  Microgrids are being increasing deployed to improve the operational
flexibility, resilience, coordinated-energy management capabilities,
self-adequacy, and increased reliability of power systems. This strong market
growth is also driven by advances in power electronics, improved control
systems, and the rapidly falling price and increased adoption of distributed
energy generation technologies, like solar photovoltaics and storage. In the
event of grid outages, microgrids can provide a backup source of power;
providing resilience to the critical loads; however, this requires that the
microgrid itself is resilient to physical and cyber threats. Building highly
resilient microgrids requires a methodological assessment of potential threats,
identification of vulnerabilities, and design of mitigation strategies. This
paper provides a comprehensive review of threats, vulnerabilities, and
mitigation strategies and develops a definition for microgrid resilience. The
paper also develops a methodology for designing resilient microgrids by
considering how microgrid designers and site owners evaluate threats,
vulnerabilities, and consequences and choose the microgrid features required to
address these threats under different situations.
