Extending voltage thresholds in MV grids to increase hosting capacity

The largest French DSO Enedis is developing a new voltage management scheme to improve the integration of a massive number of distributed generators (DG) as well as end-use electrification evolutions, by optimizing voltage thresholds for transformers, MV feeders and LV grids in network development. Current grid-planning rules for allocating voltage margins from the primary substation to the different types of customers are inherited from a period when the main voltage concern was to prevent voltage drops. The objective of this new voltage scheme is to reduce grid investment costs and to increase the hosting capacity of French MV grids for DG. Implications of this new method are illustrated through a real-life case study in which both “high generation” and “high load” network sizing reference situations are simulated. This new voltage scheme is valued in relation to the net present value of investments required to guarantee an adequate power supply quality.