Dynamic State Estimation for Radial Microgrid Protection

TL;DR

This paper explores the use of dynamic state estimation techniques, including phasor-based and dynamic methods, to improve protection in inverter-interfaced microgrids, demonstrating accurate fault detection and parameter identification.

Contribution

It introduces dynamic state estimation as a novel approach for microgrid protection, addressing challenges posed by low fault currents in inverter-based systems.

Findings

Dynamic state estimation accurately identifies model parameters during faults.

Both phasor-based and dynamic approaches are effective for microgrid protection.

Experimental results validate the method's reliability in different scenarios.

Abstract

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.