CAJ | 학술논문

针对目前我国基于有限元法的不均匀覆冰输电塔线体系力学特性研究的不足,以输电线路耐张区间的山顶杆塔为主要研究对象,考虑杆塔两侧导地线不均匀覆冰工况,对短档距侧重覆冰、长档距侧重覆冰以及档距中央重覆冰3类不均匀覆冰状态的33种具体运行工况下输电塔线体系用有限元法定量研究了不均匀覆冰的力学特性。结果表明：不均匀覆冰状态下,3层横担鼓型铁塔横担应力随基本覆冰厚度的增加呈现指数增长趋势,由于横担设计结构的差异,致使中、下横担轴向应力增长趋势较上横担平缓,而弯曲应力却增长剧烈;3类不均匀覆冰状态下,杆塔塔身应力随覆冰厚度增加量d的变化,呈现不同的变化趋势,短档距侧重覆冰时,塔身应力先减小后增大,而长档距侧重覆冰和档距中央重覆冰时,塔身应力基本呈指数增长,说明不均匀覆冰状态下塔线体系应力值同时受到档距参数的影响。
침대목전아국기우유한원법적불균균복빙수전탑선체계역학특성연구적불족,이수전선로내장구간적산정간탑위주요연구대상,고필간탑량측도지선불균균복빙공황,대단당거측중복빙、장당거측중복빙이급당거중앙중복빙3류불균균복빙상태적33충구체운행공황하수전탑선체계용유한원법정량연구료불균균복빙적역학특성。결과표명：불균균복빙상태하,3층횡담고형철탑횡담응력수기본복빙후도적증가정현지수증장추세,유우횡담설계결구적차이,치사중、하횡담축향응력증장추세교상횡담평완,이만곡응력각증장극렬;3류불균균복빙상태하,간탑탑신응력수복빙후도증가량d적변화,정현불동적변화추세,단당거측중복빙시,탑신응력선감소후증대,이장당거측중복빙화당거중앙중복빙시,탑신응력기본정지수증장,설명불균균복빙상태하탑선체계응력치동시수도당거삼수적영향。
There are differences in mechanical properties of towers and lines because of their different operating conditions,topography,microclimate and other factors,and these differences would be more prominent under ice condition.There will be unbalanced tension along the lines when the conductor and ground wires of adjacent spans are non-uniformly iced,leading to wires necking,fracture,insulators damage,rupture,tower cross arm torsion,deformation,insulators flashover and wires flashover because of the reduce of gap,these accidents seriously threat to the security of grid operation.To solve this problem,a typical tower on 500 kV transmission line in Chongqing was chosen to be an object,and an accurate finite element model in three-tower-two-line form was created.Then tower-line system was simulated in 33 different operation conditions.These operation conditions could be classified in 3 types,namely,short span was heavy iced,long span was heavy iced,and the middle segment of spans was heavy iced.Moreover,components of the tower which could reflect the operation conditions most effectively were determined to be targets and the stress values of these components under different conditions were recorded in detail.The results reveal that the stress on tower cross arms increases exponentially with the increase of basic ice thickness in non-uniformly iced state by function fitting,due to differences in structure design of cross arm,resulting in more slow increase of axial stresses of middle and bottom cross arms than the top cross arm,while bending stresses increase more quickly than the top cross arm;in three types of non-uniform ice conditions,ice tower stress changes with changes in the amount of d,showing different trends： when short-span is iced,the tower stress decreases and then increases,while the long-span and middle span are repeatedly iced,the tower stress increases at an exponential rate,indicating that uneven ice line system is affected by stress parameters.