  The propagation of failures and blackouts in electric networks is a complex
problem. Typical models, such as the ORNL-PSerc-Alaska (OPA), are based on a
combination of fast and a slow dynamics. The first describes the cascading
failures while the second the grid evolution though line and generation
upgrades as well as demand growth, all taking place in time scales from days to
years. The growing integration of renewable energy sources, whose power
fluctuates in time scales from seconds to hours, together with the increase in
demand, which also present fast fluctuations, require the incorporation of
distributed methods of control in the demand side to avoid the high cost of
ordinary control in conventional power plants. In this work, we extend the OPA
model to include fluctuations in the demand at time scales of the order of
minutes, intraday demand variations and the effect of demand control. We find
that demand control effectively reduces the number of blackouts without
increasing the probability of large-scale events.
