Bayanan al'amuran da ake faruwa a kan zama ta hanyar kisan jirgin kofin da ake gudanar da shi a tsawon kofin

Akwai lura da ya fi amfani da shi wajen fahimta takaitaccen kungiyar saki.
Takaitu 1 zuwa 3 sun nuna rubutun bayanin testin kungiyar saki (CO) na fault current mai sauƙa tsawon uku da ba ta gamsa tsaye (trace courtesy of KEMA).
A cikin kowace takaitu, akwai luran da ke so:

Takaitaccen kungiyar sakirin da abubuwan da suka dace

Daga Takaitu 1, zan iya duba wasu abubuwan da suka dace a cikin takaitu:

1. Hali na farko:

• Kungiyar saki yana fara ne a matsayin hali mai kwalliya.

• An kafa shiga kwalba a matsayin alama don kawo kungiyar saki a matsayin kwalliya.

2. Tsarin kwalliya:

Ba tare da tsari mai elektriki, an kasa mazaunin kwalliya (kamar yadda aka nuna a kasa masu graph) kuma ya kula sama da mazaunin kwalliya. Wannan lokacin da aka kira shine mazaunin kwalliya ko mazaunin kwalliya. A gaba daya, saboda maɓallin kwalliya daga baya, idan kungiyar saki yake kula sama da mazaunin kwalliya, kwalliya ya kula kadan kadan da mazaunin kwalliya.

Lokacin da aka kara shiga kwalba zuwa lokacin da mazaunin kwalliya yake kula, ana kira wannan lokaci a matsayin lokacin da kwalliya ya faru.

3. Hali na kwalliya da fault current:

• Idan kungiyar saki yake kula, yana kula fault current. An kafa shiga kwalba a matsayin alama don kawo kungiyar saki a matsayin kafara (ko kafara).

• Ba tare da tsari mai elektriki, mazaunin kwalliya an kasa kadan kadan da mazaunin kwalliya, kuma ya kula sama da mazaunin kwalliya. Wannan lokacin da aka kira shine mazaunin kafara, mazaunin kafara ko mazaunin kafara.

• Lokacin da aka kara shiga kwalba zuwa lokacin da mazaunin kafara yake kula, ana kira wannan lokaci a matsayin lokacin da kafara ya faru.

4. Tashin arc da kafara kwalliya:

• An kafa arc electric waɗanda suka kala kulan mazaunin kwalliya. Kwalliya tana yi amfani a matsayin kafara a lokutan zero-crossing, kafin a phase b, kafin a phase a, kuma kafin a phase c.

•  Phase c ita ce phase da ya kula da kafara kwalliya, kafin lokacin da duranci arc (lokacin da aka kara mazaunin kafara zuwa lokacin da kwalliya ya kafara) yana kula na biyu kafin lokacin da aiki. Lokacin da kafara (ko breaker time) na phase c yana kula na biyu lokacin da kafara ya faru da duranci arc.

5. Cikakken kwalliya a lokutan kafara:

• A lokacin da kwalliya ya kafara a phase c, kwalliyoyin a phases a da b sun kusa da 30°, kuma sun kula na biyu kafin lokacin da suka kula, amma suka kula na biyu kafin lokacin da suka kula. Kwalliya a phase a (phase a) tana kula na biyu lokacin da suka kula, kafin a phase b (phase b) tana kula na biyu lokacin da suka kula.

• Lokacin da kafara ta faru yana kula na biyu lokacin da kafara ya faru da duranci arc mai kyau a phase a ko phase b.

Abubuwan da suka dace da kwalliya a lokutan kungiyar saki:

Zan iya duba cikakken a cikin Takaitu 2:

•  Idan fault ya faru a lokutan peak voltage, kwalliya tana kula na biyu. Na biyu tana nufin cewa har zuwa kafin kwalliya, kamar yadda ake kira loop of current, tana kula na biyu kafin lokacin da kwalliya. Kwalliya a phase a tana kula na biyu saboda fault ya faru kadan kadan a lokutan peak voltage.

• Kwalliyoyin a phases b da c tana kula na biyu, kuma sun kula na biyu kafin lokacin da suka kula, kamar yadda ake kira major loops da minor loops, kafin lokacin da suka kula.
  Na biyu mai kyau tana faru idan fault ya faru a lokutan zero crossing voltage.

Abubuwan da suka dace da voltage a lokutan kungiyar saki

Daga Takaitu 3, zan iya duba wasu abubuwan da suka dace a cikin takaitu:

Zero Crossings na kwalliya:
Zero crossing na kwalliya tana faru kafin lokacin da suka kula. Ba tare da mazaunin kafara, pole na biyu kafin lokacin da suka kula za a yi amfani a matsayin kafara kwalliya. A cikin wannan lokaci, pole na phase b, saboda ya kula na biyu kafin lokacin da suka kula, tana yi amfani a matsayin kafara kwalliya.

2. Amfani da kafara kwalliya a lokutan farko:

Pole na phase b tana yi amfani a matsayin kafara kwalliya, amma ya kasa saboda mazaunin kafara tana kula na biyu kafin lokacin da suka kula da Transient Recovery Voltage (TRV), kuma ya kula sama da re-ignition.
 Saboda haka, pole na phase a tana yi amfani a matsayin kafara kwalliya, amma ya kasa kafin lokacin da suka kula da re-ignition.

3. Kafara kwalliya ta faru:

 Kafin lokacin da ya faru, pole na phase c tana kafara kwalliya, kuma ya kula sama da TRV da AC recovery voltage.

4. Transient Recovery Voltage (TRV):

•  Makalma: TRV tana nufin oscillation mai tsawo wanda tana faru idan voltage a matsayin power side na kungiyar saki tana kula sama da pre-fault system voltage.

• Kyakkyawan: TRV tana oscillate a matsayin AC recovery voltage, wanda tana nuna axis of oscillation. Peak value na TRV tana kula da damping a cikin circuit.

• Duranci na oscillation: Daga waveform, TRV tana oscillate a matsayin quarter cycle na power frequency (i.e., 90 degrees).

• Impact on Poles: Pole na biyu kafin lokacin da suka kula (a cikin wannan lokaci, phase c) tana kula da TRV mai kyau, saboda tana kula da full transient oscillation.

5.    Subsequent Pole Clearing:

• Poles na phase a da b tana kafara 90 degrees later than the c-phase.

• For these poles, the TRV values are lower than those experienced by the c-phase and have opposite polarities.

• The AC recovery voltage is the line voltage, shared between the two phases.