Within days of commissioning an SEL distribution automation control (DAC) system for the Electric Power Board (EPB) of Chattanooga, Tennessee, the system averted a widespread power outage. During a recent storm, a fallen tree severed a power line on a 46 kV looped subtransmission system, cutting power to three substations and 11,258 customers. Within seconds, the SEL DAC system isolated the faulted circuit, remotely closed two breakers, and in collaboration with an adjacent 12 kV automation system, restored power to the unfaulted portions of the network.

“Thanks to distribution automation, we’re seeing reductions in outage duration ranging from 50 percent all the way up to 100 percent,” said David Wade, COO of EPB. “The real beneficiaries of our distribution automation project are the homes and businesses we serve.”

EPB is Chattanooga’s electric power provider. It serves more than 169,000 homes and businesses across a 600-square-mile area and has invested significantly in emerging smart grid technologies. The DAC project was completed earlier this year by the Atlanta branch of SEL Engineering Services under the direction of SEL Engineer Bryan Fazzari.

“The term smart grid,” said Fazzari, “has become a bit of a catch-all term, and so it can be difficult to explain or define to electric power consumers. A successful project like this one puts a more tangible feel on precisely what utilities like EPB are doing when they invest in the smart grid.”

Director of SEL Engineering Services Bob Morris added, “Our solutions were delivered and commissioned in time to prevent what could have been a major disturbance in the delivery of power to a large group of customers.”