A black-box modeling approach for DC nanogrids

The smart grid concept is increasingly becoming popular within the academia and industry. The integration of electronic power converters as an enabler for the massive deployment of distributed renewable energy sources, along with the inclusion of control, monitoring and automation systems in the grid, has drawn the attention of many researchers. Furthermore, a transition towards dc distribution is currently under investigation due to its more suitable interface with most of the modern loads and sources, which offers benefits in terms of size, cost and reliability of the whole system. This paper proposes a black-box polytopic modeling approach as a tool for the system-level design of dc based nanogrids. This strategy allows both small and large-signal analysis of power distribution systems even when commercial off-the-shelf converters have to be integrated. In addition, the main characteristics of the dc bus signaling control, i.e. droop control, changes in power converter control mode and disconnection of loads, have been incorporated in the modeling structure.