Author Topic: Building a 6kw pure sine wave inverter using power jack boards part1 transformer  (Read 62240 times)

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oztules

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This is a copy of another thread I did on a site that France has made difficult for folks to see... and some wanted to see it..... I don't understand it... but..
It has been slightly modified to reflect the 5 picture count that this site has, so is broken up a bit.
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It's time to put some practice down in a how to style rather than a Q and A thread.
To make a nice 6kw unit that will truly do the 6kw rather than the not so real figures bandied about by PJ, we need first and foremost a better transformer.

This is easily done in Australia by procuring  "inspire" grid tie inverters off ebay for 50-80 dollars, and extracting the huge torroids from them. In this article we will assume you have procured two of them, and we will make a much better transformer than both of them put together, by making then a single core and then rewinding them. Torroids can be found in a range of other galvanically isolated grid ties as well... so we are looking for dead grid ties that are heavy ( 30kg plus)

This is a simple procedure, but one that requires patience and methodical action.... it is a true pain in the butt to do, but is simple, and a perfect foundation for your inverter.
The transformer you will create would cost around the $1800 region, if it was purchased in this country... this one I am winding will cost $120, and i will have two stainless steel boxes with ip55 rating as well left over, plus a range of very nice filters to quieten down the hash from the inverter if you want to. These grid ties have a few nice bits in them.

Here are the two transformers after pulling them from the box, and knocking the center out of them... I use a small mash hammer and a big drift to simply knock it straight through the center hole...yes it will go through....... you can drill it out if you wish like I did the first time... but it is both dangerous to the wiring and to you unless you have a good way of holding it very securely.... best just to knock it through... takes seconds, and no mess.


Once that is achieved, it is time to look at what we have got. A huge torroid the like I have never seen before. The figures on the side say 130v:240v 50hz on this one.

8831-1

The 240v winding is on the outside, and the 130v winding is on the inside.... there are several ways we can tackle this.
We can simply tape the two together, join the 240v windings in parallel, ignore the 130v windings, and wind a secondary around the two transformers, and were done.

This will work, but you will struggle to get decent wire through the center for your new primary... so not worthwhile.

Next option.... we can strip the two 240v windings off the outsides, and be left with the 130v windings on each. This is not so silly, as the 130v winding is 2 in hand, so if we stack them together, tape them up, we can series these windings and get a 2 in hand 260v winding, and a much bigger hole in the center. This is an ok arrangement, and will work well... and very easy to do.

This gives us a 260v secondary.... this is a good thing, as the reason we are doing this anyway, is to get the magnetizing currents down... otherwise we need only buy the Powerstar W7, and we get the same kind of honest power, but 5.5kwh/day losses because of the E I transformers they use... very lossy. It's that simple, if they used big decent torroids, we would not need to change anything.

So if we can "overwind" a bit, we decrease the strength of the magnetizing current needed to run the thing, so we can get the idle currents down even further... ie for a given field, it is amp turns... so more turns, less amps..... and the magnetic field in the steel can be decreased as well, and this will mean the magnetising currents will be less.

It is likely that the original configuration will be close to saturation, and a look at the graphs for this will show a non-linear relationship with current and field strength as we get progressively closer to saturation.

So if we can back off from that point even a little bit, we will get a more than linear decrease in magnetising current.. so all good.

One draw back with this approach is that you have to live with the transformer noise. This may not be an issue if you locate it well away from your living environment, but can be a nuisance if you work next to it all day.

The second draw back, is that you can get rid of a pound or two of copper, if you rewind it as a single transformer from the start........ ie those wires that are pressed together between the cores where they meet, can be gotten rid of entirely. Each transformer can then loose 1/4 of it's resistance from copper loss, and that pushes your power handling up.

Saturation: When you have designed the transformer, and it runs fine, you cannot saturate if from overload if you have a sine wave source... contrary to popular opinion.
A lot of folks think that overloading the transformer brings it into saturation, but this is not so...

