Conversion of Existing AC into DC Cable Links in Distribution Grids: Benefits and Challenges

The need for higher transmission capacities even in low (LV) and medium voltage (MV) distribution grids motivates to add direct current (DC) links to homogenous alternating current (AC) grids. The AC2DC project takes up the challenges associated with this transition. The project aims to develop the necessary concepts and guidelines for the system integration of DC links as well as to derive the requirements for the electrical equipment. This paper presents the projects first results, including an overview of the present day research work, the evaluation of a survey regarding cable types in distribution grids, an analytic derivation of the transmission capacities of DC cable systems as well as the accentuation of research gaps in the field of power electronics and test procedures for the electrical equipment.