Classic Power Curve Programming

[keyturbocars]

Ryan,

I have this HY-2000 2kW wind turbine system.  On more than once occasion, I've seen 3kW out of it, so it is conservatively rated at 2kW. 

http://www.magnet4less.com/product_info.php?cPath=8_116&products_id=498

Here is the Power vs Wind Speed graph:



Here is the Power vs RPM graph:



Since you know and understand how the Classic is programmed for wind, and considering the Power Curves of the HY-2000 wind turbine, does it look to you like it would work well with the Classic?

Edward

[Halfcrazy]

I would suspect it will be a prime candidate for a Classic / Clipper combo or maybe 2 Classics if you have a 24 volt battery bank. We generally see conservatively 2 times the power out of most turbines and closer to 3 on a bunch. A few things to ponder with turbines are:

*Can it run unloaded like the Bergey XL1?
*What is the open circuit voltage in extreme wind?
*Can you stop the turbine by shorting the phases coming in?
*Does the turbine have variable pitch blades based on centrifugal force?

The big issue with turbines is keeping them loaded that is where a form of Clipper comes in. The other issue is over voltage damaging the Classic this again is where a Clipper comes in. If you can stop the turbine in high winds by shorting the windings than the simple crowbar circuit I built for the other power turbine will work and you could experiment with resistors on the other side of the contactor to soft stop the turbine.

The issue with Variable pitch blades will be they will still furl based on rpm this will tend to limit the large gains we typically see with turbines.

[keyturbocars]

I have a 48V battery bank.  The most I've seen put out of this wind turbine during strong gusts (wind gusts in the high 30's) was 65AMP for very short spikes.  I've seen 60AMP surges quite frequently.  40-50amp is common in good winds (high 20's).

*This turbine is not designed to run without a load.  I think it would severely overspeed. 
*I am not sure on the open circuit voltage.  I've asked the factory, but that's one that they didn't answer.  Actually, they did answer (60VDC), but that's based on the controller dump load point.  I don't know if they understood what I meant my Voc.  So, I don't know the answer to this one.
*Yes, the turbine can be stopped by shorting out the 3 phases.
*No variable pitch blades based on centrifugal force. 

There is no tail furling either.  It relies on electromagnetic braking and also the blades are supposed to be aerodynamically designed to stall when they are overspeeding.  I don't know that I've ever seen this, as I've seen 3.5kW surges (high 30mph range) a couple times that made me wonder if the blades would really limit RPM in higher winds.  When I saw the ammeter pegging out at 65A, then I decided to shut down during a lull before the winds got stronger.  I'm thankfu I did because that day we had gusts peak at 57mph.  Too much of a good thing can be bad!  I'm concerned that if the power output goes too high, that I might burn out the stator and have a runaway turbine.

One of my biggest interests in the Classic is safety and reliability.  In other words, the way that it is right now, I'm happy with the power output of my HY-2000 turbine.  It's more than the factory claims.  I suspect that peak power output with the Classic might be improved some, but not the 2-3X increase of some of the Otherpower type turbine designs.  Based on what I've seen with the data on the experimental, high voltage XL-1, I'd suspect that my turbine power increase would be similar.  I'd figure that I might gain 25% output on the top end at most in terms of peak power.  I think 1 Classic unit would probably be adequate. 

My interest in the Classic is not so much "more power", but more that the higher stator voltages it would allow would reduce stator heating and reduce the likelihood of stator burnout during sustained high power output.  In other words, I'd like to have a reliable set up that can output say 3kW safely for sustained periods of time. 

Am I thinking about this correctly?  Would the Classic allow higher stator voltages and therefore reduce heating through reduced current levels?

