Ukuhanjiswa koxinzelelo kwintsimi yombane kwiintambo ze-AC zifana, kwaye ugxininiso lwezixhobo zokufakela i-cable kwi-dielectric constant, engachaphazeli ukushisa. Ngokwahlukileyo, ukuhanjiswa koxinzelelo kwiintambo ze-DC kuphezulu kumaleko angaphakathi we-insulation kwaye kuphenjelelwa yi-resistivity ye-insulation material. Izixhobo ze-insulation zibonisa i-coefficient yeqondo lokushisa elibi, oku kuthetha ukuba njengoko ubushushu bukhula, ukuxhathisa kuyancipha.
Xa ikhebula lisebenza, ilahleko eziphambili zibangela ukunyuka kweqondo lokushisa, okukhokelela ekutshintsheni kwi-resistiveivity ye-insulation material. Oku, kwakhona, kubangela ukuba uxinzelelo lwentsimi yombane ngaphakathi kwe-insulation layer ihluke. Ngamanye amazwi, kubunzima obufanayo bokugquma, amandla ombane wokuqhekeka ayancipha njengoko ubushushu bunyuka. Kwimizila ye-DC ye-trunk kwizikhululo zamandla ezisasazwayo, izinga lokuguga lezinto zokugquma likhawuleza kakhulu ngenxa yokuguquguquka kobushushu obukhoyo xa kuthelekiswa neentambo ezingcwatyiweyo, eyona ngongoma ibalulekileyo ekufuneka uyiqaphele.
Ngethuba lokuveliswa kwee-cable insulation layers, ukungcola kwaziswa ngokungenakunqandwa. Obu bumdaka bunokumelana nobushushu obusezantsi ngokwentelekiso kwaye asasazwanga ngokulinganayo ecaleni kwendlela yeradial yomaleko wokugquma. Oku kubangela ukuguquguquka kwevolumu kwiindawo ezahlukeneyo. Phantsi kombane we-DC, indawo yombane ngaphakathi komgangatho wokugquma iya kwahluka, ibangela ukuba iindawo ezinomthamo ophantsi wokuxhathisa ukuguga ngokukhawuleza kwaye zibe ngamanqaku anokusilela.
Iintambo ze-AC azibonisi le nto. Ngamagama alula, uxinzelelo kwizinto zentambo ze-AC zihanjiswa ngokufanayo, ngelixa kwiintambo ze-DC, uxinzelelo lwe-insulation luhlala lugxininiswe kwiindawo ezibuthathaka. Ke ngoko, iinkqubo zokuvelisa kunye nemigangatho yeentambo ze-AC kunye ne-DC kufuneka zilawulwe ngokwahlukileyo.
Ipolyethylene edityaniswe ngokunqamlezileyo (XLPE)iintambo ezigqunyiweyo zisetyenziswa ngokubanzi kwizicelo ze-AC ngenxa yeempawu zazo ezibalaseleyo ze-dielectric kunye nezomzimba, kunye nexabiso labo eliphezulu lokusebenza. Nangona kunjalo, xa zisetyenziswa njengeentambo ze-DC, zijongene nomngeni obalulekileyo onxulumene nentlawulo yendawo, ebaluleke kakhulu kwiintambo ze-DC eziphezulu. Xa iipholima zisetyenziswa njenge-DC cable ukugquma, inani elikhulu lemigibe yalapha ngaphakathi kwendawo yokugquma ibangela ukuqokelelwa kweendleko zendawo. Impembelelo yeendleko zesithuba kwizinto zokufakelwa kwezinto zibonakaliswa ikakhulu kwimiba emibini: ukugqwethwa kwentsimi yombane kunye nemiphumo yokuphazamiseka kwentsimi engeyiyo yombane, zombini ezona zinto ziyingozi kakhulu kwi-insulation material.
Intlawulo yesithuba ibhekiselele kwintlawulo engaphaya kokungathathi hlangothi kombane ngaphakathi kweyunithi yolwakhiwo lwemathiriyeli enkulu. Kwizinto eziqinileyo, iintlawulo zesithuba ezilungileyo okanye ezimbi zibotshelelwa kumanqanaba ombane asekuhlaleni, ukubonelela ngeempembelelo zepolarization ngendlela yeepolaron ezibophelelekileyo. I-Space charge polarization iyenzeka xa ii-ion zasimahla zikhoyo kwizinto zedielectric. Ngenxa yokunyakaza kwe-ion, ii-ion ezingalunganga ziqokelela kwi-interface kufuphi ne-electrode efanelekileyo, kwaye ii-ion ezintle ziqokelela kwi-interface kufuphi ne-electrode engalunganga. Kwintsimi yombane ye-AC, ukufuduka kweentlawulo ezilungileyo nezingalunganga azikwazi ukuhambisana notshintsho olukhawulezayo kwibala lombane lefrikhwensi yamandla, ngoko ke iziphumo zentlawulo yesithuba azenzeki. Kwintsimi yombane ye-DC, nangona kunjalo, intsimi yombane isasaza ngokwe-resistivity, ekhokelela ekubunjweni kweentlawulo zendawo kunye nokuchaphazela ukuhanjiswa kombane. Ukugquma kwe-XLPE kuqulethe inani elikhulu leelizwe zasekuhlaleni, okwenza iziphumo zentlawulo yesithuba zibe nzima ngakumbi.
I-XLPE yokugquma i-chemically cross-linked, yenza i-integrated cross-linked structure. Njengepolymer engeyiyo i-polar, ikhebula ngokwalo lingafaniswa ne-capacitor enkulu. Xa ukuhanjiswa kwe-DC kuyeka, kuyalingana nokutshaja i-capacitor. Nangona i-conductor core isekelwe, ukukhutshwa okusebenzayo akwenzeki, kushiya isixa esibalulekileyo samandla e-DC agcinwe kwintambo njengeentlawulo zendawo. Ngokungafaniyo neentambo zamandla e-AC, apho iintlawulo zendawo zichithwa ngenxa yelahleko ye-dielectric, ezi ntlawulo ziqokelelana kwiziphene kwintambo.
Ngokuhamba kwexesha, ngokuphazanyiswa kwamandla rhoqo okanye ukuguquguquka kumandla akhoyo, iintambo ezigqunyiweyo ze-XLPE ziqokelela iintlawulo ezininzi zesithuba, zikhawulezisa ukuguga kwe-insulation layer kunye nokunciphisa ubomi benkonzo yentambo.
Ixesha lokuposa: Mar-10-2025