TITLE:
Investigation of Ground Frequency Characteristics
AUTHORS:
Mohamed Nayel
KEYWORDS:
Ground; Transient; Four Electrode Method; Frequency; Impedance
JOURNAL NAME:
Journal of Electromagnetic Analysis and Applications,
Vol.5 No.8,
August
6,
2013
ABSTRACT: Four-electrode method is one of the
well-known methods in measuring ground resistivity. But, most faults currents and lightning
currents have high frequencies components. It is proposed to develop this
method to study ground frequency characteristics. A step like current was
injected into ground to measure the ground impedance. The ground impedance is
assumed to be frequency dependent parallel resistance/capacitance. Two
equations were proved to estimate ground resistivity and permittivity from four-electrode
method. An analytical model was proposed to model studied cases. The four
electrodes are divided to equal spheres and complex image method had been used
to satisfy the boundary conditions and penetration depth effects. The
calculated results show good agreement with the measured results.