大风区接触网线路参数对附加导线舞动的影响

针对大风环境下兰新高速铁路接触网附加导线发生剧烈舞动以及线间放电的现象，依据接触网附加导线结构特点，建立了附加导线有限元计算模型，并对附加导线进行找形计算。采用谐波叠加法模拟接触网附加导线处的随机风场，并对导线模型施加风荷载，利用无条件稳定Newmark法以及荷载增量法，分析接触网线路参数对附加导线舞动及线间距离的影响规律，并给出相应的舞动防治措施。结果表明：40 m及更小档距对导线在低风速及高风速下的舞动均有明显的抑制效果；将附加导线运行张力提高至6.5 kN,导线阻尼比提高至1.5%及以上能有效降低两条导线的舞动剧烈程度；接触网附加导线的档距过大，运行张力及阻尼比过小，将导致导线舞动时悬挂点张力过大，易引起导线掉线、断线等事故；随附加导线档距减小、运行张力及阻尼比增大，线间最小距离呈递增趋势；不同线路参数下(档距、运行张力及阻尼比)附加导线舞动时线间最小距离均随风速增大出现减小趋势。本研究可为兰新高铁大风区段接触网附加导线舞动及线间放电的防治提供有效的理论依据。

Influence of overhead contact system line parameters on additional conductors galloping in strong wind region

In view of the phenomenon of violent galloping and line-to-line discharge of the additional conductors of the overhead contact system (OCS) of the Lanzhou-Xinjiang high-speed railway in the strong wind environment, according to the structural characteristics of the additional conductors of the overhead contact system, a finite element calculation model of the additional conductors is established, and the type finding calculation of the additional conductors is carried out. The random wind field at the location of the additional conductors in the overhead contact line is simulated using the harmonic superposition method. Wind loads are applied to the conductor model. The unconditional stable Newmark method and load increment method are used to analyze the influence of line parameters on additional conductors galloping and line distances. Corresponding measures to prevent galloping are proposed. The results show that a span of 40 m or smaller has an obvious inhibitory effect on the galloping of the conductors under both low and high wind speeds. Increasing the tension of the two conductors to 6.5 kN and the damping ratio of the conductors to 1.5% or higher can effectively reduce the galloping amplitude of the two conductors. When the span of OCS additional conductors is too large, and the initial tension and damping ratio are too small, it can lead to excessive tension at the suspension point during galloping, increasing the risk of conductor disconnection or breakage accidents. With the decrease of span and the increase of operating tension and damping ratio of additional conductors, the minimum distance between lines shows an increasing trend. Under different line parameters (span, operating tension and damping ratio), the minimum distance between lines decreases with the increase in wind speed. This research provides an effective theoretical basis for the prevention and control of additional conductors galloping and discharge between lines of OCS in the strong wind sections of the Lanzhou-Xinjiang high-speed railway.