Accelerated Aging of MV Cables as a Function of Grid Utilization

The utilization of the electrical grid in Germany, as in other countries worldwide, will change significantly in the next years. Distribution system operators (DSO) have to adapt to various new challenges, which are mainly related to the integration of renewable and distributed energy resources (DER). The renewable power production is changing the usage behavior of the distribution network, which in turn influences the ageing of the grid components. In this respect, medium voltage (MV) networks are affected in particular, as they have a relatively high proportion of cable lines, whose ageing is strongly dependent on the load. An adaption of the Montsinger rule makes it possible to describe the degeneration of paper-insulated lead covered cables (PILC cables) in dependency of different utilization profiles. This type of cable occurs in high proportions in medium-voltage networks. To investigate the influence of renewable energies to the grid, a simulation of a synthetic network is considered that is stressed with different generation and standardized load profiles. The model indicates a significant impact of the degeneration of the cables, due to the deviating load flows through the renewable energies.