Kugadzirisa Kusarudzwa uye Kudzivirira Maitiro Ekugadzirisa e110kV Transformer Neutral Point Grounding Methods

Nhanganyaya

Mumasisitimu emagetsi ane voltage yakakwira, nzira yekuisa pasi yetransformer isina mativi chinhu chakakosha chinokanganisa kuchengetedzeka, kuvimbika, uye kugadzikana kwesisitimu. Kune masisitimu emagetsi e110kV, kusarudzwa kwenzira yekuisa pasi isina mativi kunokanganisa zvakananga mazinga ekudzivirira emidziyo, dziviriro ye overvoltage, gadziriso yekudzivirira relay, uye kuvimbika kwemagetsi. MuChina, masisitimu e110kV anowanzo shandisa a nzira yekuisa pasi inoshanda zvishoma, uko mamwe mapoinzi e transformer asina kudzika akavakirwa zvakananga asi mamwe anoramba asina kudzika, nechinangwa chekuganhurira ma "currents" e "short-circuit currents" echikamu chimwe chete uku vachidzivirira njodzi dze overvoltage.

Chinyorwa chino chinoongorora hunhu, zvakanakira, uye zvipingamupinyi zvenzira dzakasiyana dze110kV transformer neutral point grounding, chinoongorora nzira dzakanakisisa dzekudzivirira, uye chinopa mafambiro ekuvandudza mune ramangwana.

Nzira 1 Dzinokosha Dzekudzika Nzvimbo Isina Kurerekera DzemaTransformers e110kV

1.1 Kudzika Kwakananga

Kuisa pasi zvakanangazvinoreva kubatana kwakananga kwenzvimbo isina kusimba yetransformer nepasi. Nzira iyi inogadzirisa zvinobudirira kugona kwenzvimbo isina kusimba, ichivimbisa kuti panguva yekukanganisa kwepasi kwechikamu chimwe chete, kukwira kwemagetsi asina kusimba hakupfuure ka1.4 pane simba remagetsi rechikamu. Izvi zvinobatsira kudzikisa zvinodiwa zvekudzivirira michina uye kuderedza mitengo.

Zvisinei, dambudziko guru nderekuti yakakwira kwazvo imwe-phase ground fault current(kusvika zviuru zvakati wandei zveamperes), izvo zvinogona kukanganisa kugona kwecircuit breaker uye kugadzikana kwesystem. Nokudaro, grounding yakananga inowanzo shandiswa mumasystem e110kV uye voltage yakakwira uko kubviswa kwezvikanganiso nekukurumidza kunodiwa.

1.2 Kusava Nekwakasiyana-siyana

Mune hurongwa husina pasi, nzvimbo ye transformer isina kusimba inodzivirirwa kubva panyika. Kana paine kukanganisa kwepasi kwechikamu chimwe chete, simba remagetsi rinenge riri diki kwazvo (kunyanya simba remagetsi resystem), zvichiita kuti system irambe ichishanda kwenguva pfupi (kazhinji kusvika maawa maviri). Izvi zvinowedzera zvakanyanya. kuvimbika kwemagetsi.

Zvisinei, mumasisitimu asina kugarwa nevhu, zvikanganiso zvepasi zvechikamu chimwe chete zvinogona kukonzera kuti voltage yechikamu chisina kukanganisa ikwire kusvika padanho remagetsi. Kana insulation isina simba, izvi zvinogona kukonzera kuputsika, zvichikwira kuita fault yechikamu chimwe nechimwe. Pamusoro pezvo, intermittent arc grounding inogona kugadzira arc overvoltages, inosvika 3–3.5 zvakapetwa pamagetsi echikamu, zvichikonzera njodzi ku transformer insulation.

1.3 Kudzika pasi kuburikidza neSmall Impedance

Kuti pave nekuenzanisa zvakanakira nekuipira kwehurongwa hwekuisa pasi zvakananga uye husina pasi, nzira yekusimbisa impedanceinowanzoshandiswa. Izvi zvinosanganisira kugayiwa nepasi kuburikidza nekupikisa kudiki kana kuita zvishoma.

