电网技术
電網技術
전망기술
POWER SYSTEM TECHNOLOGY
2012年
3期
234-240
,共7页
重覆冰区%特高压%悬垂型杆塔%不平衡张力
重覆冰區%特高壓%懸垂型桿塔%不平衡張力
중복빙구%특고압%현수형간탑%불평형장력
heavy icing area%UHV%tangent tower%unbalanced tension
分别采用有限元分析方法与等线长法计算了典型耐张段的不平衡张力和悬垂串偏移量,这2种方法的计算结果基本一致。通过建立连续7档导线一绝缘子有限元模型,考虑多种线路设计参数的影响,分析了不同工况下重覆冰区特高压悬垂型杆塔的导线张力及不平衡张力。结果表明,覆冰加载模式、覆冰偏心和覆冰风速对不平衡张力影响不大,建议采用换算密度法模拟覆冰荷载并考虑10m/s覆冰风速。不考虑档距差和高差时,随冰厚、档距和覆冰率的增加,导线不平衡张力百分数逐渐增加,计算得到的不同冰厚下特高压悬垂型杆塔不平衡张力百分数均小于规程规定值。随高差和档距差的增加,有高差和档距差的不平衡张力与无高差、无档距差的不平衡张力比值增大;随冰厚的增加,不平衡张力比值减小。30mm及以下重覆冰区,不平衡张力百分数按照现行重覆冰区规程规定取值。40、50mm重覆冰区,应将不平衡张力百分数分别提高至35%和41%。
分彆採用有限元分析方法與等線長法計算瞭典型耐張段的不平衡張力和懸垂串偏移量,這2種方法的計算結果基本一緻。通過建立連續7檔導線一絕緣子有限元模型,攷慮多種線路設計參數的影響,分析瞭不同工況下重覆冰區特高壓懸垂型桿塔的導線張力及不平衡張力。結果錶明,覆冰加載模式、覆冰偏心和覆冰風速對不平衡張力影響不大,建議採用換算密度法模擬覆冰荷載併攷慮10m/s覆冰風速。不攷慮檔距差和高差時,隨冰厚、檔距和覆冰率的增加,導線不平衡張力百分數逐漸增加,計算得到的不同冰厚下特高壓懸垂型桿塔不平衡張力百分數均小于規程規定值。隨高差和檔距差的增加,有高差和檔距差的不平衡張力與無高差、無檔距差的不平衡張力比值增大;隨冰厚的增加,不平衡張力比值減小。30mm及以下重覆冰區,不平衡張力百分數按照現行重覆冰區規程規定取值。40、50mm重覆冰區,應將不平衡張力百分數分彆提高至35%和41%。
분별채용유한원분석방법여등선장법계산료전형내장단적불평형장력화현수천편이량,저2충방법적계산결과기본일치。통과건립련속7당도선일절연자유한원모형,고필다충선로설계삼수적영향,분석료불동공황하중복빙구특고압현수형간탑적도선장력급불평형장력。결과표명,복빙가재모식、복빙편심화복빙풍속대불평형장력영향불대,건의채용환산밀도법모의복빙하재병고필10m/s복빙풍속。불고필당거차화고차시,수빙후、당거화복빙솔적증가,도선불평형장력백분수축점증가,계산득도적불동빙후하특고압현수형간탑불평형장력백분수균소우규정규정치。수고차화당거차적증가,유고차화당거차적불평형장력여무고차、무당거차적불평형장력비치증대;수빙후적증가,불평형장력비치감소。30mm급이하중복빙구,불평형장력백분수안조현행중복빙구규정규정취치。40、50mm중복빙구,응장불평형장력백분수분별제고지35%화41%。
Both unbalanced tension in typical strain section and end displacement of insulator string due to the unbalanced tension are calculated by finite element analysis (FEA) and equal conductor length method respectively, and calculation results of the two methods are nearly the same. By means of building a finite element model for conductor-insulator in continuous seven spans and considering impacts of various design parameters of transmission line, the tension and unbalanced tension of transmission line erected on UHV tangent towers located at heavy icing area under different operating conditions are analyzed. Analysis results show that there are little influences of ice accretion modes, eccentricity of ice coating and wind speed during icing process on unbalanced tension, thus it is suggested to simulate the load of ice coating by equivalent density method while the wind speed during icing process is taken as 10 m/s. Without regard to span differences and elevations differences, the unbalanced tension percent of conductor is gradually increased with the increasing of ice thickness, span and ice accretion rate, and the calculated unbalanced tension percentages of UHV tangent tower under different ice thicknesses are smaller than those specified in the regulations; when the span differences and elevations differences are increased, the ratio of unbalanced tension of transmission line with span differences and elevations differences to unbalanced tension of transmission line without span differences and elevations differences is gradually enlarged; the unbalanced tension will be decreased with the increasing of ice thickness. For heavy icing areas with ice thickness of 30 mm and lower, the value of unbalanced tension percentages should be taken as that specified in existing regulation for heavy icing area. For heavy icing areas with ice thickness of 40 mm and 50 mm the unbalanced tension percentages should be increased to 35% and 41% respectively.