  In this paper, we introduce the novel concept of economic ports, allowing
modular and distributed optimal operation of networked microgrids. Firstly, we
design a novel price-based controller for optimal operation of a single
microgrid and show asymptotic stability. Secondly, we define novel physical and
economic interconnection ports for the microgrid and study the dissipativity
properties of these ports. Lastly, we propose an interconnection scheme for
microgrids via the economic ports. This interconnection scheme requires only an
exchange of the local prices and allows a globally economic optimal operation
of networked microgrids at steady state, while guaranteeing asymptotic
stability of the networked microgrids via the passivity properties of economic
ports. The methods are demonstrated through various academic examples.