[Robin]

The answer is yes. You will reduce the current by increasing the voltage. The stator will be very happy to run at increased power, but lower temperature. The turbine will of course be spinning faster to accomplish this.
You very well may need the Clipper. When your batteries are fully charged, the classic will quit putting current into the batteries. this will unload the turbine and it will spin as fast as the wind tells it to. The Bergey XL.1 can take this type of condition and will not go too high of voltage (based on a 48V battery bank). Tod at Bergey estimates that the output voltage will not exceed 280VDC. You may be asking why is it ok to go above 250VDC on the input of the Classic?
The Classic works differently than any other controller. All other controllers void your warranty when the max voltage rating is exceeded. We built the classic to allow the max rating PLUS battery voltage as the safe limit. The Classic will stop operating at 250V in the case of the Bergey, but 280V will not hurt it. If it was charging a 12V battery bank, it could be a problem because we would only guarantee it for 254 volts. A 24 or 48 volt battery bank is in the realm of the estimated 280V open circuit voltage. All should be ok. We call the area between max operating voltage and max allowable voltage HYPERVOC. Time will tell how well things work with all the different turbines out there. Unloaded voltage is a real concern though as the Classicmayl melt down into a gooey mess if the HYPERVOC voltage is exceeded. This condition cannot be covered under warranty, so be careful when not using a Clipper. Halfcrazy has been a beta site for the Classic for a couple of years. He has the distinction of having busted more Classics than anyone else up to this point. That is what beta testing is all about. You will notice that he designed his own interum Clipper. The diagram and description are on this forum. This home brew Clipper will work fine for now while we are developing the real Midnite clippers.

[boB]

If it was charging a 12V battery bank, it could be a problem because we would only guarantee it for 254 volts.

Robin, didn't you mean,   250V + 12V =  262 Volts Max HyperVoc ?

(or maybe, 264 V ??)


boB

[Halfcrazy]

Halfcrazy has been a beta site for the Classic for a couple of years. He has the distinction of having busted more Classics than anyone else up to this point. 

Well if anyone can let the smoke out I can

[keyturbocars]

I may need to wait until the Clipper is released before I can safely use a Classic.

What is the latest estimate of when the Clipper is due to be released?

Estimated pricing on the Clipper & Clipper Jr?

What are the functional differences between the Clipper & Clipper Jr?

If I'm remember right, I think the Clipper Jr. was going to be for 3 phase AC output only.  My understanding (might be wrong) was that the Clipper Jr would use a "crowbar" type brake.  I'm still a big fan of a "soft brake" concept to slow a turbine down in high winds.  A short circuit brake could be applied later after the turbine has slowed down.

Edward

[boB]

I may need to wait until the Clipper is released before I can safely use a Classic.

What is the latest estimate of when the Clipper is due to be released?

Estimated pricing on the Clipper & Clipper Jr?

What are the functional differences between the Clipper & Clipper Jr?

If I'm remember right, I think the Clipper Jr. was going to be for 3 phase AC output only.  My understanding (might be wrong) was that the Clipper Jr would use a "crowbar" type brake.  I'm still a big fan of a "soft brake" concept to slow a turbine down in high winds.  A short circuit brake could be applied later after the turbine has slowed down.

Edward

Time ?  Wish I knew that too.

Difference ?   You pretty much have it right but Clipper Jr.  will PWM as well.
I will short during part of the cycle.  There are ways to make it "more softer" and I
hope it ends up doing this.  Even if it is not what "I" call "soft", Jr. is still
way softer than the usual concept of "crowbar" or full braking.

I would call it more like anti-lock brakes where they pulse.  Not the type where
the brakes on your car "lock up" and you slide into a telephone pole or
off of a cliff.

Hey, I kinda like that analogy !!   But you know, life is like an analogy.

boB

[keyturbocars]

boB, The anti-lock brake analogy is good.  PWM pulsing sounds like a good way make the braking softer. 

Is the unknown release timeframe of the Clipper due to the fact that you guys are busy enough as is rolling out the Classic, or is there some other "log jam" that makes it hard to estimate when it'll be available?

Some of the test sites already have beta versions of the Clipper, correct?

So, I'm assuming the preliminary design is done, and it's a matter of making revisions and fine tuning the final design.

Edward