Analysis of the Impact of Cyber Attacks in Active Distribution Grids Onto the Transient System Stability

—An increasing number of distributed energy resources, partially or completely interconnected using information and communication technology, is expected in future active distribution grids. However, cyber attacks (e.g. data manipulation of asset parameters) might lead to a malfunction of affected components, thus resulting in a possible instability of the overall electric system. In this paper, the impact of corrupted distributed generators onto the transient system stability of a synthetic high voltage grid is analyzed using equivalent dynamic models of medium and low voltage grids. Different threat scenarios such as induced fluctuations of the infeed, short circuit events and their effects onto the transient system stability of the overlaying high voltage grid are discussed. As the results show, in today's electricity grid, the impact of cyber attacks in active distribution grids are expected to be noncritical for the transient system stability. However, considering a less robust overlaying transmission grid, in the future cyber attacks may affect the transient system stability to a greater extent.