Assessing the loadability of active distribution networks in the presence of DC controllable links

This study addresses the benefits of incorporating flexible DC links into radial distribution networks, which are subject to continuous load growth and higher levels of distributed generation penetration. To compare the use of DC links with conventional network reinforcement measures, an optimisation framework is developed. The main feature of the proposed formulation is that, irrespective of the criterion chosen to quantify the benefits of adding DC links, the same objective function is handled. Maximising or minimising a single-objective function, subject to the same set of constraints, allows different planning criteria to be assessed. The proposed optimisation framework is applied to actual networks embedding distributed generation. Two- and three-terminal voltage source converter-based DC links are considered in order to numerically illustrate the potential benefits of this technology in distribution systems.