The Northern Lights, or Aurora Borealis, are among nature’s most mesmerizing displays. They captivate onlookers with swirling ribbons of green, red, and purple light that dance across the night sky. However, behind this breathtaking spectacle lies a powerful natural phenomenon with severe implications for modern electrical infrastructure: Geomagnetic Disturbance Events (GMDs).
GMDs are triggered by solar activity, such as Coronal Mass Ejections (CMEs), which release bursts of solar wind and magnetic fields. When GMDs interact with Earth’s magnetosphere, they generate Geomagnetic-Induced Currents (GICs) that can disrupt power systems, particularly transformers.
As Solar Cycle 25 approaches its peak in 2025, the frequency and intensity of GMDs are expected to rise significantly. This cycle, marked by the Sun’s magnetic field reversal every 11 years, is anticipated to bring a surge in solar activity, including increased solar flares, sunspots, and CMEs.
With heightened solar activity, the risk of geomagnetic storms rises, posing an even more significant threat to electrical infrastructure worldwide. Condition based monitoring becomes vital during such periods of high solar activity to protect transformers from the adverse effects of GICs.
The Process of Geomagnetic Disturbance Events (GMDs) and Their Impact on Transformers
Geomagnetic disturbance events (GMDs) are driven by solar activities such as Coronal Mass Ejections (CMEs) and solar flares, both of which release immense energy from the Sun. CMEs, in particular, are massive bursts of plasma and magnetic fields that eject from the Sun’s corona at extraordinary speeds. When directed toward Earth, these ejections travel through space and collide with the planet’s magnetic field, setting off a series of reactions that ripple through the magnetosphere and atmosphere.
As CMEs reach Earth’s magnetosphere, they create sudden and dynamic fluctuations in magnetic fields through a process known as electromagnetic induction. This interaction produces geomagnetic-induced currents (GICs), which flow through the Earth’s surface and into man-made conductive systems, including pipelines, transmission lines, and electrical transformers. The extent of the currents depends on factors such as the strength of the CME, the structure of the power grid, and the conductivity of the ground in the affected region.
Once the currents enter transformers, they cause disruptions that jeopardize the stability of the electrical grid. GICs induce a quasi-direct current (quasi-DC) in transformer windings, potentially leading to core saturation, overheating, and mechanical stress.
The electromagnetic disturbance also increases reactive power demand, introduces harmonics into the system, and can even trip protective relays, compounding the risk of outages.
GMD Blackout in Quebec, Canada
The first major event that underscored the vulnerability of electrical systems to GMDs occurred in March 1989, when a powerful solar storm caused a catastrophic blackout in Quebec, Canada. The CME that triggered this storm generated intense geomagnetic activity, saturating transformers in the Hydro-Québec power grid. Protective systems failed to handle the surge within seconds, and a cascading outage left millions without electricity.
The historic event demonstrated the destructive potential of GMDs and also initiated a global focus on monitoring geomagnetic activity and its impacts on power systems.
The Effects of Geomagnetic-Induced Currents (GICs) on Transformers
Geomagnetic-induced currents (GICs) can negatively impact transformers, causing damage that can compromise the entire power system. When GICs flow through a transformer, they saturate the core, leading to overheating and mechanical stress that can degrade critical components. This damage increases the likelihood of equipment misoperation, including malfunctions in protective systems. In severe cases, it can result in complete transformer failure. Additionally, GICs depress system voltages, reducing grid efficiency and creating conditions that may trigger cascading outages if left unmanaged.
GIC sensors play a critical role in protecting transformers from these risks. Our advanced devices sense, measure, and communicate DC ground currents in real time, offering operators essential insights into the system’s health.
GIC sensors from Dynamic Ratings ensure that even transformers in remote areas of the grid are monitored by detecting the magnitude of these currents with long-range sensing capabilities. Their high accuracy provides precise data, enabling operators to identify early warning signs of stress or potential failure. This proactive approach allows for timely intervention, safeguarding transformers and maintaining the reliability of the power system.
Alarms Triggered by GICs
Geomagnetic-induced currents (GICs) can trigger various system alarms, reflecting the widespread disruption they cause to electrical grids. Overvoltage alarms are often among the first indicators of an issue, followed by significant voltage dips that signal a strain on the system. Frequency irregularities and phase imbalances frequently occur, disrupting the stable operation of grid components.
The effects of GICs extend to MVAR swings, capacitor bank tripping, and generator voltage fluctuations, all of which can destabilize the network. Additionally, unintended switching of capacitor banks and the activation of voltage-controlled capacitor systems are common during these events.
