Strategies for Coping with Unintentional Islanding as a Result of Robust Grid Connection Rules for Distributed Generation

Abstract:
This paper deals with the conflict between overall system stability in the interconnected grid and the prevention of islanding smaller network segments. A new island detection method based on capacitive voltage indicators at the substation is explained. In the past, frequency related deviations were used for islanding detection. Unfortunately, they lead to major issues for the overall system stability and had to be removed [1]. Therefore the probability of an active and reactive power balance within a separated network island increases [2]. This paper presents a practical strategy for dealing with this development and for the identification of islanding networks in the existing grid infrastructure. In addition, procedures are set forth on how unintended islanding can be terminated with existing equipment in order to allow the reconnection of the separated network.