Kev Xaiv thiab Kev Tiv Thaiv Kev Teeb tsa Optimization ntawm 110kV Transformer Neutral Point Grounding Methods

Kev Taw Qhia

Hauv cov tshuab fais fab siab, txoj kev siv transformer neutral point grounding yog qhov tseem ceeb uas cuam tshuam rau kev nyab xeeb ntawm lub cev, kev ntseeg siab, thiab kev ruaj khov. Rau 110kV lub tshuab fais fab, kev xaiv txoj kev siv neutral point grounding ncaj qha cuam tshuam rau cov khoom siv rwb thaiv tsev, kev tiv thaiv overvoltage, kev teeb tsa kev tiv thaiv relay, thiab kev ntseeg siab ntawm lub zog. Hauv Suav teb, 110kV cov tshuab feem ntau siv a txoj kev grounding zoo ib nrab, qhov twg qee qhov chaw nruab nrab ntawm lub transformer raug grounded ncaj qha thaum lwm tus tseem tsis tau grounded, lub hom phiaj yog txwv cov hluav taws xob luv luv ib theem thaum tiv thaiv kev hem thawj overvoltage.

Tsab xov xwm no tshuaj xyuas cov yam ntxwv, qhov zoo, thiab cov kev txwv ntawm ntau hom 110kV transformer neutral point grounding methods, tshawb nrhiav cov tswv yim teeb tsa kev tiv thaiv zoo tshaj plaws, thiab nthuav qhia cov qauv kev loj hlob yav tom ntej.

1 Txoj Kev Siv Av Neutral Point Tseem Ceeb rau 110kV Transformers

1.1 Kev Sib Txuas Lus Ncaj Qha

Kev sib txuas ncaj qhahais txog kev txuas ncaj qha ntawm lub transformer neutral point rau lub ntiaj teb. Txoj kev no kho tau qhov neutral point potential, kom ntseeg tau tias thaum muaj ib theem av fault, qhov voltage theem tsis yog fault tsis tshaj 1.4 npaug ntawm qhov voltage theem. Qhov no pab txo cov kev xav tau rwb thaiv tsev ntawm cov khoom siv thiab txo cov nqi.

Txawm li cas los xij, ib qho tseem ceeb drawback yog qhov tsis zoo ntawm cov khoom siv. tam sim no ua txhaum av ib theem siab heev(txog li ntau txhiab amperes), uas tuaj yeem cuam tshuam rau lub peev xwm cuam tshuam ntawm lub tshuab hluav taws xob thiab kev ruaj khov ntawm lub kaw lus. Yog li ntawd, kev sib txuas ncaj qha feem ntau yog siv rau hauv 110kV thiab cov kab ke hluav taws xob siab dua uas xav tau kev tshem tawm qhov txhaum sai.

1.2 Tsis Muaj Av Nruab Nrab

Hauv ib qho lub cev tsis muaj zog, qhov chaw nruab nrab ntawm lub transformer raug rwb thaiv tsev los ntawm lub ntiaj teb. Thaum muaj qhov txhaum hauv av ib theem tshwm sim, qhov txhaum tam sim no me me heev (feem ntau yog lub kaw lus capacitive tam sim no), uas tso cai rau lub kaw lus txuas ntxiv ua haujlwm rau lub sijhawm luv luv (feem ntau txog li 2 teev). Qhov no ua rau muaj kev txhim kho zoo heev kev ntseeg tau ntawm kev muab hluav taws xob.

Txawm li cas los xij, hauv cov kab ke tsis muaj av, qhov txhaum av ib theem tuaj yeem ua rau qhov hluav taws xob tsis muaj qhov txhaum nce mus rau qib hluav taws xob ntawm kab. Yog tias lub rwb thaiv tsev tsis muaj zog, qhov no yuav ua rau tawg, nce mus rau qhov txhaum theem-rau-theem. Tsis tas li ntawd, kev sib txuas lus arc grounding tuaj yeem tsim arc overvoltages, ncav cuag 3–3.5 npaug ntawm qhov voltage theem, ua rau muaj kev hem thawj rau kev rwb thaiv tsev transformer.

1.3 Kev sib txuas lus hauv av ntawm qhov me me Impedance

Yuav kom sib npaug qhov zoo thiab qhov tsis zoo ntawm kev sib txuas ncaj qha thiab cov kab ke tsis muaj av, qhov txoj kev grounding impedancefeem ntau siv. Qhov no suav nrog kev sib txuas lus los ntawm kev tiv thaiv me me lossis kev tiv thaiv me me.

