Commercial Wind Generator Failure

[(unknown)]

Just ran across this on another forum. A commercial unit in Europe that failed. http://www.liveleak.com/view?i=cdd_1203701257

[richhagen]

Tried to slow it down a bit, looks like one of the blades came apart and the other blades then collided with the debris from that.  Rich

[wiredwrong]

I think this is a bad bad video to post, this only happens during extreme conditions, most (maybe 99%) of the time the mills in the air are only good... posting a mill in a   storm and seeing it explode will not help the home brew cause ....if its that windy shut it down, we need more vids of mills working like they should...

just my thoughts ill go to bed now.....

[TomW]

Randy;

I think it is actually good for people to see how violent a blade failure can be.

Was interesting how the mounting pylon collapsed as soon as the imbalance from tossing a blade happened.

Not to mention how the rest of it pretty much vaporized in no time.

Truth be known, we learn more from failure than success.

Too bad posters here tend to never mention failures of some of the grand plans we saw posted.

Just me, maybe.

TomW

[ruddycrazy]

I wouldn't say it was a bad post, that video really highlights the importance of controlling the mill/ shutting it down in gales, storms etc.

It's a good example of even the big boys do get it wrong with awesum results of failure. I've had 2 blade sets fail in high winds which for me is a good learning curve. People shouldn't be ashamed of their failures and hide them, infact they should be shown so other people can learn from others mistakes.

Just my 2.2 cents

Cheers Bryan

[DamonHD]

Dead right.

We don't avoid repeats of engineering failures by covering them up.

We have to cope with the embarrassment and make the information available to others.

"Those who cannot learn from history are doomed to repeat it."

(And anyway, kinda fun to see, assuming no one got hurt other than in the bank.)

Rgds

Damon

[jacobs]

My initial thought was that it was overspeeding with no way of shutting it down....that's why it was photographed.

I no longer remember the number of blades my wind generator has thrown. Most of them were in 100+ mph winds.

[gizmo]

Obviously something was wrong and they couldn't shut it down.

The wind farm near Ravenshoe about 500km North of me went through a cyclone a couple of years ago, winds over 200kmh were measured at the site. But the windmills were told to furl and shut down, and they survived with no mechanical damage. As a extra safety measure the turbine hub has a built in battery supply and control system designed to furl the blades if it looses communication or power supply from the nacelle.

The anti windmill mob would say this proves the windfarms are dangerous, but we all know what happens to nuclear power stations when they loose control! I know which one I would prefer to have in my neighborhood.

Glenn

[windstuffnow]

  Wow... pretty amazing the power at the point of failure.  I watched it several times and it looked like one of the blades buckled and hit the tower.  Someone must have known it was going to fail or at least had some insight of failure to have a cam corder handy.  

  Thanks for sharing that!

.

[thefinis]

Does make you wonder why anyone would be filming in a storm and just happen to catch it failing unless they knew it was in danger of failing.

Finis

[fungus]

Well .. considering it was going at about 200rpm and they normally go at about 40 ... I'm not surprised it caught someones attention

[huntedheads]

Play it back frame by frame, One blade comes apart at the end (lower left) and then the necell?? (spelling) tilts foreward and the other blades are destroyed by hitting the tower.

Something must have broken when it went out of balance?

[gizmo]

I would love to know what the tip speed was just before failing? Anyone know the approx size of this turbine, we could work it out.

Glenn

[snowcrow]

  Yes, and you can see bent in the tower section thats on the ground. Now thats a serious tower strike!!!  I also noted that the blades never feathered!!  It may have been an electrical failure in the feathering controls or mechanical loading on the hub assembly, produced by the blades, that prevented the motors from turning the blades. The blade failure and tower strike were caused by the lack of feathering control that caused it over speed.

Blessings, Snow Crow

[elvin1949]

TomW

 I agree.I learned how to build bullet proof hotrod engines by blowing up a BUNCH of them.

 That was a long time ago.

later

Elvin

[Dave B]

  Hard to guess the diameter but conservatively if it was a 100' then @ 120 RPM tip speed would be 428 MPH and @ 180 RPM tip speed would be 642 MPH. At 125' diameter tip speeds would be 535 MPH and 802 MPH respectively.

  This was obviously an overspeed control failure. What a tremendous video to learn from which to me shows an amazingly engineered machine structurally and huge saftey margin before failure way beyond it's normal operating parameters.

  Anyone care to run their machine 4 to 5 times faster than your normal operating range ? Thank you for posting this link,  Dave B.  

[DamonHD]

The tips may have been going supersonic!  Wow...

Yes, excellent over-engineering in everything except the brake mechanism!

Rgds

Damon

[dinges]

A collection of pictures I gathered from the web, showing failed (some more catastrophically than others) windturbines:

http://www.anotherpower.com/gallery/album78?page=1

I get the same feeling looking at it as when looking at the debris of a plane crash, but both events can teach one lot about what parts of the construction need improvement.

Peter.