  Microgrids are localized electrical grids with control capability that are
able to disconnect from the traditional grid to operate autonomously. They
strengthen grid resilience, help mitigate grid disturbances, and support a
flexible grid by enabling the integration of distributed energy resources.
Given the likely presence of critical loads, the proper protection of
microgrids is of vital importance; however, this is complicated in the case of
inverter-interfaced microgrids where low fault currents preclude the use of
conventional time-overcurrent protection. This paper introduces and
investigates the application of dynamic state estimation, a generalization of
differential protection, for the protection of radial portions of microgrids
(or distribution networks); both phasor-based and dynamic approaches are
investigated for protection. It is demonstrated through experiments on three
case-study systems that dynamic state estimation is capable of correctly
identifying model parameters for both normal and faulted operation.
