大雨环境下雨滴对线路电晕特性的影响

Influence of Rain Drops on Corona Discharge in AC Transmission Lines Under High Rainy Condition

除了导线表面的状态和成分,导线附近大气状况也是引起导线电晕特性变化的重要因素。可听噪声、无线电干扰是反映电晕特性变化的重要参数。通过自制淋雨装置,在小型电晕笼中对单根LGJ-400/50型实际输电导线进行干燥和淋雨情况下的电晕实验,并利用无线电干扰接收机和声级计检测电晕放电情况。实验结果显示,同等电压下LGJ-400/50型导线在大雨状况下,可听噪声和无线电干扰值明显增加,在干燥时的电晕起始电压附近有最大差值;施加电压超过干燥时电晕起始电压后,随施加电压的增长,干燥和淋雨情况下的可听噪声和无线电干扰值差值均减小。

Besides condition and material of electrode surface,the dielectric distributed around the surface of electrodes has significant influence on the corona discharge.Audible noise and radio influence are two key characteristics reflecting the change of corona discharge pattern.With the self-constructed water spray apparatus,corona experiments of a single LGJ-400/50conductor were carried out in a small corona cage under both fine and rainy conditions.Corona cage is an effective and economical means for duplicating corona progress in power transmission lines with lower voltage on the conductor in the cage.The corona characteristics were measured by an electromagnetic interference test receiver and a sound meter.The results show that the audible noise and radio influence in heavy rain circumstance significantly increases compared with that of fine weather condition under the same voltage.The difference between two circumstances reaches a peak at the corona inception voltage of dry condition.Since the voltage is higher than the corona inception voltage of dry condition,the audible noise and radio influence decreases with the increasing voltage in both rainy and dry circumstances.