Wind turbines and the National Grid

jacaranda

I got to thinking recently about wind turbines, and how the physically connect to the national grid.

For instance, the national grid runs at very high voltages (110 000v - 400 000v), yet a wind turbine produces voltages in the region of about 700 volts.

The national grid also runs on 3 phase, yet turbines are not 3 phase (as far as i know).

To successfully connect a wind turbine to the national grid seems a complicated and probably expensive task.

robtri

jacaranda wrote: »

I got to thinking recently about wind turbines, and how the physically connect to the national grid.

For instance, the national grid runs at very high voltages (110 000v - 400 000v), yet a wind turbine produces voltages in the region of about 700 volts.

The national grid also runs on 3 phase, yet turbines are not 3 phase (as far as i know).

To successfully connect a wind turbine to the national grid seems a complicated and probably expensive task.

IIRC they can use a 3 phase altenator... so doesnt seem to be a huge issue for them...

quentingargan

jacaranda wrote: »

I got to thinking recently about wind turbines, and how the physically connect to the national grid.

For instance, the national grid runs at very high voltages (110 000v - 400 000v), yet a wind turbine produces voltages in the region of about 700 volts.

The national grid also runs on 3 phase, yet turbines are not 3 phase (as far as i know).

To successfully connect a wind turbine to the national grid seems a complicated and probably expensive task.

Domestic generators are usually 3 phase, but produce wild AC which is out of sync with the grid, as well as producing variable voltage between 50 and 500V or so. For domestic machines, this power is converted to DC and converterd into a synthetic AC in sync with the grid by an inverter, either single phase or 3 phase for the bigger ones.

The mega turbines are usually asynchronous - the generator spins at a fixed RPM which is determined by the frequency of the grid and the generator automatically is in sync. In fact, when connected up initially, the generator acts a motor until it gets up to speed. It then rotates slightly faster than its natural frequency, and this small difference is what puts the power into the grid.

Some recent mega-generators are huge permanent magnet generators connected up using inverters, similar to domestic setups, but on a huge scale.

It isn't really an issue as such.

mal1

Have a read through the Danish Wind Industry Association website. Might answer some of your questions.

http://guidedtour.windpower.org/en/tour/wtrb/electric.htm

Capt'n Midnight

jacaranda wrote: »

To successfully connect a wind turbine to the national grid seems a complicated and probably expensive task.

You can always convert AC of the wrong frequency to DC and then use an inverter to convert back to AC of the correct frequency and phase.

This with a few other steps happens inside every computer, television and most mobile phone chargers. Electronics are cheap.

Cheeble

jacaranda wrote: »

To successfully connect a wind turbine to the national grid seems a complicated and probably expensive task.

No, it's ordinary everyday stuff and pretty much every other kind of power generator faces similar tasks.

Whatever the pros and cons of wind turbines, connecting to the grid isn't a massive problem.

Cheeble-eers

brendanf

I found some useful info on this site - <snip>] pretty straightforward to hook up to the grid and the ESB also pay money for the electricity generated

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