Abstract
In this paper, we perform a threat modeling of architectures for controlling the medium voltage (MV) part of the power grid, arguing the importance of this topic with a brief summary of serious cyber security attacks from the last decade. As more Distributed Energy Resources (DERs) are introduced into this part of the grid, the need to control these resources arises. A threat modeling of two alternative control architectures is performed to study two different aspects. Firstly, we study and compare the cyber security of the two architectures to determine whether one of them is inherently more secure than the other. While both architectures rely on 5G, one of the architectures uses a centralized design, while the other uses a distributed design. Our results indicate that at the current level of detail, contrary to common belief, it is difficult to draw definitive conclusions as to which architecture is more secure. The second aspect we study is the applied threat modeling method itself. We evaluate and test the method and suggest improvements.