DER Control and Utility Interconnection Management of a Distributed Microgrid

This paper describes the implementation of a microgrid with upgrade of existing distributed energy resources (DERs), design of the MV interconnection, and implementation of a microgrid control system to meet the Department of Defense (DoD) needs at Fort Custer, Michigan. A battery energy storage system (BESS) was newly installed to manage intermittencies for the existing solar generation and to support the microgrid. A proven microgrid controller was added to the system with upgrade of the network interface. The individual DER assets were integrated with the Microgrid and controlled in a coordinated manner to achieve seamless islanding and reconnection with the utility grid at the point of common coupling (PCC), managed by a control-plus-protection integrated switchgear. The paper provides the test data demonstrating the improvement in resiliency through islanded operation as well as maintaining power quality when operating in parallel with the utility. The economic operation of the assets and participation in utility ancillary services for the microgrid is also discussed. This ability allows the military to reduce their TCO (total cost of ownership) to achieve their mandated energy security needs with the microgrid.