Common Insulator Failures and Preventive Measures Failures na Iyakwata da Tsohon Karkashin Yawan Hanyoyi Ko'oromin Iyakwata da Tsohon Karkashin Yawan Hanyoyi

Insulators na iji nyocha n'otu dị ka nchekwa maka ọtụtụ ọrụ n'ebe ebe etiti: na-enye aka ịkpebanye mgbanwe na-enweghị ịkpebanye. Ha na-eme kwa afọrọ obere/towers na mgbanwe, ma na-eme kwa ụlọ ebe na-ezighị mgbanwe. Na okwu dịka dielectric materials, insulators na-akọwa n'ọnụọgụ a bụ: porcelain, glass, na composite. Ịmalite ihe gbasara ọtụtụ ọrụ insulator na strategies dịka ọrụ ya na-egosi ịghọta ịkpebanye site n'ịnwe ụfọdụ ihe n'ụwa na electrical load variations, ha na-akọwapụta electromechanical stresses nke na-ekpe mmalite ọrụ na usoro mgbanwe.

​Failure Analysis​

Insulators, na-enyere ọsọ ọsọ site n'atmosphere, na-aga ịkwalite ọtụtụ ọrụ site n'ịgbasa lightning, contamination, interference nke ọkachamara, ice/snow, extreme heat/cold, na elevation differences.
• ​Lightning Strikes:​​ Ebe ọtụtụ mgbanwe na-enye na-enye n'obodo, mountains, open areas, ma ọ bụ polluted industrial zones, mgbanwe na-aga ịkwalite insulator puncture ma ọ bụ explosion site n'ịgbasa lightning.
• ​Bird Interference:​​ Research na-egosi na ọnụọgụ mkpa nke flashover incidents na-ebi site n'ọrụ ọkachamara. Composite insulators na-aga ịkwalite ọkachamara-related flashovers karịa porcelain ma ọ bụ glass types. Ọtụtụ ọrụ a na-akọwa n'110 kV na ọtụtụ mgbanwe; urban distribution networks (≤35 kV) na-aga ọtụtụ ọrụ karịa site na ọkachamara population nke ọma, voltage levels nke ọcha, air gaps nke ọcha maka breakdown, na prevention effective site n'insulator sheds without grading rings.
• ​Grading Ring Failures:​​ High electric field concentration near insulator end-fittings na-egosi grading rings n'220 kV+ systems. Ya mere, rings a na-akọwa clearance distance, lowering withstand voltage. Site n'ahụ ọhụrụ, low corona inception voltage at ring mounting bolts na-egosi corona discharge, compromising string safety.
• ​Contamination Flashovers:​​ Conductive pollutants na-akpụta n'okpuru insulator. Site n'ahụ ọhụrụ, contamination a na-akpụta insulation strength, leading to flashovers during normal operation.
• ​Unknown Causes:​​ Ọtụtụ flashovers na-aga ịkwalite ọrụ dị ka zero-resistance porcelain insulators, shattered glass insulators, ma ọ bụ composite insulator tripping. Despite inspections, causes remain undetermined. Ọtụtụ ọrụ a na-akọwa n'ọtụtụ ahụ (especially during rain) na-aga ọrụ auto-reclosing post-fault.

​Preventive Measures​

• ​Lightning Protection:​​ Address root causes (short dry-arc distance, single-point grading rings, excessive grounding resistance) by installing extended composite insulators, dual grading rings, and improving tower grounding.
  • ​Bird Damage Prevention:​​ Deploy bird barrier nets, anti-bird spikes, or protective covers on high-risk line sections.
  • ​Grading Ring Mitigation:​​ Use insulators with equal-sized sheds meeting technical spacing requirements. Increase creepage distance where necessary to reduce ice/snow flashovers. Conduct regular inspections and random tests (mechanical strength, electrical performance, aging assessment) across diverse regions/environments to prevent strength degradation, swing resistance loss, or shed aging issues.
  • ​Contamination Control:​​
  o ​Regular Cleaning:​​ Clean all insulators before peak contamination seasons; increase frequency in heavily polluted areas.
  o ​Enhanced Creepage Distance:​​ Boost insulation levels by adding insulator discs or using anti-fog designs. Field experience confirms anti-fog insulators' effectiveness in severely polluted zones.
  o ​Silicone Coatings:​​ Apply anti-pollution coatings (e.g., ceresin wax, paraffin, silicone-based materials) to improve contamination resistance.
  • ​Unexplained Flashovers:​​ Perform comparative tests on new insulators (same model) and in-service units (>3 years), including power-frequency dry flashover and mechanical failure tests. Conduct aging evaluations periodically. Implement scheduled cleaning, timely ESDD (equivalent salt deposit density) measurements, and incorporate new anti-aging agents during replacements.
  • ​General Maintenance:​​ Prohibit personnel from stepping on insulators or scraping them with sharp tools to extend service life.