Me Kari Daga Zaka Aikata Vacuum Circuit Breaker Ta Samu Rarraba? Tabbacin Masana'antu Na Ƙasa An Rufinƙa

Za Gwargwar Yadda Yake Mata Cikin Vacuum Interrupter?

Idan vacuum interrupter ya gama da mata, yawancin hanyoyi masu amfani a cikin yadda ake bukata:

• Yadda ake bukata abubuwa

• Amfani da rike

• Tana ci gaba da kuma tana amfani

• Yadda ake bukata da kuma yadda ake magance ruwan tsari na biyu

• Yadda ake bukata da kuma yadda ake magance ruwan tsari na biyar

Hanyoyin a, b, da c suna da muhimmanci. A wasu hanyoyi, al'adun da ke ciki ba za su iya sakamakon mata.

Amma, hanyoyin d da e suna da kyau don bayyana.

Saka ma neman cewa vacuum circuit breaker tana da fadin uku ta fitar da mata a fadin baya. Idan abin da ke amfani da shi shine delta-connected (ba da zafi), amfani da shi ba za su iya haifar da wani abu. Kowane wani abu ba za su faru. Fadin biyu (misali, Fadin 1 da Fadin 2) suna da amfani da shi, kuma fadin da ke da mata (Fadin 3) ya yi tasirin da ba za su faru.

Wani halayen da ke faru a kansu da zafi. A wannan hali, amfani da fadin biyu ba za su iya daya da ruwan tsari a fadin da ke da mata. Tsabta ta kasance a Fadin 3 kafin ya yi tasirin da ba za su faru, kuma wannan ruwan tsari ya ci gaba har zuwa lokacin da backup protection ya yi amfani. Amma, mukalafin da ke faru shine da karamin lalace da ke faru a cikin breaker.

Saboda haka, vacuum circuit breakers a 3–15 kV range suna da amfani da ground systems, tunan yi bayyana game da yadda ake faru a matsayin labarin bayyana a makarantun labarin da muna. Tunan yi amfani da vacuum interrupter da ke mata a cikin atmospheric pressure ("flattened" it) kuma tunan yi amfani da shi a cikin full short-circuit interruption test.

Kamar yadda aka neman, "flat" interrupter ba su iya daya da fault a fadin da ke faru kuma ya faru. Laboratory backup breaker ya yi amfani da shi da kuma ya daya da fault.

Ba da damar labari, breaker ya fito daga switchgear cell. Ya faru da soot amma ya faru da yanayin da ke faru. Smoke da soot an yi sauke da shi, unit da ke faru an kawo, kuma breaker ya zama da cikin compartment. Ba da damar ranar, ana yi wani short-circuit test—da nasara. Shekarun da suka faru ne sun bayyana labarin da aka samu a cikin labarin.

Daga cikin customers, chemical company mai yawa, an samu isolated failures a wasu circuit configurations (wanda maye air-magnetic breaker, wanda maye vacuum breaker) a wasu countries. Duka suna da common circuit configuration da failure mode: tie circuit inda power sources a duk biyu suna da amfani a biyu, wanda ke faru da kadan rated voltage across the contact gap. Wannan ne ke faru da breaker.

Failures waɗannan sun faru saboda application conditions da ke faru da ANSI/IEEE guidelines da kuma faru da kadan design ratings. Bana da wani abu da ke faru da design flaw. Amma, yadda ake faru shine da karamin lalace:

• A air-magnetic breaker case, enclosure ya faru da karamin lalace. Switchgear cells a duk biyu suna da amfani, wanda ke faru da reconstruction. Breaker ya faru da kadan.

• A vacuum breaker case, failure ya faru da kadan lalace. Faulty vacuum interrupter an kawo, arc byproducts (soot) an sauke da shi, kuma system ya zama da cikin amfani.

Labarin da muna samu a makarantun labarin, inda muna yi amfani da vacuum interrupters da ke faru, sun bayyana labarin da aka samu a cikin real-world results.

Jinkiri, several high-power tests an yi a makarantun labarin don bayyana yadda ake faru da "leaking" vacuum interrupters. An yi hole (~3 mm diameter) a cikin housing don bayyana vacuum loss. Results ne sun faru da karamin lalace:

• A 1,310 A normal current (rated continuous current: 1,250 A) an yi amfani da vacuum breaker. Ruwan tsari ya ci gaba a "faulty" breaker har zuwa 2.06 seconds inda lab backup breaker ya daya da fault. Ba wani abu ba ta faru, breaker ba ta faru, kuma only paint on the interrupter housing ya faru. Ba wani abu ba ta faru.

• Pole biyu a cikin breaker an yi amfani da 25 kA (rated breaking current: 25 kA). Arc ya ci gaba 0.60 seconds inda lab breaker ya daya da fault. Arc ya faru da hole a side of the interrupter housing. Ba explosion ba, ba flying debris ba. Glowing particles an faru daga hole, amma ba mechanical components ba, ba adjacent breakers ba ta faru. Duka damage ne ya faru a failed interrupter.

Tests waɗannan sun bayyana cewa consequences of a vacuum interrupter failure sun faru da kadan lalace compared to failures in other interrupting technologies.

Amma, tambayar da ta fi yawa ce ba what happens when it fails, amma how likely is it to fail?

Vacuum interrupter failure rates sun faru da kadan. Vacuum loss ba ta faru a yanzu.

A farkon 1960s, vacuum interrupters suna da amfani da leaks—wanda ke faru da abu. Early designs suna amfani da brazed or welded joints between dissimilar materials, ba da organic materials. Handcrafting suna da amfani, especially with borosilicate glass insulators, wanda ba su iya faru da high temperatures.

A yanzu, machine welding and batch induction furnace brazing suna da amfani da extremely strict process controls. The only moving part inside a vacuum interrupter is the copper contact, connected to the end plate via a welded stainless steel bellows. Since both ends of the bellows are welded, the failure rate of this moving seal is exceptionally low—demonstrating the high reliability of modern vacuum circuit breakers.

In fact, the MTTF (Mean Time To Failure) of modern vacuum interrupters is now estimated at 57,000 years.

Customer concerns about vacuum loss were valid in the 1960s, when vacuum breakers were new to power applications. At that time, vacuum interrupters often leaked, and surge issues were common. Only one company offered vacuum breakers, and reports indicated numerous problems.

By the mid-1970s, European-developed vacuum interrupters—like modern Siemens designs—differed fundamentally from 1960s models in materials and process control. Copper-bismuth contacts were more surge-prone than today’s chromium-copper alloys. Hand-built interrupters were more prone to leaks than today’s precision-manufactured units.

Today, rigorous process control and automation have eliminated most human variability. As a result, modern vacuum interrupters offer long service life, and the dielectric stress they impose on connected equipment is no worse than that of traditional air-magnetic or oil circuit breakers.