This document provides a recommended security architecture for distribution automation (DA) systems. It gives a set of technical measures that those designing and maintaining DA systems can use to mitigate security risks.
The medium voltage (MV) parts of the electricity grids are being more and more automated through DA. Grid operators use DA systems to measure the flow of electricity to allow the increasing use of renewable energy and electric vehicles. They use DA systems to remotely control switchgear to recover more quickly from outages.
But the increasing automation also increases the possible impact of cyber-attacks. If hackers gain access to the DA system, they may switch off the power in the MV grid. If they can also block the grid operator’s own access, it may take a long time to restore power. As the impact of such incidents is large, their likelihood should be minimized.
The security architecture gives technical measures to reduce the likelihoods. It implements a defense-in-depth strategy. Unauthorized access is prevented by multiple measures and can be detected through logging.
The architecture is intended to be used together with an information security management system (ISMS) that provides the organizational measures. The architecture is aligned with the ISO/IEC 27001:2013  standard, commonly used for ISMSs.