Grid Tie Wind Turbine for battery charging.

animatt

I know usually very high voltage and low amps. Not so good for battery charging.

I purchased a few tswind 2000w wind generator setups(new old stock) Their webpage is more like a sale brochure. Light on the details. 3m diameter rotor. Has simple spring loaded furling.

So I bought them. Really not knowing much other than rated at 2kw. I know rating are over inflated. Install manual is just slightly better than online documentation. Anyway in manual it mentioned it would have one of 2 gen heads.

Units come partly assembled , I had to take them apart to check gen head. They use the Ginlong.com generators. Seeing ginlong head I felt fairly good as they seem to have a good record in the tlgwind products.

Anyway there was

1 is at 1500w low voltage for battery charging.
others are
1800w high voltage grid tie setup. Rectifier mounted to back of generator in protected area. I will be moving this to bottom of tower. So 3 phase coming down tower.

http://www.ginlong.com/wind-turbine-pmg-pma-permanent-magnet-generator-alternator-GL-PMG-1800.htm

As can been seen at link above is really high voltage.

Giving the shaft a spin by hand voltage spikes to about 80-90v. This is dc after rectifier.

Generator is/was wired star. I believe I successfully wired to delta. Will have the generator head together tomorrow and can test out if voltage spinning by hand and if it is where it should be. If I am correct voltage drop at any rpm range will now be lower by a factor of ~1.73 . (star vs Delta)

With this lower rpm to voltage I believe the unit will work well with the Classic 250v with a clipper. It appears upper rpm could spike to 300v . Not sure where clipper voltage works to?

I really do not care about high wind production and believe I will adjust to have unit furl earlier. Probably have it furl 18mph-20mph.

This is in an area where wind is not terribly strong. So would like to maximize 7-13mph production. I know there is not alot of energy in this low wind, but 50-100w somewhat consistent production would greatly appreciated. Something to keep night time batteries from draining.

Battery array is only 24v 470ah. Day time loads are fairly well covered by the 460w solar array. I am sure I will find extra loads for any day time wind production g.


ohm rating between any of the three outputs is now 4.1ohms.

Before phases were connected together each phase measured 5.8 ohms.
I did not measure what initial star ohm rating was, but for curiosity reasons I will measure another turbine tomorrow. I am sure there is a formula for it, I just do not know it and it is easy enough to just measure another one.

Anyway looking for input about using the midnite classic. In my case 250 would be much better suited than say the 150.

Probably looking at a classic lite and a clipper. Does clipper have voltage limitations?
Maybe chris can comment I know he is well versed with wind and the midnite products.

I am aware of what tower heights should be and what wind conditions should be. This post is mainly about using the classic 250 with a modified grid tied turbine to charge 24v battery array. I do not mean to be aggressive or anything, just trying to save typing for someone.


I did post in midnite forum but figured here there is more action happening and may get more feedback.


matthew

inetdog

Re: Grid Tie Wind Turbine for battery charging.

animatt wrote: »

ohm rating between any of the three outputs is now 4.1ohms.

Before phases were connected together each phase measured 5.8 ohms.
I did not measure what initial star ohm rating was, but for curiosity reasons I will measure another turbine tomorrow. I am sure there is a formula for it, I just do not know it and it is easy enough to just measure another one.

Anyway looking for input about using the midnite classic. In my case 250 would be much better suited than say the 150.

Probably looking at a classic lite and a clipper. Does clipper have voltage limitations?
Maybe chris can comment I know he is well versed with wind and the midnite products.

To get the best use of the MidNite Classic with wind turbine, you should program in voltage versus current curve appropriate for your turbine/generator. That will allow you to optimize the low speed production. Chris can give you better info on that.

Your expectations of power seem realistic, so it may work out well for you.

If each of three windings is 5.8 ohms, then the phase to phase resistance when wired as delta would be 5.8 in parallel with 11.6, or 3.9 ohms. Allowing for some variations in your resistance measurement and the connection resistances, that is a good match to the 4.1 you measured.
The phase to phase resistance for the star (wye) combination would be just the sum of two of the coil resistances, or 11.6 if we take the 5.8 measurement as accurate.

animatt

Re: Grid Tie Wind Turbine for battery charging.

