  Power systems are subject to fundamental changes due to the increasing infeed
of renewable energy sources. Taking the accompanying decentralization of power
generation into account, the concept of prosumer-based microgrids gives the
opportunity to rethink structuring and operation of power systems from scratch.
In a prosumer-based microgrid, each power grid node can feed energy into the
grid and draw energy from the grid. The concept allows for spatial aggregation
such that also an interaction between microgrids can be represented as a
prosumer-based microgrid. The contribution of this work is threefold: (i) we
propose a decentralized hierarchical control approach in a network including
different time scales, (ii) we use iterative learning control to compensate
periodic demand patterns and save lower layer control energy and (iii) we
assure asymptotic stability and monotonic convergence in the iteration domain
for the linearized dynamics and validate the performance by simulating the
nonlinear dynamics.