• Kev Tiv Thaiv Me Me Hauv AvTxwv qhov tam sim no txhaum rau ntau pua amperes, txo qhov cuam tshuam rau lub kaw lus thaum tseem ua kom muaj kev ua haujlwm tiv thaiv sai. Txoj kev no tswj hwm overvoltages zoo thiab tsim nyog rau cov tes hauj lwm faib khoom siv cable-intensive nrog cov tam sim no capacitive loj.
• Kev Ua Av Me Me: Muaj peev xwm them rov qab rau lub kaw lus capacitive tam sim no los ntawm inductive tam sim no, txo qhov yuav tshwm sim ntawm arc reignition. Txoj kev no feem ntau suav hais tias yog txoj kev them rov qab grounding.

Kev siv av los ntawm impedance me me ua ke cov txiaj ntsig ntawm ob qho tib si ncaj qha thiab tsis muaj av, muab kev tiv thaiv overvoltage thiab kev ntseeg siab ntawm kev muab hluav taws xob. Nws yog siv dav hauv 110kV systems, tshwj xeeb tshaj yog cov uas muaj cov capacitive currents loj lossis xav tau lub zog zoo.

2 Kev Teeb Tsa Tiv Thaiv rau 110kV Transformer Neutral Points

2.1 Kev hem thawj ntawm kev siv hluav taws xob ntau dhau

Qib rwb thaiv tsev ntawm 110kV transformer neutral point feem ntau yog semi-insulated, nrog rau qhov ntsuas voltage uas tsuas yog ib feem peb ntawm qhov kawg ntawm kab. Qhov no ua rau qhov nruab nrab tsis yooj yim rau kev puas tsuaj overvoltage. Cov hom overvoltage tseem ceeb suav nrog:

• Lub zog zaus overvoltage: Tshwm sim los ntawm kev hloov kab, cov voj voog luv luv tsis sib xws, lossis kev poob ntawm qhov thauj khoom sai sai.
• Resonance OvervoltageUa rau muaj kev co vim yog kev sib cuam tshuam ntawm cov khoom inductive thiab capacitive thaum lub sijhawm ua haujlwm lossis ua yuam kev ntawm lub kaw lus.
• Kev Hloov Pauv Overvoltage: Tshwm sim los ntawm kev hloov pauv ntawm lub zog sib nqus thiab electrostatic thaum lub sijhawm qhib lossis kaw ntawm cov circuit breakers.
• Xob laim overvoltageUa rau muaj xob laim, uas muaj qhov loj thiab lub sijhawm luv.

2.2 Cov Khoom Siv Tiv Thaiv Feem Ntau

Yuav kom tiv thaiv tau qhov transformer neutral point, cov khoom siv tiv thaiv hauv qab no feem ntau siv:

• Cov Khoom Siv Tiv Thaiv SurgeCov no txwv tsis pub xob laim overvoltage thiab qee qhov kev hloov pauv overvoltages. Txawm li cas los xij, cov khoom siv tiv thaiv hluav taws xob feem ntau tsis txaus rau qib rwb thaiv tsev qis ntawm 110kV transformer neutral points, ua rau kev xaiv nyuaj.
• Qhov Sib Txawv Ntawm Kev Cais TawmCov no tiv thaiv tau qhov zaus fais fab thiab qhov resonance overvoltages. Thaum muaj overvoltage, qhov sib txawv tawg, thiab grounding qhov nruab nrab kom txwv tsis pub voltage nce. Qhov tsis zoo yog qhov nyuaj hauv kev kho qhov deb ntawm qhov sib txawv, uas tuaj yeem ua rau kev tiv thaiv tsis sib haum.
• Kev Sib Txuas Sib Npaug ntawm Surge Arrester thiab GapQhov no yog ib txoj kev tiv thaiv uas siv dav heev. Lub cuab yeej tiv thaiv hluav taws xob surge arrester tswj tau hluav taws xob overvoltage, thaum qhov sib txawv ntawm qhov sib txawv ntawm lub zog zaus thiab resonance overvoltages. Qhov sib txawv kuj tiv thaiv lub cuab yeej tiv thaiv hluav taws xob surge arrester ntawm qhov sib txawv ntawm lub zog zaus overvoltages uas yuav ua rau nws tsis ua haujlwm. Txoj hauv kev no muab cov txiaj ntsig zoo sib xws.

