接地电阻测量环境影响机理及其对策

Influencing Mechanisms of Testing Environment on Earthing Resistance Measurements and Corresponding Countermeasures

接地电阻是反映防雷装置接地效果的重要技术指标之一,而接地电阻的测量与其环境密切相关。根据电容、电磁场理论,重点分析外界干扰源(高压输电线路、电视发射台或其他基站、地下电缆、轨道等)对接地电阻测量仪影响的机理。结果表明:外界干扰源通过容性耦合、阻性耦合和感性耦合严重干扰接地电阻仪的测量,在此基础上提出了屏蔽法和等电位测量方法是接地电阻测量中防范干扰的有效方法。

The earthing resistance is one of important technical parameters to reflect the earthing effect of lightning protection system; however, the testing of earthing resistance is closely related with its environment. According to the theory of electric capacity and electromagnetic fields, the influencing mechanisms of external interference sources, such as high voltage transmission line, television transmitting station or base station, underground cable, tracks etc., on earthing resistance testers are studied. The results show that the external interference sources seriously interfere the measuring of earthing resistance testing devices through capacitive coupling, resistive coupling, and inductive coupling. On this basis, it is concluded that the shield method and the equipotentiai bonding measuring method are effective for preventing interference on earthing resistance testing.