接地材料对杆塔接地装置冲击接地阻抗的影响  

Influence of Ground Material on the Impulse Ground Impedance of Tower's Grounding Devices

作　　者：曹方圆[1] 时卫东[2] 康鹏[2] 张波[1] 

机构地区：[1]清华大学电机工程与应用电子技术系,北京100084 [2]中国电力科学研究院,北京100192

出　　处：《中国电力》2016年第10期67-73,共7页Electric Power

摘　　要：雷电流通过接地装置散流时,接地装置本身和土壤电阻率的大小都会影响散流过程,从而影响接地装置的冲击接地阻抗。基于电磁场和电路相结合的计算方法,使用自主开发的软件,计算了接地本体材料、不同接地体长度、直径和不同土壤电阻率对冲击接地阻抗的影响,并通过时域电压波形对这几个参数影响冲击接地阻抗的机理进行分析。由计算结果可知,接地体的磁导率对冲击接地阻抗影响很大。在接地体成本固定的情况下,铜接地装置的接地体长度越长,冲击接地阻抗越小。钢接地装置的接地体长度即使增长,但由于有效长度有限,其冲击接地阻抗降低幅度并不明显。随着土壤电阻率的增大,铜接地装置的冲击接地阻抗线性增加,而钢接地装置的冲击接地阻抗增加趋于平缓。Grounding devices and soil resistivity affect the diffusion process when lightning current flows through grounding devices, and inherently affect the impulse grounding impedance of grounding devices. Based on the theory of electromagnetic fields and circuit method, this paper calculates the grounding impedance with different grounding materials, different lengths and diameters of grounding body, and different soil resistivity by using self-developed software. The time-domain voltage waveform is used to analyze the mechanism of the impulse grounding impedance influenced by above mentioned parameters. The analyzing results show that the magnetic permeability of grounding body has a great influence on the impulse grounding impedance. Under invariable cost of the grounding body, the longer grounding body of copper grounding device will lead the smaller impulse grounding impedance. Due to the limited effective length, the impulse grounding impedance reduction is not obvious with the increase of grounding body of steel grounding device. With the increase of soil resistivity, the impulse grounding impedance of copper grounding device increases linearly, but the impulse grounding impedance of steel grounding device is flattened out.

关 键 词：输电线路 接地装置 冲击接地阻抗 时域电压波形 接地材料 接地体长度直径 土壤电阻率 

分 类 号：TM862[电气工程—高电压与绝缘技术]