2.3 Kev Teeb tsa Kev Tiv Thaiv Relay

Kev tiv thaiv relay rau 110kV transformer neutral point feem ntau suav nrog cov hauv qab no:

• Kev Tiv Thaiv Tam Sim No Zero-SequenceRau cov transformers uas ncaj qha grounded, kev tiv thaiv tam sim no xoom-sequence tau teeb tsa kom tshem tawm cov teeb meem hauv av sai sai. Kev tiv thaiv feem ntau yog muab faib ua ntu, nrog rau lub sijhawm luv luv rau qhov chaw txhaum thiab lub sijhawm ntev dua rau kev tripping txhua sab ntawm lub transformer.
• Kev Tiv Thaiv Voltage Zero-Sequence thiab Kev Tiv Thaiv Tam Sim NoRau cov transformers uas tsis muaj av, kev tiv thaiv hluav taws xob xoom-sequence thiab kev tiv thaiv tam sim no sib txawv raug teeb tsa. Thaum qhov txhaum av ua rau lub kaw lus poob nws qhov taw tes hauv av, ua rau qhov hluav taws xob nruab nrab nce siab, qhov sib txawv tawg. Kev tiv thaiv tam sim no sib txawv lossis kev tiv thaiv hluav taws xob xoom-sequence ua haujlwm nrog lub sijhawm ncua (0.3–0.5s) kom ua rau lub transformer mus rau txhua sab.
• Kev Sib Koom Tes Tiv Thaiv Kev Thaub QabYuav kom paub tseeb tias muaj kev xaiv, yuav tsum muaj kev sib koom tes rau lub sijhawm qeeb ntawm kev tiv thaiv xoom. Piv txwv li, lub sijhawm qeeb rau kev tiv thaiv thaub qab ntawm lub transformer yuav tsum ntev dua li ntawm txoj kab tiv thaiv uas nws thaub qab.

3 Cov Lus Qhia Txog Kev Txhim Kho thiab Kev Tshawb Fawb Txog Cov Neeg Mob

3.1 Cov Kev Txwv ntawm Cov Txheej Txheem Ib Txwm

Thaum siv cov cov khoom siv tiv thaiv kev co uas sib luag nrog qhov sib txawvyog ib txwm muaj, txoj hauv kev no muaj ntau qhov tsis zoo:

• Qhov nyuaj ntawm kev xaiv Surge ArresterNws yog ib qho nyuaj rau nrhiav cov khoom siv tiv thaiv hluav taws xob uas ua tau raws li qhov yuav tsum tau ua ntawm ob qho tib si high-continuous operating voltage thiab low lightning impulse residual voltage rau 110kV transformer neutral points.
• Cov Teeb Meem Hauv Qhov Chaw Sib Txawv: Qhov hluav taws xob tawg ntawm qhov sib txawv ntawm huab cua yog qhov sib kis, ua rau nws nyuaj rau kev sib koom ua haujlwm ntawm qhov sib txawv rau "kev poob av" thiab "nrog av" qhov txhaum.
• Qhov nyuaj ntawm kev tiv thaiv RelayKev tiv thaiv "kev poob av" (xws li xoom-sequence overvoltage thiab gap overcurrent protection) tej zaum yuav ua haujlwm tsis zoo, ua rau muaj cov qauv thaiv ntxiv, uas ua rau muaj kev nyuaj siab thiab txo qhov kev ntseeg siab.

3.2 Cov txiaj ntsig ntawm kev sib txuas hauv av los ntawm kev ua haujlwm me me

Kev tshawb nrhiav thiab kev xyaum qhia tias grounding lub neutral point ntawm ib qho me me reactancemuaj cov txiaj ntsig zoo dua li cov txheej txheem av ib nrab ib txwm muaj:

• Cov Kev Xav Tau Qib Rwb Thaiv Tsev TxoTom qab siv cov reactance grounding me me, qib rwb thaiv tsev ntawm qhov nruab nrab ntawm lub transformer tuaj yeem txo qis los ntawm 35kV mus rau 20kV, tshem tawm qhov xav tau cov khoom ntes hluav taws xob thiab qhov sib txawv thiab ua kom yooj yim rau kev teeb tsa kev tiv thaiv.
• Hom Kev Sib Koom Ua Ke Hauv AvTxoj kev no tshem tawm qhov tshwm sim ntawm ib lub kaw lus tsis muaj av, tso cai rau kev yooj yim lossis tsis suav nrog kev tiv thaiv cuam tshuam, yog li txhim kho kev ntseeg siab.
• Kev Khaws Cia Cov Txiaj NtsigNws tswj cov txiaj ntsig ntawm kev sib txuas ib nrab, xws li kev tiv thaiv xoom-sequence yooj yim thiab txhim khu kev qha, thaum txwv cov hluav taws xob luv luv ib theem.

