Analysis of the Possibilities of Selective Detection of a Single Line-to-Ground Fault in a Medium Voltage Network with Isolated Neutral

The paper analyses how the characteristics of medium-voltage network with insulated neutral and conditions under which single line-to-ground fault occurs (insulation condition value resistance) influence zero-sequence components voltage transformer station bus bar, current, currents faulted line other non-faulted power lines connected to bars. Assuming waveform medium voltages in is known, resistance on total distortion coefficient current analysed. This establishes a can be detected by controlling fault-free lines. It also examines selectively checking effective direction flow during fault. results obtained calculation were verified experimentally considered study. acceptable differences, considering degree accuracy parameters are between those show that simplifying assumptions accepted for mathematical models used correct.