Ua ntej xav txog cov txheej txheem kev tawg ntawm dielectrics, cia peb sim ua kom paub cov yam ntxwv ntawm cov ntaub ntawv no. Cov khoom siv hluav taws xob hluav taws xob yog cov khoom siv uas tso cai rau koj cais cov khoom siv hluav taws xob lossis cov khoom siv hluav taws xob uas muaj hluav taws xob sib txawv.
Cov khoom siv
Hauv kev sib piv nrog cov khoom siv hluav taws xob, cov khoom siv hluav taws xob muaj hluav taws xob ntau dua. Ib qho cuab yeej cuab tam ntawm cov ntaub ntawv no yog tsim cov hluav taws xob muaj zog, nrog rau kev sib sau ntawm lub zog. Cov cuab yeej no tau siv dav hauv cov khoom siv hluav taws xob.
Kev faib tawm
Raws li lub xeev ntawm kev sib sau ua ke, tag nrho cov khoom siv hluav taws xob insulating tau muab faib ua kua, gaseous, khoom. Qhov loj tshaj plaws yog pab pawg kawg ntawm dielectrics. Cov no suav nrog plastics, ceramics, high-polymer khoom.
Nyob ntawm cov tshuaj muaj pes tsawg leeg, cov ntaub ntawv hluav taws xob rwb thaiv tsev tau muab faib ua inorganic thiab organic.
Carbon ua raws li cov tshuaj tseem ceeb hauv cov organic insulators. Qhov kub siab tshaj plaws tiv tausCov ntaub ntawv inorganic: ceramics, mica.
Txawm li cas los xij, nyob ntawm txoj kev tau txais dielectrics, nws yog kev cai los faib lawv ua hluavtaws thiab ntuj (natural). Txhua hom muaj qee yam nta. Tam sim no, cov khoom siv hluavtaws yog ib pawg loj.
Cov khoom siv hluav taws xob dielectric ntxiv tau muab faib ua cov pawg sib cais raws li cov qauv, muaj pes tsawg leeg, cov yam ntxwv ntawm cov khoom siv. Piv txwv li, muaj wax, ceramic, ntxhia, zaj duab xis insulators.
Tag nrho cov ntaub ntawv no yog tus yam ntxwv ntawm hluav taws xob conductivity. Nyob rau tib lub sijhawm, cov tshuaj no qhia txog kev hloov pauv ntawm tus nqi tam sim no vim qhov txo qis ntawm qhov nqus tam sim no. Los ntawm ib lub sij hawm nyob rau hauv cov khoom siv hluav taws xob insulating tsuas yog ib qho conduction tam sim no, ntawm tus nqi ntawm cov khoom ntawm cov khoom no nyob ntawm seb.
txheej txheem nta
Yog tias lub zog hluav taws xob ntau dua li qhov hluav taws xob muaj zog txwv, dielectric tawg tshwm sim. Qhov no yog tus txheej txheem ntawm nws kev puas tsuaj. Nws ua rau qhov poob ntawm qhov chaw tawg los ntawm cov khoom siv ntawm nws qhov pib hluav taws xob insulating yam ntxwv.
Kev tawg hluav taws xob yog tus nqi ntawm qhov kev tawg ntawm dielectric tshwm sim.
Dielectric lub zog yog tus cwj pwm los ntawm tus nqi ntawm lub zog ntawm lub zog.
Kev tawg ntawm cov khoom dielectrics yog cov txheej txheem hluav taws xob lossis thermal. Nws yog raws li phenomena uas ua rau avalanche nce hauv cov khoom insulating ntawm tus nqihluav taws xob tam sim no.
Kev tawg ntawm cov khoom dielectrics muaj cov yam ntxwv:
- tsis muaj lossis tsis muaj zog nyob ntawm qhov kub thiab qhov hluav taws xob ntawm tus nqi conductivity;
- hluav taws xob lub zog ntawm cov khoom siv hauv qhov chaw tsis sib xws, tsis hais qhov tuab ntawm cov khoom siv dielectric siv;
- nqaim txwv ntawm txhua lub zog;
- ua ntej, qhov tam sim no nce exponentially, thiab kev tawg ntawm cov khoom dielectrics yog nrog los ntawm kev nce tam sim no;
- nyob rau hauv ib qho chaw inhomogeneous, cov txheej txheem no tshwm sim nyob rau hauv ib qho chaw nrog lub siab tshaj plaws teb zog.
