Wind turbine generators

[pajce]

How is shunt-capacitor size chosen for this wind induction generators farms?
I need rule of thumb if possible. I understand there is range for generator power factor, i.e 0.9 leading p.f. to say 0.95 lagging. Does this mean that VARs are exported to the grid in preference? If gen is 1500KW then capacitor need to be huge (1200KVAr)
Reason why I ask this is I need to model this generator, and I am stuck right now with what capacitor size to use , one for exporting or importing reactive power.

 

[dpc]

The capacitor sizing has to be done by the wind turbine supplier. Or at least they have to give you the necessary data.

This is typically done a per-turbine basis with switched capacitors. Var requirements change with output (wind speed). If you size the cap bank to correct to 1.0 at full output, you're going to be overcorrected most of the time unless you have a lot of switched stages. Wind farms average only about 30% output on average.

Induction generators have horrendous power factor when generating. Much worse than motors.

 

[Bahram7]

It all depends on the type of the rotor of the induction generator. For example if of doubly-fed type, the generator can produce reactive power so there is no need for shunt capacitors. For squirrel-cage type, the manufacturer should determine the size of the capacitor banks. Using SVC's (static compensators) should be also considered in some cases.

Bahram7

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