Power Injection Attacks in Smart Distribution Grids with Photovoltaics

In order to protect smart distribution grids from intrusions, it is important to understand possible risks and impacts of attacks. We study the optimal attack strategy of a power injection attack against the physical layer of a smart distribution grid with a high penetration of photovoltaic resources. We derive both the optimal attack signal and optimal attack location: the optimal attack signal is a step function which switches its sign at the final stage, and the optimal attack location is the node with the largest impedance to the grid substation. Numerical examples on a European benchmark model verify the developed results. Finally, both theoretical and numerical results are used to discuss feasible defense strategies against power injection attacks.