Poor mans wind turbine mppt

Deveak_Kaizen

Just wandering if anyone has ever figured out an alternative to the midnite classic and the clipper. Its the "right" way to do it and it also gets close to 2 grand. I'm looking at mid sized windmills, around 1000 watts and I want to do it without the usual direct load windmills. I have a 24 volt system. I don't see how anyone can do direct drive, its so inefficient and the cable size is huge! I am fairly certain most mppt including the midnite just needs a in series resistor bank at the correct ohm, for the voltage you want to keep it under and it needs to be larger than the windmills total output. Does this sound right? A cheaper mppt with an AUX output or even a simple voltage sensing signal to a relay to activate the resistor bank relay. Maybe two banks. One set at a higher O S*** setting and a lower bank that can't completely stop it, that way it still turns somewhat at a decent speed. I feel like no one system is reliable enough to rely on. Smaller windmills like that might do okay with some simple mechanical brakes like from a bike. Thoughts? Can a dude cludge together a decent mppt wind turbine without breaking the bank?
The only unique part of the clipper is the control board, the rest of it can easily be replicated. 

mike95490

The resistor is not usually installed in series, it's installed as a diversion load.

Ideally, you want to use some sort of breaking mechanism, like the disc brake hub off a motorcycle, or a scheme of shorting the turbine alternator windings to create enough load to slow it down.   Some windings are amenable to electrical breaking, and some are not, the mfg's data sheets should cover the preferred braking method for the turbine.   If no other method is allowable, a Dump Load must be used to load the turbine down to prevent over speed and destruction, simply disconnecting from the battery lets the turbine freewheel to excessive RPM's

having some sort of last ditch braking method, like throwing a fishing net over the blades to snarl everything up if it's starting to overspeed, is advisable.  It might take a while to untangle the aftermath, but it's better than picking rotor blades out of your car roof or the neighbors cow.

Deveak_Kaizen

I was studying pictures of the Midnite classic, are the resistors parallel to the Midnite classic input? It looks like it is and than they short out the phases at the ssr. So....it’s still connected to the charge controller, it just has a parallel path to a short with resistors in it? I take it the resistors keep the one from burning up? That might be doable on a diy scale. Just not as fancy.

mike95490

Deveak_Kaizen said:

I was studying pictures of the Midnite classic, are the resistors parallel to the Midnite classic input? It looks like it is and than they short out the phases at the ssr. So....it’s still connected to the charge controller, it just has a parallel path to a short with resistors in it? I take it the resistors keep the one from burning up? That might be doable on a diy scale. Just not as fancy.

Where are these pictures ? Photographs are not really usable as schematics as PCB's often have internal layers you cant see in a photo.

Deveak_Kaizen

Just the wiring diagram from the manual, its paralleled to the charge controller before the rectifier. The controller activates a relay which has a bus bar on the other side, shorting out all three phases. Each phase has a resistor before the relay. 
http://www.midnitesolar.com/pdfs/clipperManual.pdf
Also I found a video of a guy who made his own. 
https://www.youtube.com/watch?v=2aDdZaKE0Bk

mvas

Deveak_Kaizen said:

Just the wiring diagram from the manual, its paralleled to the charge controller before the rectifier. The controller activates a relay which has a bus bar on the other side, shorting out all three phases. Each phase has a resistor before the relay. 
http://www.midnitesolar.com/pdfs/clipperManual.pdf
Also I found a video of a guy who made his own. 
https://www.youtube.com/watch?v=2aDdZaKE0Bk

An MPPT Wind Turbine Controller, with a Power Curve, does a whole lot more than ...
simply energizing a Dump Load Resistor at a specific over-voltage.
There are very inexpensive "Dump Load" Controllers, but they usually don't provide 3-Stage Charging for deep cycle batteries.

Deveak_Kaizen

mvas said:

Deveak_Kaizen said:

Just the wiring diagram from the manual, its paralleled to the charge controller before the rectifier. The controller activates a relay which has a bus bar on the other side, shorting out all three phases. Each phase has a resistor before the relay. 
http://www.midnitesolar.com/pdfs/clipperManual.pdf
Also I found a video of a guy who made his own. 
https://www.youtube.com/watch?v=2aDdZaKE0Bk

An MPPT Wind Turbine Controller, with a Power Curve, does a whole lot more than ...
simply energizing a Dump Load Resistor at a specific over-voltage.
There are very inexpensive "Dump Load" Controllers, but they usually don't provide 3-Stage Charging for deep cycle batteries.

I'm talking about building a poor mans midnite clipper. I would still be using a midnite classic but building a DIY version of the clipper.

mike95490

Deveak_Kaizen said:

I'm talking about building a poor mans midnite clipper. I would still be using a midnite classic but building a DIY version of the clipper.

OK, let us know how that works out.   Remember, your investment in Turbine, Classic and batteries all rely on the clipper being able to absorb 150% of the turbine output for 6 hours.  (but ignore me if you never get any high winds)

MatthewLynch

If all you want is to limit the imput voltage to the Midnite you could try this.
https://gitlab.com/TiEoLibre/Analog_Battery_Regulator?fbclid=IwAR1tbggLKIdJkt6ZeE6pyURA4WWhqzeIyC4tipd7Y2hN8TIx3OE5zT7Ptjs

That is the design for an analog divert load controller. You should do some modifications so it operates at a different value. So lets say the limit of the Midnite is 150V so you set this to maybe 140V to me safe. You will laso not need the voltage temperature adjustment. 

You also have to consider what mike95490 says and have a dump load 150% the power of your turbine, otherwise you are going to be spending alot more money than what the clipper would cost.