Line of Insights

Power Quality Partnership Strengthens Reliability  

Power disturbances on transmission lines near a generating site can reveal a lot about what’s happening inside.

That’s why Transmission’s Power Quality and Generation’s Engineering groups have developed a close partnership over the past two years.

The Power Quality group uses phasor measurement units – PMUs – installed on the transmission system to collect more than a thousand measurements of electrical conditions every second. As more devices capable of capturing real-time PMU data are added to the system, the group has expanded visibility and use cases.

When the Power Quality group detects power anomalies near generating sites, they immediately alert the Generation Engineering group. Although both groups gather detailed, real-time data, Transmission’s analysis provides a different perspective.

“These devices allow us to identify abnormalities before something fails or trips,” said Jonathan Sides, a power system engineering specialist in the Power Quality group.

The data enables Generation Engineering to be proactive, working with the plant teams to perform timely inspections.

“We can track the disturbances back to components within the sites and correct the gaps that we didn’t know we had,” said Josh Brewer, general manager of Generation Engineering.

The partnership has already produced several successes, including identifying a water issue and improving an equipment connection at Allen Combined Cycle Plant; strengthening equipment connections at Kemper Combustion Turbine Plant; and identifying components damaged by a lightning strike at John Sevier Combined Cycle Plant.

At Cumberland Fossil Plant, the teams identified some sporadic power output fluctuations. Analyzing those events led to opportunities to improve main turbine control valve position feedback and take a closer look at configuration settings in the automatic voltage regulator (AVR), a critical component that keeps generator output stable by adjusting for voltage fluctuations. The teams replaced the valve feedback to ensure reliability, and they’re further studying and validating the AVR configuration.

In addition, during spring outage season, some voltage abnormalities at Gleason Combined Cycle Plant were investigated and traced to connections on a transformer fuse and fuse holder. By recognizing and improving these items early, the teams ensured continued availability of these units.

“There is value in this data beyond Transmission,” said Tim Fritch, manager of Power Quality. “Generation is more critical than ever with load growth and high-load events, and this great partnership is about making our units more reliable.”

A snapshot of real-time data, provided to Generation by the Transmission Power Quality team, shows the moment an issue surfaced at Allen Combined Cycle Plant. The red line signals the issue, which led to equipment improvements at the site.

A power disturbance at Allen Combined Cycle Plant was traced back to an equipment connection. 

The blue line reveals a power disturbance that helped the team at Kemper Combustion Turbine Plant strengthen fuse connections.

The orange line highlights abnormal performance compared to the steady blue line that marks normal operating conditions.

A water issue was identified and quickly resolved at Allen Combined Cycle thanks to power quality data.