Measurement was done with a very cheap multimeter so not sure how accurate it is. I usually just use ohm meter to measure continuality. If I needed more accurate measurements for electronics I would definitely get a better device.

Yeah I know wind is not great. This turbine was a few thousand dollars threw commerical channels and I would not be happy at all paying that with what I expect performance to be. It is a bit different when I paid alot less.

Always wanted to mess with wind and this gives me the chance at some power in normal winds as it has some size but also not costing me a fortune. I know solar would be a better investment still, but prefer to maintain a smaller battery array which I am hoping the wind will allow me to do.

Thanks for your response.
matthew

animatt

Re: Grid Tie Wind Turbine for battery charging.

Just went and measured with same multimeter and get 3.8 ohms. I just put back together the generator and well I failed in my wiring somewhere.

So what I believe must of happened is I mixed up the wiring. Basically like having coils wired in the wrong direction. Will be a bit of a pain opening it up again.

What is happening is cogging. Original wiring there was no cogging at all. If i crossed two phases together I would get a cogging affect when I spun shaft. All 3 phases sorted was smooth but obviously much harder to turn.


Let call leads A,B, and C.

Now none of the 3 phase leads are crossed/shorted but when I spin shaft there is major cogging. I did the ohm test between each of the phases and returned the 3.8 value. The first test I thought there may have been a short as 3.8 was lower than the previously reported 4.1 but as I measured all measurements were 3.8.(AB , AC, and BC)


When I shorted AB and spun the shaft it was smooth but resisting spinning. When shorting CA spun shaft spun with cogging I can not tell if there was increase resistence. When shorted BC shaft spun with resistance but smoothly.

I am totally guessing at problem.

Let call coils A,B and C.

Ai is begining end of Coil A. Af is the other end of Coil A.

I not sure it makes a difference. I thought I wired it Ai to Bf, and Bi to Cf and Ci to Af. But I guess I could have wired it Ai to Ci, and Bi to Cf, and Af to bf or something like that.

How should the wiring have taken place? Is Ai to Bf, Bi to Cf, and Ci to Af the equivanlent to Ai to Cf, Bi to Af, and C to Bf?

I will take apart the generator head again but would like help in what I am looking for. Any help would be greatly appreciated. Obviously original questions still remain.

Thanks
Matthew

inetdog

Re: Grid Tie Wind Turbine for battery charging.

animatt wrote: »

I not sure it makes a difference. I thought I wired it Ai to Bf, and Bi to Cf and Ci to Af. But I guess I could have wired it Ai to Ci, and Bi to Cf, and Af to bf or something like that.

How should the wiring have taken place? Is Ai to Bf, Bi to Cf, and Ci to Af the equivanlent to Ai to Cf, Bi to Af, and C to Bf?

I will take apart the generator head again but would like help in what I am looking for. Any help would be greatly appreciated. Obviously original questions still remain.

Thanks
Matthew

Unfortunately, it is not completely simple.
Draw a diagram of a wye and look at each leg of the wye as an arrow with a fixed direction. They are all separated by angles of 120 degrees, spread equally around a circle.
If you were to reverse the direction of one of the arrows (equivalent to reversing the leads of one coil) you will now have two arrows separated by 120 degrees and a third halfway between them.
This will not work and there is no way to fix it with external connections.
All the end points Ai for "inside", Ao for outside, etc. In the original wye, all of the i ends were tied together at the common point.

Now our goal is to make those same arrows form a closed triangle.
Start with Ai --> Ao. Place the Bi --> Bo arrow end to end with it so that Bi rests on Ao. You now have two sides of a triangle. To finish it, you have to pick up Ci --> Co without rotating it and place Ci on top of Bo. Co will then automatically land on top of Ai.
This is your correct delta wiring. Look at what happens when you connect Co on top of Bo instead. That connection is essentially a short circuit of a high voltage when you make the third connection, and the generator should show resistance all of the time, with no load wires attached at all.
If you are not noticing that, then you have not miswired the direction of your coils and something else is wrong.

Your description of " I thought I wired it Ai to Bf, and Bi to Cf and Ci to Af. " seems to be the correct way to do it, IF your i and f map to my i and o from the original connection.

