2 speed 3ph motor

[vawtman]

The motor is a Baldor and the plate is oxidized(so pics wont help much) but its ratings are has follows:

 H.P 3/1.3

 rpms 1140/1725

 Amps 8.0/5.1

 V 208/230

 What would happen when it reached around 1200rpms for the early cuttin and once the turbine overpowered that would the 4pl winding kick in and if so what would happen to the 6pl winding?

 Could one just use 1 ph from each winding(6 leads total coming from motor) for exitement and feed elements matched to the load to feed elements in a large water tank aka old fuel tank has a preheater?  Maybe gridtie also.

 There was a time delay when it switched speeds has a fan.

 I know its probably never been tried but opinions would be great.

  Thanks

[stephent]

2 speed, sounds like a star start--delta run type motor.

Or a partial winding start.

Not really a 4 pole vs 6 pole type thing.

[Flux]

This is a pole change motor, you will have to do a quick change of magnet numbers on the rotor as you increase the speed ( not easy)

Possibly it could be done as a self excited induction generator and it would be possible with grid tie.

A major snag is that only half the thing is effective at the high speed and you have a large and heavy beast for a modest output.

Flux

[jimjjnn]

Sounds like a rewind would be in order

[vawtman]

Hi Flux

 No plans to put magnets on the rotor.

 I was wondering instead gridding it, could it feed elements has an induction generator?

 Maybe a custom rewind that could make it a variable speed induction gen say 10-8-6-4 pole.Am i crazy?

 I have the turbine setup to play with this.

 Would the homebrew axial flux motor be better?Im just worried about turbine startup when its directly connected to elements and no batteries.

 Thanks

[Flux]

I suppose that if you start with a VAWT you have to gear it up anyway, but the problems of gearing the thing for those speeds is formidable.

Some of the grid tie induction machines use 2 generators with different pole numbers but they normally use separate units. Pole change machines are a complicated compromise.

Grid tie is reasonably easy but self excited induction generators will be nasty to feed to heating elements. The controller will have to maintain reasonable leading power factor excitation without running into serious saturation loss.

The high pole number machines are reluctant to self excite so beyond about 8 pole I think you will have fun, even 8 pole may not be good.

Whatever you use you will not start up against a resistive load, with permanent magnet you will stall the wind rotor. With self excited induction you will not get the alternator to excite with resistive load unless you go drastically over speed.

I don't know what a homebrew axial flux motor is.

Flux

[vawtman]

Flux i have been totally frustrated trying to match the load of the thing(vawt)for over a year now.Not giving up.

 Tried a motor conversion geared up 5hp with skewed mags and could spin it with 2 fingers but when geared 1:3 the blades had startup problems the slight lumpiness felt turning it over reverberated through the blades.So would need some type of clutch to help the blades breakthrough that.

 Next i thought i would gridtie it by using a induction generator but until the tower gets done(just coming out of winter).Need about 25ft to get to good swirly winds.The problem with that i think would be the gen would drop in and out right?

 So for now i just want to heat water.Could i use the induction gen to run the elements if a 2pl relay was used to latch to the element when things start?

 The axial flux motor has i call it, is just the basic units here but with pulley instead of blades.Its that 12/36 stator with brake rotors.Thought about gridding this using an inverter not sure yet on that.

 Confusion can be fun;<>?)

 Thanks for all your help overtime

[Flux]

You are up against it all ways with a VAWT. I doubt that you will get it to turn the induction motor if you gear it up to over 1000rpm even if the motor is not excited.

A decent motor conversion would generate at about 200 rpm and if you can't gear to that speed and start against slight cogging you will probably not gear to 1000 against bearing friction.

At the other end, when it is running in a high wind you need a monster load to hold it down, the two requirements are not compatible.

When you say an axial motor, do you mean axial alternator as in dual rotor?

This is the best alternator for starting, there is only bearing friction and if you make it big enough you should be able to direct couple it, if you have to gear you will only need a small speed increase. It may not solve your high wind problem but you have that to come.

Unfortunately the VAWT requires elegant control technology for starting and speed limiting so you will struggle with the desire to do it with low tech control.

You will certainly need some sort of relay ( mechanical or electronic) to bring the load on after you have come out of stall, but that doesn't overcome your enormous starting losses through a high ratio gearbox. Some sort of servo assisted centrifugal clutch on the input of the gearbox seems the best option but I see many snags there unless you have the facilities to build something special.

Flux

[vawtman]

Flux,

 When you say an axial motor,do you mean axial alternator as in dual rotor?

 Yup,same thing only a pulley instead of blades.Different stator though.

[Ponderance]

in retrospect to using a fixed high ratio gearbox, you might consider building a CVT transmission for gearing up and using a centrifugal brake to keep from over-speeding the alternator... provided you have the equipment and parts.

just an idea...

[vawtman]

Ponderance,

 What is a cvt transmission?

Thanks for ideas.

[Ponderance]

CVT = Continuously Variable Transmission, they are commonly used on snowmobiles and various other ATV's such as the 6 wheeled amphibious trucks like the ones from this site -- http://www.attexatvs.com/

it works much like an automatic transmission except instead of using hydraulic fluid and many clutches, it uses centrifugal force to change the belt pulley size/ratio.