Selective detection of simple grounding faults in medium voltage power networks with resonant earthed neutral system

The Influence of the Characteristics of the Medium Voltage Network on the Single Line-to-Ground Fault Current in the Resistor Grounded Neutral Networks

“…Figures [15][16][17] show that the value of the fault current (I d = 3 * I 0 ) depends insignificantly on the value of the zero-sequence voltage of the medium voltage bars in the absence of the phase-to-earth fault, which is no longer true for the current in the neutral grounding resistor of the medium voltage network (R n from Figure 1), respectively, for the capacitive current of the medium voltage network with a neutral grounding resistor. From Figure 14 it is found that for R t = 500 Ω and the loss angle of the insulation δ = 6 • , the current I 0 n increases from 14.5 A when U 0 e = 0 to 16 A when U 0 e = 500 V (represents 4.33% of U + e ), meaning an increase of 9.37%.…”

“…(b) Figures [14][15][16][17] show that the zero-sequence voltage of the medium voltage bus bars does not significantly influence the values of the zero-sequence current at the fault location; thus, implicitly the ground fault current can be neglected in the calculation. For example, for a perfect insulation (loss angle of 0 • ) and a ratio of U 0 e to U + e + of 5%, the error is 4.61%, whereas for a loss angle of 6 • (tanδ = 0.105) and a ratio of U 0 e to U + e of 5%, the error is 4.23%.…”

“…The sequence components method is used to calculate the fault current. In the literature it is shown that in the case of a phase-to-ground fault the sequence networks are connected in series [13][14][15][16][17][18], [21] (pp. 474-507), [22] (pp.…”

“…In works [13][14][15][16][17][18] are presented different methods for detecting line-to-ground faults that occur in medium voltage electrical networks. In the case of faults with very high fault resistance, the method of controlling the effective value of the current through the neutral grounding resistor of the medium voltage network is more efficient [3,4,7,10,19,20].…”

Analysis of positive and negative sequence parameters of overhead power lines over transient phases caused by short-circuits

“…An important selection criterion is the proportion of the electrical and electronic circuit components, rotating electrical machines, electrical networks, automatic control systems, etc., in the simulated system, as some programs, through their design, implement better some of these subsystems, than others. Under these conditions, the choice of one simulation program or another depends largely on the user's previous experience and how his specific problems are solved quickly and efficiently by the chosen program [18,19,20,21,22,23,24,25,26,27,28,29,30].…”