Micro CoGen.

Quote from: BruceM on January 12, 2016, 03:57:38 PM
The Mecc Alte prices for AVR would send me running away, also. 

Strange thing is, only last year I could buy 8Kw AVR controled single phase 2 pole TWIN BEARING
Mecc Alte alternators for well under the price of their cheapest AVR, and now when I go back
to price units, this is the extortionate price one guy quoted me,
ECP3-2S/4 B3/14    8kva     1050.00 + vat, and I have to collect it from the other eind of the country.
It is like everything else in Ireland, we are run but the elite and theiy control the business world, they
would rather sell you nothing than charge you a decent price, their model is charge four times the price
and shift 1/4 the amount of units, shure cuts down on expenses staff and hard work for them.
In this particular sector, Ireland is flooded with companies who produce generating units, they
neither want nor care for anyone other than the guy who comes to them to spend a ransom
on something they will be paying for for years to come, if the banks don't lift it first, where
ther cycle starts again in someone elses name.

Regards, john

Hi BruceM

The AVR's from Mecc Alte are not cheap, one is €545.00 and the DSR version is €555.00.
I would worry about the reliability of aftermarket ones.
Personaly, I have never had an AVR problem, but at the same time would trust a transformer
more, I have one 50 years old and still working.
The transformer controled alternators are also capable of starting huge loads and their voltage
actually rises, they just seem more dependable and tolerant.

I will pursue the transformer rectified and fed to a cheapish 4 stage charger as a backup and educational exercise.
The same generator will power it as will power whatever setup I end up with, so no waste.
I too will be utilising the full output of my generator via a victron charger inverter, which has load sharing built in.
Beats me why it is so difficult to find a dc generating end at a reasonable price, I must check with my local forklift dealer
what it would cost for a replacement DC motor for an electric forklift, have a feeling it will be big bucks,  if not one of these
that runs on 48 volts may be suitable to re apropriate as a charging supply, I had one and sold it like a fool, man bought it
to use with a hydro setup to charge batterys.

Regards, john

Hi mike90045

I intend to use a standard 50Hz 230 volt alternator, it may be single or 3Ph depending
on the prices and availability of a new 10 Kva trnasformer controled unit.
A few years back single phase transformer controled units were easier to
locate around here, now it seems they are not producing them due to the
downturn globally in such sales, so I may have to go for 3Ph, am
definately avoiding an AVR controled unit for this job.

Regards, john

Hi Thob, thank you for your input, interesting to know, but I kind of thought there had to be some reason we can not simply use
any ordinary transformer for welding, am guessing sticking would be the norm if we did, and smoke would be the most likely
outcome, otherwise no one would need two such differing transformers, just wondering in the cure is in simply stripping out whatever
means of regulation they employ, as this alone could be the main difference between the transformers. Will t some tests in the future,
though for now this significent difference between an ordinary transformer and a welding one is enough to take another route.

Regards, john

Sory mike90045, someone messing with your name when I was away from computer

Hi mike 90045

The wilding transformer is 50hz, and as for windmill and solar, they have not been purchased yet, and in any event will be rectified and fed to the charge controler, their output
will not have to go anywhere near the transformer, it is for charging via my generator, and yes, my idea was to rectify the transformerThis output and feed this to a charge controler, though I would classify it more as a battery charger as it will be charging batterys with a steady input from the transformer/generator, as the solar / wind end of things are to follow and will need to be fed to a charge controler, I do see there is a distinction in the two aproaches and have solved it near the bottom of my rant which explains what I am trying to do.

Thanks mike945009

What am I doing

Am re evaluating staying connected to the electricity grid.

My intention is to get a battery bank, inverter / charger
and put together a new generator to do the charging when
wind or solar are not producing enough to charge the batterys.

I am doing this in the order the components become available to me
at the right cost, leaving the expensive ones to last in order to
pick up a bargan when am educated enough to know what I actually
need and what constitutes a bargan.

I am currently awaiting quotes for a new alternator, and like all
components required reliability is of great importance and thus
my move away form electronics, the new alternator will be transformer
controled, which should make it more reliable, easy for me to test, and if need be rewound.
I can not work on or repair an AVR which means handing out large sums of money to repair or replace
one when it goes wrong, in this case the transformer costs between 1/3 and 1/2 the price of an AVR,
depending on whether its and oem and on how complex one wants to go.

