Evaluation of earth fault current estimation method from fault records

The fault current level is a critical parameter for assessing the hazard posed by step and touch voltages, particularly during earth faults, which are the most common type of fault at the medium voltage (MV) level. Estimating the fault current provides an objective means of evaluating the risk level associated with these faults without the need for experimental measurements. Thi s paper presents a verification and evaluation of a specific method for residual current estimation, based on the analysis of data stored in fault records. The study focuses on evaluating this method using several tens of fault records obtained during artificially created earth faults in various locations of MV network.