You can do some basic testing by temporarily bringing all six wires out of the generator head and shorting each coil individually, one at a time. The resistance and cogging or lack of cogging should be the same for all three. If not, then there is a defect in the generator somewhere.

animatt

Re: Grid Tie Wind Turbine for battery charging.

I understood what you are saying although, not sure it is easy to test.

I will attach several photos.

The stator is attached to the upper housing using some set screws. It is then dropped in over the shaft with magnets. I do not have any real tools that make pulling the bottom part of the housing (shaft bearings and magnets) apart from the upper part of the generator which is just the stator. Real pain to do it. I was rushing and slipped up and almost broke fingers just 1 hour ago. Luckily 3 fingers got pinched instead of 1. Hurt a bit but will get the stator off and look at the wiring again.


So I can pull each wire out and do ohm readings, but have to put it all back together to check to see if cogging is happening. Then the fight to get it apart again.

Thanks for the replies.

Matthew

inetdog

Re: Grid Tie Wind Turbine for battery charging.

animatt wrote: »

I understood what you are saying although, not sure it is easy to test.

So I can pull each wire out and do ohm readings, but have to put it all back together to check to see if cogging is happening. Then the fight to get it apart again.

Thanks for the replies.

Matthew

Cogging can also happen with or without any load applied if you did not get the stator lined up perfectly centered. Often specialized tools are needed to do this, or at a minimum feeler gauges to check the spacing. If there are no adjustments, you may perhaps have put the two parts back together rotated from the correct orientation. Are there closely fitting alignment pins between the two halves? (just saw the pictures)
Chris can tell you a lot about the risks of moving things by hand when powerful magnets are involved. You are fortunate!

animatt

Re: Grid Tie Wind Turbine for battery charging.

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animatt

Re: Grid Tie Wind Turbine for battery charging.

Set screws determine how the stator goes into the upper housing. It holds it in place. The bottom housing is just the bearings shaft and magnets. Since these rotate I can not see there being an issue there. I think pics may help.

Maybe I am wrong though

animatt

Re: Grid Tie Wind Turbine for battery charging.

The top housing(with installed stator via set screws slides over the shaft and then 5 larger screw slide through top housing and start threading into the bottom. There is lip on the top houses that forces the bottom housing the open just a bit. I would imagine this would help with alignment. Things are really tight in there. I just slowly work the screws around bringing the two halfs together start. Seeing how things get installed I can not think it is an alignment thing although very little knowledge here.

I could see alignment of the 2 magnetic rotors on an axial flux being very important, but in radial flux not so sure.

Anyway feeling brave again and will try to get two halves apart.

You talk about Ai and Ao. Does it matter which is which as long as I am consistent with the 3 phases. Like where in wye they were tied together you said was Ai,Bi, and Ci. As long as I Connect i's to o's and not connect it to itself (Ai to Ao).

matthew

animatt

Re: Grid Tie Wind Turbine for battery charging.

If one of the 3 leads was grounded to the housing could that explain what happened.

Could that mean I wired it properly. I would imagine it would keep ohm reading the same but not sure if it would produce cogging?

I got housing opened again, and see there is some stripped/cut area on the 3 leads. If they were touching each other it would have affected ohm readings. But what if one was touching the case?



I ask because I have taken apart the leads and have the 6 ends exposed.

2 of the 6 ends can not easily be traced back to which winding they come from.

I still have to look closer and really look at those 2 ends, but it APPEARS I connected in the way we have said it was correct.

thanks
Matthew

animatt

Re: Grid Tie Wind Turbine for battery charging.

Now our goal is to make those same arrows form a closed triangle.
Start with Ai --> Ao. Place the Bi --> Bo arrow end to end with it so that Bi rests on Ao. You now have two sides of a triangle. To finish it, you have to pick up Ci --> Co without rotating it and place Ci on top of Bo. Co will then automatically land on top of Ai.
This is your correct delta wiring. Look at what happens when you connect Co on top of Bo instead. That connection is essentially a short circuit of a high voltage when you make the third connection, and the generator should show resistance all of the time, with no load wires attached at all.
If you are not noticing that, then you have not miswired the direction of your coils and something else is wrong.


