Analysis of the Influence of the Insulation Parameters of Medium Voltage Electrical Networks and of the Petersen Coil on the Single-Phase-to-Ground Fault Current

Abstract

Settings of protection are essential to ensure the sensitivity and selectivity needed to detect defects. Making the correct settings requires the calculation of the fault currents with as little error as possible. Fault currents are influenced by the parameters of the electrical networks, including the state of the insulation and the Petersen coil, which changes during their operation electrical networks. This paper analyzes how the insulation parameters of medium voltage power lines, the parameters of the Petersen coil used to treat the neutral of the medium voltage electrical network and the value of the resistance at the fault location influence the fault current in the case of a single-phase fault. The large number of single-phase faults that occur in medium voltage electrical networks justifies this analysis. The symmetrical components method was used to calculate the fault current. The results obtained by calculation were verified experimentally by causing a single-phase-to-ground fault in a real medium voltage network. The paper presents the situations in which the analytical calculation of the single-phase-to-ground fault current can lead to inadmissibly large errors, even over 50%, but also the situations in which the errors fall below 3%.

Ground Fault in Medium-Voltage Power Networks with an Isolated Neutral Point: Spectral and Wavelet Analysis of Selected Cases in an Example Industrial Network Modeled in the ATP-EMTP Package

“…Many research works are devoted to the analysis of ground fault phenomena in MV networks with resonant-grounded [9][10][11] or resistor-grounded [12] neutral and containing overhead lines [4,[13][14][15]. However, the operating conditions of these networks differ significantly from those of distribution networks installed in underground mines [1].…”

Research on single-phase grounding fault detection method based on vision transformer

“…When a single-phase ground fault occurs in the distribution network, the line voltage remains symmetrical and does not immediately affect the power supply to the terminal, which improves the reliability of the power supply to a certain extent [2][3][4]. When a single-phase ground fault occurs in a distribution network using low-current grounding, the fault can run for 1-2 hours, but the two-phase voltage of the non-faulted line will increase to the original value multiplied by the square root of 3, which will have a certain impact on the insulation of the distribution network, and more seriously, it may cause large-scale power outages [5]. Therefore, we must quickly identify the occurrence of single-phase ground faults when they happen.…”

A Novel Faulty Phase Selection Method for Single-Phase-to-Ground Fault in Distribution System Based on Transient Current Similarity Measurement

“…Arc suppression coils have been widely used in power distribution systems in China and Europe [1,2]. When a single-phase-to-ground fault (SPG) occurs in the distribution network, the arc suppression device will compensate the fault current and then prevent the fault arc from reigniting [3,4].…”