Overload management of autonomous microgrids

Load-shedding is a mechanism to prevent overloading of the autonomous microgrids (MG). To minimize load-shedding, extra support can be provided by the embedded floating batteries in the autonomous MG. Furthermore, two islanded neighboring MGs can be interconnected to support each other. For this, the state of charge (SOC) of the floating batteries should be above the minimum SOC and extra generation capacity needs to be available in the distributed energy resources (DER) of the neighboring MG. In this paper an overload management strategy based on these two options is presented. This strategy needs to decide the connection time of the floating batteries as well as the interconnection time of the two neighboring MGs. It should also decide when the battery to be disconnected or the two interconnected MGs to be isolated. This paper focuses on a decentralized approach based on monitoring the frequencies of the MGs. The proposed strategy is validated by PSCAD/EMTDC simulations.