Are you saying ohms reading will change?

I have the six leads out. I do not know which ends were i and which were o.

I have 4.2 ohms of resistence between phases .

If I switch say Ai with Ao but everything else stayed the same I would assume that would be like having direction of coils changed.

So instead of Ao with Bi and Bo with Ci and Co with Ai it would be Ai with Bi and Bo with Ci and Co with Ao

I measured ohm reading and get the same 4.2 ohms. Which to me makes sense to me.

Getting a bit frustrated with the situation right now and may take tomorrow off to think about it. Initially opening generator I thought it was going to be difficult then it appeared very easy. But that was later at night. Getting back to reality it is about as difficult as I thought. First time is always a pain.

Anyway thanks for responses. See if Chris responds tonight.
Matthew

inetdog

Re: Grid Tie Wind Turbine for battery charging.

animatt wrote: »

the generator should show resistance all of the time[/B], with no load wires attached at all.
If you are not noticing that, then you have not miswired the direction of your coils and something else is wrong.


Are you saying ohms reading will change?

I was not careful in my choice of words, and additionally I actually said it backwards.
I was referring to resistance to turning. And what I should have said was that if you wired one of the coils backwards in the triangle, there would be resistance to spinning with no external loads attached.
If the wiring is right, it should spin freely, although maybe with some slight cogging, until you put a load (resistor or short) onto one or more of the windings.

animatt

Re: Grid Tie Wind Turbine for battery charging.

Thanks for the clarification. I was kind of thinking that. But this last post is definitely more clear.

I definitely wired it incorrectly then as it feels like cogging that happens when 2 phases are shorted together.

I will try to study the windings tomorrow.

It is just different then the axial flux layouts. Axial flux has coil a,b,c a,b,c ...

It does not appear the radial flux is wired like that or atleast where the 6 leads come out to me is strange. I would have thought the 6 leads would come out of coil sets that were all together(one after another). But is not the case. 6 leads come out of an area that is about 8-9 coils.
Not sure if coils are made and jumps a few coil holder spots and works it way back around. I see no point in that.

I will study it a bit more before making anymore changes. Flexing the wires around I broke a lead and had to solder one back on. Not terrible in itself but rather not have solder joints everywhere.

matthew

inetdog

Re: Grid Tie Wind Turbine for battery charging.

animatt wrote: »

Not terrible in itself but rather not have solder joints everywhere.

So true. If the generator overheats at high wind speed and gets hot enough to melt the solder (not impossible) then the connection may break and the turbine will spin faster....

animatt

Re: Grid Tie Wind Turbine for battery charging.

Did not really have much time to mess around with it today.

The rotor has 16 magnets and there are 72 coil spots. SO I would imagine each phase has 24 coils.

so there is a 1 to 4.5(16 to 72) ratio between magnets and coils.

Axial flux have a very different ratio. Otherpower is 1.33 magnets per coil.

So I am having a little issue of wrapping my head around the wiring in this radial flux.

It appears that the coils go something like a , b, c , x ,a,b,c ,x .... where x is a coil but I am not sure the phase. I will attach close up photos tomorrow.

Hopefully I can wrap my head around the wiring and be more certain in correctly wiring it delta. Really prefer not to open gen head again after it is done.

matthew

animatt

Re: Grid Tie Wind Turbine for battery charging.

I really thought I had it figured out. But guess not. I am getting to hate taking the thing apart. I will be happen once I am past this hurtle.u

Will take your advise. I will be extending the six leads to outside the gen head. I believe it is 19awg wire. SO I will just put a 2' section of #18 wire to each lead. This will bring the leads outside. Then I will just test outside the head and will try to label all wires. Then connect it as delta outside the head. It is easy enough to water proof. And if I want to change back to star wiring it will be very easy. There is a protective area that will keep direct exposure to the elements to a minimum.

I will be back once I get the delta wiring working.
Matthew

ChrisOlson

Re: Grid Tie Wind Turbine for battery charging.

animatt wrote: »

So I am having a little issue of wrapping my head around the wiring in this radial flux.

Mathew, that stator is a serpentine wound stator. I doesn't have coils with two legs like the typical axial generator has. It is wound like an electric motor with one big coil per phase and the windings are stuffed into the stator teeth in a serpentine fashion.

