避雷器残压衰减技术在变电站二次设备防雷中的应用

Application of Technology to Attenuate Residual Voltage on Lightning Arrester for Lightning Protection of Secondary Equipment in Substation

为避免避雷器动作后产生的高残压造成二次设备的损坏,针对避雷器残压远远大于二次设备芯片耐雷水平的情况,研制开发了对避雷器残压有大幅衰减作用的中和变压器。试验表明,中和变压器对避雷器的残压衰减率可达90%以上,使二次设备的耐雷水平与残压衰减后的避雷器形成合理的绝缘配合。运行经验表明,中和变压器的使用极大地降低了二次系统雷击故障率。目前该技术已实际应用在多个综合自动化变电站中,并取得了良好的效果。

In order to avoid destruction of secondary equipment by high residual voltage on the lightning atrester after discharge, neutralizing transformer has been developed to largely attenuate the residual voltage on the lightning attester which would be far higher than the durability to lightning of secondary equipment. Experiment show that the neutralizing transformer can attenuate the residual voltage up to more than 90 % to realize a reasonable coordination between the attenuated residual voltage of lightning attester and lightning protection level of secondary equipment. It has also verified by operation experience that the application of neutralizing transformer greatly reduce the lightning failure rate of secondary equipment. Now this technology has been practically applied in many composite automation substations with fine effects.