چەندین جۆر و مەسەلەی ئاسایییەکانی دەرئاپێچەکانی بەرز بیتەوەرە؟

Bênraşîna bêhêranî ya dana biha navenda ji sereke yên rêzeyên elektrîkî ye. Deterioration di şertên operasyonan de yên switchgear û yek ji ser pir pêcanên serekan yên çûnekên rêzeyên elektrîkî ye. Dema ku, çi wan divê nan çûnekên herî çimkîn yên switchgear-ê bêhêranî?

I. Klasifikasyona Switchgear-ê Bêhêranî

(1) Çeşdanên Derveyî û Nederveyî

Li gorî şertnameyên cihêdan, switchgear-ê bêhêranî li dervey û nederveyî çeşd kirin. Switchgear-ê nederveyî li ser rêzeyên 10 kV û yê din jêr hêvi hatin. Li gorî çevên primîr, wan dikarin ve wekî switchgear-ê gire/dergir, switchgear-ê tie oil, switchgear-ê bus section, û waniyê ve bernamekirin. Li switchgear-ê gire/dergir 10 kV, circuit breakers-ê oil-immersed û vacuum tevger hatin. Wan circuit breakers ên hevalbendîn mekanizman spring-operated û electromagnetic ne, lê hêndike werger û permanent magnet mekanizman bikar hin. Jî tiştên switchgear-ê vêjîn di structur de girîng jêrind, ku heta jêrindiyekan sensor û cihêdan.

(2) Çeşdanên Fixed û Withdrawable

Li gorî karberdariyê, switchgear-ê bêhêranî li fixed û withdrawable (draw-out) çeşd kirin. Di demên kevn de, power plants withdrawable switchgear-ê ji bo systemên station service zafirand, lê fixed types li ser utility power supply systems çimkîn hatin. Bi peşindayi teknolojî û çêkirina çend productên nû, malperên tradîsyonal hatin guherandin. Mînasa, metal-clad withdrawable switchgear ji fixed switchgear-ê konvansyonel hatiye evolûsyon kirin. Vê tîpa ji designa fully enclosed ve taybetmend û compartments-ê functionally separated hatiye. Ev operasyonan serparast, interlocking against misoperation, maintenance, û reliability-ê operasyonan serkerd hatiye.

(3) Developementa Switchgear-ê Bêhêranî

Di demên kevn de, bi developement û widespread adoptiona compact vacuum circuit breakers, medium-mounted switchgear (ji bilavê switchgear with circuit breakers mounted in the middle compartment) li ser tîpa nûya metal-enclosed, armored, withdrawable switchgear piştiye. Medium-mounted switchgear zafiratin ziyan, herî girîng miniaturization of the draw-out unit û mechanization of manufacturing processes, ku precision-ê trolley û guide rail fabrication girîng kirin.

Hêndike manufactureran trolley (including the main circuit breaker) û switchgear cabinet separately shipment dikin, ku on-site assembly û commissioning bê problem e û smooth insertion û withdrawal garantibin. Ji bo interchangeability-ê xweş, performance li ser floor conditions-ê uneven site biguherne. Tîpa metal-clad withdrawable switchgear-ê ev safe, reliable operation û convenient maintenance zafirat, ku li ser power supply systems piştiye.

II. Analiza Common Faults-ê li Switchgear-ê Bêhêranî

Analiza fault-ê dîsa ku most switchgear failures ji insulation, conduction, û mechanical issues re hatine.

(1) Failure to Operate or Maloperation

Ev herî çimkîn fault-ê li switchgear-ê bêhêranî ye, ji du kategorî re hatine. Yekem mechanism-ê mechanical failure û transmission system, mînasa mechanism jamming, component deformation, displacement û damage, loose û stuck tripping/closing solenoids, broken û loose pins, û latch failure. Duwanjin electrical control û auxiliary circuits, including poor contact in secondary wiring, loose terminals, incorrect wiring, burned-out closing/tripping coils (due to mechanism jamming û faulty selector switches), inflexible auxiliary switch operation, û failures in control power supplies, closing contactors, û limit switches.

(2) Switching and Closing Failures

Ev faults ji circuit breaker-ê xwe re hatine. Li oil-immersed circuit breakers, common issues include oil spraying during short circuits, arc chamber damage, insufficient breaking capacity, û explosions during closing. Li vacuum circuit breakers, typical problems are vacuum interrupter û bellows leakage, reduced vacuum level, restriking when switching capacitor banks, û ceramic housing fractures.

(3) Insulation Failures

Insulation performance involves balancing various voltages (including normal operating voltage û transient overvoltages), protective measures (e.g., surge arresters), û insulation strength to achieve a safe û economical design. Insulation faults mainly manifest as: external insulation flashover-to-ground, internal insulation flashover-to-ground, phase-to-phase flashover, lightning overvoltage flashover, flashover, pollution flashover, puncture û explosion of porcelain û capacitor bushings, insulator post flashover, û flashover, puncture, û explosion of current transformers (CTs), as well as porcelain insulator fractures.

(4) Current-Carrying Faults

Li switchgear-ê rated 7.2–12 kV, primary cause of current-carrying faults is poor contact at the isolation stabs, leading to overheating û melting of contacts.

(5) External Forces û Other Faults

Ev include impacts from foreign objects, natural disasters, short circuits caused by small animals, û other unpredictable external û accidental faults.