三极法中电压补偿电极的位置对接地电阻测量准确度的影响

Voltage Compensation Pole Position Effect on Measurement Accuracy of Ground Resistance for Three-pole Method

根据电磁学原理和互电阻理论,建立电压降法测量防雷接地电阻时三个电极位置关系的数学公式。分析认为三个电极相对位置的不确定性是接地电阻测量中产生误差的主要原因,电极的位置关系满足特定的公式是消除测量误差的必要条件。分析了接地电阻的两种测量方法,建议采用直线法对防雷装置接地电阻进行检测,以满足检测结果的精度要求。

According to the principles of electromagnetism and mutual resistance theory,a mathematical formula of three-electrodes positional relationship were built when the voltage drop method was used to measure the grounding resistors of lightning protection.The analysis results show that the relative position uncertainty of the three electrodes is the main reason of the measurement error,and the positional relationship which meets specific formula the between the electrodes is a necessary condition to eliminate measurement errors.The two measurement methods of ground resistance were analyzed.It is suggested that the straight-line method is used to measure the ground resistance of lightning protection device ,which meets the accuracy of detection results.