  A previous study has shown that coordinating DERs to protect the distribution
grid can significantly reduce the infrastructure upgrades needed to address
future increases in DER and electrification penetrations. Implementing such
coordination in the real world, however, is challenging due the temporal and
spatial uncertainties about the loads and renewable generation, smart meter and
network delays, incomplete information about the grid, different consumer
objectives and privacy constraints, and scalability of the coordination scheme.
This paper describes a day-ahead 2-layer DER coordination scheme that addresses
these challenges. A global controller uses historical load data to compute
day-ahead hourly demand upper and lower bounds for each consumer node. It then
solves a largest volume axis-aligned box optimization problem to determine
corresponding supply power bounds which if followed, ensures grid reliability.
A local controller at each consumer node then determines the DER power
injections which satisfy the consumer's objectives while obeying its supply
bounds. Simulation results demonstrate, for example, that this scheme can
capture 62% of the reduction in transformer violations achievable by the
perfect-foresight centralized controller used in the aforementioned previous
study.