• Kudzivirira Kudiki Kudzika: Inoderedza simba remagetsi kusvika mazana emaampere, ichideredza simba remagetsi pahurongwa uku ichigonesa kushanda nekukurumidza kwekudzivirira. Nzira iyi inoderedza mavoltage zvinobudirira uye yakakodzera kune network dzinoshandisa tambo dzine ma capacitive currents makuru.
• Kudzika Kwekuita Zvidiki: Inogona kudzima capacitive current yesystem kuburikidza ne inductive current, zvichideredza mukana wekuti arc reekend itangezve. Nzira iyi inowanzoonekwa senzira yekudzika pasi yakabhadharwa.

Kuisa pasi uchishandisa small impedance kunobatanidza mabhenefiti emasystems ese ari maviri akananga neepasi, zvichipa kudzvinyirirwa kwe overvoltage uye kuvimbika kwemagetsi kwakanyanya. Inoshandiswa zvakanyanya mumasystems e110kV, kunyanya ayo ane capacitive currents akakosha kana anoda simba remhando yepamusoro.

2 Dziviriro Yekugadziriswa kwe110kV Transformer Neutral Points

2.1 Zvinotyisa zveKupfuura Mwero

Huremu hwekudzivirira hunowanikwa mu transformer ye110kV hunowanzo kuve hwakafanana ne isina kuvharwa zvakanyanya, ine chiyero chemagetsi chinomira chikamu chimwe chete muzvitatu chemugumo wemutsara. Izvi zvinoita kuti nzvimbo isina kusimba ive panjodzi yekukuvadzwa nemagetsi akawandisa. Mhando dzemagetsi akawandisa dzinosanganisira:

• Kuwedzeredza Kwesimba reMagetsi: Zvinobva pakuchinjana kwemitsara, mashort circuits asina kuenzana, kana kurasikirwa nemutoro kamwe kamwe.
• Kuwedzeredza kweResonance: Zvinokonzerwa nekutenderera kunokonzerwa nekudyidzana pakati pezvinhu zvinosimudzira uye zvinokwanisa kushanda panguva yekushanda kwesystem kana zvikanganiso.
• Kuchinja Kupfuura Mwero: Zvinobva pakushandurwa kwesimba remagineti neremagetsi panguva yekuvhurwa kana kuvharwa kwemacircuit breakers.
• Mheni Yakawandisa: Inokonzerwa nekurova kwemheni, inoratidzwa nehukuru hwakakura uye nguva pfupi.

2.2 Zvishandiso Zvinodzivirira Zvakajairika

Kudzivirira nzvimbo isina kusimba yetransformer, zvishandiso zvinotevera zvekudzivirira zvinowanzo shandiswa:

• Zvibatiso zveKukwira: Izvi zvinoderedza overvoltage yemheni uye mamwe ma switching overvoltages. Zvisinei, zvidziviriro zve surge arresters zvinowanzo shomeka pa insulation level yakaderera ye 110kV transformer neutral points, zvichiita kuti kusarudza kuve kwakaoma.
• Mapoka Ekuparadzanisa: Izvi zvinodzivirira kubva pakuwanda kwemagetsi uye kukwira kwemagetsi. Kana magetsi akawandisa, gap rinoputsika, zvichiita kuti nzvimbo isina kusimba igare pasi kuti iganhurire kukwira kwemagetsi. Dambudziko nderekuoma kwekugadzirisa daro regap, izvo zvinogona kukonzera kusawirirana kwekudzivirira.
• Kubatana Kwakafanana kweSurge Arrester neGap: Iyi inzira yekudzivirira inoshandiswa zvakanyanya. Chinodzivirira kukwira kwemagetsi chinobata overvoltage yemheni, ukuwo gap ichibata frequency yemagetsi uye resonance overvoltages. Gap iyi inodzivirirawo surge arrester kubva paovervoltage yemagetsi akawandisa anogona kukonzera kukundikana kwayo. Nzira iyi inopa zvakanakira zvakawanda.

