Gimba na Noma da Modooyi na Reclosing Daga Zama
Yanzu, zai iya kategorize wani wurin da ke cikin wurare-raren reclosing zuwa hanyar daidai: single-phase reclosing, three-phase reclosing, composite reclosing, da disabled reclosing. Ana iya zaba da hanyar daidai mafi inganci a gaba da tushen abincin da kuma shaida na system.
1. Single-Phase Reclosing
Akwai ƙarin ɗaya na 110kV da ma ɗauke suna amfani da three-phase single-shot reclosing. Daga rayuwarsa, akwai fiye da 70% na noma daidai na short-circuit a wurin da ke cikin solidly grounded systems (110kV da ma ɗauke) su ne single-phase-to-ground faults. A wurin da 220kV da ma ɗauke, saboda kyakkyawan fase spacing, ana iya haɗa tsawon single-phase ground faults zuwa 90% daga duk noma. A wannan lokacin, ta kara daɗi daɗi da phase mai yawa ko da ya yi reclosing—da kuma biyu da shi da take daɗi da energy a lokacin reclosing—yana da muhimmanci sosai wajen samun daidaitaccen abincin abubuwa da kuma samun shaida na system. Saboda haka, single-phase reclosing yana da amfani a solidly grounded systems da 220kV da ma ɗauke.
Ana iya amfani da shi:
Wurin da ke cikin 220kV da ma ɗauke;
Wurin da ke da weak interconnection bayan biyu na masu abubuwa (da kuma electromagnetic loop networks da ke da weak connection through lower-voltage lines);
High-voltage outgoing lines daga masu steam turbine generator units masu yawa.
2. Composite Reclosing
Composite reclosing yana amfani da single-phase reclosing don single-phase-to-ground faults da three-phase reclosing don phase-to-phase faults.
Ana iya amfani da shi a wurin da ke amfani da three-phase reclosing, amma single-phase reclosing yana ba da muhimmanci a gaba da samun shaida na system ko kuma samun abincin abubuwa.
3. Three-Phase Reclosing
Three-phase reclosing yana nufin hanyar da, idan yake da single-phase ko phase-to-phase fault a wurin da ke cikin transmission ko distribution, protective relay yana kara daɗi daɗi da tripping ta hanyar da automatic reclosing device yana kara daɗi da reclosing ta hanyar da.
Wannan hanyar yana da amfani a wurin da ke da strong interconnection bayan masu abubuwa da masu abinci, ko kuma bayan biyu na masu abubuwa masu shaida.
Akawar hanyoyi da za su iya faru automatic reclosing:
I. Non-Correspondence Initiation (Position Mismatch Start)
Non-correspondence initiation yana faru idan status control ta breaker ba a tabbata da matsayinta.
Protection device yana amfani da input position ta breaker (yanayi "trip position" contact) don tabbatar matsayinta. Idan wannan input yana kasa, yana nufin cewa breaker yana kusa. Idan switch ta control yana cikin "closed" position a wannan lokacin, yana nufin cewa breaker ya kara daɗi. Wannan batuwar da ke cikin control da matsayinta yana kara daɗi da reclosing function—yanayi "position mismatch initiation."
Wannan hanyar yana iya faru reclosing don protective relay trips da kuma unintended breaker tripping ("stealth tripping").
Muhimmanci: Simple da kuma da zama.
Abubuwa: Yana iya ba da fail idan contacts ta position relay ko auxiliary breaker contacts suka ra'ayi.
II. Protection-Based Initiation
Protection-based initiation yana nufin faru reclosing process bayan protective relay yana faru trip command.
Ba ɗaya da protective trip, device yana tabbatar loss of line current da kuma faru reclosing. Yanayi, protection device yana da digital input "external trip to initiate reclosing," wanda yana ba da shiga don second protection set a dual-redundant configuration don trigger reclosing a first set.
Wannan hanyar yana taimaka wajen karin configuration reclosing, saboda software ta protection yana tabbatar fixed reclosing mode, wanda yana ba da shiga don simple da kuma da zama.
Yana iya haɗa false trips da protection maloperation ta shaida, amma bai iya haɗa unintended "stealth tripping" da circuit breaker ta shaida.
III. Summary
Protection-based initiation da non-correspondence initiation suna da amfani a gaba da shi. Modern microprocessor-based protection relays suna da amfani da biyu. Wasu designs masu yawa suna kammala external mismatch contacts da kuma suna faru reclosing directly idan, a bangaren ba da external trip command (misali, manual ko remote trip), device yana tabbatar change from "closed" to "open" position.
