Large Industrial Wind Powered Electricity Generators

dvmdsc wrote:

"1. Top heavy is the best momentum stabilizer. Most of all the forces act in that axis. Especially with gusty winds. - more reactive weight where needed

5. If the generator/gearbox should be on floor level, means on top should be an enormous wheel with a short shaft and a gear work with long high torque shaft to the bottom."

1. This requirement can be very well addressed by a suitable flywheel.

5.You could transmit the rotary motion by using two synchronous cranks acting one on top end and one at the bottom end acting through a connecting rod(tubular steel truss structure for lightness and strength).

D.RAMAKRISHNA NAIDU

"5.You could transmit the rotary motion by using two synchronous cranks acting one on top end and one at the bottom end acting through a connecting rod(tubular steel truss structure for lightness and strength)."

How do you allow for slew with this system? (which I take to be like the treadle sewing machine linkage)

(dvmdsc - or a chain drive?)

I think you will find the rotor inertia is greater than any flywheel addition practically achievable. Also that the rotor presents enough gyroscopic stresses without the need to add more. Also that the tower has to withstand the axial load equal to watts generated, so will easily support the generator mass.

But do continue, it's interesting.

Chain drive to end the joke? Thanks

And you know these windmills seek the wind direction, that is also rotation. One more unneeded complication

"How do you allow for slew with this system? (which I take to be like the treadle sewing machine linkage)"

What a stupid mistake, eh?? Thanks.

Okay, to make up for it, how about mounting the generator in the rotor hub itself??

See post 6

Follow the links and have a good prowl about the Mawson pages - lot of interesting stuff on all aspects of what they are doing and how it performs - including real time output data and graphs.

I think that has already been mentioned somewhat earlier in this blog by someone else, but here goes:-

Due to the sheer size of the blades to allow as much power to be generated as possible, the prop RPM is severely reduced so as to not let it fly apart due to centrifugal force.

(there are videos on YouTube demonstrating this actually happening when the prop folding mechanism fails in stronger than normal wind conditions....!)

Therefore the prop speed is simply not high enough to generate 50 or 60 Hz needed, and adding more poles to the generator is also impractical (4 or 5 times more!!!).....so some type of gearing is needed to speed up the generator/alternator relative to the prop speed.....Remember at the end of the day, any particular wind powered AC generator has a fixed operating speed due to the need to produce a fixed frequency to feed into the mains system.

Maybe one day someone will invent a "gearbox" to allow different prop speeds, but basically that will just add complication, cost and even more weight. But if ever done then possibly one of those infinitely variable gearboxes that some car manufacturers have produced over the years......you never know!!

GA.

That is a precise and well put answer and educated me at the same time.

Most of what you said was also common sense too....

Thanks.

I agree, I have designed a wind generator this way and its building and maintenance cost is lower than the conventional one. It has also other advantages.

This design is also better from the point of view the electrical connexions.

Maybe somebody made the conventional design that was followed without a serious analysis by other engineers.

Arturo Pérez Rodríguez

Dr.Industrial Engineer

As you neglected to mention exactly which post you were replying to (or to reply to a post) CR4 has placed your answer "well down the page", I for one would rather not to search around and guess which of the preceding posts you meant. So the end result is often in such cases is that your reply just gets ignore.

May I therefore suggest two things:-

1) Use the "Reply" button when replying to a post, this "links" you to that post and anyone who cannot remember what the person before wrote exactly (me for instance!) can simply click on the link and read it again.

2) Join CR4 properly, as "guest" posts are largely ignored anyway, even if your post is done correctly, as anyone not confident enough to post his avatar/CR4 name at least is "one scared bunny!".....or so it might appear to the reader.

You appear to know something of this area (I for one would be interested to find out just how efficient your version was in comparison to a conventional one of the same size), I am sure I am not alone in wishing to learn more from anyone with such knowledge (but not from ANY guest), so please join CR4 asap.

Have a great day as well!!

check out this article http://machinedesign.com/article/hydraulic-wind-turbines-0420

A number of early windmills did exactly this, but there is still a need to service the top components, and shaft torque in the down transmission limits power.

The hydraulic transmission has great potential in terms of storage of power, so extended viability in marginal or quixotic conditions.

However the newer turbines use a multiple winding solution that eliminates the gearbox mass and associated losses.

Enercon E-30 wind turbine - Mawson Station Antarctica

You may transmit the torque and therefore the mechanical energy to the bottom by means of an hydraulic pump/turbine set. The resultant installation will be usefully for fast and easy maintenance at the ground level and a lightly top installation.

But this will be practical only on land. Offshore in the sea, better keep the traditional solution.

These design decisions usually come down to cost. With the true cost being made up of the initial cost, construction costs, maintenance costs and system efficiency.

Wind turbines are a fairly mature technology, being supported by a wide range of companies, so it's highly probable that the way it's being done now is the best way.

Sir,

There are wind mills which are having vertical axis. Two blades are attached to it like bow. IN side view it looks circular. The profile is aero profile.Engineers have tried Three blade design also. However the two blade design was proved more efficient. Central shaft arrangement needed is stronger. The motion transfer is at bottom and the maintenance at top is only change of the bearings(over-design the bearings for the thrust and you get the most economical wind mills.) I will try and send the specifications in about a weeks time.

Regards

kiran