Reduction of power grid fluctuations by communication between smart devices
This work provides a solution to a critical stability issue in power grids for grid operators and renewable energy integrators, building on prior DDC methods.
The paper addresses the problem of large frequency fluctuations in power grids caused by dynamic demand control (DDC). By introducing communication among DDC devices to coordinate actions, the method reduces pending tasks by a factor of 10 and significantly reduces or eliminates large frequency fluctuations.
The increase of electric demand and the progressive integration of renewable 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 on the supply side. Here we focus on dynamic demand control (DDC), a method in which appliances can delay its scheduled operation if the electric frequency is outside a suitable range. We have recently shown that DDC effectively reduces small and medium-size frequency fluctuations but, due to the need of recovering pending tasks, the probability of large demand peaks, and hence large frequency fluctuations, may actually increase. Although these events are very rare they can potentially trigger a failure of the system and therefore strategies to avoid them have to be addressed. In this work, we introduce a new 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 for this method the amount of pending tasks decreases by a factor 10 while large frequency fluctuations are significantly reduced or even completely avoided.