A NEW APPROACH FOR ANALYSIS OF NONCONVENTIONAL GROUNDING INSTALLATIONS BY MEANS OF FEM

摘要

Grounding installations with electrodes encased in current-conductive medium (in most of the cases concrete with current-conductive ingredients inside) are more and more often met for application in high voltage electrical power facilities, such as power substations and power plants, where the soil resistivity has inadmissibly high values or there is an increased risk of electrochemical electrode corrosion. Since the conventional grounding installations analysis and design are performed easily by analytical calculations or via specialized commercial software products, the same is not valid for grounding installations with conductive medium incased electrodes. In such cases the FEM implementation is an excellent approach for modeling and design of this non-conventional type of grounding installations regardless of the engaged electrodes type, their configuration and geometry. Furthermore, using FEM it is easy to investigate the respective grounding installation behavior in fault situations e.g. calculation and graphical interpretation of earth surface voltage distribution, maximum step- and touch-voltages calculations in case of short circuits etc. The procedures and studies presented inhere are performed for single conductive concrete encased electrodes but the same approach is suitable for design of overall grounding installations involving conductive concrete encased electrodes.