Makarantar Kirki na Tsakiya Da Dukkuka

Tsohon Kirki a Gas Circuit Breakers

A gas circuit breakers, tsohon kirki shi ne abin da yake take kula da tsari na kirki da yawa na breaker. Tsohon kirki yana iya kasancewa wasu hundred volts zuwa wasu kilovolts, bata-bata da alamomin da suka haɗa. Duk da cewa, wanda ake bayyana masu muhimmanci da suka haɗa da tsohon kirki:

1. Tsari na Kirki

• Sassan: Tsohon kirki na kirki yana da mutane da tsari na kirki. Idan tsari na kirki yana zama mafi yawan, tsohon kirki da ke bukatar don gudanar da kirki yana zama mafi yawa.

• Bayani: Idan magana da gas circuit breaker suka zama, kirki ta faru a kan biyu. Tsari na kirki yana iya zama mafi yawa daga farkon gasar da suka haɗa saboda harkokin kirki (arc stretching) a lokacin da an haɗa da magnetic fields ko gas flow. Mafi yawan tsari, mafi yawan tsohon kirki, wanda yana ba da nasara don kula da kirki saboda an buƙaci masu yawa don gudanar da ita.

2. Nau'in Gas

• Sassan: Tsohon kirki yana da muhimmanci a nan nau'in gas da ke aiki, kamar pressure, temperature, da ionization state.

• Bayani: Nau'ukan gas suna da dielectric strengths da thermal conductivities da dama, wadannan yana haɗa da yadda ake gudanar da kirki. Misali, sulfur hexafluoride (SF₆) yana amfani a matsayin gas da ake amfani a high-voltage circuit breakers saboda insulating properties da kyau da ability to quickly de-ionize after the current passes zero. Gas da dielectric strength mafi yawa sun buƙaci tsohon kirki mafi yawa don gudanar da kirki, wanda yana ba da nasara don kula da kirki.

3. Abubuwan Magana

• Sassan: Abubuwan magana na arcing contacts yana da muhimmanci mai yawa ga tsohon kirki, yana haɗa da tsohon kirki na anode da cathode regions.

• Bayani: Tsohon kirki mafi yawa a gaseous arc yana faru a kan body na kirki, ba a kan surfaces da suka haɗa. Amma, abubuwan magana yana haɗa da tsohon kirki na anode da cathode, wanda ake kira cathode and anode fall. Abubuwan magana da work functions mafi yawa (e.g., copper, silver) suna da cathode falls mafi yawa, amma wannan yadda yake da muhimmanci mai yawa ga tsohon kirki da dukkan. Saboda haka, zabi abubuwan magana yana da muhimmanci mai yawa ga tsohon kirki da dukkan.

4. Cooling of the Arc

• Sassan: Tsohon power na kirki yana daidai da current da tsohon kirki. Idan kirki ta ci gida heat da cooling, zai buƙaci tsohon power tare da tsohon kirki.

• Bayani: Cooling of the arc yana faru a kan conduction, convection, da radiation. A gas circuit breakers, gas flow (da ake amfani a puffer mechanisms ko magnetic blowout coils) yana taimaka cooling the arc da reduce its temperature. Idan kirki ta ci gida, yana zama mafi yawan conductive, wanda yana ba da nasara don buƙaci tsohon kirki. Tsohon kirki mafi yawa yana ba da nasara don kula da kirki saboda an buƙaci masu yawa don gudanar da ita.

5. Current Through the Arc

• Sassan: Gaseous arcs suna da negative volt-ampere characteristic, meaning that the arc voltage increases as the current decreases and vice versa.

• Bayani: Idan current approaches zero during the current zero crossing, the arc voltage tends to rise sharply. This is because the arc becomes less stable at low currents, and the reduced number of charge carriers leads to a higher resistance, resulting in a higher voltage drop. Conversely, at higher currents, the arc is more stable, and the voltage drop is lower. This behavior is important for understanding how the arc behaves near current zero, where successful interruption is critical.

6. Arc Voltage Random Excursions and Collapses Near Current Zero

• Sassan: Near the current zero crossing, the arc voltage exhibits random excursions and collapses, which are critical for arc extinction.

• Bayani: As the current approaches zero, the arc becomes increasingly unstable. The arc voltage may fluctuate randomly due to the rapid changes in the arc's physical state, such as the density of charged particles and the temperature. These fluctuations can cause the arc voltage to spike suddenly, leading to a collapse of the arc. If the arc voltage rises sufficiently, it can exceed the recovery voltage of the system, causing the arc to be extinguished. This phenomenon is crucial for ensuring that the arc is successfully interrupted at current zero.

Gaba

Tsohon kirki a gas circuit breakers yana da muhimmanci da abin da suka haɗa, including the arc length, the type of gas, the contact material, cooling effects, and the current through the arc. Tsohon kirki yana da muhimmanci ga tsari na kirki, particularly near current zero, where random excursions and collapses can determine whether the arc is successfully extinguished. Understanding these factors is essential for designing and operating efficient and reliable gas circuit breakers.