DHS photo Extra-high-voltage transformers are huge, custom-built systems, but DHS has demonstrated a way to quickly replace damaged units.

The nation’s infrastructure cannot tolerate power outages, so when there’s an outage, rapid recovery of the power grid is essential.

The DHS Science & Technology Directorate recently completed a pilot demonstration intended to deploy and energize fast-recovery extra-high-voltage transformers so the utility industry can dramatically reduce blackout time associated with transformer-related outages.

EHV transformers, which can weigh hundreds of tons, transmit more than 90 percent of all power on the grid. They’re vulnerable to sustained outages, however, because they’re often located at remote substations.

Currently, it can take months to replace an EHV transformer, assuming a spare is available. If not, it can take even longer. Most are manufactured overseas, making them difficult to procure.

DHS showed that its smaller, lighter emergency EHV Recovery Transformer prototype can be deployed and energized within days instead of months. The drill started March 12 at an ABB Inc. transformer manufacturing plant in St. Louis, where three transformer units were disassembled and loaded onto flatbed trucks for an 800-mile trip to a substation near Houston. There they were re-assembled and connected to the grid by March 17, reducing recovery time by approximately 75 percent.

"We successfully demonstrated the rapid transport, installation and commissioning of the Recovery Transformer in the grid in less than one week," said Sarah Mahmood, program manager in the Science & Technology Directorate. Mahmood said DHS will  monitor the transformer’s performance for the next year to validate its design and operational behavior.

The need for a mobile, spare recovery transformer was identified by the utility industry after 9/11 as part of an infrastructure security initiative by the Electric Power Research Institute.

Of course, protecting the nation’s critical infrastructure is a key DHS mission, and the electrical grid is one of the 18 key infrastructures whose disability would immediately harm the economy and national security. The power grid is even more critical, since most other infrastructures, such as water, communications and  transportation, depend on the availability of the electrical grid.

"For example, you need electricity to power the pumps at a water treatment facility, or to power transmission antennas for communication systems," Mahmood said.

Mahmood said the DHS Recovery Transformer technology is applicable to all utilities operating at high voltages on the transmission network throughout the entire country. Operationally, the units are designed to function the same as a traditional EHV transformer.