Imeshwa kwa Miamala Mingi: Solosho Jipya la Ulinzi na Kudhibiti ya Akili kwa Mzunguko wa FC wa Umeme Mkali

I. Mawazo ya Suluhisho​

Suluhisho hili linatafsiriwa kufanya mazingira muhimu za ubora wa umuhimu wote kwa vituo vya FC kutokana na "High-Voltage Vacuum Contactors + High-Voltage Current-Limiting Fuses". Limeundwa kusaidia usalama na utambuzi wa midamo mikubwa, transformers za upatikanaji na makundi ya capacitors kwenye kiwango cha 3kV hadi 12kV, hasa kwa matumizi ya kiuchumi yanayohitaji kutumika mara kwa mara na uhakika (kama vile viwanda vya umeme, viwanda vikubwa na madini). Uwezo wake wa kuwa muhimu unaelekea kwa ufanisi wa kutoa huduma zinazofanana katika kuzuia maambukizo na magonjwa ya overload na short-circuit, pamoja na kutoa fedha, usalama na teknolojia.

​II. Matukio ya Kitaalamu ya Vifaa Vikuu​

​1. High-Voltage Vacuum Contactor (Kitambulishi na Kutokomeka Overload katika Vito la FC)​​
High-Voltage Vacuum Contactor ni kipengele chenye kazi ya kutumia na kutokomeka overload current mara kwa mara. Matukio yake tekniki ni:

• ​Mfumo wa Utengenezaji:​​
• ​Vacuum Interrupter Chamber:​​ Inatumia muhuri wa ceramic na ukosefu wa vacuum ndani ya 1.33×10⁻⁴ Pa, ikisaidia kukuza arc kwa kupunguza kwa sasa, kutokosa mafuta na kushindwa kutumika.
• ​Insulation Mounting Bracket and Interlocking Mechanism:​​ Imetengeneza fusible mounts na imeandaliwa na mekanizimu muhimu wa interlocking trip. Hii inasaidia: ① Ikiwa fuse yoyote inapungua, inachukua muda mfupi kwa contactor kumpaka, kutoa kazi ya single-phasing; ② Ikiwa fuse yoyote haijawekwa, inasimamia contactor kutoka kufunguliwa, kusaidia usalama wa kazi.
• ​Operating Mechanism:​​ Inatumia electromagnetic mechanism, inaweza kufungua na kufunga mara kwa mara hadi 2000 times/hour, zaidi ya uwezo wa circuit breakers.
• ​Principle ya Kazi na Kutokomeka:​​
• ​Interruption Principle:​​ Inatumia uwezo wa vacuum medium wa kuwa na insulation na uwezo mkubwa wa kutokomeka arc. Arc ya metal vapor imetokomekwa kwa sasa kwenye point ya zero-crossing, na kurejesha nguvu ya dielectric haraka. Chopping current yake ni chini ya 0.5A, inaweza kupunguza overvoltages za switching, inaweza kusaidia motor insulation.
• ​Holding Method:​​ Inaelekeza electrical self-hold (saving energy, low noise) na mechanical self-hold (high reliability, anti-interference) methods. Wateja wanaweza kuchagua kulingana na mahitaji ya kazi (e.g., the LHJCZR series uses mechanical self-hold).
• ​Key Rated Parameters:​​

​2. High-Voltage Current-Limiting Fuse (Kitambulishi cha Short-Circuit katika Vito la FC)​​
High-Voltage Current-Limiting Fuse ni kitambulishi cha mwisho cha short-circuit faults. Matukio yake ni:

• ​Kazi ya Mwisho:​​ Hutambua protection ya instant (quick-break). Ikiwa short-circuit fault kubwa (current zaidi ya breaking capacity ya contactor), element ya fusible inapungua haraka na kutokomeka vito kabla current iripokee peak yake. Muda wa kutokomeka ni fupi (millisecond level), kuboresha limit ya energy ya fault current na kusaidia equipment ya downstream kutokosa.
• ​Mistari ya Chaguo:​​
• ​Rated Voltage:​​ Lazima si chini ya rated voltage ya system, kutoa overvoltage ya fuse operation kutokosa kwenye rated voltage ya equipment (maranyingi inahitajika kuwa chini ya 2.5 times phase voltage).
• ​Rated Current:​​ Inahitajika kujadili normal/overload currents, starting inrush characteristics (e.g., motor starting current, transformer magnetizing inrush), na kusaidia selective coordination na upstream protective devices (e.g., relays).
• ​Role Positioning:​​ Ni backup protection katika vito la FC. Overloads ya normal na short-circuit currents ndogo zinapatikana na comprehensive protection device kutoa signal kwa contactor kutokomeka. Fuse hutumika tu ikiwa fault current ipitapo breaking capacity ya contactor au ikiwa contactor hautokomeke.

​III. Guidance ya Chaguo kutokana na Object iliyoprotekta​

​1. Chaguo la Motor Protection Fuse​
Motor starting currents ni magumu na muda mrefu, inahitajika kujadili vizuri ili kutekeleza nuisance operation.

