Influence of Non-Linear Load on Single-Phase Fault Current in Electrical Networks with Isolated Neutral

The paper considers the influence of a non-linear load on the single-phase fault current in electrical networks with an isolated neutral. The conducted studies are aimed at assessing the electrical and fire safety of electrical networks operating in such a neutral grounding mode, when a significant number of non-linear consumers appear in them. It has been established that the presence of higher harmonics in the load current can lead to an increase in the effective value of the fault current. A method for calculating currents in the place of insulation damage is proposed, taking into account the non-linearity of the load. The influence of the transient resistance at the site of a single-phase fault on the value of the fault current and on its spectral composition is described. The experimental studies performed on a low-voltage power grid model confirmed the reliability of the calculations. This research was funded by the Federal Agency for Fishery of Russian Federation (contract No. 122030900054-0).