Performance of earthing systems at steady-state and under impulse conditions

It is important to have a proper protection system in order to protect any equipments from high currents. High impulse currents can be caused by lightning, temporary over voltages and over loading. Under protection systems, a few research areas can be addressed such as on relay protection systems, SCADA or Supervisory Control and Data Acquisition and lightning protection systems. The effectiveness of these protection systems must have to rely on the proper design of earthing systems, to ensure high impulse currents can be discharged effectively to the ground. Study on the performance of earthing systems under impulse conditions has becoming important due to its different characteristics than that at steady-state conditions. However, it is still unclear on many aspects of differences in the performances of earthing systems under high impulse conditions such as reduction of earth resistance, ´nonlinearity´ in earthing systems and degree of this nonlinearity. This paper is therefore directed into this direction.