Ferroresonance overvoltage? Wuhan UHV tshwj xeeb hauv kev tsim khoomseries resonance, nrog rau ntau yam khoom xaiv thiab 15 xyoo ntawm kev tshaj lij kev kuaj hluav taws xob. Thaum nrhiavseries resonance, xaiv Wuhan UHV.
Ferroresonance overvoltage yog ib qho overvoltage sab hauv uas feem ntau tshwm sim hauv kev faib khoom sib txuas uas qhov nruab nrab qhov nruab nrab tsis ncaj qha hauv av. Txawm li cas los xij, hom kev sib tsoo no kuj nquag tshwm sim nyob rau hauv siab -voltage power grids qhov twg qhov nruab nrab point yog ncaj qha grounded.
Muaj ntau ntau inductive thiab capacitive Cheebtsam nyob rau hauv lub hwj chim system. Thaum hloov lossis ua haujlwm tsis zoo, cov khoom siv hluav taws xob thiab cov khoom siv hluav taws xob no tuaj yeem tsim cov oscillation circuits nrog ntau qhov sib txawv, ua rau muaj qhov tshwm sim resonance nyob rau hauv qhov kev txiav txim ntawm ib qho hluav taws xob sab nraud thiab ua rau resonance overvoltage. Resonance feem ntau ua rau overvoltage nyob rau hauv ib feem ntawm daim phiaj hluav taws xob, uas ua rau muaj kev phom sij rau cov khoom siv hluav taws xob, txawm tias ua rau overcurrent thiab hlawv cov khoom siv, thiab tseem tuaj yeem cuam tshuam cov kev ua haujlwm ntawm cov khoom siv tiv thaiv overvoltage. Ntau hom resonant overvoltages tuaj yeem tsim nyob rau hauv cov tshuab nrog cov qib sib txawv thiab cov qauv. Resistive thiab capacitive Cheebtsam nyob rau hauv ib qho system feem ntau suav hais tias yog cov kab tsis sib xws, thaum cov khoom siv inductive feem ntau muaj peb hom kev sib txawv ntawm cov yam ntxwv. Ua raws li peb qhov inductance tsis, nyob rau hauv qee qhov kev txwv tsis pub muaj peev xwm thiab lwm yam xwm txheej, peb hom kev sib txawv ntawm qhov tshwm sim tuaj yeem tshwm sim.
1. Linear resonance: Cov inductance tsis tas li, thiab tus nqi inductance tsis hloov nrog qhov voltage lossis tam sim no ntawm cov khoom.
2. Ferroresonance: Inductive Cheebtsam nrog hlau cores yuav muaj saturation phenomenon, thiab inductance tsis tas mus li, tab sis hloov nrog cov variation ntawm tam sim no los yog sib nqus flux.
3. Parameter resonance: Inductance tsis tau hloov pauv raws li lub zog ntawm sab nraud
Cov yam ntxwv ntawm ferroresonance overvoltage:Nyob rau hauv ib txwm ua hauj lwm tej yam kev mob, lub inductive reactance nyob rau hauv lub series Circuit Court ntawm inductance thiab capacitance yog feem ntau ntau dua lub capacitive reactance. Vim muaj qee yam, qhov voltage ntawm ob qho kawg ntawm inductance nce, ua rau cov tub ntxhais hlau ntawm inductance kom saturate thiab inductive reactance txo, ua rau inductive reactance thiab capacitive reactance theem, thiab txawm inductive reactance yog me dua capacitive reactance, ua rau theem reversal thiab ferroresonance.
Yog vim li cas rau qhov tshwm sim ntawm ferromagnetic resonance
Hauv lub zog hluav taws xob, cov kab hluav taws xob dav dav tuaj yeem ua kom yooj yim rau hauv cov kab hluav taws xob sib txuas ntawm cov resistor R, inductive reactance ω L, thiab capacitive reactance 1 / ω C. Thaum qhov xwm txheej ntawm ω L =1 / ω C tshwm sim hauv Circuit Court, resonance yuav tshwm sim, thiab overvoltage thiab overcurrent yuav tshwm sim ntawm inductive Circuit Court thiab capacitive. Vim lub fact tias lub capacitance impedance ntawm Circuit Court yog qhov tseem ceeb ntawm qhov tsis tu ncua ntawm qhov zaus; Thiab inductive reactance feem ntau yog tsim los ntawm coils nrog hlau cores. Thaum qhov hluav taws xob hloov pauv tam sim ntawd, cov tub ntxhais hlau yuav sai sai saturate, thiab inductive reactance yuav txo qis thaum cov tub ntxhais hlau saturates. Yog li ntawd, resonance feem ntau tshwm sim vim qhov saturation ntawm cov tub ntxhais hlau, qhov twg ω L=1/ω C.
Cov xwm txheej rau kev tsim ferromagnetic resonance
1. Qhov nruab nrab qhov nruab nrab qhov nruab nrab tsis muaj kev paub txog ib qho -theem grounding, ib zaug -phase disconnection los yog tripping, intermittent discharge, thiab hnyav peb -theem load asymmetry.
