180 volt PMDC Stalls

[behoof]

I've put up for testing a Danfoss PMDC with the specs of

   1-1/2HP

   1800rpm

   180volt

on a furling mount.

  24- volt system

  16- Liberty 1000 100AH in series/parallel

Flexcharge NC25A-24 charge controller

Diversion load

4 Siemens 85w solar panels

C&D AutoReg Float Charger w/Eq (I've got some questions on this too)

I had a 5' aluminum 3 blade here and wanted to use it until I can get something more suitable, like an 8' or 8 1/2' as zubbly had mentioned on IRC. But until then this is what I have. I'm just not a wood carving kinda person so I'm probably going to have to find someone that makes the blades or blade blanks but that's another part of this.

We've had some really great wind here recently and I've got a panel voltmeter and ammeter that agrees with my Fluke that when this PMDC reaches sufficient RPM for 28 +/- volts it just won't go any further. When I benched it with my AC motor and pulley set up it really cranks out the amps but as I say, it seems to stall just below 30volts.

I'm thinking that this blade set just doesn't have the power (sustainable inertia(if that's a correct phrase)) to power it past this point. When at that point and a substantial gust would hit a few times it would go over 30volts and the amps would follow it up but the gusts were short lived. So, at least I've seen it go over 28 or so volts.

Someone on IRC mentioned using a resistive load to allow this to get past this point but I'm still pretty new to this electronically, so I'm not sure what they mean or how I could accomplish this? I'd like to continue using these blades until I can make the change to blades that match this more appropriatly?

behoof

[CmeBREW]

Thats a nice motor/generator. Why can't I ever find those. Certainly, like you said an 8' set of blades will get that thing kicking the amps. If you could switch to a 48v setup that would let it start rockin' and rollin'with only a 5 footer set. Other than that, the resistive load is the way to go, but I don't know enough 'bout that. Others do no doubt.

[willib]

He might want to try a 36 Volt system first ,

i just found recently a very nice 1.5 HP Dc motor , 90 V at 2600 RPM , 11.4 Amps

It puts out a good voltage just spinning it by hand..

It was at the side of the road in a treadmill machine ..

Why somone would 'pay' the electric company to excercize is beyond me , but i'm glad someone did

 

[behoof]

Hi willib,

My charge controllers and battery chargers and such are all 24volt so I really don't want to make a change like that, I wouldn't think.

I had someone on the IRC mention using a resistive load in the lead from the jenny but that's all I know. I've searched the site and just can't find the info on how to do this to use this 5' blade.

As I mentioned in the original post I need to find someone that makes blades or the blanks soon too.

Anyway, thanks, behoof

[zubbly]

hi Beehoof,

if thats the motor we discussed before, i think it had a small shaft (can't remember for sure).

5 foot is about max for a 1/2 inch shaft. 6-7 foot max for a 5/8 shaft, 8-9 foot for a 7/8 shaft.

these are just guidlines.  if you must exceed, please consider a jack shaft incorporated into the design.

zubbly

[willib]

I'm sure DanB or Flux can elaborate on the use of a resistive load between the generator and the batteries.

But i just ran a little test with my exercize bike-alt setup..

i inserted a .5 OHM , 100 Watt resistor between the alt and battery and everything else being equal, it raised the rpm by 10 for the same voltage and current compared to without it.

email me if you would like to try an experimental set of blades for summertime.

[Jerry]

I think I know the aluminumblades you are using. I'd like to compaire those to my 5ft blade in my wind tunnel when its done. will you be selling those when you get your 8ft blade set.

I will be trying some of Arts 8 ft blades this summer, but down wind, they flex some.

                        JK TAS Jerry

[behoof]

Perhaps I'll let them go when I get a new set of blades up and running. Stay in touch, this blade set is a Boast Buster from TLG Windpower that I bought a while back for another PMDC I had. They worked great on the smaller unit but just don't have it for this one. Oh well, I had them so I gave it a shot but now to follow zubbly's advice.

[behoof]

Willib,

You've got mail !!