Talabarin da Kaɗanjiya na Daɗiyya da Hanyoyin Ƙananan Kwamfuta a Jiha ta Tsakiyar 20kV na Vietnam

1. Bayani

A cikin yankunan kasar Wiyetnam, tushen 20kV reclosers na da muhimmanci wajen inganta karkashin kula tsakiya a kan yanayi mai karfi. Wadannan abubuwa, to da IEC 62271-111 da TCVN, ana samun sakamakon salt fog, humidity mai yawa, da kuma typhoons, wanda ya ba da kyau ga hukumomin kalmomin adawa. Wannan takarda ya nuna kalmomin adawa masu IP67-rated reclosers a Wiyetnam da kuma a bayyana ayyukan inta gaba don inganta karkashin jirgin kula.

2. Stressors Na Tsarin Yanayi Da Kalmomi Masu Sakamako

Tsarin yanayi a yankunan Wiyetnam ya ba da abubuwan sakamakon:

• Corrosion Ta Salt Fog: Chloride ions suna haɗa da sakamakon oxidation daga duk abubuwa masu kwalliya, musamman a cikin enclosures masu IP67 ingress protection (dust-tight and protected against temporary immersion).

• Insulation Degradation Saboda Humidity: Yawan moisture (relative humidity >85%) ta ci gaba da dielectric strength, wanda ya ba da partial discharges.

• Mechanical Stress Saboda Typhoon: Wind mai yawa da kuma flying debris zai iya tabbatar da duk abubuwa masu kofin ko kuma kafara mekanismoci masu kofin.

3. Kalmomin Adawa Da Ayyukan Inta Gaba
3.1 Contact System Failures

Lakari: Overheating, arcing, ko kuma tripping mai yawa.
Root Causes:

• Salt deposition take sa contact resistance.

• Oxidation of silver-tungsten contacts saboda humidity.

Ayyukan Inta Gaba:

• Apply hydrophobic coatings (e.g., PTFE) on contact surfaces.

• Implement scheduled ultrasonic cleaning (every 3 months).

• Upgrade to sealed contact chambers compliant with IEC 62271-111.

3.2 Insulation Breakdown

Lakari: Flashovers, ground faults, ko kuma sudden outages.
Root Causes:

• Moisture ingress through cable glands or seals.

• Tracking on porcelain insulators exposed to salt pollution.

Ayyukan Inta Gaba:

• Replace ceramic insulators with silicone rubber (CTI ≥600).

• Use cable glands with IP67 certification and corrosion-resistant materials.

• Conduct periodic dielectric tests per TCVN 6137 standards.

3.3 Control Unit Malfunctions

Lakari: Erratic tripping, communication loss, ko kuma failure to reclose.
Root Causes:

• PCB corrosion from salt aerosol penetration.

• Power supply instability due to voltage sags.

Ayyukan Inta Gaba:

• Enclose control boards in nitrogen-purged compartments.

• Install surge protectors compliant with IEC 61643-1.

• Implement remote monitoring via IEC 61850 protocol for real-time diagnostics.

3.4 Mechanical Jams

Lakari: Delayed operation ko kuma failure to actuate.
Root Causes:

• Rust formation in spring mechanisms.

• Debris accumulation in guide rails.

Ayyukan Inta Gaba:

• Use stainless steel 316L for moving parts.

• Design self-cleaning enclosures with inclined surfaces.

• Lubricate pivot points with lithium-based grease resistant to saltwater.

4. Standards Compliance and Preventive Measures

Deployment of reclosers in Vietnam adheres to:

• IEC 62271-111: High-voltage switchgear standards for operational safety.

• TCVN 6137: Insulation coordination requirements for 20kV systems.

• IP67 Rating: Protection against dust and immersion up to 1 meter for 30 minutes.

Key Preventive Measures:

• Material Selection: Aluminum alloy enclosures with epoxy powder coating (60μm thickness).

• Environmental Testing: Annual salt spray tests (ASTM B117) and humidity cycling (IEC 60068-2-30).

• Predictive Maintenance: Infrared thermography every 6 months to detect early overheating.

5. Case Study: Haiphong Coastal Substation

In 2023, a 20kV recloser in Haiphong failed due to salt-induced contact erosion. Remedial actions included:

• Retrofitting IP67-rated cable entries.

• Upgrading to silver alloy contacts with 99.9% purity.

• Installing a weather station to trigger pre-emptive maintenance during typhoon alerts.

• Post-intervention, the recloser's mean time between failures (MTBF) increased by 27%.

6. Kammala

Addressing recloser faults in Vietnam's coastal 20kV grid requires a synergistic approach combining robust design (IP67 enclosures), strict adherence to IEC 62271-111/TCVN standards, and proactive environmental mitigation. By integrating material science innovations and predictive maintenance, utilities can achieve a 30% reduction in outage duration, aligning with Vietnam's goal of enhancing power grid resilience in climate-vulnerable regions.