To wire it delta identify the start and end leads of each phase. To identify the polarity of the phase hook a small 1.5V "D" cell battery up to a phase, and holding a small ferrite 'fridge magnet near the stator teeth you will be able to feel it either being attracted or repelled (depending on the polarity of the battery and whether the N or S pole of the magnet is held near a coil). Each progression of a stator tooth takes you to the next phase. By using the battery to power the stator coils, and the magnet, you can determine whether you have correctly identified the start and end leads of each phase, because each phase will act the same (either repel or attract the magnet with the same pole facing the stator) with the battery hooked up the same on three progressive stator teeth (phases).

Once you have correctly identified the start and end leads to wire it delta you hook (phase number and Start or End):
1E to 2S
2E to 3S
3E to 1S

Those three connections between the phases are also where the three "legs" or power leads are connected.

However, this being said, I would not use an iron core radial in delta configuration because you're bound to get some serious cogging due to circulating currents in the delta winding due to the relatively large pole area and inadequate cancelling at the sine wave zero cross. Instead I would use it IRP (Individually Rectified Phases) by running six wires down the tower and putting a single phase full-wave bridge on each phase - then parallel the output of the bridge rectifiers.

With IRP you will get no cogging, the same voltage as delta configuration (single phase voltage), and 2x the wye ampacity of the winding.
--
Chris

animatt

Re: Grid Tie Wind Turbine for battery charging.

Thanks for the wonderful reply.

So if I IRP.

In your naming scheme
I would connect 1E and 2S to a single phase rectifier? 2E and 3S to another and 3E and 1S to another?

Then their outputs get paralleled?
I would imagine that adding a capacitor would not help anything. If directly connected to a Classic it has its own capacitors and I do not need to worry about smoothing the pulses? And if I directly connected to a battery well the battery would not need it. I know the generator would not do very well at all hooked directly to a battery, It is more about if something breaks could I direct connect until I have a replacement.

Any guide on heatsink sizing for rectifiers. I can not seem to find a guide?
Also since this generator in question will not be dealing with very high amperage does it hurt to have a larger rectifier. I am thinking if I did not modify furling I would not expect to see more than say 12 amps (at 250v) and probably a good bit less than 12a. If I put a 35 amp rectifier or a 50 amp rectifier does it hurt anything?

I do plan to modify furling to keep unit below 1200w but just in case I get lazy or something want to understand better.

Thanks again for your other response.

Matthew

ChrisOlson

Re: Grid Tie Wind Turbine for battery charging.

No, just connect 1E and 1S to one rectifier and so on. Each phase goes to a full-wave bridge. Then parallel the DC side of the bridges. It will put as smooth of power as any three-phase with hardly any ripple. I've flown many, many, many IRP configured turbines over the years, including a Jacobs 23-10 that I tried to use for battery charging once, except that was a parallel wye configured winding with 12 leads coming out of the Fidelity generator.

It does not hurt to put a larger rectifier on it. But three of those little 600V "cube" type rectifiers will work fine and they're pretty cheap. They got a screw hole in the center and just screw them to a piece of 1/4" aluminum plate for a heat sink and they'll be fine.

Test that wired IRP and let me know what you get for voltage at the desired operating rpm (spin it with a 1/2" drill if you have to). I'm pretty sure it can be made to work with a Classic 250. Just be careful with a high voltage DC generator. A string of solar panels at 250 volts will only put out maybe 8 amps or something. A wind turbine generator puts out enough volts and amps usually to weld 1/2" steel and if you accidentally touch the leads at the very least you'll get a new hairdo.
--
Chris

animatt

Re: Grid Tie Wind Turbine for battery charging.

I am very new to wind gens and it is more of a toy at this point. Building one was a bit more than I wanted to commit to for my first one. I definitely will not be in a med- high wind area like you are. All of my power will come in at below 13-15mph, as almost anytime wind is over that speed is 30+ mph. I would definitely not need all that power during wind storms. I read a lot of your wind comments all over the place and appreciate the help.

Kind of reads like your jacobs did not do so well for battery charging? Is that because you were stalling you blades? I would imagine that is something the classic helps with . Make wind gens more flexible.

