  We study the performance of a decentralized integral control scheme for joint
power grid frequency regulation and economic dispatch. We show that by properly
designing the controller gains, after a power flow perturbation, the control
achieves near-optimal economic dispatch while recovering the nominal frequency,
without requiring any communication. We quantify the gap between the
controllable power generation cost under the decentralized control scheme and
the optimal cost, based on the DC power flow model. Moreover, we study the
tradeoff between the cost and the convergence time, by adjusting parameters of
the control scheme.
  Communication between generators reduces the convergence time. We identify
key communication links whose failures have more significant impacts on the
performance of a distributed power grid control scheme that requires
information exchange between neighbors.

Optimization and Control