Thats the alternator covered.

Charging the batterys, and to do this I also want to avoid using components that can fail easily
and which I also can not repair.
This was my reason for wanting to use a transformer to reduce the voltage coming from my generator,
and use simple components such as rectifiers and a few caps to create the DC.
This may work out well enough, as again I can test and repair a transromer, so If this transformer
aproach would work, I have a welding transformer that I only need to connect into, all the leads are
redily available without opening up the unit, it is also oil cooled and in great order.
I can also buy cheapish AC welders, if anything does give up on the transformer end so am not tied up.

The main issues with this aproach other than my lack of knowledge, is that I still need a charger or charge controler
to charge the batterys, and thus am in territory I do not like, reason being I can not diagnose or fix them.
But I have no choice, and during my research I have come to realize that I will have to use an inverter also, which
is more electronics that I do not understand of can fix.

Bottom line, I can see that using a transformer is a more fault tollerent and dependable way to get the voltage and current
I need, but at what cost, there is going to be losses in efficiency, and probably more so than going the more electronic
route.
This is my conondrum, go the transformer route, and buy an inverter charger that will accomodate either my generators transformed and
rectified voltage and solar or wind input, or buy an inverter charger that can take 230 volts form my alternator, and the DC from
solar or wind.

Well complicated as it may look, thanks to people on the forums, and my own research, I have been pointed to and found numerous
products that can do all I need, victron energy do a charger inverter that can take ac OR dc input, which solves all my problems,
but at a slight cost in effiency, the product is only 94-95% efficient, but am not so sure this is all that bad, because it serves two
puroses, where for example a comparatively priced outback only does the inverting at 98-99% eficiency, this product inverts, charges,
and to top it off load shares, this load sharing will eek back the quoted losses, because I can run the generator to charge and at the same time,
keep it loaded heating water or whatever else, such as washing machine duty, it will even cut the batterys in when the preset ac level from the generator
has been reached. All this functionality saves a lot of wiring and setting up a micro controler to achieve similar.
I do however intend to impliment my transformer idea and a cheaper charger as backup and would realy apreciate peoples input on whether or not
my idea with the welding transformer will work, and what issues I should watch out for, such as current rushing in or out of the transformer on startup
and shutdown and how to protect against this, for all I know a welding transformer as oposed to a standard 240-80volt transformer could be way better at controling harmonics, ironing out ripple, stabilising current or voltage, or not as the case may be, thats why I posted here, can't understand why poeple in the business can't come out and tell me, the answers are either one is better than the other, and here is why.

Thank you all for looking in and helping out.

Kind regards, john

Thanks mike90045

I have learned much from your answers, and will consider whether or not to go ahead with my idea, given the high voltage I will only do so for testing and education purposes.

I am now questioning the fesability of using a transformer based AC Welder rectified to supply a charge controler / inverter, below is a link to this post, I hope someone will once again take on my many questions, and in return hopefully help a lot of others who are consideing exiting the controlled sanctioned taxed to the hilt existance our so called governments are pushing down our throats.

Below is a link to my new idea, an 80 volt 180amp output welding transformer, which will keep the voltages quite low.
http://www.microcogen.info/index.php?topic=3460.0

Many Thanks to all

Thank you Tom, I have taken in all I can and will be proceeding with caution, the high DC voltages involved here have concerned me all along, and I do not plan putting this into operation but may impliment it as a test case.

I am now questioning the fesability of using a transformer based AC Welder rectified to supply a charge controler / inverter, below is a link to this post, I hope someone will once again take on my many questions, and in return hopefully help a lot of others who are consideing exiting the controlled sanctioned taxed to the hilt existance our so called governments are pushing down our throats.

Below is a link to my new idea, an 80 volt 180amp output welding transformer, which will keep the voltages quite low.

http://www.microcogen.info/index.php?topic=3460.0

Many Thanks to all.

Lots of people seem to be looking for a system to charge 48 volt battery banks, and hense my query.

I have a pickhill engineering transform based welder, 400 / 240 volt 7 0r 8kw welder, there are no electronics at all involved here, I have only ever opened it up to change the cooling oil which is the reason it is now 50 years old and still in perfect working order, and on the cooling oil front, the quantity can be upped to keep the transformer even cooler if need be, passive cooling uses no extra resources either.

