Page 38 - TECHNOPHILIC

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When an eerie blue glow lit up the sky
above New York City last December, some

were disappointed to learn that aliens
weren’t involved. The cause was, in fact,
terrestrial: a transformer had exploded at
a local power plant. For the most part,
transformers, which help power
companies transmit electricity efficiently
by altering voltages, are relatively safe.
Fewer than one percent explode—but
those explosions can be deadly, and result

in flying projectiles, toxic fires, or oil spills.

Transformers rupture due to a build up of excess pressure in the tank in which
they are encased, which is usually filled with mineral oil that acts as a coolant.
Contaminants within the oil, the degradation of transformer parts, and

electrical storms can all cause a fault, called an internal arc, that results in a
rapid release of energy. The internal arc inside the transformer heats up the oil
and the oil burns to create a gas which causes high pressure. Conventional tank

designs are not capable of resisting such high energies which can reach up to
150 megajoules, equivalent to 150 sticks of dynamite. ABB , based in Varennes

, Canada has been working for over seven years to build a more resilient
transformer tank. Their solution, described in a paper published 12 June 2019
in IEEE Transactions on Power Delivery, is called TXpand. The idea is startlingly

simple: design a tank that’s flexible enough to deform to absorb all that extra
pressure without rupturing. “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.” 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.”
Source: https://spectrum.ieee.org