Reverse supply of an AC distribution feeder through a Medium Voltage DC link

Abstract

Abstract. Medium Voltage Direct Current grids seems a promising solution for meshing AC grids, in order to enhance their distributed generators hosting capacity. The DC link is created through power electronics interface converters, which allow implementing different functions through suited control strategies. In particular, the paper investigate the possibility of supplying AC connected loads in island operation, i.e. separated from the mains, when a fault occurs in one of the AC grids. A 5 MW link is considered in the paper. Relevant power converters has been designed and modelled in a digital simulation environment. A complex control strategy for the management of the complete process of island supply and reconnection to mains, involving also communication between converters and grid protections, has been implemented and tested through simulations. Simulation results confirms the effectiveness of the proposed approach.