Evaluation of Measurement Accuracy of Ground Impedances in Counterpoise according to Location of Auxiliary Electrodes

보조전극의 위치에 따른 매설지선의 접지임피던스 측정정확도의 평가

The ground resistance has been used as a method of estimating the capability of counterpoise. When transient currents blow through a ground electrode, it is reasonable to evaluate the performance of ground electrode system as a ground impedance instead of ground resistance. However, the measurement method of ground impedance for counterpoise is not clearly presented. This paper describes the measurement method of ground impedance considering the earth mutual resistances and AC mutual coupling. When we measure the ground impedance, the error due to earth mutual resistances depends on the distance between the auxiliary electrodes and the electrode under test. The measurement accuracy of high frequency ground impedance is mainly influenced by the location of the current electrode and the potential electrode.