Harmonic imbalances further complicate the situation, causing additional alarms and system trips. Together, these disruptions highlight the need for robust monitoring solutions to prevent cascading failures.
GIC Sensors Engineered for Comprehensive Protection and Monitoring
Dynamic Ratings’ GIC sensors are engineered to provide comprehensive monitoring in utility environments. They offer a range of features designed to meet various operational needs. Our sensors include an adjustable sensing range that can be tailored to specific applications, ensuring flexibility for diverse grid requirements.
Our Hall Effect Sensor delivers exceptional response times and linear performance across the full operating range, enabling precise and reliable measurements. With broad sensing capabilities, the sensors effectively measure pure DC and quasi-DC signals up to 3Hz, maintaining high accuracy even under fluctuating conditions. Additionally, the core material ensures temperature stability, allowing the sensors to function accurately across various environmental conditions.
Durability is a critical focus in the design of these sensors. That’s why we build our products to withstand the harsh conditions typical of utility environments. They are available in split and dual sensing cabinet configurations, making them suitable for installation on transformer neutral ground connections without requiring extensive modifications. The embedded Hall Effect sensor is optimized explicitly for GIC applications, enhancing its ability to effectively detect and measure DC ground currents.
To simplify installation and maintenance, the sensors feature conduit access with a type LB conduit body and a 1/2” NPT fitting, providing easy access for inspection, wire pulling, and routine servicing. A built-in 4th-order low-pass filter is precisely tuned to 3Hz, ensuring signal clarity by eliminating interference from higher frequencies.
The bracket design supports accurate placement around the conductor, offering additional conduit support for the 4-20mA output, further enhancing the ease of deployment. These features combine to make Dynamic Ratings’ GIC sensors an indispensable tool for protecting transformers and maintaining grid reliability during geomagnetic disturbances.
Continuous Monitoring for Proactive Asset Management
In the past, utilities often relied on periodic, offline inspections to evaluate the health of transformers. However, these methods have proven inadequate in the face of increasing geomagnetic disturbance (GMD) activity.
Continuous online monitoring has become essential. It offers real-time insights into transformer conditions and empowers operators to make data-driven decisions while responding proactively to potential risks. This proactive approach enhances accuracy by eliminating the errors associated with manual readings and mechanical drift.
Real-time data enables dynamic risk mitigation, allowing operators to detect and address emerging issues before they escalate into significant failures. Monitoring systems also optimize grid performance by calculating the maximum safe load for transformers, ensuring efficiency without compromising reliability.
At Dynamic Ratings, our advanced monitoring solutions bridge the gap between outdated offline practices and modern, proactive asset management, helping utilities reduce maintenance costs, minimize outages, and extend the lifespan of critical infrastructure.
Why Asset Management is Essential
Understanding why asset management is critical to safeguarding electrical infrastructure is key, and the efficacy of that asset management involves a comprehensive process of planning, designing, managing, implementing, and supporting asset monitoring systems.
Dynamic Ratings offers LIFESTREAM® Support Services to guide utilities through each stage of this process, from developing foundational program goals to implementing reliable systems and maintaining them over the long term. Our lifecycle approach ensures transformers are consistently monitored and protected, reducing risks and improving grid reliability.
Meeting Industry Standards and Ensuring Grid Reliability
Compliance with industry standards, such as the North American Electric Reliability Corporation (NERC) TPL-007, is essential for managing GMD risks. These standards require utilities to assess and mitigate the impact of geomagnetic disturbances on their infrastructure.
By leveraging technologies like transformer monitoring, utilities can meet regulatory requirements and enhance the overall reliability of their power systems. Monitoring GMDs and GICs in real-time allows operators to maintain grid stability, even during periods of intense solar activity.
Embracing Proactive Asset Management
As Solar Cycle 25 peaks, the risk of geomagnetic disturbance events will continue to rise. While the Northern Lights captivate us with their beauty, they also remind us of the potential threats solar activity poses.
Utilities can protect their transformers, ensure reliable power delivery, and embrace a proactive approach to asset management by investing in advanced monitoring solutions, such as asset performance management software. At Dynamic Ratings, we are committed to helping our clients navigate these challenges with innovative monitoring technologies that safeguard their assets and support grid resilience.
Please contact us today to learn more. You can also sign up for one of our informative user group meetings, which offer an opportunity to collaborate about industry issues, share feedback, and attend training sessions.
Author: Tyler Willis, Dynamic Ratings