Thermal breakdown
Nws tshwm sim thaum muaj qhov loj dielectric poob, thaum cov khoom siv los ntawm lwm qhov cua sov, thaum lub zog hluav taws xob tsis zoo. Xws li kev puas tsuaj ntawm dielectric yog nrog los ntawm kev nce hauv hluav taws xob tam sim no vim muaj qhov txo qis hauv qhov tsis kam nyob rau hauv qhov chaw uas muaj kev kub ntxhov. Cov txheej txheem zoo sib xws tau raug pom kom txog thaum ua tiav thermal puas ntawm dielectric tshwm sim hauv qhov chaw tsis muaj zog. Piv txwv li, thawj cov khoom siv hluav taws xob insulating yuav yaj.
Signs
Dielectric kev puas tsuaj muaj cov yam ntxwv:
- tshwm sim hauv qhov chaw tsis zoo ntawm cov cua sov tshem tawm mus rau ib puag ncig;
- breakdown voltage txo nrog nce ambient kub;
- hluav taws xob lub zog yog inversely proportional rau lub thickness ntawm dielectrictxheej.
yam ntxwv dav dav
Cia peb ua tus yam ntxwv tseem ceeb ntawm kev tawg ntawm dielectrics. Lub ntsiab lus ntawm cov txheej txheem nyob rau hauv qhov poob ntawm cov khoom siv hluav taws xob insulating ntawm nws cov yam ntxwv thaum tus nqi tseem ceeb ntawm cov hluav taws xob hluav taws xob muaj zog tshaj. Muaj ntau ntau hom txheej txheem no:
- hluav taws xob tawg ntawm dielectric;
- txheej txheem cua sov;
- electrochemical aging.
Hluav taws xob sib txawv tshwm sim los ntawm kev cuam tshuam ionization los ntawm cov hluav taws xob tsis zoo, tshwm sim hauv qhov hluav taws xob muaj zog. Cov txheej txheem no yog nrog los ntawm kev nce ntxiv ntawm qhov ceev tam sim no.
Yog vim li cas rau cov txheej txheem thermal hauv lub insulator yog qhov nce ntawm cov cua sov uas tsim los ntawm lub kaw lus vim muaj kev cuam tshuam ntawm hluav taws xob conductivity lossis los ntawm dielectric poob. Qhov tshwm sim ntawm qhov kev puas tsuaj no yog kev puas tsuaj thermal ntawm cov khoom siv hluav taws xob.
Thaum lub zog tawg ntawm dielectrics hloov pauv, kev hloov pauv tshwm sim hauv cov qauv ntawm cov khoom siv hluav taws xob, thiab cov tshuaj muaj pes tsawg leeg ntawm dielectric kuj hloov. Yog li ntawd, ib qho irreversible txo nyob rau hauv lub rwb thaiv tsev kuj yog pom. Hauv qhov no, hluav taws xob laus ntawm dielectric tshwm sim.
Nyob rau hauv nruab nrab gaseous
Kev tawg ntawm cov roj dielectrics tshwm sim li cas? Vim yog cosmic thiab hluav taws xob hluav taws xob, muaj qee qhov me me ntawm cov khoom siv hluav taws xob hauv huab cua. Muaj ib qho acceleration ntawm tsis zoo electrons nyob rau hauv lub tshav pob, vim hais tias lawv tau txais lub zog ntxiv, tus nqi ntawm cov ncaj qha nyob ntawm lub teb lub zog thiabtxhais tau tias txoj kev ntev ntawm cov khoom ua ntej kev sib tsoo. Ntawm tus nqi tseem ceeb, kev nce hauv electron txaus yog pom, uas ua rau muaj kev sib cais ntawm qhov sib txawv. Cov txheej txheem no cuam tshuam los ntawm ntau yam. Qhov tseem ceeb tshaj plaws ntawm cov no yog kev xaiv teb. Muaj kev sib raug zoo ntawm hluav taws xob lub zog ntawm cov pa roj thiab siab thiab kub.
kua nruab nrab
Qhov kev tawg ntawm cov kua dielectrics muaj feem xyuam rau qhov purity ntawm cov khoom siv hluav taws xob insulating. Muaj peb qib:
- cov ntsiab lus ntawm cov khoom siv tsis huv thiab cov dej emulsion hauv dielectric;
- kev huv si;
- muab ntxuav thiab degassed.
