Ground Impedance Tests

ground impdeance testing, ground earth test

In order to simulate a single-phase fault a test current is injected into one of your power lines by using a frequency variable current source and grounding the remote end of the line. Then you measure the voltage between the grounding system and a spike driven into the soil close to the fence around a substation. You repeat this measurement by increasing the distance between the spike and the grounding system until the voltage is not increasing anymore. The voltage of the last measurement location is now calculated up to the ground potential rise under real fault conditions.

For suppression of interferences, conventional test methods use high power injection at the mains frequency. You can freely select the frequency with our system. Injecting a signal with a frequency higher or lower than the mains frequency and applying a steep filter suppresses the interference effectively. Our test systems use this technique and allow you to inject much smaller currents for gaining accurate measurement results.

Recommended solutions for ground impedance testing

CPC 100 + CP CU1

Impedance measurements of large grounding grids

COMPANO 100

Impedance measurements for small stations