A new sensitive detection algorithm for low and high impedance earth faults in compensated MV networks based on the admittance method

Since the majority of all electrical faults in distribution networks are single line to earth faults, these events have a significant impact on the overall quality of power supply. The resonant earthing approach allows to limit the fault current in case of single pole earth faults (ground faults) and leads to a significant increased rise time of the recovery voltage. Consequently, most of the arcing ground faults will self extinguish and the quality of power supply is greatly increased. As a result a general trend towards the use of resonance earthing can be observed all over Europe. Due to the minimised fault current continuous network operation during sustained earth fault is possible. On the other hand, sensitive and highly reliable earth fault protection schemes are required to identify the faulty feeder without unwanted interruption of supply. In this paper, a new detection algorithm for low and high impedance earth faults based on the admittance method is presented.