If you look at the equations, you need a frequency change or a voltage change to saturate the core... load  current makes no difference.. nix....
So providing your inverter does not clip, you should not saturate the core, no matter how hard you press it. All this extra current put into the system will be working against the wire fields as MMF and back MMF, the magnetising current remains the same... so I think the load losses are in the copper... so if we can get copper R down, we are well on the way to more power for longer. ( eddy currents and hysteresis will also play a part, but not much in a torroid comparatively.)

ie any transformer ( because we know the core does not saturate from over loads) can take large currents...so the output current is only limited by the heating and regulation ie can be massively overloaded for short periods. The voltage will sag in proportion to the copper losses, but provided it is released before it burns up, it will survive... but it won't saturate.... so.... a 100w tranny will stand say 10kw..... but only for maybe  milliseconds before the copper fuses.. this is extreme, but you can see what we are driving at. Basically the difference between a 1kw and a 10kw transformer is how fast we can keep temp from rising beyond safe. ( alright, the voltage regulation will be total crap too )

So a 2kw transformer may handle 10kw fine if it is...... say .....oil cooled, and so becomes rated at 10kw. The grid tie ones are inside a sealed box, so are "under rated" so to speak because they have little chance to get rid of the heat, but must run all day at full power or for a fair bit of it, so although they are rated at 1.5kw inside the box at 100% duty cycle, once outside, and with most of the windings gone, they are very much increased in power handling ability.

Edit: I edited the above, but it is still yuk, the idea is there, the expression is not....... but you get the idea.

Thats why the PJ can do the 8kw for a short period of time, sadly, the transformer gets hot fairly  quickly... but the cores will do it fine... the copper won't. PowerJack has taken this to extremes, and sometimes uses a single transformer with a fan instead of two transformers... obviously hoping for a very low duty cycle.

So after all that, the next possibility is to unwind it totally... and start from scratch.. with three cores used,  we could loose a complete transformer worth of copper, with 2 cores we get rid of 2 sides of wire..... so our copper losses get less, and if we want we have the option of more copper as well, as the hole size remains the same, but the turns is decreased by half or 2/3rds ( depending on core count)

I have done all three styles. A complete rewind is best for noise and performance.. so the suffering is worthwhile.

Moving right along....

Here we are with some of the tape coming off. We use a small former of some type to roll the plastic on. This is to be reused, and is an easy way to unwind, and rewind... and is boring as hell....

8832-2

And here we are with the plastic off the outer layer:

8833-3

Here we can see the unwinding stick. It is about 800mm of 6mm x 38mm steel, with notches in the end to take the wire. It must be fully insulated with a few layers of tape so that the steel cannot touch the enamel as you weave the thing back and forward through the core.

There is a right and a wrong way to use this, and if you look at the wire as the stick is passing from  right to left, you can see that the wire being unwound is on top of the stick, this will stop horrible kinking, and make it very easy...... you'll be surprised how unfit you are until you try this for a few hours.
8834-4
Notice how kinked the wire is on the stick... once we get a layer off, we need to straighten it out.... first step is to hook it onto something solid....and give it s stretch..... thusly. The kinks get worse as we get closer to the core.


5 pics is it for this site, so we will have to go again.

.......oztules
Flinders Island Australia

oztules

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Part 2 of part 1.. so to speak....

Now we have a stick full of kinky wire, we unwind it out, and give it a stretch... using the tow ball on a car is one way I guess....
8835-0

Delicate is not my strong point..... so unroll your wire off your stick, and stretch it a bit to get the main kinks out of the way.. then use this next hi tech wire straightener... thing... simple but effective.

8836-1

It can take two passes on the inner windings, as their corner kinks are far more pronounced than the outer wires corner bends.......... this is work hardening it unfortunately too.

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Then wind it up on a spare former  like this.... and try to keep it very neat, so the wires do not cross, this will help to not introduce more ripples in the wire.

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Then it is a matter of just plugging away until you find the core itself.
So we have now found our core and it looks like this...

8839-4

By the time you get it all off you will have over 7 lbs of wire there 2mmsq...

run out again....


.................oztules
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oztules

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Now we strip off the last layer of plastic, and we get left with this after we pull off the glass layers from one end. There were a few manufacturers fo these for inspire, and they may be slightly different in how they terminate etc, but the cores will be very very similar

8840-0

So we get two of these cores with glass on one end only of each, so we can join the cores together with glass and epoxy like this.

