Application of energy routers for frequency support in an AC/DC multi-microgrid system

This paper presents solutions for frequency support in a cluster of microgrids by using DC-link-based energy routers interface. With this interface, the cluster of AC microgrids is interconnected by a DC common link. With such an AC/DC multi-microgrid system, the stability of the system can be improved by supporting the voltage of the common DC-link among microgrids or by sharing the load through proper frequency coordination strategy. The proposed solution takes into account the privacy of the MMG members. First, a chosen topology of the energy router and its controlling strategy are addressed. Next, three different methodologies for frequency supporting are presented. Finally, a simulation model, which is an islanded multi-microgrid system with an energy router interface, is built in MATLAB/Simulink environment to evaluate the efficiency of the proposed method.