Control of series-cascaded grid-forming microgrid configuration with a storage device

With the increase of inverter-based energy resources in power grids, it is imperative that the frequency stability is maintained and inverters can be controlled to improve frequency damping by using grid-forming inverters (GFM). The microgrid that is formed by several DGs that are connected in series is called a series topology microgrid. The series topology with individual LC output filters benefits from utilizing lower and different dc-link voltages. One of the drawbacks in series topologies is that the series cascaded DG microgrids have rarely been discussed when it comes to a different configuration combinations of DGs such as dispatchable and non-dispatchable DGs. In this paper, a comprehensive study of series-cascaded microgrid configuration consisting of master and slave DGs with a storage device is done. The power circuit, control circuit, and results are shown.