Generic microgrid controller with self-healing capabilities

Generic Microgrid Controller (GMC) specifications, developed at the University of California, Irvine (UCI) to support the standardization of microgrid controllers and guide IEEE standards were applied to the UCI Microgrid (UCIMG) for testing and deployment. While transition and dispatch capabilities of GMC were simulated and demonstrated, response of the controller to internal faults while islanded or to inadvertent trip of generation were not addressed previously. The present study adds self-healing capabilities to the GMC for islanded microgrid operations with the goal to enhance reliability of serving critical loads, and resiliency of the system. To verify and assess self-healing attributes as well as impacts on reliability and resiliency while islanded, the self-healing capability was simulated on the UCIMG model developed on MATLAB Simulink. The model was enhanced with recently deployed redundancies including two new switchyards and redundant lines, and was then divided into sections to (1) focus on critical and high priority loads, and (2) reduce the number of nodes and computational requirements. Our study explores the resiliency of a real system microgrid platform using the FLISR (fault location, isolation and service restoration) approach as the self-healing capability as part of the microgrid controller. This expert systems approach with precalculated and predetermined sequence makes it a practical and simple solution which can be implemented without having to deal with computational limits of the controller and time constraints. Results show that, even with a fault-induced circuit outage during islanded operation, critical loads can be served by interconnected circuits and rapidly dispatched switching, thereby minimizing the loss of critical and noncritical loads, and increasing reliability and resiliency.