The Aug. 14, 2003, Northeast blackout pointed out a major weakness in the grid-monitoring system. During a cascading failure, grid operators learned that they needed a more accurate picture of what is actually happening in the power system to have better control and prevent outages.
Dominion Virginia Power is starting to test the new technology of “synchrophasors” with the goal of making the grid more reliable and efficient. Dominion is working with Virginia Tech and Quanta Technology on this research and development project funded by a $1.5 million grant from the Department of Energy.
“If you characterize the current state of technology for monitoring the power system as an X-ray image, synchrophasor technology will provide MRI-quality data,” said Arun Phadke, distinguished professor emeritus at Virginia Tech. “Dominion’s system is a unique and good proving ground for application of these techniques.”
Phadke’s work with synchrophasors began nearly 27 years ago. He invented the key building block of this technology, the phasor measurement unit (PMU).
A PMU system uses sensors to sample voltage and current at specific locations at up to 30 times per second. This is faster than the two to four times per second sampling of the supervisory control and data acquisition system currently in use. PMUs are sampled from widely dispersed locations in the power system network and synchronized using a GPS radio clock. The enhanced sampling provides faster, better diagnostic capabilities to predict surges and outages.
“I’m thrilled to see this technology moving from the lab to the grid,” said R. Matthew Gardner, Dominion’s lead engineer on the project. “For our system operators, it’s the ‘Wizard of Oz’ moment when the world goes from shades of gray to full, living color.”