• ​Protection Coordination Logic:​​
• ​Overload Protection (e.g., stall, repeated starting):​​ Inapatikana na inverse-time relays, kukutana na contactor kutokomeka.
• ​Short-Circuit Protection:​​ Inapatikana na fuse.
• ​Coordination Requirement:​​ Rated current ya fuse lazima kuwa zaidi ya motor starting current, na time-current characteristic curve yake lazima kuongezeka na curve ya relay kwa point moja kuboresha coordination.
• ​Selection Reference (Excerpt):​​

• ​Key Point:​​ Muda mrefu na ukurasa wa kuanza zaidi, rated current ya fuse link lazima ziwe zaidi.

​2. Chaguo la Transformer Protection Fuse​
Chaguo lazima liweze kusaidia fuse kutokosa closing magnetizing inrush current na kutoa protection ya muhimu kwa faults za ndani.

• ​Selection Reference (Excerpt):​​

​3. Chaguo la Capacitor Bank Protection Fuse​
Capacitor bank switching hutokosa high-frequency, high-amplitude closing inrush currents, kunipa maoni mapya kwa chaguo la fuse.

• ​Special Consideration:​​ Lazima tuhakikishe fuse inaweza kusaidia let-through energy (I²t) ya closing inrush current. Tuntutanayo: Inrush let-through energy < 0.7 times minimum pre-arcing energy ya fuse.
• ​Selection Requirements:​​
• Rated current ni mara 1.5~2.0 rated current ya capacitor.
• Ikiwa inrush current ni zaidi, tafakari: ① Chagua dedicated capacitor fuses (e.g., WFN series); ② Ongeza series current-limiting reactor na capacitor; ③ Ongeza series damping resistor katika branch.
• ​Recommendation:​​ Series current-limiting reactor lazima litumike ikiwa (Inrush Peak Current * Inrush Frequency) > 20000 au operations zaidi.

​IV. Mzunguko wa Matumizi na Mifano​

​1. Mzunguko wa Matumizi​
Suluhisho la vito la FC si kwa kila mtu. Mzunguko wake unafuata:

• ​Midamo Mikubwa:​​ ≤ 1200 kW
• ​Transformers za Upatikanaji:​​ ≤ 1600 kVA
• ​Makundi ya Capacitors:​​ ≤ 1200 kvar
  Kwenye kiwango zaidi, chagua suluhisho la vacuum circuit breaker na breaking capacity na thermal stability zaidi.

​2. Mifano ya Uthibitisho​
Suluhisho hili limefanikiwa kutumika katika mifano mingi, kufanya kazi salama na uhakika:

• ​Mfano 1: Viwanda vya Chemistry, Texas, USA (Operations Zaidi na Environment ya Explosion-Proof)​​
• ​Maelezo ya Project:​​ Viwanda vikubwa vilivyohitaji control ya start-stop kwa midamo mikubwa na compressor motors kwenye production lines nyingi, na mahitaji ya explosion-proof na uhakika.
• ​Advantages Demonstrated:​​ Contactors 2000 operations/hour frequency inafanikiwa kutosha process adjustment needs; precise coordination between the fuse and relay ensured accurate short-circuit protection for motors under frequent starting without nuisance operation; the low chopping current (<0.5A) provided by the vacuum interrupter effectively suppressed switching overvoltages, protecting the insulation of older motors. The overall solution saved significant investment compared to vacuum circuit breaker switchgear.
• ​Mfano 2: Viwanda vya Gari, Bavaria, Germany (Transformer and Capacitor Compensation Protection)​​
• ​Maelezo ya Project:​​ Viwanda vya smart manufacturing vilivyohitaji supply ya umeme bora kwa robotic servo systems nyingi, na dry-type distribution transformers na capacitor compensation banks.
• ​Advantages Demonstrated:​​ Fuse rated current selection fully considered transformer magnetizing inrush characteristics, avoiding nuisance operation during closing. For the capacitor banks, dedicated fuses successfully withstood the closing inrush impact (I²t verification passed). The contactor's low bounce ensured capacitor switching without re-ignition, safeguarding power quality on the grid.

​V. Marejeo ya Uwezo wa Suluhisho​

1. ​Uhakika Nguvu:​​ Vacuum interrupter chamber is maintenance-free with a mechanical life of up to millions of operations; fuses provide millisecond-level quick-break protection.
2. ​Usalama Mkubwa:​​ Mechanical interlocking mechanism prevents single-phasing operation and closing with potential hazards; low chopping current protects equipment insulation.
3. ​Ushindi Fedha:​​ Compared to vacuum circuit breaker switchgear, FC switchgear offers lower cost, smaller size, and extremely high cost-effectiveness.
4. ​Ubunifu:​​ Contactors can be seamlessly integrated with microprocessor-based protection devices, enabling remote monitoring, intelligent control, and data upload.
5. ​Usalama Rasilmu:​​ Core components are designed for maintenance-free operation; after fuse operation, only replacement with a same-specification fuse link is required, making operation simple.