Wind Farm Questions

[handy10]

I was noticing the wind farm on I65 north of Indianapolis the other day and several questions occurred to me. (1) Will the generator head rotate more than 360 degrees? (2) How is the current transferred from the generator to the transmission lines? (3) How is the frequency controlled as the blades turn at different speeds?

Here are my answers about which I have no idea of correctness.

(1) They will turn more than 360 degrees otherwise there would be something like jibes experienced on sail boats.
(2) If answer (1) is correct, the power must be transferred through split rings. If so, are there ultra-low resistance rings?
(3) Mechanical gearing turns the rotor at constant speed regardless of blade speed.

Thanks for your thoughts.

 

[gar]

150222-2144 EST

Some answers to some of your questions may be answered at http://en.wikipedia.org/wiki/Wind_turbine with close reading. There are many references that may provide more complete answers.

.

 

[electrofelon]

Good questions. I dont know the answers either but am curious and have wondered often, hopefully someone who knows will chime in. I always assumed they were set up like an induction generator. They have variable pitch blades so it seems very feasible and would seem to require less equipment than processing and synching variable frequency power, but again that is just speculation.

 

[GoldDigger]

I was noticing the wind farm on I65 north of Indianapolis the other day and several questions occurred to me. (1) Will the generator head rotate more than 360 degrees? (2) How is the current transferred from the generator to the transmission lines? (3) How is the frequency controlled as the blades turn at different speeds?

Here are my answers about which I have no idea of correctness.

(1) They will turn more than 360 degrees otherwise there would be something like jibes experienced on sail boats.
(2) If answer (1) is correct, the power must be transferred through split rings. If so, are there ultra-low resistance rings?
(3) Mechanical gearing turns the rotor at constant speed regardless of blade speed.

Thanks for your thoughts.

1. Usually slip rings and brushes. Forcing the head to motor around 360 degrees can be a problem. (Note that for consumer sized wind generators using a flexible cord with lots of slack and correcting manually when needed is actually a viable option. The wind does not often progress around a full circle.

2. Probably! Or else the units use high voltages instead of high currents.

3. Not normally. Two main alternatives are use of DC (rectified) from the generator to drive an interactive inverter or the use of writeable pole generators which can produce a constant frequency independent of rotation speed. As noted, variable pitch propellers can also be used to keep a constant shaft speed under some conditions.