高电压技术
高電壓技術
고전압기술
HIGH VOLTAGE ENGINEERING
2011年
9期
2178-2184
,共7页
王志勇%余占清%李雨%何金良%耿屹楠%梁曦东
王誌勇%餘佔清%李雨%何金良%耿屹楠%樑晞東
왕지용%여점청%리우%하금량%경흘남%량희동
特高压(UHV)%直流(DC)%输电线路%雷电防护%绕击%先导发展
特高壓(UHV)%直流(DC)%輸電線路%雷電防護%繞擊%先導髮展
특고압(UHV)%직류(DC)%수전선로%뇌전방호%요격%선도발전
ultra high voltage(UHV)%direct current(DC)%transmission line%lightning protection%shielding failure%leader progress
雷电绕击是影响高压输电线路安全稳定运行的关键因素之一,特高压直流线路对雷电防护的需求与常规线路相比更加迫切。为此介绍了基于先导发展法的特高压直流线路雷电绕击跳闸率分析方法;利用该方法针对±800 kV特高压直流线路绕击特性开展仿真研究,分析了绕击跳闸率随绝缘水平、保护角的变化规律,研究了典型地形条件下雷电绕击路径和绕击电流的分布特性,分析了山坡、山脊和跨谷地形条件下线路的绕击跳闸率,研究了线路极性对跳闸率的影响。研究表明,减小保护角可明显降低绕击跳闸率,在山坡地形条件下,外侧导线由于受屏蔽减弱更易受到雷击,雷电先导可从近似水平的方向击中导线;跨谷深度增加时,由于地面屏蔽作用减小,雷击跳闸率明显提高;理论分析和运行经验都表明,直流线路正极导线遭受雷击的概率远高于负极,线路位于山脊时雷电绕击基本发生在正极导线侧。
雷電繞擊是影響高壓輸電線路安全穩定運行的關鍵因素之一,特高壓直流線路對雷電防護的需求與常規線路相比更加迫切。為此介紹瞭基于先導髮展法的特高壓直流線路雷電繞擊跳閘率分析方法;利用該方法針對±800 kV特高壓直流線路繞擊特性開展倣真研究,分析瞭繞擊跳閘率隨絕緣水平、保護角的變化規律,研究瞭典型地形條件下雷電繞擊路徑和繞擊電流的分佈特性,分析瞭山坡、山脊和跨穀地形條件下線路的繞擊跳閘率,研究瞭線路極性對跳閘率的影響。研究錶明,減小保護角可明顯降低繞擊跳閘率,在山坡地形條件下,外側導線由于受屏蔽減弱更易受到雷擊,雷電先導可從近似水平的方嚮擊中導線;跨穀深度增加時,由于地麵屏蔽作用減小,雷擊跳閘率明顯提高;理論分析和運行經驗都錶明,直流線路正極導線遭受雷擊的概率遠高于負極,線路位于山脊時雷電繞擊基本髮生在正極導線側。
뇌전요격시영향고압수전선로안전은정운행적관건인소지일,특고압직류선로대뇌전방호적수구여상규선로상비경가박절。위차개소료기우선도발전법적특고압직류선로뇌전요격도갑솔분석방법;이용해방법침대±800 kV특고압직류선로요격특성개전방진연구,분석료요격도갑솔수절연수평、보호각적변화규률,연구료전형지형조건하뇌전요격로경화요격전류적분포특성,분석료산파、산척화과곡지형조건하선로적요격도갑솔,연구료선로겁성대도갑솔적영향。연구표명,감소보호각가명현강저요격도갑솔,재산파지형조건하,외측도선유우수병폐감약경역수도뢰격,뇌전선도가종근사수평적방향격중도선;과곡심도증가시,유우지면병폐작용감소,뢰격도갑솔명현제고;이론분석화운행경험도표명,직류선로정겁도선조수뢰격적개솔원고우부겁,선로위우산척시뇌전요격기본발생재정겁도선측。
Shielding failure of lightning is the key problem for safe operation of high voltage transmission lines,and lightning protection for ultra high voltage DC transmission lines are more significant.The method for analyzing the shielding failure rate of ultra high voltage transmission lines based on the leader progress method was introduced,by which the shielding failure characteristics were calculated.Effects of insulating levels,shielding angles and terrains on shielding failure rate were analyzed.Moreover,lightning path and current distribution of shielding failure under typical terrains were studied,and influence of polarity on shielding failure rate was analyzed.Results show that the shielding failure rate decreases with the decreasing of shielding angle.The conductor at outside of mountain slope is easier to be stricken because the shielding effect of ground lines is worse,and the lightning may strike the conductors horizontally.The shielding failure rate rises with increasing of valley depth.It is shown by both calculation and operation experiences that the shielding failure rate of the positive pole is much higher than the negative pole,and shielding failure trips almost happen on the positive pole on top of mountain ridges.