Stalling Issue on turbine

[Hogheavenfarm]

I see, I had it backwards. I understand the resistance is blocking the current and the turbine will spin up. So a "cool" filament allows current flow and a "hot" one restricts it. Odd that it started and spun up with the bulb (21 ohms-cool) but wont spin up with the resistor (1 ohm). I guess I need some testing data during some wind with it spun up. Maybe later this evening or this weekend. Maybe the filament in the bulb heated rapidly and the resistance increased quickly allowing the spinup? I couldnt see the bulb as that last front came through with rain and I had the bulb covered with a 5 gallon pail to keep it dry. Something for me to look at this weekend.

 

[NIFE]

I see, I had it backwards. I understand the resistance is blocking the current and the turbine will spin up. So a "cool" filament allows current flow and a "hot" one restricts it. Odd that it started and spun up with the bulb (21 ohms-cool) but wont spin up with the resistor (1 ohm). I guess I need some testing data during some wind with it spun up. Maybe later this evening or this weekend. Maybe the filament in the bulb heated rapidly and the resistance increased quickly allowing the spinup? I couldnt see the bulb as that last front came through with rain and I had the bulb covered with a 5 gallon pail to keep it dry. Something for me to look at this weekend.

It spins up with the bulb because 21 ohms doesn't load it much. It bogs down because 1 ohm is too low. You either have to work down from 21 ohms or work up from 1. Because it used to work, I think it will be on the lower end.

 

[Hogheavenfarm]

I ordered another 2 resistors. will look for some 20w incandescent bulbs, or maybe something low wattage I can screw in there. I can add the other resistor tonite or tomorrow by jumping it into the circuit.

 

[Hogheavenfarm]

Second resistor is wired in series with the first one now, but wind has died down, so I guess a 2 ohm preload on it at this point. I will wire in a 4000 w water heater element as a dumpload tomorrow.
update - I purchased a 7.5w nightlight filament bulb and a 20w filament bulb to test as well.
For now (with the two resistors now in series) will splice in the jumper with a 30amp fuse as a bypass, that way I can change things up on the fly...
Wind predicted for this afternoon, as soon as the snow stops.

 

[Hogheavenfarm]

quick update - i did get the two extra dump load resistors in, and started a set of tests last weekend (which appeared promising even) and the wind was cooperating as well, but real life got in the way for now, so had to stop for now, but hopefully will continue soon as things should even out some in the coming days. I did find another sparrow nest inside and cleaned it out and placed more screening, I also noticed what appeared to be a blade wobble while staring at it in a prestart breeze (6mph) and found the hub had loosened slightly in the past year, so climbed up and tightened that (and found the bird nest). Tied it off facing east for now until I can get back to it.

 

[NIFE]

The SSR looks interseting but I know the turbine will put out more than 60v. something like this maybe better? 250VDC at 40 amps? I know its a bit overkill, but since this imported stuff has a high failure rate, staying away from full scale operation might make it last longer?
What would I trigger the relay with? I could parallel the turbine feed, but that would kick it in too low (3v?) The minimum voltage doesnt seem to be adjustable. I could use a solar panel (I have some 100w panels around) that would kick in around 20v or so, but only during the day.
An old school centrifugal rev limiter would work well, very steampunk.

I have a 40 amp version of a SSR you are considering above. I simulated charging a 12v car battery with a turbine using a variable power supply. It does just what I hoped for. It looks like a SSR, heat sink, and a linear taper potentiometer would be all you need to field test. This along with the series resistor(s) you are experimenting with should fix all your issues. You might even be able to remove the resistor and gain some efficiency. My power supply is limited to 30 volts so there is a little uncertainty about what 60 volts does to it. I think the SSR will turn on fast enough resulting in battery charging which will instantly drop the turbine voltage to near the battery voltage. Wont know until you try it. Might need to stick a 20 volt Zener diode in there somewhere. What will make the SSR fail is disconnecting the battery from the circuit while the turbine is running. The potentiometer I was using is 250K ohms. It is too sensitive. I think the best value will be in the 10-20 thousand ohm range.

 

[Hogheavenfarm]

Thanks for those stats. Hopefully I may be able to get back to this project this weekend, but my 92 yr old mom is in the hospital and we have been taking care of things there, not sure when I get get enough time right now. I will Update this thread as things return to a "more normal" situation.

 

[Hogheavenfarm]

Well, a bit of a follow up. Still tied up caring for mom, but I did start getting things in place. I set up a personal weather station directly in front of the turbine, about 6ft away (just enough for the tail to miss it) and at the same height. I also installed a security camera that will monitor the turbine and weather station remotely, so I can evaluate issues while I am at work (that seems to be when the wind kicks up!). I did verify over the weekend that the UNLOADED turbine will track the wind nicely at 4-5 mph, and will start spinning at 7.5 mph, all of which was in the original design, so that much is confirmed. More testing was not possible at this time as wind speeds were hovering at about 5-6 mph steadily, so only occasional gusts were able to spin it. All test equipment is laid out for easy access in the barn. We are scheduled for rain all week, so I dont expect much, but will take anything I can get.

 

[HighDesertOffgrid]

I am sending wind your way. 40-60mph sustained with 80-100mph gusts for the last 3 days.

 

[Hogheavenfarm]

Yup - got that, overnight delivery I think. Had to tie the turbine off for that one. Did do some minor testing around the outskirts of it though. Had some decent wind on weekends but nothing really where I need it (15-20 mph sustained), although March isn't over yet. The weather station and security camera help me do some testing remotely, but I have yet to get a decent amp reading on the incoming line, so far all I have seen is 0.2amps at 14.5v, but even that is suspect as my meter is cheap and keeps losing zero calibration. That was at 64rpm, so all in all, my original design seems to have been realized. I was off on my startup windspeed, I designed for 5.5mph and its closer to 7 mph, but it appears I have a cogging issue contributing to that.

 

[Hogheavenfarm]

Well, just an update for now. We have had a good windy month and I have come to a few conclusions.
My startup speed is to high, needs to be closer to 5 mph instead of 7.5 mph. I can raise the height or increase the blade size to help that.
Furling is not fully functioning, While my tail is correct for square inches (407) it is too heavy (1/8" stainless steel). If I make it out of 3/16" plexi, but it will throw the balance off, so not sure what to do there, I cannot move the C/G from where it was designed. Fortunately it doesn't seem to overspeed.
There is some cogging, I can address this when I take the unit down for maintenance.
The mast needs to be higher, this I knew from the start, so I have been working on this. I am only at 12 feet now, nowhere near enough, I do have a 28 ft aluminum pole coming this year.
Pinning the rotation also helps keep it in the wind zone and less likely to wander, it is locked out of turning 360 degrees, 90 degrees are locked out facing west, which faces a large cliff and mountain about 1/4 mile away, so never a prevailing wind from that direction, also prevents my feed line from twisting up.
As for charging batteries, it works, but has to overcome the resistance to get the blades up to speed. At 60 rpm (about 10-14mph wind) it puts out 13.7v, I have not been able to check the amp output though. Its been up to 200+ rpm in these 30 mph winds, there is a slight blade imbalance at that speed, so I will need to check distance between blade tips as the weights all match.

 

[brandnewb]

Bees like wind turbines also. Ask me how I know.

how do you know?

 

[brandnewb]

anyway, I will advise the following to others that are dealing with stalling issues.

make sure that the phases are open until a certain threshold.

If the phases are always "ON" then one effectively has a "break" of some kind and the low wind speeds can not overcome it.