The Use of Digital Twins in Inverter-based DERs to Improve Nanogrid Fault Recovery

Nanogrids provide a redundant mode of operation when the grid power fails. Nanogrids use data communication networks to coordinate power and energy between distributed energy resources (DERs). Under the corner-case of simultaneous communication failure and electrical faults, it can be difficult for the energy storage system with grid-forming/grid-following capability to select the correct operational mode. This paper proposes the use of a digital twin to assist in minimizing the degradation on the nanogrid caused by loss of communication during islanded operation under electrical fault conditions. The structure of the digital twin is proposed, and the construction of a virtual twin is presented. The error vector produced by the difference between the physical twin and virtual twin is demonstrated in various fault conditions. Lastly, the paper presents a discussion of how the error vector could be used to make inferences about the nanogrid state and to choose actions during off-nominal communication.