Characteristic study of two-layer vertical grounding system for variation of length rod and high frequency injection current (100kHz–14MHz)

Soil has unique characteristics when injected with currents. These characteristics depend on frequency and magnitude of current injection. Grounding system on power frequency consider only resistive properties. However at high frequency, the parameters not only used resistance; capacitance and inductance parameter must also be considered. In this research, testing method performed by measuring two-layer vertical grounding by injecting a low magnitude current (μA-mA order) and injection frequency between 100kHz to 14 MHz in three models of two-layer vertical grounding system. The result shows that at high frequency, three model has a significant increase in grounding impedance; for longer rod and higher frequency injection current, grounding impedance will be smaller.