Me ke kaya da reclosers a gasar karamin kable na?

1. Bayanin Hanyoyin Kirki da Reclosers a Najeriya

Takamantar da karamin zabe ta kasa na Najeriya yana samun hanyoyin kirki, musamman a matsayin 20kV, wanda ke taimakawa mafi girma da kungiyar kasashen. A shekarar 2024, kusan 65% na shirye-shirye na 20kV na karamin zabe ta kasa na Najeriya ke amfani da hanyoyin kirki, wanda ke yiwuwa kan abubuwan al'umma kamar barazan, fitafitai, da kuma gajimare. A cikin wannan yanayi, reclosers suna fito da muhimmanci a kan cin karamin zabe ta kasa. Wadannan abubuwa suna ci gaba da siffofin IEC 62271-111, suka dogara da abubuwan al'umma na hanyoyin kirki a Najeriya, wanda ke taimaka da rike masu zabe mai karfi da kuma inganta tushen bayan wasu.

2. Kudancin Funtodolin Reclosers a Hanyoyin Kirki
2.1 Ingantaccen Tushen Wasu Mai Tsawon Yau Da Duk

Hanyoyin kirki a Najeriya suna samun tushen wasu mai tsawon yau da duk, kamar kowane wadanda ake bude da barazan (wadanda suka yi nasarar ~30% daga duka tushen wasu a arewa) ko mutanen kirki da suka shiga gasar. Reclosers wadanda ake sanar da su a hanyoyin kirki na 20kV suna neman wasu masu tushen da suka rike kisan damin birnin layi. Misali, recloser a Nha Trang’s 20kV overhead network zai iya haifi tushen wasu mai barazan da ya faru, da kuma rike damin birnin layi, don in ba damin birnin layi a lokacin da aka faɗa. Idan an yi damin birnin layi, zai iya ba da damin birnin layi har zuwa; idan ba, recloser zai yi hankali a cikin takardun damin birnin layi da aka bincika.

2.2 Ingantaccen Tushen Wasu Mai Tsawon Da Duk

A cikin halayen tushen wasu mai tsawon da duk - kamar juye masu kirki da ya faru saboda kafuwar fitafitai ko karamin sararin mota - reclosers suna yi hankalin damin birnin layi (yanayi 3–4 kafa) kafin ake lokaci. Wannan yadda tana tabbatar da damin birnin layi ba kungiyar da ya faru ba, amma an yi damin birnin layi a kungiyoyi da ba suka faru. A Hanoi’s urban overhead lines, recloser da ake sanar da shi a 3 damin birnin layi zai iya haifi tushen wasu mai tsawon da duk a cikin kungiya, wanda ke taimaka da kungiyar da ya faru kawai ne da damin birnin layi, ba kungiyar daban-daban ba.

2.3 Gargajiya Da Farkon Abubuwan Karamin Zabe

Reclosers a Najeriya’s 20kV overhead systems suna gargajiya da sectionalizers da fuses don in inganta ingantaccen tushen wasu. Misali, recloser da ake sanar da shi a farko da sectionalizers a hanyoyin kirki a Da Nang zai yi damin birnin layi kafin ake faru tushen wasu, tare da sectionalizers na biyu suka ruwaito damin birnin layi. Idan damin birnin layi na recloser ba ya faru ba, sectionalizer na biyu ga tushen wasu zai haifi shi, wanda ke taimaka da damin birnin layi a kungiyar da ya faru kawai ne, ba kungiyar daban-daban ba.

3. Siffar Fanni na Reclosers Don Hanyoyin Kirki
3.1 Tashar Fanni Na 20kV Overhead Networks

• Voltage and current ratings: Reclosers a Najeriya’s 20kV overhead lines suna da rated voltage na 24kV da kuma continuous current rating na 600–1200A, wanda ke daidaito waɗannan suna da kyau a cikin mafi girma da kungiyar kasashen da kuma kungiyar kasashen.

• Synchronous power coefficient (Psyn): An dogara shi don in taimaka waɗannan reclosers su ci gaba da P_syn values wanda ke saukar da synchronism loss a lokacin da damin birnin layi, hata a hanyoyin kirki mai tsawo (misali, 50 km rural feeders a Nghe An Province).

3.2 Adaptaibinta Al'umma Ta IP67 Rating

Al'ummukan Najeriya - wanda ke da humidity mai tsawo (80–95% a shekarar), rainfall mai tsawo (kafin 3,000 mm/year a arewa), da kuma fitafitai - tana buƙatun tsohon inganta. IP67-rated reclosers:

• Sun tsohon dust ingress, wanda ke muhimmanci a hanyoyin kirki na kasashen da ke tsaftace masana kwalliya.

