ISO-NE continues to gain international recognition for innovative Oscillation Source Location Technology

In the six years since its launch, ISO New England has received significant international acclaim for its innovative Oscillation Source Location (OSL) technology, which provides grid operators with detailed information identifying equipment causing oscillations on the power system. These oscillations, like ripples on the surface of a pond, can radiate outward from their epicenter, such as a malfunctioning power plant, and affect power systems thousands of miles away.

The ability to swiftly identify the source of these oscillations is crucial, notes Slava Maslennikov, Technical Manager of Advanced Technology Solutions at ISO New England. His team has worked to develop the OSL application for that purpose.

 “The first step in efficient mitigation is to answer: who is causing oscillation?” Slava said.

Global impact and collaboration

The influence of the OSL application extends far beyond New England. Over 26 organizations and companies have requested the OSL software, with more than 10 already implementing it. These organizations include the grid operator in India, which has successfully integrated ISO New England’s on-line OSL application into their control center operations—highlighting the technology’s global significance.

The collaborative efforts surrounding OSL have also gained international recognition. A technical report, “Forced Oscillations in Power Systems,” by the Institute of Electrical and Electronics Engineers (IEEE) PES Oscillation Source Location Task Force, features significant contributions from ISO New England.

In 2021, the IEEE PES Oscillation Source Location Task Force, chaired by Frankie Zhang, Principal Analyst of Advanced Technology Solutions at ISO New England, partnered with the North America Synchrophasor Initiative (NASPI) to organize a worldwide contest for oscillation source location methods. This contest drew participation from 21 teams across the globe.

“We provided the teams realistic for real-life simulated test cases. That allowed for an apples-to-apples comparison the efficiency of used by teams OSL method for practical implementation. We then ranked team’s results in places with the objective to find out which methods were most successful,” Maslennikov said. “People were using different methods from artificial intelligence (AI) to model based, but in the end, eight teams from nine first places used the ISO method, which is proof of our technology’s efficiency.”

Harnessing the power of Phasor Measurement Units (PMUs)

The foundation of OSL technology lies in Phasor Measurement Units (PMUs), also known as synchrophasors, installed throughout the region’s transmission system. These PMUs continuously measure power grid voltage, current, frequency, and phase angle in multiple substations across the power system at a rate of 30 times per second. Maslennikov underscored the transformational impact of PMUs, explaining, “This system allows us to capture actual system dynamic behavior, a significant improvement over the traditional 4-second interval measurement system by SCADA. With PMU measurements, we’ve been able to observe system behaviors previously unnoticed.”

Uncovering forced oscillations

Since the deployment of PMUs, hundreds of instances of “forced oscillations” up to and even exceeding 100 MW have been detected. In 2017, Maslennikov’s team introduced a 24/7 fully automated, online Oscillation Alarm Notification service, which detects oscillations, initiates the OSL application run, collects the OSL results and compiles it into email notifications sent to all relevant contacts within ISO New England and the New England control area. Currently, there’s an ongoing project to integrate OSL results into ISO-NE’s Energy Management System, which allows control room operators more efficient real-time monitoring, control, and optimization of the electric power grid.

Not a hypothetical threat

The risks of oscillations were evident on January 11, 2019, when an event occurred in the power system thousands of miles away from New England, but sent ripples through the entire Eastern Interconnection. Within a mere 17 minutes, the entire power system was oscillating, causing power swings of up to 200 megawatts in transmission lines.

OSL rapidly identified the problem as outside of New England, and the technology’s automated notification system reassured ISO control room operators that the issue was beyond their control.

Addressing challenges in an evolving energy landscape

As the energy landscape evolves with the integration of renewables and distributed energy resources (DERs), ensuring grid reliability becomes an increasingly complex challenge. Dean LaForest, manager of real-time studies at ISO New England, emphasized the importance of the OSL application in addressing these emerging challenges.

“The technology is helping us to focus in on problems that we haven’t found yet, or that we haven’t determined potentially exist,” LaForest said.  “As the New England grid transitions to large inverter-based resources, such as offshore wind farms, these new-generation resources have the potential to interact with existing large generators and DERs in ways that have never been seen before. Software like OSL will help us see things before they progress to an event that might impact the transmission system and hundreds of thousands of customers.”