土壤非线性击穿效应对垂直接地体散流特性的影响

发布时间：2018-04-28 10:24

本文选题：垂直接地体 + 冲击特性　；参考：《电网技术》2017年05期

【摘要】：基于L-D(Liew and Darveniza)提出的土壤非线性击穿模型,利用Taku Noda和Yoshihiro Baba等分别提出的导体在无耗介质和有耗介质中的细导线处理方案,开发了一套三维时域有限差分(three dimension finite-difference timedomain,3-D FDTD)算法,研究了在不同雷电流幅值和波形以及土壤低频电导率作用下,土壤非线性击穿效应对垂直接地体受土壤击穿影响的散流区域、冲击阻抗和暂态地电位升等参数的影响。结果表明,当土壤低频电导率为0.02 S/m和0.005 S/m时,垂直接地体横向散流半径分别约为0.5 m和1.2 m;接地极尖端部位的纵向散流区域分别约为0.3 m和0.9 m。此外,暂态地电位升的变化特性与注入的雷电流幅值和波头时间以及土壤低频电导率密切相关,但无论是否考虑土壤击穿效应,垂直接地极冲击阻抗最大值保持不变,仅决定于土壤低频电导率等相关土壤特性参数。工程上定义的冲击阻抗值仅表征了未考虑土壤击穿情况下的稳定阶段阻抗值,远小于文中计算的冲击阻抗最大值。
[Abstract]:Based on the soil nonlinear breakdown model proposed by L-D(Liew and Darvenza, a 3-D finite-difference time-domain 3-D FDTD algorithm is developed by using the thin conductor processing scheme proposed by Taku Noda and Yoshihiro Baba in lossless and lossless media, respectively. Under different lightning current amplitude and waveform and soil low frequency conductivity, the effects of soil nonlinear breakdown effect on the parameters such as impulse impedance and transient earth potential rise in vertical grounding system affected by soil breakdown were studied. The results show that when the soil low frequency conductivity is 0. 02 S / m and 0.005 S / m, the transverse diffusing radius of the vertical grounding body is about 0. 5 m and 1. 2 m, respectively, and the longitudinal diffusing region at the tip of the earth pole is about 0. 3 m and 0. 9 m, respectively. In addition, the variation of transient ground potential rise is closely related to the amplitude of lightning current injected, the time of wave head and the low frequency conductivity of soil, but the maximum impulse impedance of vertical grounding pole remains unchanged regardless of whether the soil breakdown effect is considered or not. It only depends on the soil characteristic parameters such as the low frequency conductivity of soil. The value of shock impedance defined in engineering only represents the impedance of stable stage without considering soil breakdown, which is far less than the maximum value of impact impedance calculated in this paper.
【作者单位】：气象灾害预报预警与评估协同创新中心(南京信息工程大学);云南电网有限责任公司电力科学研究院;苏州气象局;
【基金】：国家重点基础研发项目(2014CB441405) 国家自然科学基金项目面上项目(41575004)~~
【分类号】：TM862

【相似文献】