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and then we simply rewind on two or three layers of tape that we have on our bobbins from the unwind... and we have this..... ready to start again.

8842-2


It is the rewind time.

I think I will wind this with 114 turns on the secondary and around 14 turns on the primary.


I know this is a bit like watching paint dry, as the pics all look the same... but if your doing it for the first time, you probably want to see every stage... so here we go.
First we wind the secondary one in hand. There will be three of these... this is what the first one looks like. It is one in hand... even though it looks two. I followed their pattern of placing two wires side by aide rather than making each wire equidistant. This allows us to use the inter winding tape to advantage... ie the next layer has a depression to lay into.. two wires again.

8843-3

It took two reels of wire, so there is a join in there. It is helpful to put some tape/ texta/ whatever on the 45 degree positions, and calculate how many turns you should have by the time you get to each point. I wanted 114 turns so roughly 114/8=14.25 turns to each station. This is important if you want a tidy and easy to work with transformer. It means the second layer goes in easily between the first layers wires.

This  next one is after the epoxy has been painted on all over. This sticks the whole mass together, but you don't want too much that is takes up any space... just glue everything together, don't let it run and gather anywhere.... space in valuable

You can see the tape under the epoxy I used as reference points for the 14 turns

8844-4

run out of room again.....


...............oztules
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oztules

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continued...
Now we put a layer or two of tape to make sure there will be no chance of wires touching the first winding. They would be almost the same potential, but we don't want these to have any chance of failure.. it looks like this, and we can see the outputs there too.


8845-0

and here

8846-1

And here is a pic of the second layer going on. Showing the former that we roll inside the center to pull the wire through smoothly. The wire is orientated so that it unrolls against the walls.. We can see how the winding lays between the first wires now.... very useful reference.

8847-2

here is the second layer finished

8848-3


Before you join the layers together in parallel, it is important you check that the wire turns are the same, and the phasing is correct.

So join one set of ends  together as you would to parallel the windings, and put neutral on that, leave the other two wires open.

Now attach an active on one of the floating wires.........with a globe or similar in series as a fuse and soft start. Without the globe, you will blow any size fuse your house has..... it will blow any fuse if you get anywhere near zero crossing... once running it uses almost no power.

Turn it on. Now measure the input voltage across that live winding... then on the other winding that is loose at one end. Both voltages should be the same .. exactly the same.
Now measure between the active of the winding and the floating end of  the other winding.. they should be the same potential, so the measurement should be zero volts.

If all good, then turn off and connect the windings in parallel for keeps ( twist and solder) ...... otherwise add or subtract turns until it is right.  Minimum is 114 turns... don't subtract below that, add instead.

8849-4
 The aerosharp inverters have  1.6mm wire , not 2mm, so I wound this with 1.6 just to see.

It will require at least one more winding for power carrying. The aerosharp 3kw one I have has a bigger hole than the inspire, and that helps lots, hopefully yours does too.

It is much easier using the 1.6 rather than the 2mm stuff, but now there is an extra layer to do..... always something..... The inspire with it's 2mm wire can use just 2 layers.

So, more epoxy, then more wire tomorrow.... then the primary.

One interesting thing of using the epoxy, is that it helps the cooling, stops the noise, fills in any micro cracks in the second hand wire.... and also gets slimy when still runny. This allows you to fairly easily move the wires around on the plastic substrate very easily... for cosmetic purposes. So while the wire is tight and does not want to move in that picture, tomorrow when the epoxy goes on, it will be easy to tidy it up some... and hopefully make it symmetrical. This looks better... but importantly makes making the third layer the same as the second, as the wiring will simply fit in the gaps again, making it easy to keep the turns the same...

Remember, a turn is counted as a wire going through the hole. Don't care how it ends up, but has to be through the hole... thats where the magic happens. So this takes away the confusion of half turns at the start or finish.... if it goes through the hole, it counts as 1 turn. If you only count the wires in the core, you will be fine.

This will have to carry 8 amps for 6kw on each secondary wire. Should be no problem for 1.6 wire fairly well cooled. Thats at 100% duty cycle.

