A Fault Supervision Method for Inslanded and Converters-Based Microgrids with Integration of Renewable Generation

SCHIERLOH, RODRIGO M.; GODOY, J.L.; VINCITORIO, FABIO M.; SALCEDO, CRISTIAN L.

Rio de Janeiro

Conferencia; THE XIV LATIN-AMERICAN CONGRESS ON ELECTRICITY GENERATION AND TRANSMISSION - CLAGTEE 2022; 2022

UNESP

The need to supply the rapid increase in global energy consumption through clean and sustainable generation encouraged the development of microgrids as an important part of the smart grid and distributed generation paradigm. The operation of microgrids implies a series of challenges such as energy management strategies and protection systems to ensure a safe and stable operation. The variability of renewable resources and the low inertia of electronic converters produce variable fault currents in microgrids during faults, particularly in island mode operation. For this reason, traditional protection systems based on activation by defined current levels can fail. In this work, a rule-based supervision algorithm for fault detection and location in islanded microgrids that include renewable generation and storage devices is proposed. The method provides an additional security layer to the traditional protection included in electronic converters by detecting, locating and isolating faults; thus providing information on the status of devices. It requires voltage and current measurements and is based on comparing measured and predicted variables using line and generation models. The approach is applied to a fault simulation model of an islanded microgrid that includes photovoltaic panels and batteries. Simulations are carried out in different scenarios, which possess different solar radiation levels, battery states of charge, and fault types and locations (e.g. on the different busses, AC or DC). In particular, for failure scenarios with low solar radiation and low battery state of charge, the converter protections do not work, however, the supervision strategy permitted detection, location and isolation of the fault by means of the corresponding circuit breakers.