Black-start of microgrids: Insights based on demonstration sites in Europe and India

This paper provides an insight into power system restoration on a small scale, where the distributed generation in microgrids is used to facilitate black-start strategies to provide faster and efficient power restoration. The idea was to employ non-conventional and renewable generation for black-start provision in microgrids with implementation of grid-forming strategies and control coordination. Both AC and DC microgrids, operating in grid-connected and islanded modes, were considered in this work and exemplified on three study cases based on the demonstration sites of the Re-Empowered project (locations in Denmark, Greece and India). Case studies include a larger system in Bornholm, where the network was sectionalized into two smaller microgrids and subsequently established simultaneously, before being synchronized and interconnected. Two additional studies are based on a smaller scale AC and DC islanded micro-grids, where different methods for black-start were considered.