In this application, thats fairly unlikely, as the batteries will start to grizzle if we keep that up hour after hour, so full power will likely only be transient... maybe 30 mins max for 6kw-9kw cont... and even that is hard to see. This one will spend it's life at 500 watts average for 12 kwh/day, but should handle 10kw fairly comfortably for short bursts. For off grid, it seems 400 - 900 watts average  is the normal usage. So providing your inverter can do very large bursts for say 15 mins, then it is unlikely you will ever feel like your off grid. So if the hot water is running, the microwave running, the toaster is going and the kettle goes on.... the inverter just runs as normal.... but we can see that these loads will not run forever. So providing our transient ability is huge ( 15-20kw), and our short term high power is in the 30 min range, it is highly unlikely that we will ever resort to overload shut down from temp, and the boss will never complain of not being able to vacuum while the washing is on and the water heating  and boil the jug etc etc etc.

If you expect more, then another layer will give you better duty cycles. ...... ie 4 layers will mean that each secondary need only carry 6 amps for a 6kw load. 6 amps in a 1.6mm wire is pretty conservative, and only takes another hour to accomplish.... it's roll your own territory.

Your limiting factor will become how much copper you can get in the hole for the primary. This one will probably only get 50mmsq wire, but 6kw will be only 120 amps, and air cooled means that 50mmsq will be easily enough..

If anyone else has anything to add, please speak up, all this is from scratch, so I have had to invent every step. There are probably better ways of doing this stuff, and I'm all ears.


................oztules

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oztules

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Ok This is where we have wrapped the first two windings up, and now ready for the last and final hv winding.

8850-0

And here is the final winding before epoxy

8851-1

and with epoxy

8852-2

Whew glad thats over for this one.
Now I we only have to wind the 14 turns of heavy wire and we are DONE :) :) :) :) :)



Well had to use 30mmsq wire... hard as hell... might just as well have been solid core... it was very nicely work hardened.

After making lots of gutteral noises, we ended up with this.... thats after using the car and a 6 ton guillotine (as an anchor) to stretch it straight....

8853-3

It will easy do the 6kw, as in open air 30mmsq it is good for 180amps.... and thats well over the 6kw we wanted.
Or at 6000w, we will have .66% loss in the copper primary, and even less in the secondary ( 40 watts lost@6000w in the primary and about 17w in the secondary ) .. more than I would like, but less than 60 watts is controllable and about 1% loss or less all up ... plus 25 watts lost in iron loss... 85w total from the 6000w so 1.4% losses total from the looks of it) The air spilled from the mosfets fan at that level will keep it easily cool enough. I suspect. Bigger wire would have been better, but an island means you get what you can sometimes... it is easy to rewind when I find something heavier.. prefer to get 50mmsq in there.


It will look like this when we are finished



Thats the two aerosharp boxes cut and joined to make a big box. S/steel and aluminum. Will make a fine unit.

Well thats it for the transformer anyway.

......................oztules
« Last Edit: June 08, 2015, 02:57:00 PM by oztules »
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oztules

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This is what we are aiming for...
Here is the stuff to go in it



and here it is finished.. bur for the labeling.



Next  ( part 2 of series ) we get the PJ power and control card, and the transformer and put them together n this box or another one I did from a 3kw aerosharp unit.. a single box with the smaller 8kw cards.
Loaded with a few thousand watts ( 1.8kw or so) on the smaller unit looks like this. This one has only been driven up to 5kw so far.... the bigger one has had longish runs at over 8kw ( >25mins)... and thats more than I expected to do too.



Thats  worth a shot I reckon... and inverter for less than $500aud, that runs a house effortlessly.


........oztules
Flinders Island Australia

clockmanFRA

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Frome us Folk here in France, we Thank oztules for posting here on Fieldlines.

I have my 15kW boards ordered, and just at this very moment sourcing 2 Torroids.
Everything is possible, just give me time.

