Probabilistic Risk Evaluation of Microgrids Considering Stability and Reliability

Microgrids are being developed with higher penetration of renewable energy sources and utilization of power electronics. The functionality of microgrids is normally measured by two indices, stability and reliability, which are highly influenced by system configuration and generation/load mission profiles. Although system-level modeling approaches have been proposed to evaluate both the said indices for microgrids, they are still considered independently due to the mismatch in their timescales. To this end, it limits the derivation of a comprehensive risk framework to exploit the interdependencies between stability and reliability. Hence, this article addresses this gap for the first time in the realm of microgrids by proposing a probabilistic risk framework by considering stability and reliability simultaneously. Long-timescale reliability are basically decomposed into shorter timescale events, whereas stability is treated as probabilistic events to be integrated into the risk evaluation. This framework can quantify the operation risk of microgrids, thereby providing a more intuitive approach to the design of microgrids. To validate the ruggedness of the proposed framework, system stability and reliability are assessed and interpreted under experimental conditions.