Acquisition and Integration of Empirical Ageing Data of MV Cables in the Asset Management of MV Grids

Inhalt:
Distribution system operators in Germany and worldwide are facing rising pressure to operate their electrical grids as reliably, efficiently and cost-effectively as possible. In particular, the medium-voltage network represents a major task here. It represents a large proportion of the distribution networks, but in this voltage level – unlike in the high and extra-high voltages – currently there are few measurement and monitoring points that allow conclusions about the utilization or the condition of the cable sections. For this reason, system operators often have to rely on assumptions and estimates for asset simulations, since there is usually insufficient data available on the operating equipment to make well-founded statements on typical service lifetime curves. Therefore, a project was initiated to artificially age paper insulated lead covered cables at an accelerated rate. With the experimental setup, the degeneration process of NKBA cables will be investigated in detail. The goal of the project is to accurately investigate the ageing behavior during the service life up to the failure of the individual cable specimens. The system is fully automated to document the continuous ageing process. Regular monitoring of relevant characteristic values, such as dielectric parameters, temperature, currents and voltages, will generate a comprehensive database. Based on the data obtained, reliable diagnostic criteria and procedures for describing the ageing behaviour and evaluating the remaining service life can be derived in the future.