Neil

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Where are you buying the 15kw boards?

clockmanFRA

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Neil, I am getting mine from ..............  http://www.ebay.co.uk/itm/Main-Board-Control-Board-for-LF3000-15000w-pure-sine-wave-power-inverter-/121372307145?pt=LH_DefaultDomain_0&var=&hash=item1c425a6ec9   

(This was an original Link from Oztules)

According to the suppliers it will take 4 weeks to get to France.  ::)

I have 4 Toroids on there way here, 2 PJ 4kW & 2 PJ 5kW, but again its another 4 weeks wait.  ::)
« Last Edit: June 16, 2015, 01:35:51 PM by clockmanFRA »
Everything is possible, just give me time.

dgd

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That UK supplier on EBay says ships to worldwide then just about lists the whole world in the exclusion list including my location New Zealand.
Anyone know an alternative source of these boards?

Dgd
Off grid since 4/2000
Midnite C150,C250,Clipper, 2.8Kw PV, 2Kw turbine,1025Ah24v FLA (1999), SW3024E (1997), 3q16 48v300Ah LiFeYPO4 6Kw OzInverter, Arduino DUE web monitor.

frackers

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That UK supplier on EBay says ships to worldwide then just about lists the whole world in the exclusion list including my location New Zealand.
Anyone know an alternative source of these boards?

Dgd

I got mine from Cher (bloomininverter) by 'PM'ing via the ebay.com.au site.  The original advert excluded NZ but was not clear what the price of the 15kw boards was and I wanted 2 sets anyway. Ended up with a shared carriage price for the 2 sets and they were shipped direct to Christchurch from whereever!!
Robin Down Under (Or Are You Up Over)

clockmanFRA

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This 10000W PowerJack has arrived here, total weight is 38kgs, manufactured in 2014.

8873-0

The wife giggled at the bizzare manual and the even worse transaltions, and the awfull girlie photos. “Are they taking the p..ss”, she said ,”or are they really that unconnected with the real buisness world. It looks to me that they are stuck in the a 1970’s .”

I have also obtained a 8000W PJ, but getting it here is a nightmare with the folk from PJ. There invoice dept is bizarre, and seems to have no relationship to the products themselves. One minute I bid and it says In Europe, No EEC custom charges etc and delivery in 8 days.
 I get it, fleebay, and pay, then I get a deliver note with a 2 month delivery. I politely complain and the transaction is cancelled and then re-initiated.
So I don't expect miracles with the arrival of the 8000W, even though I paid for a European UPS delivery.

I looked up getting some torroids from here in Europe....   http://www.ebay.co.uk/itm/Toroidal-Transformer-2000VA-2x115V-2x115V-1x230V-Sedlbauer-RSO-825080-/231266730770?pt=LH_DefaultDomain_3&hash=item35d8924312  ………     but 2 of these would be  about the same price as my 2 complete PJ's I just purchased.

Interestingly the 2000va toroid is  about 215mm x 115mm,  while the 10000w PJs toroidal’s in the inverter I now have, are 175mm diameter x 95mm.  hmm.

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But then the case of the 10000w PJ is 34inch/860mm long and only a 195mm width inside.

8876-3
Everything is possible, just give me time.

oztules

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I thought you were going to just buy the boards.... never mind.

The two fans on the transformers tell you they are under done, thats why I build my own, but I suspect that unit will run your house very well, provided the loads are less than 4kw for any extended period of time.

The power ratings are unrealistic with those transformers for continuous use..... but you will be surprised at what it will start and run.

I bought my original power jack because I could not get torroids at a sensible price, and you can add transformers from extra units to get the continuous power ratings up if you wish.... may be cheaper than torroids there.

My transformer weighs over one and a half times your total unit weight, and almost as much as your complete SMA .... I went overboard the other way.

So, even as it is, it should do a good job, let us know how it goes.... never played with the 10kw boards or units.... interesting pics too. It may well be that it is fine as it is for your purposes... very few folks drive inverters as hard as I do for a single dwelling. Once you add the grid ties to it, you will have some serious power to play with.

I had 3kw of grid tie running today... I just let then turn themselves off from O/Voltage (255v)... will get around to controlling properly one day.... he said.


.....................oztules
« Last Edit: June 21, 2015, 10:45:55 AM by oztules »
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clockmanFRA

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Oztules, I have purchased the big 15kW Control & Power boards, and I am awaiting delivery.

My idea was to buy these 2 PJ's the 10000W & a 8000W, have a look inside which had the best toroids and do one of your 'Animal Inverters' from 2 of the PJ Torriods. Retain one of the PJ's as a spare/back up for my present Sunny Island 6. And take a few months building your design.

