Abstract
Due to the age structure of many cable distribution networks with the associated reduced insulation strength or due to the progress of the cable construction, it is increasingly necessary to implement alternative concepts for the star-point treatment (low ohmic, transient low ohmic in resonant grounded networks) instead of the resonance star-point detection. However, the high fault currents or the associated fault location concepts or the increase in the residual currents lead to new requirements for the earthing and fault current return systems, in particular regarding the people’s safety in case of an earth fault.
In this study, the authors show the effect of conductive structures (cable shields, cable earthing electrodes) on the fault current distribution as well as the earth potential rise in urban cable grids in the case of high current earth fault. Even under the influence of fault currents of a few kA a majority of the observed touch and step voltages is permissible in global earthing systems. It is further shown which mechanisms are responsible for this behavior.
In this study, the authors show the effect of conductive structures (cable shields, cable earthing electrodes) on the fault current distribution as well as the earth potential rise in urban cable grids in the case of high current earth fault. Even under the influence of fault currents of a few kA a majority of the observed touch and step voltages is permissible in global earthing systems. It is further shown which mechanisms are responsible for this behavior.
| Translated title of the contribution | Global earthing systems in urban cable grids |
|---|---|
| Original language | German |
| Pages (from-to) | 420-425 |
| Number of pages | 6 |
| Journal | Elektrotechnik und Informationstechnik |
| Volume | 134 |
| DOIs | |
| Publication status | Published - 1 Dec 2017 |