Misalai mai yawa na iya kawo amfani da ita?

Zai na wani Over Current Relay?

Takardar Overcurrent Relay

Overcurrent relay shine babban wurin da ke gudanar da kowane current bayan da ba da zarura don voltage coil.

Sana'a ta Hanyoyi na Over Current Relay

Yawan muhimmanci a cikin overcurrent relay shine current coil. A lokacin da tsohuwa, yanayin maganin mafi yawa cewa bai iya jin daidai kan yanayin alama ko karfi da ke dace da elementin relay. Amma idan current ya zama da kyau, yanayin maganin ya zama mafi yawa, tare da yanayin alama da karfi, kuma ya haifar da elementin mai tsarki a yi canza abin da ke contact a cikin relay. Wannan sana'a ta hanyoyi ya faruwar da dukkan abubuwan overcurrent relay.

Abubuwan Over Current Relay

Idan za a iya kawo fahimta da lokaci na hanyoyi, akwai abubuwan overcurrent relay masu shirye-shirye, kamar:

• Instantaneous over current relay.

• Definite time over current relay.

• Inverse time over current relay.

Inverse time over current relay ko inverse OC relay zai iya zama da inverse definite minimum time (IDMT), very inverse time, extremely inverse time over current relay ko OC relay.

Instantaneous Over Current Relay

Sana'a ta hanyoyi da takarda na instantaneous over current relay shine ma'ana. A cikin instantaneous overcurrent relay, core magnetic ya kasa da current coil. Yawan iron, da suka tabbatar da hinge da spring mai karfi, ya jagoranci cewa ya zama mafi yawa a lokacin da current ya zama da kyau da threshold da aka sa, wanda ke dace da normally open (NO) contacts. Idan current ya zama da kyau, yanayin maganin ya zama mafi yawa, tare da ya haifar da iron zuwa core, kuma ya kasa contacts.

Muna ce pickup setting current wa ce ma'anar pre-set value of current a cikin relay coil. Ana kiran wannan relay a matsayin instantaneous over current relay, saboda, a fadada, relay ya hanyar da current a cikin coil ya zama da kyau da pick up setting current. Ba a haɗa da intentional time delay. Amma akwai inherent time delay wanda ba a iya duba tun daga lokaci. A cikin fadada, lokacin hanyoyi na instantaneous relay shine kiman lokaci na milliseconds.

Definite Time Over Current Relay

Wannan relay ya faruwar da intentional time delay a lokacin da current ya zama da kyau da threshold. Definite time overcurrent relay zai iya a yin adjustment don trip output a lokacin da aka sanar da exact amount of time bayan ya pick up. Saboda haka, ana da time setting adjustment da pickup adjustment.

Inverse Time Over Current Relay

Inverse time overcurrent relays, da ake samun ne a cikin induction type rotating devices, sun hanyar da kowane current da aka sanar da, suna hanyar da kowane lokaci da current. Wannan siffo shine ma'ana don hanyoyin fault clearing a lokutan da suka zama da yawa. Da kuma wannan inverse timing zai iya a yin programming a cikin microprocessor-based relays, wanda ke hada da versatility su a overcurrent protection.

Inverse Definite Minimum Time Over Current Relay ko IDMT O/C Relay

A cikin overcurrent relay, ya fi kiyaye a yi perfect inverse time characteristics. Idan system current ya zama da kyau, secondary current daga current transformer (CT) ya zama da kyau har zuwa lokacin da CT ya zama da saturation, inda ya haifar da increase a cikin relay current. Wannan saturation ya nuna limit na inverse characteristic effectiveness, wanda ya haifar da fixed minimum operation time har zuwa lokacin da fault level ya zama da kyau. Wannan behavior na define IDMT relay, wanda ake sanar da inverse response initially, wanda ya zama stable a lokacin da current levels ya zama da kyau.