  In this paper, we employ a bi-level control system to react to disturbances
and balance power mismatch by coordinating distributed energy resources (DERs)
under packetized energy management. Packetized energy management (PEM) is a
novel bottom-up asynchronous and randomizing coordination paradigm for DERs
that guarantees quality of service, autonomy, and privacy to the end-user. A
hardware-in-the-loop (HIL) simulation of a cyber-physical system consisting of
PEM enabled DERs, flexible virtual power plants (VPPs) and transmission grid is
developed in this work. A predictive, energy-constrained dispatch of aggregated
PEM-enabled DERs is formulated, implemented, and validated on the HIL
cyber-physical platform. The energy state of VPPs, composed of a fleet of
diverse DERs distributed in the grid, depending upon the distinct real-time
usage of these devices. The experimental results demonstrate that the existing
control schemes, such as AGC, dispatch VPPs without regard to their energy
state, which leads to unexpected capacity saturation. By accounting for, the
energy states of VPPs, model-predictive control (MPC) can optimally dispatch
conventional generators and VPPs to overcome disturbances while avoiding
undesired capacity saturation. The results show the improvement in dynamics by
using MPC over conventional AGC and droop for a system with energy-constrained
resource