2. Ferroresonance muaj feem xyuam rau hlau core saturation. Feem ntau, ntxov ntxov saturation ntawm lub TV hlau tub ntxhais deteriorates lub volt ampere yam ntxwv, tshwj xeeb tshaj yog thaum siv ib tug nruab nrab grounded TV nyob rau hauv ib tug nruab nrab ungrounded system.
3. Thaum lub sijhawm hloov pauv, yog tias hom kev ua haujlwm tau ua raws li cov xwm txheej resonance lossis thaum peb -theem Circuit Court breaker raug hloov tawm ntawm theem, nws yuav ua rau muaj hluav taws xob thiab qhov hloov pauv tam sim no, ua rau ferromagnetic resonance.
4. Thaum disconnecting ib tug Circuit Court breaker nruab nrog parallel capacitors, yog hais tias lub capacitance ntawm parallel capacitors phim lub inductance tsis nyob rau hauv Circuit Court TV, ferromagnetic resonance overvoltage kuj tshwm sim, ua rau cov khoom puas.
5. Tawm tswv yim thiab txiav tawm tsis muaj- thauj lub npav, kaw tam sim ntawd ntawm TA, tam sim ntawd ploj ntawm ib zaug -theem grounding, sab nraud cuam tshuam rau lub cev.
Txwv thiab tshem tawm ferromagnetic resonance overvoltage
(1) yav dhau los, txhawm rau tiv thaiv ferromagnetic resonance hauv busbars, kev ntsuas xws li tshem tawm cov kab hluav taws xob sib txuas ntawm cov hluav taws xob hluav taws xob thiab ua kom ntev ntawm cov kab khiav hauj lwm thaum lub caij tsheb npav rov qab ua haujlwm feem ntau tau coj los ntxiv rau kev txhim kho cov khoom siv tiv thaiv resonance ntawm ob sab. Hauv paus, cov kev ntsuas no tsis zoo. Lub hauv paus ua rau ferromagnetic resonance nyob rau hauv voltage transformers yog lub electromagnetic hlau core inductance ntawm lub transformer thiab lub kaw lus capacitance rau hauv av. Yog li ntawd, xaiv ib tug voltage transformer nrog zoo excitation yam ntxwv los yog siv ib tug capacitive voltage transformer yog ib tug zoo daws. Txoj hauv kev los tiv thaiv qhov no yog siv lub capacitive PT
(2) Ntxiv cov damping resistor rau qhov qhib delta winding ntawm lub tshuab hluav taws xob hluav taws xob hluav taws xob, nrog tus nqi tsis kam ntawm R ＜=0.4Xt (Xt yog qhov excitation impedance ntawm ib zaug -theem winding xam rau qhov qis voltage sab ntawm lub transformer nyob rau hauv rated kab voltage), yuav tshem tawm ntau yam harmonic resonance phenomena. Rau cov kab hluav taws xob ntawm 35KV thiab qis dua, tus nqi R feem ntau yuav tsum yog 10-100 Ω. Yog hais tias lub damping resistor txuas nrog qhib delta winding rau lub sijhawm ntev, tus nqi kuj tsis tuaj yeem tsawg dhau. Txwv tsis pub, thaum ib qho txuas ntxiv ib zaug -theem grounding txhaum tshwm sim nyob rau hauv lub kaw lus, 100V fais fab zaus xoom kab sib txuas voltage yuav tshwm sim ntawm ob qho kawg ntawm qhov qhib delta winding, ua rau transformer overload. Vim li no, nws yog qhov zoo tshaj plaws los siv cov tsis-linear resistors, uas tuaj yeem ua kom ntseeg tau tias tshem tawm cov resonance thiab ua tau raws li lub peev xwm ntawm cov transformer.
(3) Nruab ib qho av capacitor ntawm lub busbar kom ua tiav Xw/Xt ＜=0.01, kom resonance tsis tuaj yeem tshwm sim.
(4) Siv cov kev ntsuas hloov mus ib ntus, xws li siv cov kab hluav taws xob thaiv hluav taws xob, ua kom lub qhov nruab nrab ntawm qhov hloov pauv mus ib ntus, thiab siv qee cov kab lossis cov cuab yeej siv tau ua ntej. Rau 220KV rov qab tsheb npav ua haujlwm hauv qhov piv txwv yav dhau los ntawm tsab xov xwm no, txhawm rau tshem tawm cov resonance series, nws raug pom zoo tias: 1. Thaum thim rov qab lub tsheb npav, tom qab disconnecting lub tsheb npav khi hloov, qhov voltage ntawm lub tsheb npav nres yuav tsum tau kuaj tam sim kom pom tias nws yog xoom. Thaum lub tsheb npav voltage ntau dua qhov induced voltage, lub disconnected bus khi hloov yuav tsum raug kaw tam sim ntawd. Thaum lub tsheb npav resonance tsuas yog pom tom qab lub sijhawm kaw ntev, nws feem ntau tsis tso cai kaw lub npav khi hloov pauv. Hloov chaw, ib qho kev tivthaiv uas tsis muaj hluav taws xob yuav tsum raug xaiv kom tshem tawm cov resonance ntawm lub tsheb npav disconnected.