ABSTRACT Distribution system operators (DSOs) face increasing challenges in managing the low voltage (LV) distribution grid due to the integration of new assets (e.g., photovoltaic panels, electric vehicles) and new activities (e.g., energy sharing, frequency reserves), which can lead to unexpected voltage and current congestions. To avoid this, this paper introduces an innovative approach to calculate the maximum operating envelope (OE) for each end‐user, ensuring safe grid operation. The OE is defined as the injection and offtake limits allocated to an end‐user based on the available capacity of the local network or the overall power system. The proposed method is based on a relaxed unbalanced three‐phase optimal power flow, and is benchmarked against a conventional non‐optimised approach. The methodology is applied to both the IEEE EU LV Testfeeder and 49 real‐world delta‐connected LV feeders in Brussels (Belgium). Results demonstrate that the optimal solution improves the available flexibility by 7% to 10% compared to traditional methods, unlocking significant flexibility while ensuring grid safety. In addition, three feeder types are identified, demonstrating how grid characteristics influence individual and aggregated flexibility. Results confirm that optimal selection enhances grid flexibility while ensuring fair and practical OE allocation, supporting DSOs in adapting to evolving network demands.
Delchambre et al. (Thu,) studied this question.