In planning for distributed energy resources (DER) in a microgrid, careful consideration must be taken to ensure the DER and microgrid are resilient during both grid-connected and islanded operation. Microgrid fault stability is top of mind. There are many factors considered in the design of a microgrid, including the size of an existing DER, or the size of a new DER, the preferred DER and microgrid control technology and the material and labors costs.
Many electric customers are investing in microgrids and DERs while maintaining a utility connection to provide additional reliability and resiliency during grid disturbances, which could interrupt electrical service.
This paper discusses protection topics that need to be considered when analyzing microgrid fault stability. Areas examined are fault contributions and voltage ride-though concerns with synchronous generators and inverter based DERs. A case study simulated on a real time power system simulator is presented in this paper.