Technological assessment of distributed generation systems operation during extreme events

This paper explores key technical characteristics of distributed generation systems that influence their operation during extreme events, such as natural disasters. In order to assess availability, the study follows a quantitative approach based on minimal cut set theory and Markov chains and processes. Availability models both for distributed generation sources depending on lifelines and for renewable energy sources are summarized. The importance of diverse power sources and the need for local energy storage are commented in order to address the variable output of renewable energy sources and the dependency on lifelines. The relevance of multi-port power converter topologies and bidirectional power flow is also explained. The manuscript continues with a description of relevant standards, such as IEEE 1547, and explains the effect that these standards, control needs, and the islanding prevention techniques have on residential distributed generation systems. Alternative configurations to conventional grid-tied inverters are commented. The discussion presented in this paper is supported by circuit prototypes experiments and by practical empirical observations from damage assessments and from a microgrid Sendai, Japan which was operating when the March 2011 earthquake and tsunami affected this area of Japan.