白沙水电站防雷设计改进措施探微

Improvement Measures of Lightning Protection Design of Baisha Hydropower Station

针对广东四会白沙水电站因雷击发生频繁烧毁设备和造成机组停机等现象进行原因分析,发现该电站主要故障与事故原因是防雷措施不完善造成的。在2022年机组改造时,对该电站的防雷设计也进行改进,主要是限制中压侧雷电侵入波的陡度,抑制发电机绕组中性点侵入波的全反射过电压以及低压侧,按IEC相关LEMP的原则正确划分LPZ和分级选择设备的绝缘配合水平。经过改进,今年虽遭几次雷击,电站均未出现设备故障或损坏现象,防雷效果良好。经了解,广东省此类电站甚多,相应防雷措施可供其借鉴。

An analysis of the frequent occurrence of equipment damage and unit shutdown due to lightning strikes at the Baisha Hydroelectric Power Station in Sihui,Guangdong province,reveals that the primary faults and incidents at the station are due to inadequate lightning protection measures.In 2022,the lightning protection design of the station was enhanced to limit the steepness of the lightning intrusion wave on the medium-voltage side,suppress the total reflection overvoltage and low voltage of the inrush wave at the neutral point of the generator winding,and correctly divide the LPZ and select the insulation coordination level of the equipment according to the principles of IEC related LEMP.After these improvements,the power station has experienced several lightning strikes so far without any equipment failures or damages,demonstrating the good effect in lightning protection.The corresponding lightning protection measures can provide a reference for similar power stations.