Aiki na yadda ake amfani da circuit breakers mai vakansi na tashar kwaikwayo
A cikin farkon 2007, kamar da shugaban kasa na tattalin arziki na Huaibei Mining Group, an yi aiki a tashin ala'udduka masana 10kV a Arewacin Yankin. Abubuwan da suka dace sun hada da kawo wani ZN20 takalmi mai tsayi a kan gida zuwa hukumar da suka fi sani 10kV disconnector - oil - immersed circuit breaker.
Daga baya, SN10 - 10 oil - immersed circuit breakers suka yi aiki a lokacin da yawa, wanda ya haɗa da ci gajerar zafi a cikin hukumomin. Wannan ya ba da ake magance zafi kowace shekaru biyu, wanda ya haɗa da aiki mai yawa a lalace. Kuma abubuwan da suka yi aiki su ne a yi aiki a kan 'yan adadin mutane, kuma wasu wurare su ne da kyakkyawan addini mai yawa da kusa a yi aiki. Kuma a nan a yi amfani da relay protection ya ba da ake bayyana kowace shekaru biyu, wanda ya haɗa da aiki mai yawa da kusa a yi aiki.
Don inganta aiki mai sauƙi, muna karatu a yi ala'udduka waɗannan circuit breakers zuwa vacuum circuit breakers. Wannan ala'uddukan ya ba da aiki mai yawa kuma ya kafa ayyuka mai sauƙi don aiki mai zurfi da kuɗi a kan masana a cikin lokaci.
Abubuwan da ke Zan Tsayen Vacuum Circuit Breakers
A cikin ala'uddukan masana 10kV a Arewacin Yankin, muna samun fahimta mai sauƙi game da abubuwan da ke ZN20 type vacuum circuit breaker. Waɗannan breaker ya faru ne daga me kungiyar operating mechanism, box body, vacuum tubes, insulation frames, da insulators. Ya faru ne da layout mai tsayi da operating mechanism ta fi a cikin fadada.
A cikin box body mai faruwar harshe, abubuwan da suka sauki suka fi a cikin bakwai. Mechanism ya haɗa da main shaft tun daga connecting plates. Idan main shaft ya kari, crank arms da aka fixa a cikinsu suka haɗa da insulators, wanda suka haɗa da moving conductive rod na vacuum tube don a yi aiki a kan switching. Both closing and opening operations can be manually or electrically controlled through the operating mechanism. Kuma ana amfani da AC/DC dual-purpose energy-storage motor, auxiliary contact mechanisms, da operation counter. Clear "ON" and "OFF" status indicators on the panel facilitate intuitive monitoring of the breaker's operational state.
Waɗannan breaker ta yi aiki a kan vacuum tubes don kawo hukumomi mai tsayi. Kamar da aka nuna a Figure 1, vacuum tube ya faru ne daga moving conductive rod, static conductive rod, moving and static contacts, shield, bellows, da ceramic enclosure. Ana sa a cikin ceramic housing da high vacuum degree typically ranging from 10⁻⁴ to 10⁻⁷ Torr (Note: The original text "104 - 10⁻⁷ Torr" might be a typo; the correct range should be 10⁻⁴ to 10⁻⁷ Torr), bellows ya kasance da moving conductive rod a fadada kuma da moving end cover a bakwai. Wannan component mai tsayi ya ba da aiki a kan operating contacts a kan baya, amma ta yi aiki a kan maintaining complete hermeticity. Shield around the contacts absorbs metal vapor generated by the vacuum arc during current interruption, preventing contamination of the insulation housing.
A cikin ala'uddukan, muna samun fahimta mai sauƙi game da advantages of vacuum circuit breakers over traditional oil-immersed ones:
Application Effects
A cikin ala'uddukan, muna samun fahimta mai sauƙi game da operating mechanism na vacuum circuit breaker closes the vacuum tube contacts through the elastic energy of the energy-storage spring, which is independent of the manual energy-storage speed, ensuring fast closing performance. Mechanism has three motion states: energy storage, closing, and opening.
Vacuum circuit breaker interrupts current by extinguishing the vacuum arc when the current drops to zero. At the moment the vacuum arc extinguishes, the density of electrons, positive ions, and other particles between the contacts rapidly decreases. Within microseconds, the contact gap essentially restores its original high vacuum degree and exhibits high withstand voltage, capable of withstanding the recovery voltage without breakdown to complete the interruption process. Therefore, even if a high voltage is applied shortly after the current zero-crossing, the contact gap will not break down again—meaning the vacuum arc can be completely extinguished at the first current zero-crossing.
Application Effects
Since the ZN20 10kV high-voltage vacuum circuit breakers were put into operation in June 2007 after the transformation, they have shown excellent performance. The circuit breakers feature fast opening/closing speeds, low operation noise, and accurate and reliable actions.
Compared with the previous oil-immersed circuit breakers, which required frequent refueling and heavy maintenance workload, the vacuum circuit breakers have significantly reduced maintenance tasks and costs, bringing tangible economic benefits. In the over 20 years of operation before the transformation, the substation experienced several misoperation accidents (such as forcibly opening the disconnector while the oil-immersed circuit breaker was in the closed position), causing varying degrees of equipment damage.
After the transformation, the high-voltage switchgear eliminated disconnectors, with each circuit controlled by a single vacuum circuit breaker. When the circuit breaker is opened, the breaker cart can be withdrawn, serving the function of a high-voltage disconnector. Additionally, the switchgear is equipped with mechanical and electrical locks in accordance with the "Five Prevention" requirements, effectively avoiding misoperation accidents, reducing the accident rate, and ensuring safe operation.
