不同电压等级下架空导线对雷达的无源干扰

输电线路对邻近无线电台站的无源干扰可能影响无线电台站信号的有效接收和发射,因此准确计算在外界电磁波入射情况下输电线路的电磁散射是确定两者合理避让间距的基础。其中对于雷达台站而言,由于雷达的工作方式等影响,架空导线是影响雷达探测的主要因素。高压架空输电线等设施作为障碍物,如果距离雷达站过近,会破坏雷达阵地反射面的要求,使雷达波瓣变形,进而影响探测性能;还会对雷达造成一定的遮蔽角或电磁波减弱,从而使雷达遗漏目标或探测距离降低。由于在不同电压等级下,输电线路的分裂系数、杆塔类型决定的线路高度及排列方式都会发生改变。针对一般情况下应用多级子算法开展架空导线的等效半径、高度和水平排列对雷达的无源干扰计算,得出了三条结论:当计算频率低于450 MHz时,可以用等效半径模拟分裂导线计算,高于这一频点情况下必须建立分裂导线模型;在误差允许的范围内,导线高度对电场强度遮蔽损耗的影响较小;同时导线水平排列不存在前后导线的遮蔽现象。从而对研究输电线路对无源干扰的影响具有应用指导作用。

Passive interference of overhead conductors to radar under different voltage levels

: The passive interference of transmission lines to nearby radio stations may affect the effective reception and transmission of radio station signals. Therefore, it is the basis for determining the reasonable avoidance distance between the two. For radar stations, overhead wires are the main factors affecting radar detection due to the influence of the working mode of the radar. In this paper, the multi-level sub-algorithm is applied to calculate the passive interference of the equivalent radius, height and horizontal arrangement of overhead conductors. It is concluded that when the calculation frequency is lower than 450MHz, the equivalent radius can be used to simulate the split conductor calculation. Above this frequency, the split conductor model must be established; within the allowable range of error, the wire height has less shielding loss on the electric field strength; at the same time, the horizontal arrangement of the wires does not have the problem of shielding of the front and rear wires. This provides a modeling basis for studying the effects of transmission lines on passive interference.