Reduction of power grid fluctuations by communication between smart devices

Abstract

The increase of the electric demand and the progressive integration of renewable energy sources threatens the stability of the power grid. To solve this issue, several methods have been proposed to control the demand side instead of increasing the spinning reserve in the supply. Here we focus on dynamic demand control (DDC), a method in which smart devices can autonomously delay its scheduled operation if the electric frequency is outside a suitable range. While typical control schemes can effectively reduce small and medium size frequency fluctuations, the probability of large demand peaks, and hence large frequency fluctuation, may increase due to the need of recovering pending tasks. Although these events are rare they can potentially trigger a failure of the system and therefore strategies to avoid them need to be addressed. In this work we introduce a method including communication among DDC devices belonging to a given group, such that they can coordinate opposite actions to keep the group demand more stable. We show that, with minimal information exchange, our method reduces the amount of pending tasks by a factor 10 while large frequency fluctuations are significantly reduced or even completely avoided.