2.3 Kugadziriswa kweDziviriro yeRelay

Dziviriro ye relay ye 110kV transformer neutral point inonyanya kusanganisira zvinhu zvinotevera:

• Dziviriro Yezvino yeZero-Sequence: Kune ma transformer akadzika pasi zvakananga, dziviriro yemagetsi isina kutevedzana yakagadzirirwa kubvisa zvikanganiso zvepasi nekukurumidza. Dziviriro inowanzo kamurwa kuita zvikamu, nekunonoka kwenguva pfupi kwenzvimbo yezvikanganiso uye kunonoka kwenguva refu kwegumburisa mativi ese e transformer.
• Dziviriro yeZero-Sequence Voltage uye Gap Current Protection: Kune ma transformer asina kugarwa, dziviriro yemagetsi ye zero-sequence uye dziviriro yemagetsi ye gap current zvinoiswa. Kana dambudziko repasi rikaita kuti sisitimu irasikirwe ne ground point yayo, zvichikonzera kukwira kwemagetsi e neutral point, gap rinoputsika. Dziviriro yemagetsi ye gap kana dziviriro yemagetsi ye zero-sequence inoshanda nekunonoka kwenguva (0.3–0.5s) kuti ikanganise transformer kumativi ese.
• Kurongeka kweDziviriro Yekuchengetedza: Kuti zvive nechokwadi chekuti sarudzo inoitwa, kunonoka kwenguva yekudzivirira kunofanira kurongeka. Semuenzaniso, kunonoka kwenguva yekudzivirira kwekuchengetedza pa transformer kunofanira kunge kwakareba kupfuura kwekudzivirira kwemutsara kwainochengetedza.

3 Mazano Ekugadzirisa uye Kuongorora Nyaya

3.1 Miganho yeNzira Dzechinyakare

Panguva iyo kushandiswa kwe zvidziviriro zvekuwedzera simba zvakaenderana nenzvimbo dzisina chinhuZvakajairika, nzira iyi ine zvikanganiso zvakawanda:

• Dambudziko muKusarudzwa kweSurge Arrester: Zvakaoma kuwana zvidziviriro zve surge zvinosangana nezvinodiwa zve high continuous operating voltage uye low lightning impulse residual voltage ye110kV transformer neutral points.
• Matambudziko muKugadzika Kwemukana: Voltage yekuputsika kwemugero wemhepo inogona kupararira, zvichiita kuti zviome kuronga mashandiro emugero nemazvo mamiriro e "kurasikirwa kwevhu" uye "nevhu".
• Kuomarara kweDziviriro yeRelay: Dziviriro kubva ku "kurasikirwa nevhu" (senge zero-sequence overvoltage uye gap overcurrent protection) inogona kusashanda zvakanaka, zvichiita kuti pave nezvimwe zvinodiwa zvekudzivirira, izvo zvinowedzera kuomarara uye zvinoderedza kuvimbika.

3.2 Mabhenefiti eGrounding kuburikidza neSmall Reactance

Tsvagiridzo nemaitiro zvinoratidza kuti kusimbisa nzvimbo isina kwayakarerekera kuburikidza nekuita kudikiine mabhenefiti makuru pane nzira dzekare dzekugadzirisa pasi:

• Zvinodiwa zveInsulation Level zvakaderedzwa: Mushure mekushandisa small reactance grounding, huwandu hwe insulation ye transformer neutral point hunogona kudzikiswa kubva pa35kV kusvika pa20kV, zvichibvisa kudiwa kwe surge arresters nemaburi uye zvichiita kuti dziviriro ive nyore.
• Nzira Yokubatanidza Yakabatana: Nzira iyi inobvisa kuitika kwehurongwa hwakaparadzana husina kugadzikwa, zvichiita kuti zvive nyore kana kuti zvisashande zvakanaka, nokudaro zvichiwedzera kuvimbika.
• Kuchengetwa Kwezvakanakira: Inochengetedza mabhenefiti ekuisa pasi zvishoma, zvakaita sekudzivirira zero-sequence kuri nyore uye kwakavimbika, ukuwo ichideredza mapfupi emagetsi echikamu chimwe chete.

