Friday, August 15, 2003

WHY WAS PHILLY SPARED?: The Inquirer brings the story:

Technicians in Valley Forge saw the sudden power surge. Circuit breakers tripped. And within four minutes, the electricity grid that serves Pennsylvania and New Jersey had clamped off the spike that blacked out much of the Northeast yesterday, shielding Philadelphia and points south from the disruption.

As a result, the Mid-Atlantic grid, operated by Valley Forge-based PJM Interconnection L.L.C., experienced only a few spillover blackouts in sections of northern Pennsylvania and northern New Jersey.

Never mind that nine seconds is shorter than four minutes. The Courier-Post seems to make a little more sense:

South Jersey escaped a big blackout Thursday - and you can thank the technology of the regional power grid system.

As soon as the electricity failed in New York and elsewhere in the Northeast, transmission lines in New Jersey apparently started pumping juice toward blacked-out areas.

This strained the Garden State's intricate network of power lines, transformers and substations - but the blackout did not cascade down the line to South Jersey.

A system of relays, a little like circuit breakers, "isolated and sectionalized" the surge, said Phillip Harris, president of PJM Interconnection, the region's power pool.

In a sense, the equipment used by the utilities within the PJM grid prevented the blackout from spreading any farther south than North Jersey and northeastern Pennsylvania.

Meanwhile the blame Canada party has raised its ugly head.

No comments: