Need help thinking out a good system.

[jxc582]

Does anyone know how much power a 2.984 kw motor will produce as a generator anyway?

So, I have a Xantrex st2500 grid tie that is designed for solar panels. It requires inputs are at least 48v. The motor is rated at 210v dc.

I see two options

1)

I can charge a 48v battery bank with a controller that is paralleled to the grid tie. I'd think that could regulate to voltage so it won't fry the grid tie.

2)

I can charge a 12v bank with a controller and parallel a voltage increasing circuit to supply my grid tie.

The second loses efficiency do to the voltage increasing but I would be able to get power from my wind generator more frequently in low winds.

I read some of the posts here and can see you electrical guys can help this MET out.

Thanks

Jake

[jxc582]

I checked it and turning it by hand as fast as I can produces around 10v. So does that mean I should go with the 12v setup that I had described above.

[snowcrow]

The Xantrex st2500 grid tie will not work well with a windmill. It is not setup to handle a constantly varying input. I guess you could power it with a battery bank, but you lose a lot of power in the process. A Windboy is made for the job and can handle the varying input. The battery bank will do you no good as a backup if the grid goes down, unless, you also have a inverter and auto-transfer switch load center setup. Grid ties do not work without grid power, they just sit there waiting for a reference pulse. The motor you speak of sounds a lot like the ones I seen on ebay, correct me if I'm wrong. Is the motor rating for input for use as a motor?, if so, I think you may find it lacking in output for your needs. Check the short circuit current and post your findings.

Blessings, Snow Crow

[wdyasq]

The call comes in .... however, the person in need gives only the information 'I'm drowning'. Well it's a big ocean out there - well, actually lots of them, and we have no idea where to send the help. They may be drowning in the swimming pool - or the bath tub. But the caller expects immediate response.

I can think of many configurations of motors that have kW designations ... There are many types, DC in many voltages and several configurations and AC is more than many.

So, with probably 500 variables in part 'A' of the question you expect an answer?

I'll leave this one to the clairvoyant.

Ron

[Flux]

Your motor could probably make about 2.5kW at about 30% over its rated speed as a motor.

The fact that you only get about 10v by hand indicates that it is a high speed motor.

You will roughly reduce its output in relation to the operating speed to nominal speed.

At 12v you will be down to under 200W. At 48v you could get about 800W but probably at far too high a speed for direct connection.

Don't know anything about your inverter but it will not accept wind directly without batteries. Not sure if it can accept batteries or just solar and I don't have time to look it up.

The motor sounds like a dead duck for real power, may be fun for a small 12v project to amuse yourself.

Flux

[jxc582]

I was under the impression that it cycled that logarithm to adjust for the power output changes. Granted, the fluctuations of a windmill far exceed that of a solar array. With  a paralleled battery charging load the fluctuations shouldn't be to bad (I hope). I got the grid tie broken for 250 and I am repairing it (looking around for those last key parts). The windyboy or my choice the outback would be better suited for this but I don't have so much money. The motor was given to me from Penn state. The rating is off the motor so I think that would be an input. It is anti-islanding, so grid power outage would cause a lot of power to be dumped by the charge controller but I can't afford an alternative.

What do you think the output would be then?

If I spin it by hand with an ampmeter I get 1 to 2 amps.

[Flux]

Much as I originally suspected. About 200W at 12v which you will never match to the inverter voltage.

About 400W in higher winds at 24v, still problems with voltage.

48v you may get 600W in a gale with a small prop screaming, far too fast for significant power in normal lower winds. Max prop about 7ft if you are prepared to let it scream at 24v. smaller at 48v.

Comfortable rating 6ft prop at 12v but don't expect much in the way of output, never worth grid tie.

Flux

[jxc582]

Just curious what if I gear it 2 or 3 to one and put a 10ft prop on it?

[jxc582]

Also, is this variation of rpm, voltage, and amperage:

-would voltage and amperage vary linearly with one another.

-would either voltage or amperage vary to rpm^2

It has been a couple of years since I did induced current equations.