3.3 Kev Tshawb Fawb Txog Cov Ntaub Ntawv

Ib qho piv txwv yog kev hloov pauv chaw nres tsheb 110kV. Tus qauv tsim thawj zaug siv a lub tshuab ntes hluav taws xob sib luag nrog qhov sib txawvrau kev tiv thaiv qhov chaw nruab nrab. Txawm li cas los xij, tom qab txais yuav qhov me me reactance grounding, qhov xav tau ntawm qib rwb thaiv tsev ntawm qhov chaw nruab nrab ntawm lub transformer tau txo qis, cov khoom siv tiv thaiv tau yooj yim dua, thiab kev ntseeg siab ua haujlwm tau zoo dua. Kev suav qhia tau hais tias qhov kev tiv thaiv av tuaj yeem txwv qhov txhaum tam sim no rau ob peb puas amperes, thiab kev tiv thaiv xoom-sequence tuaj yeem sib koom ua ke tau yooj yim.

Muaj lwm qhov teeb meem uas cuam tshuam txog qhov teeb meem hauv 110kV substation qhov twg qhov teeb meem av ib theem ib ntus ntawm txoj kab nkag mus ua rau qhov sib txawv ntawm qhov nruab nrab tawg thiab transformer tripping. Kev tshuaj xyuas qhia tau hais tias txawm hais tias qhov teeb meem ntawm txoj kab yog ib ntus, qhov cov lus tawm tswv yim los ntawm ntau tus lej ntawm cov asynchronous motorsntawm sab thauj khoom muab lub zog rau lub arc, txhawb nqa qhov txhaum. Qhov no qhia tau tias rau cov transformers nrog cov khoom siv loj ntawm lub cev muaj zog (qhov sib npaug), kev tiv thaiv qhov nruab nrab tag nrho, suav nrog xoom-sequence overcurrent, gap current, thiab xoom-sequence voltage tiv thaiv, yog qhov tseem ceeb thaum lub sijhawm tsim.

4 Xaus Lus thiab Kev Cia Siab

Kev xaiv ntawm 110kV transformer neutral point grounding txoj kev thiab nws cov kev teeb tsa kev tiv thaiv yog ib txoj haujlwm ntau yam uas yuav tsum tau xav txog cov qauv ntawm lub kaw lus, cov yam ntxwv ntawm kev thauj khoom, thiab cov kev xav tau kev ntseeg siab. Txawm hais tias txoj kev ib feem ntawm av ib txwm muaj ua ke nrog cov khoom siv surge arresters thiab qhov sib txawv yog qhov tshwm sim, nws ntsib teeb meem hauv kev xaiv cov cuab yeej thiab kev teeb tsa kev sib koom tes. txoj kev av me me reactancemuab lwm txoj hauv kev zoo, uas yuav txo qhov yuav tsum tau rwb thaiv tsev, ua kom yooj yim rau kev tiv thaiv, thiab txhim kho kev ntseeg tau.

Cov qauv kev loj hlob yav tom ntej yuav tsom mus rau cov hauv qab no:

• Kev Siv Cov Khoom Siv TshiabXws li cov qhov sib xyaw ua ke lossis cov qhov sib xyaw uas tswj tau siv ua ke nrog cov khoom siv tiv thaiv hluav taws xob, txhim kho kev ntseeg siab thiab kev raug ntawm kev tiv thaiv.
• Kev Siv Tshuab Tiv Thaiv DigitalSiv kev tiv thaiv raws li microcomputer nrog cov algorithms siab heev (piv txwv li, kev txheeb xyuas waveform, kev tshuaj xyuas harmonic) los txhim kho qhov rhiab heev thiab kev ntseeg tau ntawm kev tiv thaiv qhov txhaum hauv av.
• Kev Tsim Kho thiab Kev Hloov KhoTsim cov khoom siv tiv thaiv cov ntsiab lus nruab nrab uas tau teeb tsa thiab modular kom yooj yim rau kev tsim qauv thiab kev saib xyuas.

Hauv kev xaus lus, kev ua kom zoo dua ntawm 110kV transformer neutral point grounding method thiab kev teeb tsa kev tiv thaiv yog qhov tseem ceeb rau kev txhim kho kev nyab xeeb, kev ntseeg siab, thiab kev ua haujlwm ntawm lub zog fais fab. Nrog rau kev nce qib ntawm thev naus laus zis, cov kev daws teeb meem ntse thiab ua haujlwm tau zoo dua yuav tshwm sim thiab tau txais kev siv dav dav.