Subscribe options

Select your newsletters:

Please enter your email address:

@

Your email address will only be used for the purpose of sending you the ITER Organization publication(s) that you have requested. ITER Organization will not transfer your email address or other personal data to any other party or use it for commercial purposes.

If you change your mind, you can easily unsubscribe by clicking the unsubscribe option at the bottom of an email you've received from ITER Organization.

For more information, see our Privacy policy.

News & Media

Latest ITER Newsline

  • Cooling water system | The tanks within a tank

    Deep inside the bowels of the Tokamak Building, the entrance to one of most spectacular rooms of the whole installation resembles that of a broom cupboard. [...]

    Read more

  • ITER assembly | Last major assembly contract signed

    One year after finalizing two major machine assembly contracts, the ITER Organization has chosen the contractors who will carry out assembly and installation ac [...]

    Read more

  • ITER Science | The towering importance of data

    The most important product of ITER is data, which will be used to produce the information needed to build models for DEMO and commercial reactors—and much more. [...]

    Read more

  • Image of the week | In my arms!

    In late November, one part of the 'shell' that encloses every vacuum vessel sector—a right-hand outboard thermal shield panel—had been mounted on a giant pre-as [...]

    Read more

  • Brexit | The UK will remain part of ITER

    'It was a great Christmas present,' says Ian Chapman, head of the United Kingdom Atomic Energy Authority. Many in the ITER community would agree. The Brexit neg [...]

    Read more

Of Interest

See archived entries

When a transformer purrs

The low, regular "purring" of the transformer was the sign that everything was fine. Electricity was gently flowing from the grid substation to the 400 kV ITER switchyard, and from there into one of the four 22 kV worksite transformers.
 
Tension is palpable as Jeremy Sanna (ITER Organization), Cedric Gazza (ENGAGE), Gilles Consolo (ITER Organization operation manager for the 400kV switchyard) and Laureano Linan Delgado (FERROVIAL) verify the 400 kV circuit breaker before commissioning. (Photo Francesco Campostrini) (Click to view larger version...)
Tension is palpable as Jeremy Sanna (ITER Organization), Cedric Gazza (ENGAGE), Gilles Consolo (ITER Organization operation manager for the 400kV switchyard) and Laureano Linan Delgado (FERROVIAL) verify the 400 kV circuit breaker before commissioning. (Photo Francesco Campostrini)
Achieving the "energization" of the ITER worksite, albeit for less than one hour, was the culmination of two months of preparation in close coordination with the French transmission system operator RTE (Réseau de transport d'électricité).
 
Technically under European responsibility, the final operation on 30 March—an ITER Council and European milestone—was long and painstaking and required both finesse and expertise.
 
Procured by the US and manufactured in Korea, the transformer to be energized "had not seen power since undergoing factory acceptance tests in late 2014," explains Joël Hourtoule, the ITER Electrical Power Distribution Section Leader.
 
"A transformer that stays idle for such a long time loses what we call its 'magnetic remanence.' When it is turned on again, the inrush of current can cause important mechanical stress that we need to control."

The difficulty is to precisely adjust the relay settings of the circuit breakers that protect the transformer—one notch too low and the circuit breaker trips when it shouldn't; one notch too high and the fault current might damage the transformer.

"Of course we have charts and curves and electronic measurements, but in this kind of situation nothing beats the experience of the Electrical Division's old hands," adds Joël.

The first settings, "too conservative," caused the transformer to trip. The second, following an hour-long analysis of dozens of parameters, proved effective.

The transformer's purring, hesitant at first, soon stabilized—as if the 150-tonne beast was expressing satisfaction.
 
The energization procedure will be repeated before the summer for each of the three remaining 22 kV transformers of the steady state electrical network (SSEN); then, by the end of the year, the same operations will be conducted on the massive pulsed power electrical network (PPEN) transformers, procured by China.
 
However, it will be another eight or nine months before parts of the ITER worksite and buildings can progressively draw power from the grid.
 
For Joël Hourtoule and the "old hands" in his team, the energization of the 22 kV transformer marked the culmination of a full decade of work. "We began designing the system in 2007, defined the Procurement Arrangements, monitored fabrication, supervized the installation ... for engineers, it is a rare privilege and satisfaction to carry a project from inception to completion."


return to the latest published articles