云南电力技术
雲南電力技術
운남전력기술
YUNNAN ELECTRIC POWER
2015年
1期
7-10
,共4页
水树老化%XLPE电缆%有限元法%电场%疲劳断裂
水樹老化%XLPE電纜%有限元法%電場%疲勞斷裂
수수노화%XLPE전람%유한원법%전장%피로단렬
water tree aging%XLPE cable%FEM%electric field%fatigue fracture
采用有限元法对水树起始机理进行了分析研究。有限元分析结果显示: XLPE绝缘内的局部微观缺陷导致电场畸变,水分积累形成椭圆水珠,对周围绝缘一起产生交变Maxwell应力作用,导致材料疲劳断裂。随着疲劳断裂的发展及水分的积累,逐渐发展形成相互连接的充水微孔和细枝,并最终发展形成水树。水树形成后,水树尖端电场畸变,当水树发展到一定长度或受到过电压作用,就会发展形成电树,并导致绝缘击穿。针对水树老化问题,提出了一些抑制和处理水树老化问题的方法和建议。
採用有限元法對水樹起始機理進行瞭分析研究。有限元分析結果顯示: XLPE絕緣內的跼部微觀缺陷導緻電場畸變,水分積纍形成橢圓水珠,對週圍絕緣一起產生交變Maxwell應力作用,導緻材料疲勞斷裂。隨著疲勞斷裂的髮展及水分的積纍,逐漸髮展形成相互連接的充水微孔和細枝,併最終髮展形成水樹。水樹形成後,水樹尖耑電場畸變,噹水樹髮展到一定長度或受到過電壓作用,就會髮展形成電樹,併導緻絕緣擊穿。針對水樹老化問題,提齣瞭一些抑製和處理水樹老化問題的方法和建議。
채용유한원법대수수기시궤리진행료분석연구。유한원분석결과현시: XLPE절연내적국부미관결함도치전장기변,수분적루형성타원수주,대주위절연일기산생교변Maxwell응력작용,도치재료피로단렬。수착피로단렬적발전급수분적적루,축점발전형성상호련접적충수미공화세지,병최종발전형성수수。수수형성후,수수첨단전장기변,당수수발전도일정장도혹수도과전압작용,취회발전형성전수,병도치절연격천。침대수수노화문제,제출료일사억제화처리수수노화문제적방법화건의。
XLPE cables water-tree aging mechanism is analyzed by the finite element method ( FEM) . The analysis results show that: microscopic defects inside the insulation lead to the electric field distortion and cause the accumulation of the moisture to form ellipsoid water droplets. which together apply the alternating Maxwell stress for the arounding insulator and resulting in fatigue frac ̄ture. Under the Maxwell stress, plenty of water-filled branches and viods caused by fatigue fracture interconnected together and e ̄ventually to form the water tree. When the water tree grows to a certain extent or been subjected to an impact voltage would develop an electrical tree and cause the breakdown. In order to solve the water tree aging problem, the paper concludes some methods and recommendations to inhibit and effectively deal with the aged cables.