Seroiusly, cost wise it worked out better bidding on fleebay and getting 2 PJ's than buying normal torroids.

I do not have access to any PV Installers in the UK to get some scrap toriods, ( I have been banned from that UK RE Sustainability Forum, the SMA debacle), nor do I have access here in France to any handy scrap yards.

 My SMA Sunny Island 6 is misbehaving, and I cannot leave the AC Coupling GTI's continually switched on, as the high charge rate is damaging my GEL 1300ah batteries. So having a spare PJ will give me peace of mind just in case I loose the SI6, for whatever reason.

My main concern is that the PJ's torroids 175mm in diameter and 95mm thick are going to have a sufficiently large centre hole to get that Final Big 14 turns of cable to pass through. ?

Everything is possible, just give me time.

oztules

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If you cobble the transformers together ( check the actual voltages before you do ...( PJ is not renowned for putting together two units the same  twice if they are from the very cheap bargain bin  still very very worthwhile, but needs care to mix and match). If they are the same, you may as well run them as 4 parallel series units, this will probably put you above the SMA capability, with little work at all..... add in 15kw board... and you are on the way to big.... if you want bigger, then more transformers.

You can also use all the little ferrite torroids to get the idle current down further.... throw it all in a box, and you will have a useful unit and lots of backup too.

Been a few years now, and the electronics have not failed in normal use, so you may never need the spares, but nice to have them  anyway.

The only difference between the 10 and 15kw boards are the 20000uf less caps for the 10000 one. I think you will find the fets are the same, and program difference or a tiny resistor difference for the current sense.

The new boards should have the replaceable fet cards on them... neat idea, not sure if it is a good one though ( thermal bonding less direct?)..... but I have not been able to fault them either.

So it looks like you will have a pile of stuff to play with there.... and it may be the cheapest way to buy transformers is  the PJ like I found in the first place. So if you want more iron, then more units, get the transformers........., and the spare cards are free... and fans and battery posts etc.....

You should be pleasantly surprised what they can actually do for cheap cheap units. I could buy 6 15kw units complete for the price of the SMA. On current performance, thats 12 years of performance ( I suspect more like 30 years, as there is no sign the main unit here is going to change state any time soon).
18 transformers to play with in different combo, and 5 complete spare power cards.... WOW.

Next thing is to get the GTI under control, even a bang bang would be worthwhile... the reason I stay with flooded lead..... darn hard to kill them with too much juice... and thats the usual thing from  unregulated GTI, and 10kw or more of solar.... I will address that soon... hopefully.

On that note, I noticed that if the batt voltage gets up to 59v, that the inverter will drive a few volts higher..... so maybe that can be used as a rough guide at the GTI end to back off and keep the voltage to 240 not 243.... simple pwm before the GTI using the AC voltage for guidance may be all thats needed perhaps??

................oztules

Flinders Island Australia

Neil

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Just wondering why they are rated so high but can only handle 1/2 the k watts

Is it their toroids or the other components?


oztules

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Size is the problem, and they are super cheap.
While they can easily do their headline figures for short bursts, long term high wattage costs heat... so if you can get rid of the heat, then by all means they will do as they claim...... but even at 90% efficiency, you looking at an immense amount of heat at 10 or 15 kw.

So you need bigger transformers with thicker wiring for the same power.... and you need bigger het sinks for the fets and more of them to get the rds on down ( not really important with only 3.7milli ohm fets already ) but switching losses up in the 4us region is not easy. These things will switch up to the first 80% of fully on in around 50nano seconds from the scopes I have seen, and thats not sloppy at all..... but still need heat sink cooling.

Al this is a problem to selling inverters that you can actually lift. I can't lift mine on my own, as it is over 70kg now... but it is a hybrid.

So it can be said that they are chinese watts.... but their performance is truly staggering considering the low cost, and they are fairly  easy to improve greatly... but they are not for everyone....

A cheap reliable powerful unit they could claim.... but they can't help themselves going over the top apparently. If they actually did what they claim, they would be over  twice the size at the very least. Even the SMASI6 of Clockmans, is really only a 4kw unit.... certainly not a big deal anymore.

