Kugawa kwa mphamvu zamagetsi mu zingwe za AC ndi kofanana, ndipo cholinga cha zipangizo zotetezera mawaya chimakhala pa chokhazikika cha dielectric, chomwe sichimakhudzidwa ndi kutentha. Mosiyana ndi zimenezi, kugawa mphamvu zamagetsi mu zingwe za DC kumakhala kwakukulu mkati mwa chotetezera ndipo kumakhudzidwa ndi kukana kwa zinthu zotetezera mawaya. Zipangizo zotetezera mawaya zimakhala ndi kutentha kotsika, zomwe zikutanthauza kuti pamene kutentha kukukwera, kukana kumachepa.
Pamene chingwe chikugwira ntchito, kutayika kwa ma core kumapangitsa kutentha kukwera, zomwe zimapangitsa kuti resistivity ya zinthu zotetezera kutentha isinthe. Izi zimapangitsa kuti mphamvu yamagetsi mkati mwa chinthu chotetezera kutentha isinthe. Mwanjira ina, chifukwa cha makulidwe omwewo a zinthu zotetezera kutentha, mphamvu yamagetsi imachepa pamene kutentha kukukwera. Pa mizere ya DC trunk m'malo opangira magetsi ogawidwa, kuchuluka kwa kukalamba kwa zinthu zotetezera kutentha kumakhala kofulumira kwambiri chifukwa cha kusinthasintha kwa kutentha kwa malo poyerekeza ndi zingwe zobisika, zomwe ndizofunikira kuziganizira.
Pakupanga zigawo zotetezera mawaya a chingwe, zinthu zosafunika zimalowetsedwa mosalekeza. Zinthu zosafunikazi zimakhala ndi mphamvu zochepa zotetezera mawaya ndipo zimagawidwa mosagwirizana motsatira njira yozungulira ya gawo lotetezera mawaya. Izi zimapangitsa kuti mphamvu zosiyanasiyana zotetezera mawaya zikhale zosiyana m'malo osiyanasiyana. Pansi pa mphamvu ya DC, mphamvu yamagetsi mkati mwa gawo lotetezera mawaya zimasiyananso, zomwe zimapangitsa kuti madera omwe ali ndi mphamvu zochepa zotetezera mawaya azikalamba msanga ndikukhala malo omwe angathe kulephera.
Zingwe za AC siziwonetsa izi. Mwachidule, kupsinjika kwa zipangizo za chingwe cha AC kumagawidwa mofanana, pomwe mu zingwe za DC, kupsinjika kwa kutenthetsa nthawi zonse kumakhala kofooka kwambiri. Chifukwa chake, njira zopangira ndi miyezo ya zingwe za AC ndi DC ziyenera kuyendetsedwa mosiyana.
Polyethylene yolumikizidwa ndi mtanda (XLPE)Zingwe zotetezedwa zimagwiritsidwa ntchito kwambiri mu ntchito za AC chifukwa cha makhalidwe awo abwino a dielectric ndi physical, komanso chiŵerengero chawo cha mtengo wapatali ndi magwiridwe antchito. Komabe, zikagwiritsidwa ntchito ngati zingwe za DC, zimakumana ndi vuto lalikulu lokhudzana ndi mphamvu ya malo, zomwe ndizofunikira kwambiri mu zingwe za DC zokhala ndi mphamvu yamagetsi yambiri. Pamene ma polima amagwiritsidwa ntchito ngati mphamvu ya chingwe cha DC, misampha yambiri yomwe ili mkati mwa gawo lotetezedwa imayambitsa kusonkhanitsa mphamvu ya malo. Zotsatira za mphamvu ya malo pa zipangizo zotetezera magetsi zimaonekera makamaka m'mbali ziwiri: kusokonezeka kwa mphamvu yamagetsi ndi zotsatira za kusokonezeka kwa mphamvu yamagetsi, zomwe zonsezi zimawononga kwambiri mphamvu ya zinthu zotetezera magetsi.
Kulipira kwa malo kumatanthauza kulipira kochulukirapo kupitirira kusagwirizana kwa magetsi mkati mwa gawo la kapangidwe ka chinthu cha macroscopic. Mu zolimba, ma positive kapena negative space charges amamangiriridwa ku mphamvu zomwe zili m'malo osiyanasiyana, zomwe zimapangitsa kuti polarization ichitike mu mawonekedwe a ma bound polarons. Kulipira kwa malo kumachitika pamene ma free ion ali mu dielectric material. Chifukwa cha kayendedwe ka ma ion, ma negative ion amasonkhana pa interface pafupi ndi positive electrode, ndipo ma positive ion amasonkhana pa interface pafupi ndi negative electrode. Mu AC electric field, kusamuka kwa ma positive ndi negative charges sikungagwirizane ndi kusintha kwachangu kwa mphamvu yamagetsi, kotero zotsatira za space charge sizimachitika. Komabe, mu DC electric field, electric field imagawidwa malinga ndi resistivity, zomwe zimapangitsa kuti ma space charges apangidwe ndikukhudza kugawa kwa electric field. XLPE insulation ili ndi ma localized states ambiri, zomwe zimapangitsa kuti space charge ichitike kwambiri.
Kuteteza kwa XLPE kumalumikizidwa ndi mankhwala osiyanasiyana, zomwe zimapangitsa kuti pakhale kapangidwe kogwirizana. Monga polima yopanda polar, chingwecho chingathe kuyerekezedwa ndi capacitor yayikulu. Pamene kutumiza kwa DC kuima, kuli ngati kuyitanitsa capacitor. Ngakhale kuti pakati pa conductor pali pansi, kutulutsa bwino sikumachitika, zomwe zimasiya mphamvu zambiri za DC zomwe zimasungidwa mu chingwecho ngati ma space charge. Mosiyana ndi ma AC power cables, komwe ma space charges amachotsedwa kudzera mu dielectric loss, ma charges awa amasonkhana pa zolakwika zomwe zili mu chingwecho.
Pakapita nthawi, chifukwa cha kusokonekera kwa mphamvu kapena kusinthasintha kwa mphamvu yamagetsi, zingwe zotetezedwa za XLPE zimasonkhanitsa mphamvu zambiri za malo, zomwe zimapangitsa kuti chotetezera kutentha chikhale chokalamba komanso kuchepetsa nthawi yogwira ntchito ya chingwecho.
Nthawi yotumizira: Mar-10-2025