  Microgrids are autonomous clusters of generators, storage units and loads.
Special requirements arise in interconnected operation: control schemes that do
not require individual microgrids to disclose information about their internal
structure and operating objectives are preferred for privacy reasons. Moreover,
a safe and economically meaningful operation shall be achieved in presence of
uncertain load and weather-dependent availability of renewable infeed. In this
paper, we propose a hierarchical distributed model predictive control approach
that satisfies these requirements. Specifically, we demonstrate that costs and
safety of supply can be improved through a scenario-based stochastic control
scheme. In a numerical case study, our approach is compared to a certainty
equivalence and a prescient scheme. The results illustrate good performance as
well as sufficiently fast convergence.
