Research on Ground Impedance and Ground Admittance of the Buried Cable

In order to be convenient for choosing the calculation expression of buried cable's ground impedance, some of common expressions to calculate the buried cable's ground impedance were compared by theoretical analysis and numerical simulation. Then, the changing laws of ground impedance and admittance with earth conductance were analyzed. At last, the influence of ground admittance on buried cable's electromagnetic transient response was researched. Results show that: some expressions are accurate enough in low frequency, but when the frequency is high, the calculation deviation is large; buried cable's ground impedance is not sensitive to the ground conductivity, but the ground admittance varies strongly with the ground conductivity; and ground admittance has important influence on buried cable's electromagnetic transient analysis.