Hauv kev ua tib zoo ntxuav cov kua dielectric, tsuas muaj hluav taws xob hloov pauv. Vim qhov sib txawv tseem ceeb hauv qhov ntom ntom ntawm cov kua thiab roj, qhov ntev ntawm txoj kab hluav taws xob txo qis, uas ua rau muaj qhov nce ntxiv hauv qhov hluav taws xob tawg.
Hauv kev lag luam hluav taws xob niaj hnub no, kev siv cov khoom siv hluav taws xob ntshiab yog siv, tsuas yog muaj me ntsis ntawm impurities hauv lawv tau tso cai.
Nws yuav tsum raug coj mus rau hauv tus account tias txawm tias qhov tsawg kawg nkaus ntawm cov dej emulsion hauv cov kua hluav taws xob insulating cov khoom ua rau txo qis hauv hluav taws xob muaj zog.
Yog li, lub zog dielectric thiab kev tawg ntawm dielectrics yog cov muaj feem cuam tshuam. Cia peb xav txog cov txheej txheem tawg hauv cov kua nruab nrab. Cov dej emulsion yog polarized nyob rau hauv ib qho hluav taws xob teb, ces lawv poob rau hauv qhov chaw nruab nrab ntawm lub polar electrodes. Ntawm no lawv yog deformed, merged, thiab txuas hniav yog tsim,nrog me ntsis hluav taws xob tsis kam. Nws yog ntawm lawv qhov kev sim tshwm sim. Cov tsos ntawm cov txuas hniav ua rau txo qis ntawm lub zog ntawm cov roj.
Ntawm cov khoom siv hluav taws xob insulating
Cov kev txiav txim siab ntawm kev tawg ntawm cov khoom dielectrics tau pom lawv daim ntawv thov hauv kev tsim hluav taws xob niaj hnub no.
Ntawm cov kua thiab ib nrab-kua dielectric cov ntaub ntawv tam sim no siv hauv tshuab, transformer thiab capacitor roj, nrog rau cov kua hluavtaws: sovtol, sovol.
Cov roj ntxhia tau txais los ntawm cov khoom siv feem ntau ntawm cov roj crude. Nruab nrab ntawm lawv tus kheej hom muaj qhov sib txawv ntawm viscosity, hluav taws xob yam ntxwv.
Piv txwv li, cov roj cable thiab cov roj capacitor tau ua kom zoo heev, yog li lawv muaj cov yam ntxwv zoo heev. Non-flammable synthetic kua yog sovtol thiab sovol. Yuav kom tau txais thawj zaug, chlorination cov tshuaj tiv thaiv ntawm crystalline diphenyl yog nqa tawm. Cov kua nplaum pob tshab no yog cov tshuaj lom thiab tuaj yeem ua rau khaus khaus, yog li ntawd, thaum ua haujlwm nrog xws li dielectric, kev ceev faj yuav tsum tau ua tib zoo saib.
Sovtol yog ib qho sib xyaw ntawm trichlorobenzene thiab sovol, yog li cov khoom siv hluav taws xob insulating no yog tus cwj pwm los ntawm qis dua viscosity.
Ob leeg cov kua hluavtaws yog siv los ua kom cov ntaub ntawv niaj hnub no tau nruab rau hauv cov khoom siv AC thiab DC.
OrganicHigh-polymer dielectric cov ntaub ntawv yog tsim los ntawm ntau monomer molecules. Amber, roj hmab ntuj, muaj cov yam ntxwv siab dielectric.
Waxy cov ntaub ntawv xws li ceresin thiab paraffin muaj qhov sib txawv ntawm qhov sib txawv. Xws li dielectrics muaj cov qauv polycrystalline.
Nyob rau hauv niaj hnub hluav taws xob engineering, yas, uas yog cov khoom sib xyaw, yog nyob rau hauv kev thov. Lawv muaj cov polymers, resins, dyes, stabilizing cov neeg ua haujlwm, nrog rau cov khoom siv plasticizing. Raws li lawv txoj kev sib raug zoo rau cov cua sov, lawv tau muab faib ua cov khoom siv thermoplastic thiab cov khoom siv thermoset.
Rau ua haujlwm hauv huab cua, hluav taws xob cardboard yog siv, uas muaj cov qauv denser piv rau cov khoom siv.