It would also appear I would not need to know the start or the end of any of the wires, just I need to know the pairs they are in. Is that correct? I may try to identify start and ends for practice anyway to see what kind of cogging happens when wired normal delta. I am curious if I actually wired it correct delta and just the serious cogging you talk about is causing me issues.

Thanks again for the help.

On power consumption/ heat generation of bridge rectifier. Would that be voltage drop x Amps

So at 5 amps it would need to dissipate about ~1.4x5= 7 watts.

10 amps = 14 watts

Is this correct? I would imagine it would be a bit lower than these values due to the sine wave but at what factor I am not sure?

Thanks again.
Matthew

ChrisOlson

Re: Grid Tie Wind Turbine for battery charging.

Yes, you only need to identify the pair of wires for each phase and hook that pair to a full-wave bridge.

The Jake is too big for battery charging. It can produce 10 kW @ 25 mph. The caveat is that it has a wound field generator so I had to provide battery power to drive the field in the generator, and never came up with a good way to regulate the field current other than using a rheostat - and never got any power out of it below 10 mph wind speed. I backed the governor springs off so the blades would feather sooner but that was hard on the governor shafts, blade sleeves and spider.

When all that failed I tried to build a mini-grid with it but the old Jacobs inverter with a choke was problematic and that didn't work either. In the end it was a fun experiment but I took the turbine down and sold it because a 25,000 kWh/year wind turbine is basically only practical for grid-tie. A 23 foot diameter turbine running up against the governor in 15 mph wind because it has nothing to do is basically just a good way to wear out expensive machinery.
--
Chris

inetdog

Re: Grid Tie Wind Turbine for battery charging.

animatt wrote: »

It would also appear I would not need to know the start or the end of any of the wires, just I need to know the pairs they are in. Is that correct?

Yes.

And if you go with three full wave rectifiers as Chris described, you will need a total of three full-wave assemblies or 12 individual diodes. (Each single phase input full-wave rectifier consists of four diodes.)
But if you go with a single three-phase rectifier or build one from individual diodes you will end up using only six diodes to do the same job. The voltage drop at any moment will still be two diode drops, but the heat dissipation will only be spread over 6 diodes instead of 12, so that could be a downside. It might also be a bit harder to troubleshoot if there were problems.

gww1

Re: Grid Tie Wind Turbine for battery charging.

If you used three bridge rectifiers and hooked all six wires to the rectifiers, does it really matter that the three coils be seperated to and put on individual rectifiers? In other words, I had a six coil turbine that I put on six rectifiers but did not worry that each coil was to an exact retifier. It seemed to work fine.

Thanks
gww

ChrisOlson

Re: Grid Tie Wind Turbine for battery charging.

It will work fine. However, it's best to keep one phase on one bridge for neatness of the installation and troubleshooting/diagnostic purposes in the event you blow a phase or diode, or have a wiring problem. If the generator drops a phase, for instance, and you want to check resistance on the winding, or check voltage from it, it's easy to identify the two leads of the phase if they're both on one bridge. Otherwise you end up scratching your head trying to figure it out later. Or at the very least, even if you include a wiring diagram in the rectifier box for what wires are run to what bridges, five years later the turbine drops a phase and somebody else works on it - they study the diagram and go, "who hooked this up?"
--
Chris

animatt

Re: Grid Tie Wind Turbine for battery charging.

So if I had 12 amps max coming out of the generator. I would have to dissipate 1.4v x 12a= 16.8 watts. This would be across the 3 bridge rectifiers.

16.8/3 = 5.6 watts per rectifier?

I really curious as I have some older cpu heat sinks that I would see how viable there usage was.

Also something came to mind about measure speed of generator spun by a drill?
I would imagine something like http://www.amazon.com/CyberTech-Digital-Photo-Tachometer-Contact/dp/B001N4QY66
is what I would want to determine rpms?

matthew

ChrisOlson

Re: Grid Tie Wind Turbine for battery charging.

That's correct. The total amount of power dissipated in the rectifiers will depend on the total amp output of the unit.

