TXpand – Protecting the Power Grid from ruptures

Rupture resistant transformer solution from Hitachi ABB Power Grids avoiding potential explosions and saving millions of dollars.

Transformers are the muscles of the power grid, enabling electricity to be utilized efficiently and effectively. They perform this essential and demanding task constantly – 24/7 for decades, with virtually no downtime, while subjected to every stress and surge in the power system.

Transformers are incredibly reliable and robust, yet studies show that even these most dependable components can fail and in every 1000 service-years a catastrophic failure and fire is predicted1, 2. These failures can be dangerous and have a huge impact on the supply of power – so it is vital to mitigate even this unlikely risk.

This challenge is amplified further in HVDC bulk transmission systems, in which several gigawatts of power capacity could be lost in the event of a failure.

Solution

In a collaboration with Canadian transmission system operator Hydro-Quebec, Hitachi ABB Power Grids developed a rupture-resistant transformer tank solution; TXpand.

Combining our knowledge, the two companies developed sophisticated computer models allowing vulnerable areas to be strengthened while simultaneously making previously rigid areas flexible. This allows the transformer to literally expand during a major internal failure, absorbing the energy and preventing or controlling a potential rupture.

This technology has been deployed in Canada for several years and verified with a full-scale test in 2018, demonstrating TXpand’s capability to resist an internal failure of 20 megajoules (MJ) – 20 times the energy contained in a stick of dynamite.

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In an ideal world, neither Hitachi ABB Power Grids nor transformer operators would see the impact of this solution. Transformers are designed to not to fail and system operators carefully manage their grids to avoid damage to their power equipment. Yet unexpected surges, lightning strikes or other unforeseen events can happen and so, therefore, can catastrophic failures.

A hypothetical failure in the largest transmission systems, could mean the loss of several gigawatts of power – worth millions of dollars per day – and this would be only the beginning of the cost to society.

By utilizing the TXpand rupture-resistant solution; fire, oil leakage and damage to surrounding equipment could be avoided in the unlikely event of a failure. Thus, the resulting outage would be a small fraction of the time – a spare transformer could be in place within hours, as opposed to weeks of cleanup, repairs and maintenance.

Of course, finally, and most importantly, avoiding a rupture could save lives.