Smart grid upgrades should help prevent blackouts (Philadelphia)

Surfers may catch waves, but power-transmission grid operators like to measure them. And thanks to the American Recovery and Reinvestment Act, they’re going to get better technology to help them do just that.

Valley Forge-based PJM Interconnection Inc. and the 12 companies whose transmission systems are part of its grid will receive $13.9 million in stimulus funds over the next three years from the Department of Energy to help pay for upgrades that bring the system a step closer to functioning as a so-called smart grid.

The money will cover half the $27.8 million cost of installing 91 phasor measurement units, or PMUs, in substations in 10 different states.

Philadelphia-based Peco Energy Co. will commit $100,000 and get the same amount from the DOE to deploy three PMUs, which are also called synchrophasors.

The company will put one in a substation in Whitpain, Montgomery County, and two in substations outside nuclear power plants owned by Peco’s Chicago-based parent, Exelon Corp. The power plants are the Limerick Generating Station on the Schuylkill River in Montgomery County and the Peach Bottom Atomic Power Station on the Susquehanna River in York County.

The DOE grant “is kind of kick-starting the use of the technology,” said Cathy Engel, Peco’s manager of communications.

PMUs get their names because they measure phasors, which are mathematical representations of the wave forms generated by alternating current.

Just as waves on an ocean convey information about weather conditions, the waves on a power grid convey information about the state of the grid.

Being able to measure them in real time enables grid operators not only to know what’s going on in the grid at the moment, but, based on prior data, what could happen and what actions, if any, they need to take.

The PMUs being deployed thanks to the DOE grant take measurements 30 times a second, although other PMUs can take measurements more frequently. Considering that many of the monitors now in place on power grids take measurements once every four seconds, that’s a huge upgrade.

Read the full story in the Philadelphia Business Journal.