3.3 Kuongorora Nyaya Yenyaya

Muenzaniso wekuchinja kwechiteshi chemagetsi che110kV. Dhizaini yekutanga yakashandisa chinhu chinodzivisa kukwira kwemhepo chakafanana nepakatiyekudzivirira nzvimbo isina kusimba. Zvisinei, mushure mekushandisa grounding small reactance, kudiwa kwe insulation level ye transformer neutral point kwakadzikira, michina yekudzivirira yakarerutswa, uye kuvimbika kwekushanda kwakawedzerwa. Kuverenga kwakaratidza kuti grounding resistance inogona kuganhurira fault current kusvika mazana mashoma amperes, uye zero-sequence dziviriro inogona kurongeka zviri nyore.

Imwe nyaya yaisanganisira kukanganisa muchiteshi chemagetsi che110kV uko kukanganisa kwepasi kwechikamu chimwe chete pamutsetse unouya kwakaita kuti pave nekukanganisika kwenzvimbo isina kusimba uye transformer igumbuke. Ongororo yakaratidza kuti kunyangwe kukanganisa kwemutsetse kwaive kwenguva pfupi, mhinduro kubva kunhamba yakawanda yemamota asina kurongekakudivi remutoro kwaipa simba re arc, zvichiramba paine dambudziko. Izvi zvinoratidza kuti kune ma transformer ane mota dzakawanda dzinorema (zvakaenzana nemanyuko), dziviriro yakakwana yenzvimbo dzisina kusimba, kusanganisira zero-sequence overcurrent, gap current, uye zero-sequence voltage dziviriro, zvakakosha panguva yekugadzira.

4 Mhedziso neMaonero

Kusarudzwa kwenzira yekudzika pasi ye110kV transformer neutral point uye marongerwo ayo ekudzivirira ibasa rine mativi akawanda rinoda kutariswa kwechimiro chesystem, hunhu hwemutoro, uye zvinodiwa zvekuvimbika. Kunyange zvazvo nzira yechinyakare yekudzika pasi isina chikamu pamwe chete nezvinodzivirira kukwira kwemhepo nemaburi zvakajairika, inosangana nematambudziko mukusarudza mudziyo uye kuronga kubatana. nzira yekudzika pasi ine reaction smallinopa imwe nzira inovimbisa, inogona kuderedza zvinodiwa zvekudzivirira kupisa, kurerutsa dziviriro, uye kuvandudza kuvimbika.

Mafambiro ebudiriro yeramangwana achatarisa pane zvinotevera:

• Kushandiswa kweMidziyo Mitsva: Zvakadai semaburi akabatanidzwa kana maburi anogona kudzoreka anoshandiswa pamwe chete nezvinodzivirira kukwira kwemvura, zvichiwedzera kuvimbika uye kururama kwekudzivirira.
• Tekinoroji yekudzivirira yedhijitari: Kushandisa dziviriro inobva kumakomputa nemaitiro epamusoro (semuenzaniso, kuzivikanwa kwewaveform, kuongorora kweharmonic) kuvandudza kunzwisisika uye kuvimbika kwekudzivirira kukanganisa kwepasi.
• Kugadzika uye Kugadzirisa: Kugadzira michina yekudzivirira ine mwero uye yakajairika kuti zvive nyore kugadzira nekugadzirisa.

Muchidimbu, kugadzirisa nzira ye110kV transformer neutral point grounding uye marongerwo ekudzivirira kwakakosha pakuvandudza kuchengetedzeka, kuvimbika, uye mashandiro ehupfumi emagetsi. Nekufambira mberi kwetekinoroji, mhinduro dzakangwara uye dzinoshanda dzinotarisirwa kubuda uye kushandiswa zvakanyanya.