PW线升高或架设避雷线雷电防护效果综合评估

Comprehensive Evaluation on Lightning Protection Effect of Elevating the Protection Wire or Setting Lightning Conductor of Catenary System

升高PW线兼做避雷线或单独架设避雷线可以有效提高接触网雷电防护性能。为了评估2种改造方案雷电防护效果,通过电磁暂态仿真程序(EMTP)仿真计算接触网2种改造方案耐雷性能;并基于电气几何模型(EGM)推导了自耦变压器(AT)供电方式接触网雷击跳闸率计算式,计算了改造前后雷击跳闸的变化。计算结果表明:2种方案均可以有效提高接触网反击耐雷性能,第1种方案反击耐雷性能提高20%左右,第2种方案反击耐雷性能提高40%左右,对绕击耐雷性能影响不大。通过对跳闸率计算可以发现,采用第1种方案总雷击跳闸率有效降低64.9%,而采用第2种方案总雷击跳闸率有效降低70.4%。同时,接触网改造后增加了反击跳闸率,并且随着接地电阻的降低,反击跳闸率降低。计算结果可为接触网防雷改造提供参考依据。

Elevating the protection wire or setting the lightning conductor is an effective measure to improve the lightning protection performance. In order to evaluate the lightning performance of two schemes, we analyzed the lightning per- formance by the EMTP software. Based on the electrical geometry model, the calculation formula of the lightning trip rate of auto transformer （AT） power supply mode is derived. Moreover, we also calculated the lightning trip before and after transformation. The calculation results show that two schemes can improve the lightning protection of back striking. The lightning performance of back striking of the first scheme increases by about 20% and the second scheme increases by about 40%. The two schemes hardly have effects on lightning protection performance of shielding failure. The total lightning trip-out rate of the first scheme decreases by about 64.9% and the second decreases by about 70.4%. At the same time, the back striking trip-out rate also increases. And the back striking trip-out decreases with the decrease of grounding re- sistance after the catenary construction. The results can provide references for the lightning protection of catenary construction.