Vulnerability Analysis of Satellite based Synchronized Smart Grids Monitoring Systems

The large scale deployment of Wide-Area Monitoring Systems (WAMSs) could play a strategic role in supporting the evolution of the traditional power systems towards smarter and self healing grids. The correct operation of these synchronized monitoring systems requires a common and accurate timing reference usually provided by satellite based Global Positioning System (GPS). Although, these satellites signals provide timing accuracy that easily exceeds the needs of the power industry, they are extremely vulnerable to radiofrequency interference. Consequently a comprehensive analysis aimed at identifying their potential vulnerabilities is of paramount importance for a correct and safe WAMSs operation. Armed with such a vision, this paper presents and discusses the results of an experimental analysis aimed at characterising the vulnerability of GPS-based WAMSs to external interferences. The paper outlines the potential strategies that could be adopted to protect GPS receivers from external cyber-attacks and proposes decentralized defense strategies based on self organizing sensor networks aimed at assuring the correct time synchronization in the presence of external attacks. Keywords—Wide Area Monitoring Systems, Phasor Measurement Unit, Global Positioning System, Radio Frequency Interference.