Ring connected microgrid clusters for improved resiliency in distribution systems with high solar PV penetration

A ring-connected microgrid cluster can be formed by connecting geographically closed microgrids for mutual power sharing to increase the system's reliability. Real-time power balance within individual microgrids and power sharing among the microgrids of an islanded microgrid cluster would be challenging during contingencies if they are not properly sized and controlled. We propose a technique to design a ring-connected microgrid cluster that has several distributed energy resources. The amount of power flow via interconnecting cables was decided considering the size of the energy storage of the neighboring microgrids. A control system was designed to minimize the effect of severe transients in the neighboring microgrids in the network. The performance of the proposed technique was verified using a ring-connected microgrid cluster with four microgrids derived based on a real distribution system. The results illustrated that the proposed ring-connected microgrid cluster could maintain the power balance of the networked microgrid during the contingencies of neighboring microgrids, increasing the resiliency of the system compared to the radial and islanded operations.