人工触发闪电引发的低压电源系统过电压特征

Characteristics of Induced Overvoltage Generated by Triggered Lightning in the Low Voltage Power Supply System

针对全国自动气象站采集器屡遭雷击致使不能正常业务运行的现象,开展了自动气象站电子设备电源系统雷电防护试验。利用人工触发闪电技术,对自动气象站采集器电源线路感应过电压进行了观测,对雷击造成的感应效应和采集器等电子设备的雷电防护关键技术进行了探讨。分析了多回击触发闪电引起输电线路的感应过电压特征、浪涌保护器(SPD)残压特征以及与触发闪电之间的关系。结果表明:近距离触发闪电的回击过程在架空线路上产生峰值达十几kV的双极性感应过电压,过电压可分为主峰值段和后续过电压两个阶段,其平均持续时间分别约100μs和4 ms,后续过电压持续时间与回击后连续电流的波动有关;在人工触发闪电的初始连续电流阶段也能感应>2 kV的过电压,且持续时间较长,过电压集中段时间约12 ms,平均电压332.5 V,其对输电线路造成的危害也不容忽视。SPD残压峰值与触发闪电电流峰值有较好的正相关关系,相关系数为0.86,SPD残压特性稳定,在一定程度上起到了限压泄流的作用。

The lightning protection on the power system of electronic equipment was tested, as AWSs collectors nationwide have been frequently struck by lightning and failed to operate normally. Using the artificially triggered lightning techniques, the induced effects caused by the lightning and the key lightning protection techniques research were developed near the lightning channel . The induced overvoltage characteristics and SPD residue voltage characteristics caused by triggered lightning with multiple return strokes on the transmission line of an AWS, as well as the relationship with the triggered lightning, were analyzed. The results show that： （a） The return strokes of the near triggered lightning generate bipolar induced overvoltages on the overhead line, with peaks up to more than 10 kV. The overvoltages can be divided into the main peak phase and the subsequent overvoltage phase, which last about 100μs and 4ms respectively on average. The period of the subsequent overvoltages is related to the fluctuation of the continuous current behind return stroke of the triggered lightning; （b） Overvoltages of 2 kV or above can be induced at the initial continuous current phase. They last a long period of time and concentrate about 12ms, with the mean voltage being a32.5V. Its potential damage to the transmission line cannot be neglected. Residue voltages of SPD play an effect on limiting voltage and releasing current in a degree with stable performance, and there is positive correlation between its peak value and peak current of triggered lighting, the correlation coefficient is 0.86.