• Sun tsohon submersion a 1 meter of water for 30 minutes, wanda ke muhimmanci a hanyoyin kirki na kasashen da ke tsaftace masana kwalliya kamar Mekong Delta.

• Sun tsohon corrosion-resistant enclosures (e.g., stainless steel or powder-coated aluminum) don in taimaka da salt mist a kasashen na kofar yamma kamar Quang Ninh.

3.3 Compliance with IEC 62271-111

National grid Najeriya tana buƙatun IEC 62271-111 compliance for reclosers a 20kV overhead lines, wanda ke taimaka da:

• Uniform testing for dielectric strength, short-circuit breaking capacity, and mechanical endurance.

• Interoperability between reclosers from different manufacturers, crucial for grid expansion projects in HCMC and Hanoi.

• Standardized fault recording capabilities, enabling grid operators to analyze fault patterns (e.g., seasonal lightning strikes in Central Vietnam).

4. Turutan Reclosers Da Amfanan Su a Hanyoyin Kirki a Najeriya
4.1 Vacuum Reclosers: The Mainstream Choice

• Advantages: Long service life (20–30 years), minimal maintenance, and high arc-quenching efficiency, making them ideal for remote rural overhead lines in provinces like Kon Tum.

• Case study: In Phu Yen Province, vacuum reclosers on 20kV overhead lines have reduced annual maintenance visits by 70% compared to traditional circuit breakers, lowering operational costs for EVN (Vietnam Electricity).

4.2 SF6 Reclosers: Specialized Urban Applications

• Use cases: Compact design suits urban overhead lines with limited right-of-way (e.g., Hanoi’s Old Quarter). SF6 reclosers can be installed on narrow poles without compromising performance.

• Environmental considerations: Though SF6 has high global warming potential, Vietnam’s urban areas prioritize space efficiency, with strict regulations with recloser to minimize emissions during maintenance.

5. Impact on Reliability and Grid Modernization
5.1 Improved SAIDI and SAIFI Indices

Incorporating reclosers in 20kV overhead lines has significantly improved Vietnam’s system reliability:

• SAIDI (System Average Interruption Duration Index): Reduced from 18 hours/year in 2015 to 8.5 hours/year in 2024 for overhead line-fed areas, thanks to reclosers clearing transient faults without manual intervention.

• SAIFI (System Average Interruption Frequency Index): Dropped from 12 interruptions/year to 5.2 interruptions/year in regions like Thanh Hoa, where IP67-rated reclosers on overhead lines mitigate weather-related faults.

5.2 Enabling Smart Grid Initiatives

Modern reclosers in Vietnam’s overhead networks are equipped with:

• Remote communication capabilities: RS485 or LTE modems for SCADA integration, allowing real-time monitoring of 20kV overhead lines in HCMC’s smart grid pilot projects.

• Data logging: Fault current magnitude, duration, and reclosing times, which help EVN optimize protection settings for overhead lines in different climatic zones.

6. Challenges and Future Trends
6.1 Vegetation Management Conflicts

Overhead lines in rural Vietnam often pass through forested areas, where tree growth can cause repeated faults. Reclosers alone cannot resolve root causes, requiring coordinated vegetation management. In 2023, EVN piloted "smart recloser-vegetation monitoring" systems in Lam Dong Province, combining recloser fault data with drone-based tree trimming schedules.

6.2 Climate Change Adaptation

With increasing typhoon intensity, reclosers in coastal overhead lines need enhanced durability. Vietnam is exploring reclosers with higher impact resistance (e.g., IK10-rated enclosures) and redundant power supplies (solar-powered backup) for overhead lines in storm-prone regions like Quang Binh.

6.3 Standardization and Local Production

To reduce import dependency, Vietnam’s Ministry of Industry and Trade is promoting local manufacturing of IEC 62271-111-compliant reclosers. A 2024 joint venture between EVN and a Korean manufacturer aims to produce 10,000 units/year of 20kV reclosers for overhead lines, targeting 60% cost reduction compared to imported models.

7. Conclusion

In Vietnam’s 20kV overhead line networks, reclosers serve as the backbone of reliable power distribution, balancing technical efficiency with environmental resilience. From IP67-rated devices withstanding tropical storms to IEC 62271-111-compliant models enabling grid interoperability, these devices have transformed fault management in overhead systems. As Vietnam progresses toward a smart grid, reclosers will continue to evolve—integrating advanced sensors, AI-based fault prediction, and renewable energy compatibility—to meet the demands of a growing economy and a rapidly urbanizing population. Their role in overhead lines remains indispensable for ensuring that electricity reaches every corner of Vietnam, from the bustling cities to the most remote villages.