The PJ have cheapened the market to some extent, and showed that the emperor may not be as well dressed as you thought.

If they could get the charger change over controlled properly from charging back to inverter.... they would be easy to recommend. But you need to turn off the inverter before the source, and thats a recipe for destruction..... one day you'll forget.... or power will fail......at least they are dirt cheap to fix.

...............oztules
Flinders Island Australia

Neil

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thanks oztules,

I'm thinking of buying the 220v 10kw boards and making my own transformers for it,
        and I'm guessing one transformer for each phase. What size wire would you suggest?

Neil

oztules

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Firstly, I'd buy the 15kw... not much different in price, but 50% bigger programming and more caps ( 20000uf bigger). just makes things simpler.

How much do you intend to pull continuous ( over 30 mins at a time)...... and .........can you get torroid cores. E cores work fine, but will eat large amounts of idle current... if you have 40kgs of e core, ( equivalent to 20kgs of torroid)  you'll likely lose 5kwh/day in idle costs, 2.5 if the core is classy, and you use a 15-20Uh ferrite inductor in series, but big iron losses in these, even the good cores.

The 15kw cards are good for 5kw cont at least, maybe 6-7kw with better cooling. Instant power is absolutely huge if your transformer is tight enough.

" and I'm guessing one transformer for each phase.".... that question bothers me... what do you mean?.... these are single phase units.


.................oztules
Flinders Island Australia

Neil

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oh, I thought they were split phase, right now I have a Xantrex 24-3600 110 volt, so I'm only using half of my sub panel the other half needs 110 volts out of phase with the other, if that makes sense.



clockmanFRA

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oztules,

I have managed to obtain 2off New Toroidal cores at a very good price, from the UK, not actually paid for them yet but I have an invoice. With OD of 180mm, and an internal hole dia of 90mm, and a thickness /height  of 60mm. Weight is about 8.5kg each.

It seems that I can also get some cores at 190mm OD, and 90mm hole, but the height max is still 60mm, would the 190mm be better.? It would give me a thicker core ?.

According to my reckoning on your jottings, that's about 8kgs of copper at 1.8mm diameter, I have 4kgs 1.8mm already from my wind turbine coil winding days.  So thats 3 x 3 layers of 114 windings with 1.8mm dia copper.  Am I on the right track.?


Now I need  about 100 meters of that 18mm wide Mylar tape.

What Fun?
Everything is possible, just give me time.

oztules

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Neil, split phase is simply the transformer. Nothing more. It means you have a center tapped secondary  so  110v-0-110v and a normal board and primary.

The center tap is your neutral, and either 110v out put is 180 degree out of phase with each other... this means 110v to neutral for each phase, and 220v from phase to phase. The electronics could care less.... except for the current sense. Makes it difficult to know where to sense it from the secondary side.

Clockman, ........ more core is more gooder... if the price is not too crazy.... more core, means less turns... so the 114 is not set in concrete.... less turns for the winding person appeals to me too.

"So thats 3 x 3 layers of 114 windings with 1.8mm dia copper. ".... if you mean three layers of 114 turns, then yes Three layers is  possibly overkill unless your really going to hammer it for longish periods..... water heating is all I can think about or air conditioner....... but you will have the GTI to help there too.

I did the three layers of 1.6 just for the hell of it, two would probably have been enough for more intermittent  usage... but I err on the bigger size so I only have to do it once no matter  what i use it for.

The copper..... there is the odd kilo in the primary too. 50mmsq battery or welding cable adds up .


Those cores with the 15kw boards will make a fine unit.


................oztules

Flinders Island Australia

clockmanFRA

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I managed to get 2off toroidal cores at the 190mmOD, 90mm dia hole, and each 60mm thick/high, so that's 19kgs of core.

Being done here....... http://www.airlinktransformers.com/toroidal_cores/
and will dispatch to France.

Copper enamelled winding wire available here......... http://www.scientificwire.com/acatalog/Polyester_Enamelled_Copper_Wire.html
and yes they will post to France.

The PowerJack 15Kw boards turned up yesterday, without any French Custom charges, yippee.

