Low-voltage cable systems: aluminium conductor corrosion and online monitoring

The role of the low-voltage grid is changing from being just the final step in the power supply chain to facilitator of renewable energy generation on residential level. Therefore, its importance is steadily increasing in terms of grid reliability. Parts of the low-voltage grid, however, are ageing. These developments increase the need of distribution system operators to further find economically feasible ways to monitor and diagnose their low-voltage assets. Firstly, this paper looks into degradation mechanisms, in particular corrosion of aluminium conductors, a phenomenon that may, for instance, occur in case a damage is inflicted to a cable without directly causing a loss of connection. Secondly, the presence of high peak currents with short duration are being measured in the field. The research aims to create better understanding of the relation between the occurrence of peak currents and subsequent failures in the connection.