I suppose CPU heat sinks will work. But high voltage turbines run the rectifiers so cool that that you could probably get by without a heat sink at all. As opposed to some of my older 4.0 meter direct hooked 24V turbines that would put out 100-125 amps in good wind - now those rectifiers got seriously hot and I burned out quite a few of them.

Basically what you need is a rpm/DC volt figure for that generator. It's most accurate to spin it at the rpm the rotor will turn at, but then you need strobe tach to measure the speed. If you don't have a strobe tach I wouldn't waste the money buying one unless you have other uses for it.

You can turn the generator by hand too at a comfortable speed (like 100 rpm with a vice-grip attached to the shaft). Maintain a constant voltage (as much as possible) at that speed and count the revolutions for one minute. Then divide the revolutions by the volts to get a rpm/volt figure for the gen. The voltage of a permanent magnet generator is a direct relationship to the speed, no matter what speed it runs at. So using the hand method will get you close enough to figure out how high it's going to go on open voltage for the Classic.

Example: if you get 50 volts @ 100 rpm the generator requires 2 rpm/volt. So at 300 rpm it'll run at 150 open volts, at 400 rpm - 200 open volts, and so on.
--
Chris

gww1

Re: Grid Tie Wind Turbine for battery charging.

Chris

"what idiot hooked this up?"

That would be me. I do see where you are coming from.

Thanks
gww

animatt

Re: Grid Tie Wind Turbine for battery charging.

Okay got housing back open, soldered new leads on. 14awg stranded wire thhn 90c rated.

I am supposed to have the rectifiers waiting in the mail box. I will have to check later.

Have another question about efficiency of generator head. My cheap multimeter is currently reading 5.3-5.4 ohm per phase.

Now to figure out Resistence I am thinking in IRP it is the same as delta (R phase)/1.414 =3.75 ohms in this case if that reading of 5.3 is correct.

So losses to heating coils would be the 3.75 x I^2= So for 6 amps =135 watts. For 12 amps = 540 watts.

Efficiency would be (V x I) / (I^2 x R + V x I) reduced to V/(IxR+V) ???


So at 250v 4 amps efficiency would be 250/(4x3.75+250)= 94.3 % efficient (1000watts collected 60 watts dissipated)

at 100v 10 amps efficiency would be 100/10x3.75+100 =72.7% efficient. (1000 watts collected 375 watts dissipated)

at 30v 33.3 amps efficiency would be 30/33.3x3.75+30 = 19.3% efficient (1000 watts collected 4158 watts dissipated)

Am I correct in the above calculations.

I would ASSume the head could take a bit of heat as the iron core fits tight against the aluminum body.

But what realistic power levels could one expect the generator to tolerate/ dissipate safely.

http://www.ginlong.com/wind-turbine-pmg-pma-permanent-magnet-generator-alternator-GL-PMG-1800.htm for specs.

matthew

ChrisOlson

Re: Grid Tie Wind Turbine for battery charging.

In IRP the generator really has to be considered as three single-phase generators. The resistance is not the same as delta configuration. The resistance in delta will be roughly 1/3 of what it is in wye, which is considerably lower than single phase resistance because you have phases paralleled in delta.

IRP configuration is a weird duck. It performs very close to delta configuration (and for all practical purposes the efficiency in IRP can be considered to be the same as in delta) but with no problems with circulating currents in the winding like you will get with delta.

You can't use a cheap multi-meter to measure winding resistance and figure efficiencies. You need a DLRO to check a motor or generator winding for that. Also, this is a iron core so you are going to have some serious reactance losses in the core at higher speeds. Basically, the only way to come up with an efficiency figure for an iron core is to test it on a dyno.
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Chris

animatt

Re: Grid Tie Wind Turbine for battery charging.

okay. My main point about looking at "efficiencies" was more a look at what kind of heat would have to be dissipated by the aluminum housing. I know at higher wind speeds heat rejection becomes greater. I guess it not really an issue if documentation it to be believed although I tend to like to do that. Original generator at rated power was producing 6amps wired star 5 ohm resistance per phase. So if I keep irp setup to around 6-8 amps I should be in good shape with lower resistance. At 250v@6-8a that is more than I would need to harvest. I should have everything back together and have rpm tested tomorrow.
rectifiers did make it here.

thanks for the continued responses.
matthew