  Residential microgrids (MGs) may host a large number of Distributed Energy
Resources (DERs). The strategy that maximizes the revenue for each individual
DER is the one in which the DER operates at capacity, injecting all available
power into the grid. However, when the DER penetration is high and the
consumption low, this strategy may lead to power surplus that causes voltage
increase over recommended limits. In order to create incentives for the DER to
operate below capacity, we propose a proportional-fairness control strategy in
which (i) a subset of DERs decrease their own power output, sacrificing the
individual revenue, and (ii) the DERs in the subset are dynamically selected
based on the record of their control history. The trustworthy implementation of
the scheme is carried out through a custom-designed blockchain mechanism that
maintains a distributed database trusted by all DERs. In particular, the
blockchain is used to stipulate and store a smart contract that enforces
proportional fairness. The simulation results verify the potential of the
proposed framework.
