Introduction: Substation protection and control systems require each device to be synchronised to UTC (Co-ordinated Universal Time), which is currently achieved using Global Positioning System (GPS). Recent studies on GPS use and dependency have highlighted the vulnerabilities of GPS signals, and a robust solution for time synchronisation based on more diverse sources of time should be developed. This project investigates alternative timing solutions that could deliver independent time references into substations, minimising the risk of a single source failure.

Objectives: The project aims to investigate the benefits, costs and challenges of using alternative technologies (i.e. multi-GNSS, IEEE 1588 based time dissemination over optical fibre, and holdover clocks) to reduce security risks and enhance resilience of the existing GPS-based solution for substation time synchronisation.