I added an indicator light showing when power is being drawn off. Visually its easier to know when to take readings.
I wonder if this type of device were set for 10 - 20 volts above a battery bank if it would push more amps into the battery in pulses. Normally what happens is the turbine output matches a battery voltage and then has to push against the voltage. Maybe the momentum of running over battery voltage would be a benefit.
Thoughts?
-- Edited by Lynx on Wednesday 7th of March 2012 02:29:35 PM
Any net voltage above the battery voltage gets deposited across the generator windings and dissipates as heat. That is one reason why a too low resistance load does not transfer power to the load.
A too high resistance load also does not transfer maximum power, although it deposits less voltage across the windings.
Hi, I think the output would still be locked to the battery voltage. I am still trying to resolve the problems with my project. It look like your circuit would benefit by adding a buck converter. When the buck converter pulses on and off, the turbine would maintain momentum during the off cycle. The cut in adjustment on your project could then be used to help illustrate the algorithm needed for MPPT control for battery charging.
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Lets find renewable solutions to reduce energy cost
I added an indicator light showing when power is being drawn off. Visually its easier to know when to take readings.
I wonder if this type of device were set for 10 - 20 volts above a battery bank if it would push more amps into the battery in pulses. Normally what happens is the turbine output matches a battery voltage and then has to push against the voltage. Maybe the momentum of running over battery voltage would be a benefit.
Thoughts?
-- Edited by Lynx on Wednesday 7th of March 2012 02:29:35 PM
I beefed up the control circuit with 1 watt resistors and replaced the rheostat, relay and the arc supressor. I also moved the volt reading wires so they report OCV and then the load voltage. The lights as a load aren't as practical as the resistors.
Maybe this will spark some creative thought. And it may be interesting for some of you to see how volts drop with the load. You can calculate amps from the volt reading as well if you know the Ohms are 60. And because roughly 750 watts equals a Hp we can calculate Hp at a wind speed. And if you know rpm you can calculate torque from Hp.
Try controlling one of my Mann Smart Drives. I burn up every thing in its path most of the time. I have more burns on my fingers from ripping wire apart that are on fire.
The lighbulbs worked fine when I had wind. I could light anywhere from 20-150 watts of Halogen bulbs. The problem is, this circuit wasn't designed to do this. It was designed for a single windspeed.
So at higher powers I smoked the rheostat and the relay. Volts shot up to 120.
While the lightbulbs are exciting, this circuit needs to be used for a set windspeed. At 60 - 80 watts its like a little toaster oven. At 150 watts its more like a BBQ.
The lightbulbs were a fail. The resistance is so low when they are cold the turbine stalls trying to heat them up before it can get to running resistance. So what happens is the amps get pulled high and the relay chatters and opens.
There is not much wind today so maybe it isn't a fair test.
Oh well, the resistors work. They just aren't as exciting as seeing bulbs glow.
Yes I understand that it can be used for a torque brake, But as I have said electricity is not my best subject, It looks a good way of resulving my problem as I need to test over many tip speeds. Like yourself it depends how I set up the turbine can have an opperational tipspeed of 1 or over 3 high torque low speed or lower torque higher speed. so as I can adjust my blades it would save a lot of time for than just addind additional batteries for higher speeds.
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Mark
A blinkered horse doesn't always win the race, and could fall at the first hurdle.
I didn't really respond to your question because I thought it was an exclamation.
It is possible to make this a torque brake because that is what it is. Knowing volts across the load you can calculate watts and then you can calculate Hp and torque. Just drop the volt readings you see into a spreadsheet.
One problem I encounter using real wind is that when you pull power out it doesn't often settle down to a steady amount of power. Finding peak power at any given wind speed is a ticklish task. That's why I made this variable cutin device.
Now I have to reconfigure this box. I need to make it able to handle three different wind speeds. So I will pick 10, 15, 20 mph. 20 miles per hour has 8 times more power than 10 mph.
Tonight I will replace the 60 Ohm resistor with bulbs in series that I can select with a switch.
2 - 10 watt halogen 28 Ohms, for 24 volts and .833 amps 10 mph = 20 watts, cutin at 40 volts (114 rpm)
+ 2 - 20 watt halogen 14 Ohms for 48 volts and 1.14 amps 15 mph = 60 watts, cutin at 80 volts (230 rpm)
+ 2 - 50 watt halogen 6 Ohms for 72 volts and 2.23 amps = 20 mph =160 watts, cutin at 120 volts (340 rpm)
I am not sure what will happen with all 6 halogens in series. I know the 10 watt bulbs will be bright and the 50 watt will be dim. But I don't really if this will work. This is getting to be a "horse and buggy" MPPT.
$1000's to do what a flashlight can do! Some guys fish too.
