Islanding and Reconnection of Converter Based Distributed Generation Systems

In English In this paper a method for reconnecting islanded distributed generation systems is presented. Islanding of a distributed generation system may result from a fault or malfunction of protective elements. The behavior of local voltage and frequency control in case of islanding is investigated. A method for reconnecting the distributed generation system and the behavior of voltage and frequency control in case of reconnection are also investigated. It is found that islanding and reconnection with preserved voltage and frequency control is possible also in the case of local control without communication. Still communication of low bandwidth is required for the reconnection scheme presented here. The method presented is verified in simulations.