High-Voltage DC Contactor Wiring Essentials: Polarity Requirements and Safety Guidelines Muhimmin Mazauni Yadda Ake Kula Aiki Da Kontakta DC Na Farko: Rukunin Tsakiyar Talauci da Kungiyoyin Kwaikwayo
Maimaitaici Masu Daji Na Tashin DC Suna Da Karamin Farko Ta Fiye
Wannan ya fi dace a cikin abubuwa da ke kusa da tashin da dama da masu amfani.
Dalilai Da Karamin Farko Ta Fiye Yake Kan
Siffofin Tsakiya
Tashin DC ba ta da mafi yawan zero-crossing, wanda ya zama hankali a kan tsarin tsakiya. Karamin farko (yadda tashen yake) zai iya haifar da nasarar stretching da kuma idan tsakiya.
Kudin Tushen Da Ake Gargadi
Wasu maimaitaici suna da aiki a kan gargaɗi tsakiya (kamar magnetic blowout coils da permanent magnets) don yadda tashen yake. Tashi mai karamin farko na iya haifar da nasarar gargaɗi tsakiya.
Jukunan Maimaitaici na Ilimi
Wasu maimaitaici suna da jukunan gargaɗi tsakiya ko surge suppression (misali, diodes, RC circuits). Karamin farko mai tsabta zai iya shiga wasu waɗannan muhimman abubuwa.
Fasaha Da Yake Samun Tashi Mai Karamin Farko
Gargaɗi Tsakiya Ba Ya Sanya: Ingantaccen tsakiya ya zama da takaice, wanda ya shirya maimaitaici da kuma zama da takamfiyar tsari.
Haifar Da Nasarar: Rikitar maimaitaici ya zama, kuma kisan karama ya zama da takaice.
Risalawa: Idan an samu abubuwan ilimi (kamar suppression diodes), zai iya shiga short circuits ko kuma faɗuwar abubuwa.
Abubuwan Lalle Don Amfani Da Maimaitaici Masu Daji
Inrush Current
Dalilai Da Inrush Current Yake Faru
Maimaitaici masu daji na tashin DC suna da amfani a cikin tushen DC na inverter (energy storage), power modules (charging piles), electronic control units (electric vehicles) da sauransu. Tushen DC na wannan abubuwa suna da capacitors, wadannan suka da muhimmanci a cikin energy buffering, power balancing, filtering high-frequency harmonics and noise, maintaining stable DC bus voltage, protecting power devices, and improving the dynamic response of the system. Amma wannan ya fiye da capacitive load, wanda yake iya shiga inrush current saboda farkon voltaje a kan maimaitaici masu daji na tashin DC.
Fasaha Da Inrush Current Yake Samu
Inrush current zai iya shiga maimaitaici masu daji na tashin DC zuwa sticking. Idan coil bai gaske, maimaitaici ba za a iya buƙata, kuma zai iya bounce open automatically bayan lokacin takaice.
Inrush current zai iya shiga maimaitaici masu daji na tashin DC zuwa one-sided sticking. Idan coil bai faru, relay bai ci gaba, amma maimaitaici na biyu zai iya buƙata.
Inrush current zai iya shiga maimaitaici masu daji na tashin DC zuwa uneven contact, wanda yake iya haifar da effective contact area, kuma zai iya shiga kisan karama, kuma yana da risalawa.
Load-Bearing Interruption
Maimaitaici masu daji na tashin DC suna da hankalin da suka da take a cikin load-bearing interruption (live breaking) musamman da AC maimaitaici. Sabubbin da ya fiye shine tashin DC ba ta da natural zero-crossing point, wanda yake iya haifar da gargaɗi tsakiya. Wadannan ne muhimman points and countermeasures:
Hankalin Load-Bearing Interruption
Tsakiya Mai Tsabta: Tashin DC ba ta da zero-crossing point, saboda haka tsakiya zai iya zama da takaice, wanda yake iya shiga maimaitaici zuwa ablation ko kuma welding.
Energy Mai Tsabta: Idan inductive loads (kamar motors da transformers) bai gaske, zai faru induced voltage mai tsabta, wanda yake iya shiga insulation ko kuma shiga abubuwa.
Impact of Polarity: Idan maimaitaici a cikin design mai karamin farko, tashi mai karamin farko na iya haifar da hankalin tsakiya.
Teknologi Gargaɗi Tsakiya Maimaitaici Masu Daji Na Tashin DC
Hallolin Load-Bearing Interruption
Pre-charging Circuit (Common in Electric Vehicles)
Idan maimaitaici na biyu bai faru, pre-charging resistor ya kunshi inganta inrush current da kuma haifar da energy during breaking.
Arc-Extinguishing Auxiliary Circuits
RC Snubber Circuit: Connected in parallel with the contacts to absorb inductive energy.
Freewheeling Diode: Provides a current loop for inductive loads (note polarity matching).
Metal Oxide Varistor (MOV): Limits overvoltage.
Step-by-Step Breaking
First break the small-current auxiliary contacts, then break the main contacts (such as in dual-contact design).
Abubuwan Lalle
Current/Voltage Limitation: Ensure the breaking current does not exceed the rated breaking capacity of the contactor (e.g., 1000V/500A); otherwise, it may fail.
Polarity Matching: If the contactor is of unidirectional design, it must be energized in the nominal direction; otherwise, the arc-extinguishing capability will decrease.
Load Types:
Resistive Loads: Easier to break (low arc energy).
Inductive Loads: Require additional protection circuits (such as diodes).
Capacitive Loads: Be wary of inrush current during closing (may cause contact adhesion).