Ntawm cov txheej txheej hluav taws xob insulating cov ntaub ntawv nrog cov yam ntxwv dielectric, peb qhia txog textolite, getinaks, fiberglass. Cov laminates no, uas siv silicone los yog resole resins ua tus khi, yog cov dielectrics zoo heev.
Cas ntawm phenomenon
Muaj ntau yam laj thawj rau kev tawg ntawm dielectrics. Yog li ntawd, tseem tsis tau muaj txoj kev xav thoob ntiaj teb uas yuav piav qhia tag nrho cov txheej txheem ntawm lub cev no. Txawm hais tias qhov kev xaiv ntawm rwb thaiv tsev, nyob rau hauv qhov kev tshwm sim ntawm kev puas tsuaj, ib tug channel ntawm tshwj xeeb conductivity yog tsim, qhov loj ntawm uas ua rau ib tug luv luv Circuit Court nyob rau hauv cov khoom siv hluav taws xob. Dab tsi yog qhov tshwm sim ntawm cov txheej txheem zoo li no? Muaj qhov tshwm sim siab ntawm qhov xwm txheej ceev, raws li qhov tshwm simCov cuab yeej hluav taws xob yuav raug muab tshem tawm.
Nyob ntawm cov txheej txheem rwb thaiv tsev, kev tawg tuaj yeem muaj qhov sib txawv. Rau cov khoom dielectrics, cov channel khaws cov conductivity tseem ceeb txawm tias tom qab qhov tam sim no raug kaw. Gaseous thiab kua hluav taws xob insulating cov ntaub ntawv yog tus cwj pwm los ntawm kev txav mus los ntawm cov khoom siv hluav taws xob. Yog li ntawd, muaj ib qho kev kho tam sim ntawd ntawm kev tawg channel vim qhov hloov pauv ntawm qhov hluav taws xob.
Hauv cov kua, kev tawg yog tshwm sim los ntawm ntau yam txheej txheem. Ua ntej, optical inhomogeneities yog tsim nyob rau hauv qhov chaw ntawm lub electrodes, nyob rau hauv cov chaw no cov kua poob nws transparency. A. Gemant txoj kev xav txiav txim siab qhov kev tawg ntawm cov kua dielectric ua ib qho emulsion. Raws li kev suav ua los ntawm cov kws tshawb fawb, vim yog qhov kev ua ntawm hluav taws xob, cov dej noo noo coj mus rau hauv daim ntawv elongated dipole. Nyob rau hauv cov ntaub ntawv ntawm ib tug siab teb lub zog, lawv ua ke, uas contributes rau cov paug nyob rau hauv lub tsim channel.
Thaum ua ntau qhov kev sim, nws pom tau tias yog muaj roj hauv cov kua, ces nrog qhov nce ntxiv hauv qhov hluav taws xob, npuas yuav tshwm sim ua ntej tawg. Nyob rau tib lub sijhawm, qhov tawg ntawm cov kua dej no txo qis nrog kev txo qis lossis nce qhov kub thiab txias.
Zoo kawg
Cov khoom siv niaj hnub dielectric tau txhim kho raws li kev lag luam hluav taws xob tsim. Tam sim no, thev naus laus zis los tsim ntau hom dielectrics tau niaj hnub ua kom tsim tau cov dielectric pheej yig nrog kev ua haujlwm siab.
NrogCov ntaub ntawv xav tau tshaj plaws nrog cov yam ntxwv sib xws yog qhov txaus siab rau iav thiab iav enamels. Kev teeb tsa, alkaline, teeb, capacitor, lwm yam ntawm cov khoom no yog cov khoom ntawm cov qauv amorphous. Thaum calcium thiab aluminium oxides ntxiv rau qhov sib tov, nws tuaj yeem txhim kho cov khoom siv hluav taws xob zoo thiab txo qhov kev pheej hmoo ntawm kev tawg.
iav enamels yog cov ntaub ntawv uas ib txheej nyias ntawm iav tso rau ntawm cov hlau nto. Cov thev naus laus zis no muab kev tiv thaiv txhim khu kev tiv thaiv corrosion.
Tag nrho cov ntaub ntawv uas muaj hluav taws xob insulating yam ntxwv yog dav siv nyob rau hauv niaj hnub technology. Yog tias dielectric tawg raug tiv thaiv raws sijhawm, nws muaj peev xwm tiv thaiv kev puas tsuaj rau cov cuab yeej kim.
