Researchers at the University of Texas at Austin have developed a sensor that attaches to energized power lines and detects hidden grid threats, including tree limbs contacting conductors, before they lead to outages or wildfires.

The sensor alerts utility personnel when it detects a potential issue, allowing crews to respond before damage occurs. Without this type of monitoring, utilities may only become aware of a tree-contact event if it is discovered during routine inspections or reported after visible signs, such as smoke, appear.

For more than five years, researchers at the university's Center for Electromechanics (CEM) have been developing the technology, combining edge computing, telecommunications, power harvesting, and machine learning through laboratory and field testing.

"Power lines face many undetected threats, from tree limbs momentarily touching the power lines during wind gusts to aging grid components nearing permanent failure," said Pablo Paz, research associate at CEM and technical lead for the project. "It was rewarding to see the instrumentation perform exactly as designed and to witness the field results align with our laboratory tests."

Self-Powered Monitoring

The monitoring device consists of two clamp-on units that linemen can install on energized power lines. A single sensor can monitor activity along miles of line.

Rather than requiring auxiliary transformers or pole modifications, the sensors power themselves by inductively harvesting a small amount of current from the line, reducing installation complexity and cost.

Researchers say the system can also identify the location of faults, including vegetation contact, helping utilities target inspections following severe weather instead of patrolling long stretches of line.

"In the event of a windstorm, utility employees might have to drive dozens or even hundreds of miles to inspect power lines," said Shannon Strank, deputy director of CEM. "If we can give them specific locations to inspect, it will greatly speed up the process."

Detecting High-Impedance Faults

During one month of field testing near Seguin, Texas, last fall, the sensor recorded 34 events compared with three detected by conventional equipment.

Tree contact with power lines is classified as a high-impedance fault. Researchers said these events have historically been difficult to detect until they become severe enough to trigger conventional monitoring equipment.

They noted that growing electricity demand, aging infrastructure, and more volatile weather have increased the need for improved grid monitoring technologies.

Monitoring Large Electrical Loads

In addition to detecting vegetation-related faults, researchers are evaluating the sensor's ability to monitor large electrical loads, including data centers.

According to the research team, modern data centers rely heavily on high-frequency power electronics, such as graphics processing units (GPUs), creating electrical conditions that differ from those of traditional grid loads. Researchers say the sensor could help utilities monitor these loads while identifying early signs of equipment degradation.

"We're trying to see indications that an event is coming via signals exposing early degradation and fatigue in advance of failure and outage," Strank said. "With early mitigation, these components can be serviced before a catastrophic event occurs."

Laboratory and Field Testing

To develop and evaluate the technology, CEM researchers built a laboratory power system with multiple energized power lines equipped with both the UT sensor and conventional monitoring equipment.

Researchers use a controlled setup in which a tree branch is brought into contact with an energized conductor while cameras and monitoring equipment record the event. While conventional monitoring equipment shows little change, the UT sensor detects a clear signal when the branch contacts the line.

Researchers noted that although field events are infrequent, they can have significant consequences. They cited the 2024 Smokehouse Creek Fire in the Texas Panhandle, which killed two people, destroyed more than 100 homes, and burned more than 1 million acres. Laboratory testing allows researchers to evaluate dozens or hundreds of simulated events each day without risk.

"It helped to see the things I was learning in class being applied in the laboratory, which has given me invaluable hands-on experience," said Joseph Spiro, a recent UT electrical and computer engineering graduate who worked on the project. "It is also exciting to learn that the lab results are predicting what is happening on the grid."

The project has involved collaborations with Verivolt, LLC, NI, Capstan Technologies Inc., Eaton, Wood County Electric Cooperative, Guadalupe Valley Electric Cooperative, Argonne National Laboratory, Idaho National Laboratory, and Sandia National Laboratories over the course of its more than five-year development.