采用长垂直接地极的TB型接地装置优化设计

Optimized Design of TB Grounding Device by Using Long Vertical Grounding Electrode

针对输电线路杆塔TB型接地装置采用长垂直接地极的冲击降阻效果进行研究。设计了一种绝缘短屏蔽的方法定量计算垂直接地导体的最优长度,得到其与土壤电阻率之间的拟合关系;对垂直接地导体的优化布置方式进行理论分析,并通过实例验证了不同垂直接地导体布置方式下的冲击降阻效果。结果表明:利用绝缘短屏蔽的方法确定长垂直接地导体最优长度的方法可行;最优长度随着土壤电阻率的增大而增长;当接地装置尺寸较小时,由于屏蔽效应,延长单根垂直接地导体长度比增加垂直接地导体数量的冲击降阻效果好。

This paper studies effect of impulse resistance reduction for the TB grounding device of power transmission line tower by using the long vertical grounding electrode. It designs a kind of insulated short shielding method to quantitatively calculate the optimal length of the vertical grounding conductor and obtain the fitting relationship between the optimal length and soil resistivity. Meanwhile, it analyzes optimal arrangement patters of the vertical grounding conductor theoretically and verifies effects of impulse resistance reduction under different arrangement patterns on the basis of actual examples. The results indicate it is feasible to determine the optimal length of the long vertical grounding electrode by using the insulated short shielding method. In addition, the soil resistivity is higher, the optimal length is longer. As the size of grounding device is small, the impulse resistance reduction effect of increasing length of single vertical grounding conductor is better than that of increasing numbers of the conductor due to shielding effect.