架空传输线雷电感应电压计算公式分析与修订

利用二维时域有限差分法(FDTD)实现了对雷电感应电压的计算,并与已有研究成果对比验证了该方法的有效性。研究分析了DL/T 620-1997中规程公式估算架空传输线雷电感应电压峰值的精度,其中定性研究发现,雷电感应电压峰值与电流幅值、架空线高度之间为正相关关系,而与距离成负相关关系,这种敏感性关系与FDTD的模拟结果相同;而定量研究结果发现,规程公式计算的雷电感应电压值与FDTD计算的电压值相比均偏小。在此基础上,本文提出通过修订系数k对规程公式进行改进,通过FDTD模拟确定了修订系数k的取值为1.6,将规程公式修订为40 I0·h·S-1。最后,本文利用LIOV程序对修订后的规程公式进行精度检验,结果发现,当雷击通道与架空传输线之间距离为100 m和400 m时,修订后规范公式计算得到的雷电感应电压峰值最大误差仅为3.7%和5.5%,从而证明,利用修订后的规程公式可以更加准确地计算架空传输线上的雷电感应电压峰值。

Analysis and revision for formula of lightning induced voltage on overhead transmission line

The two-dimensional finite difference time domain(FDTD) method is used to calculate the lightning induced voltages in this paper. By comparing with the previous research results, the effectiveness of the proposed method is verified. Then, the qualitative and quantitative analysis on the formula of induced voltage peak in the DL/T 620-1997 are discussed. The qualitative research results show that the lightning induced voltage peak is positively correlated with current amplitude and overhead line height, but negatively correlated with the distance. These results are the same with the FDTD simulation results. But in the quantitative research, the calculation result from rule formula is smaller than that from FDTD simulation. On this basis, the revision coefficient k is proposed to improve the formula, and k is determined to be 1.6 and the formula should be revised to 40 I₀·h·S^-1. Finally, the accuracy of the revised formula is tested by the LIOV software. When the distance between the lightning channel and overhead transmission line are 100 m and 400 m, the results show that the maximum error of voltage peak value are only 3.7% and 5.5% respectively. It can be proved that the peak value of lightning induced voltage on the overhead transmission line can be calculated more accurately by using the revised formula.