 The Control board and the Power board are the same as what's in the 10000w PJ Inverter unit, except for the extra 2 capacitors on the 15kW board.

 I am going to strip this 10000w PJ Inverter unit for spares, but as I did not pay much for it, (just a bit more than the 15kW boards  :)), I will ask you sometime how I can get the 10000w boards up to 15kw.  But one step at a time. Oh yes those 2 toroids in the 10000w PJ have 1.6mm dia wire.

I will keep the 8000w PJ, yes it also has just arrived, as is, but its 2 toroids are only 155mm OD. I suppose I could use those 10000 toroids in the 8000 some time ?. Any how the 8000 will make a good emergency back up.

Yes got 6 meters length, 3kgs, of 50mm/2 new, good price/scrap it was end of roll, so its nice and fresh and good to bend. he he.

Oztules, yes I also prefer to slightly over engineer, so getting my 'Animal Inverter' to run as much as possible will be my aim. I do have 3 Gites nearly finished, a large-ish 3 storey house, my workshops and a lecture theatre under construction, all of which will have GTI's PV on their roofs.
 We have wood burner stoves, and all our houses are electric underfloor heating, but these are all getting to Passive House standard, so energy use is not excessive.

I will now wait a couple of weeks until everything arrives here.

Is there anything else, I could add during winding, to increase efficiency/keep heat down, like 2 in hand, or extra layer, ? as I now have lots and lots of 1,8mm dia enamelled copper wire.   I know that we don't want to much copper because of resistance and copper loss, but I am just wandering.?

Thanks
 



Everything is possible, just give me time.

oztules

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The PJ transformers have a huge number of 1.6mm wire for the primaries.... the W7 has 40 in hand ( or thereabouts) of 1mm wire, I assume that the PJ has 16 or so in hand.. I have not bothered to look.

10kw and 15kw boards are the same except for programming of the current transformer... easy to change with the resistor across the secondary winding of the CT.... or a wire in shunt with the ct .
There is 20000uf more caps on the 15kw power board, that should be all assuming the fets are the same

The 8000w pj will run the house very well as a back up I expect, as would the 10kw unit.... odd to think they will probably replace the SMA with little or no difference.... how many could you buy for the same money I wonder.

You can wind as many in hand for the secondaries, three layers of 1.8 is more than the commercial boys would use i think, 4 would be way over the top, but would contribute to a cooler unit.... gee thats serious though. This will decrease copper loss... more copper, the lower the loss.

You need to track down the ferrite ecores e65 will be enough , or very large ferrite  torroid rings and see if you can get turns of battery cable into those.... for 15-20uh.
Living on the continent, you have all sorts of stuff available, remote island in the wilderness forces difficult choices sometimes.

You have enough stuff there to power a small village.... and you have total control of your destiny too.... thats the satisfying part.

..........oztules
« Last Edit: June 24, 2015, 05:06:22 PM by oztules »
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Neil

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oztules, that's what I thought, but wasn't sure if that was done before the transformers, when will you be bringing out your part 2 of the wiring of the boards?


clockmanFRA, that pj inverter you just received is it a 220 volt unit?


Thanks for the info
Neil

Bruce S

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OZ;
Somehow my little 3-inhand jewel thief torriod seems woefully inadequate  :-[
A kind word often goes unsaid BUT never goes unheard

oztules

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"when will you be bringing out your part 2 of the wiring of the boards?"... soon as I can get to it.

When you seem to be the only person that can put batteries into a torch on  an island, you tend to get swamped....

Today... me and the dog were going to just cut some wood, and relax a bit.. it's winter... but i got suckered into building a 40 meter H beam aerial at a neighbors place, and dangling off a very tall ladder in a gale force wind,... when we got it up, we thought we would have  a beer or two, and then 4 alternators  from tractors and cars turned up, and an electric fence unit, and a vacuum cleaner.....a tv/dvd ,  a boat auto navigator unit ...... and I'm retired and am not running a business......... what happened to " me time" I wonder...... and I can't say no.... I'm not wired that way....dammit.

8879-0

Hopefully tomorrow ... no one turns up, and I can get some of this junk out of the way.

Bruce.... you never know, it might grow up to be a biggie :)


......oztules
Flinders Island Australia