Medium voltage network planning considering the current network and geographical restrictions

Within the scope of the structural change of the electrical power supply, distribution system operators face significant challenges. The expansion of distributed and renewable generation as well as the integration of new consumers brings many distribution networks to their limits of operation. Consequently, there is a need for network expansion. To implement suitable future network development regarding the change of the supply task, distribution system operators utilize reference network planning. For reference network planning usually a green field approach neglecting the existing network is approached. In most cases this leads to impractical reference networks. Considering the current network in the planning process can lead to more practical reference networks. Additionally cost reduction potentials can be identified, because using existing cable routes is cost-efficient in most cases due to high costs for cable trenches. This publication presents a methodology considering the current network structure and existing empty conduits within computer-based reference network planning. To increase the degrees of freedom in the planning process additional line routings are generated using geographical data. This approach enables a consideration of exact geographical restrictions for additional line routings. The findings of this study present a realistic reference network for a Swiss supply area and prove potentials for cost reduction by multiple use of cable trenches.