusela luhluke. Ngamanye amazwi, ngobukhulu obufanayo bokukhusela, i-voltage yokuqhekeka iyancipha njengoko ubushushu bunyuka. Kwimigca ye-DC trunk kwizikhululo zamandla ezisasazekileyo, izinga lokuguga kwezinto zokukhusela likhawuleza kakhulu ngenxa yokuguquguquka kobushushu obuphakathi xa kuthelekiswa neentambo ezingcwatyiweyo, nto leyo ebalulekileyo ekufuneka iqatshelwe.
Ngexesha lokuveliswa kwee-layers ze-insulation zekhebula, ukungcola kuyangeniswa ngokungenakuphepheka. Ezi ngcola zine-insulation resistivity ephantsi kwaye zisasazwa ngokungalinganiyo kwicala le-radial le-insulation layer. Oku kubangela ukuguquguquka komthamo kwiindawo ezahlukeneyo. Phantsi kwe-DC voltage, intsimi yombane ngaphakathi kwe-insulation layer nayo iya kwahluka, nto leyo ebangela ukuba iindawo ezine-insulation resistivity ephantsi ziguge ngokukhawuleza kwaye zibe ngamanqaku anokungaphumeleli.
Iintambo ze-AC azibonisi le nto. Ngamazwi alula, uxinzelelo kwizinto zentambo ze-AC lusasazwa ngokulinganayo, ngelixa kwiintambo ze-DC, uxinzelelo lobushushu luhlala lugxile kwiindawo ezibuthathaka. Ke ngoko, iinkqubo zokuvelisa kunye nemigangatho yeentambo ze-AC kunye ne-DC kufuneka zilawulwe ngokwahlukileyo.
I-polyethylene edityanisiweyo (XLPE)Iintambo ezigqunyiweyo zisetyenziswa kakhulu kwizicelo ze-AC ngenxa yeempawu zazo ezibalaseleyo ze-dielectric kunye nezomzimba, kunye nomlinganiselo wazo ophezulu weendleko zokusebenza. Nangona kunjalo, xa zisetyenziswa njengeentambo ze-DC, zijongene nomceli mngeni omkhulu onxulumene nokutshaja kwendawo, okubaluleke kakhulu kwiintambo ze-DC ezine-voltage ephezulu. Xa iipolymers zisetyenziswa njenge-DC cable insulation, inani elikhulu leembambo ezikwindawo ngaphakathi komaleko wokugqunywa kwezinto zibangela ukuqokelelwa kweentlawulo zendawo. Impembelelo yeentlawulo zendawo kwizixhobo zokugqunywa kwezinto ibonakaliswa kakhulu kwiinkalo ezimbini: ukuphambuka kwentsimi yombane kunye neziphumo zokuphambuka kwentsimi engeyiyo yombane, zombini ezi ziyingozi kakhulu kwizixhobo zokugqunywa kwezinto.
Itshaja yesithuba ibhekisa kwitshaja engaphezulu ngaphaya kokungathathi cala kombane ngaphakathi kweyunithi yesakhiwo sezinto ezi-macroscopic. Kwizinto eziqinileyo, iitshaja zesithuba ezilungileyo okanye ezimbi zibotshelelwe kumanqanaba amandla akwindawo ethile, nto leyo enika iziphumo ze-polarization ngendlela yee-polaron ezibotshelelweyo. I-polarization yetshaja yesithuba yenzeka xa ii-free ions zikhona kwi-dielectric material. Ngenxa yokuhamba kwee-ion, ii-negative ions ziqokelelana kwi-interface kufutshane ne-electrode elungileyo, kwaye ii-positive ions ziqokelelana kwi-interface kufutshane ne-electrode engalunganga. Kwintsimi yombane ye-AC, ukufuduka kweetshaja ezilungileyo nezingalunganga akunakuhambelana notshintsho olukhawulezileyo kwintsimi yombane ye-frequency yamandla, ngoko ke iziphumo zetshaja yesithuba azenzeki. Nangona kunjalo, kwintsimi yombane ye-DC, intsimi yombane isasazwa ngokwe-resistivity, ekhokelela ekwakhiweni kweetshaja zesithuba kwaye ichaphazela ukusasazwa kwentsimi yombane. I-XLPE insulation inenani elikhulu leemeko zeendawo ezithile, okwenza iziphumo zetshaja yesithuba zibe nzima kakhulu.
Ukufakelwa kwe-XLPE kudityaniswe ngeekhemikhali, kwenze isakhiwo esidityanisiweyo esidityanisiweyo. Njenge-polymer engeyiyo i-polar, intambo ngokwayo inokufaniswa ne-capacitor enkulu. Xa ukudluliselwa kwe-DC kuyeka, kufana nokutshaja i-capacitor. Nangona i-conductor core isekelwe, ukukhutshwa okusebenzayo akwenzeki, okushiya inani elikhulu lamandla e-DC agcinwe kwintambo njengeentlawulo zesithuba. Ngokungafaniyo neentambo zamandla ze-AC, apho iintlawulo zesithuba zichithwa ngokulahleka kwe-dielectric, ezi ntlawulo ziqokelelana kwiziphene kwintambo.
Ngokuhamba kwexesha, ngenxa yokuphazamiseka kwamandla rhoqo okanye ukuguquguquka kwamandla angoku, iintambo ezigqunywe nge-XLPE ziqokelela iindleko zesithuba ezininzi, zikhawulezisa ukuguga komaleko wokugqunywa kwe-insulation kwaye zinciphisa ubomi benkonzo yentambo.
Ixesha leposi: Matshi-10-2025