2012-10-04 - ABB, partnering with the US Department of Homeland Security, the Electric Power Research Institute (EPRI) and CenterPoint Energy, delivered modular transformers from its St. Louis facility to a Texas substation within 20 hours in an emergency drill. These “spare tire” transformers can be shipped and fully energized in less than a week.
By ABB Communications
The transmission grids across the United States form the backbone of American electric infrastructure, providing the long-haul delivery of electricity from power generation plants to distribution networks. There are approximately 129,000 kilometers (km) (80,000 miles) of extra high-voltage (EHV) transmission lines in the US, making up the grid, which has always been vulnerable to various long-term outages, the costs of which can potentially run into billions of dollars.
As a result, a consortium was formed over the past decade by the US Department of Homeland Security (DHS) Science & Technology Directorate (S&T) and consists of DHS S&T, the EPRI, CenterPoint Energy Inc. and ABB.
The goal of this Rapid Recovery Transformer program, or RecX, is to increase the resilience of the nation’s electric transmission grid by drastically reducing the recovery time associated with transformer outages.
The first prototype transformer was designed by the RecX consortium, built by ABB in its St. Louis transformer factory, transported on a lowboy tractor-trailer during a coordinated emergency test run, and is now installed at a CenterPoint Energy substation for testing.
Successful test run
In early April, 2012, DHS announced that a successful emergency drill had been completed during five days in March to move, deploy and energize three single phase, fast-recovery transformers that serve as prototypes for the utility industry to dramatically reduce the recovery time associated with transformer-related outages.
RecX transformers, designed by the consortium and built at ABB’s transformer facility in St. Louis, Missouri, were disassembled and loaded onto lowboy flatbed trucks for a 1290-km trip to a substation near Houston, Texas.
It took around 20 hours to deliver the transformers and within five days they were deployed and energized, including the re-assembly of the cooling systems, conservers and bushings and connection to the grid.
The RecX team worked closely with officials in Missouri, Arkansas and Texas to work out pre-approval and logistics as they drove through highways in these states.
The need for rapid recovery transformers
High-voltage, or extra high-voltage (EHV) transformers are the most vulnerable components in the grid. They are often located in remote substations, making them difficult to replace in an emergency. They generally weigh hundreds of tons and are usually too large to transport by road, and can take months, if not years to replace, if they are built from scratch. This can have extensive social and economic effects especially if multiple EHV transformers are damaged at the same time, such as in a hurricane.
The RecX prototype was designed to replace the most common EHV transformers used by utilities – the 345/138 kV autotransformer. The RecX design principle was to make the unit modular, transportable, and quick to install, but the challenge was to reduce the transformer’s weight to less than 59,000 kg (it actually weighs in at less than 57,200 kg) and its size so that it was truck shippable, while maintaining its performance and reliability.
These rapid recovery transformers will be tested and evaluated for one year at the CenterPoint Energy substation in Texas.
“Through this project, DHS S&T was able to partner ABB and the private sector to develop a solution before a major problem or crisis was experienced,” said Sarah Mahmood DHS S&T program manager.
ABB offers the largest variety of transmission and distribution equipment compliant with IEEE/ANSI, IEC and other local standards for the power grid and smart grid worldwide.
Photo courtesy of DHS S&T
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