Page 38 - E-Newsletter

38

“It’s a bit like blowing up a balloon” says Jean-Bernard Dastous, a research
scientist from Canadian power supplier Hydro-Québec, which collaborated with
ABB on the project. “If it’s very rigid, it will be difficult to expand the balloon.

But if it’s made of a very flexible material, it’s easier for you to inflate it.” To
design what ABB calls an “arc resistant” tank, the team first had to create a

mechanical model that could predict the pressure at which a given tank would
deform and subsequently rupture, based on its size and material properties.
Hydro-Québec, in particular, wanted ABB to build a tank that could withstand

20 MJ of energy without rupturing—a level that would cause a “catastrophic
failure” in most transformers and one that Dastous says “would cover 95

percent of faults occurring on thenetwork.”

ABB spent months building a full size tank. For safety reasons the tank was

filled with water instead of oil and contained a replica of the active part of a
transformer. In the first test, the team injected pressurized air measuring 200
atmospheres . The tank bulged at its sides, but did not explode. In the second

test they hoped that the tank would rupture at a given pressure at the top
because less oil will spill into the environment. Their test methodologies

worked. The specifications, to be implemented in the coming months will
hopefully lead to fewer transformersexploding.

Brodeur says: “Because we are able to prevent most of the tank rupture cases,
it’s safer for the people who work around the transformer and it’s also very

good for the environment because we can prevent major oil spills and toxic
fires.”