Increasing Ireland’s electric grid resilience

In times of geopolitical tension, the electric grid is vulnerable, not least since many control systems rely on satellite time data signals which can be jammed. According to a case study involving HEAnet, the national research and education network (NREN) of Ireland, it will be possible to monitor the utility grid without “space-based” time, thereby increasing resilience significantly.

Time synchronized measurements are key to controlling the utility grid and become even more important in a sustainable energy system since renewable resources such as wind and solar fluctuate more than conventional energy sources.

Electrical power grids are monitored by instruments called Phasor Measurement Units (PMU), which use time synchronized measurements of voltage and current waveforms. PMUs most often rely on time data generated by global positioning satellites such as GPS. Unfortunately, these satellite signals are known to be easy to jam. Not only hostile governments but also criminal groups or even individuals can do that.

Satellite signals can be disturbed easily

In this context, jamming would mean preventing a receiver from obtaining valid signals from a positioning satellite. While annoying, jamming is at least easy to detect – there is no signal. A more malicious activity is known as spoofing. Here, the receiver is deceived into following a falsified signal, not from the authentic satellite. If well-constructed, the spoofed signal is indistinguishable from the real signal.

Previously, spoofing of satellite signals was a topic limited to military, academic, and niche radio hobbyist due to complexity and the cost of equipment. This has changed, as a combination of cheap equipment and open-source software will be enough to create false signals.

Consequently, malicious jamming and spoofing of satellite signals is regarded by governmental security agencies as a major cyber physical attack surface affecting critical national infrastructure.

Taking advantage of NREN infrastructure

In the new case study by HEAnet and partners Queen’s University Belfast and Atlantic Technological University, an alternative solution to “space-based” time is proposed, namely Precision Time Protocol (PTP). PTP generally operates over private, wired Ethernet networks and is therefore not vulnerable to the same attack vectors as satellite signals. It uses hardware time stamping, on the Physical Layer (PHY) that will synchronize the hardware clock down to picosecond resolution.

When used on the Internet, PTP must transverse public infrastructure which may not support hardware time stamping. This will degrade the quality of time from end to end.

In the solution investigated by the Irish NREN and partners, an electrical monitoring system based on PMUs will be installed across sites under the control of HEAnet. This alleviates several technical and organizational issues in the creation of a dataset that may be shared with electrical power researchers. The geographically diverse locations of the NREN sites will allow researchers to investigate how electrical phenomena propagates throughout the electricity network and develop novel approaches to facilitation of decarbonization technologies.

An additional benefit is that the time synchronized sensor network presents a unique opportunity to study time transfer using PTP over a wide geographical area, thus providing an opportunity to explore innovative approaches which address the risks associated with satellite signal jamming and spoofing.

The text is inspired by the article “Time Synchronization Makes Monitoring the Utility Grid Possible without using “Space-Based” Time” at the HEAnet website.