I can not remember what the inside of this welder even looks like as it has not been used much since the migs came to me 25 years ago, but the gist of it is, the welder can be fed either 400 volts or 240.

On the output side, there are two main options, either 50 or 80 volts.
Then there is the adjustments for welding, there are about eight of these from 30 amp to 180 amp.

Could I simply take the 80 volt welding leads, rectify this output and use that through a charge controller to charge batteries, am thinking with a bit of filtering this would work.

The part of the equasion I understand least is, what position to set the welders amp control knob, it is one of those that lifts up and rotates and is then lowered again into a notch, which is obviously a tap off the transformer.
In my way of thinking it would seem that setting the welders amp knob to the highest setting would provide 80 volts at the highest amperage.

Now as I said, I do not remember what the transformer looks like inside the box, so when I adjust the amps knob, am I adjusting on the transformers secondary, and in any event, how does inductance help or hinder my idea of taking this 80 volts at the welders rated 180 amps in order to feed an inverter or charge controler, am thinking the indcutance is what keeps the amps steady, and the voltage will take care of its self, as altering speed is the only way to alter the voltage other than the pull of the load sinking it a bit or long lines coming into play, which wont matter to the rectified input to the charge controler as it handles a voltage within a range.

I have this welder anyway, and do not see any point in it sitting there when I can re purpose it and still have if for when needed, and avoid buying a transformer if it will work out for me.

One last point, does a transformer fed from a capacitor regulated alternator smooth out the harmonics induced, or do they multiply and get worse.

Thanks to everyone in advance.

Thangk you mike90045

Now I understand the corect way to calculate the DC value of an RMS AC voltage.

In the graphic below perhaps you could tell me what I propose is going to work or not.
I have a 3ph alternato that produces 230 / 400 volts AC, what I want to do is rectify
the three 230 volt terminals, I need the common in the center of the Y in order to get
this 230 prior to rectification, so am I right in thinking I also need to rectify this common,
and if so, how do I do this in order to make the common available to the three legs I am
rectifying, I know I do not need the common rectified if I were using the 400 volt three ph
side of things, but am not sure if the same principle applies to the 230 side, though I can not
see how it does.

Thanks again Tom

Glad someone understands my problem. The pheonix  inverters I looked into a year ago, do the load sharing thing, they are disigned for boat owners, who sometimes have
shore power, ie, mains, and a genny on board, the idea being one assists the other and shares the loads, one being charging, the other being whatever you have your inverter
plugged into aside from the battery bank.
The reason I do not rectify the whole gennys output is and feed it to the inverter is that the voltage I am currently messing with is too high, 230 ac rectified is 325volts and
finding an inverter that wants that may be a challenge, its safer for me to dump it to heating via the programable relay on the inverter or a current relay.

I will look into the inverters you mention, sometimes the brands that are populare in the US are not to be got here, anyway, plenty of experimenting and planing to do first.

Im only susing out whether or not this will work,
I will be connecting the generator to an inverter charger that can load share, this way when I need to top up the battery bank, I can start the generator and charge them, this will initially take a lot of currenrt, but when this initial charging phase is done, the generator would be wasting fuel while the batterys are topped off and conditioned, and it is at this point the dc rectified current will be used to heat water while the batterys are being topped off, this way the engine is kept loaded heating water. I could let the inverter charger actually heat the water instead of using the dc to do it, but I want this DC circuit as a backup incase the inverters power sharing gives bother, or I come across a cheap inverter that does not have power sharing.
Im only trying to grasp the principles of this, and will test as I go along.

Thanks Tom

To simplify things, will this work

Here is a schematic of the alternator in question, it is a Mecc alte BTO3, transformer controlled 3 ph,
230/400 volt y connected setup.

Hi everyone

Can I take two 230 feeds from a three phase 400/230 volt alternator, one live from each phase and use the common neutral / centre of the y
and put both lives through a bridge rectifier and from there take the DC out to feed an inverter, or can I go as far as to take a 230 volt feed from all three phases
and the common centre of the y and rectify them to feed an inverter.

Bottom line I have a three phase alternator, and do not want to buy a single phase of the correct kva rating, and am hoping I can harness either 2/3 of 3/3 of
the power my 3ph alternator already has, rectify it to dc and use it to heat water in dump load mode or feed an inverter charger in standard mode, it is 10kva
6 wire three phase, I either have 230 volt or 400 volt, have not seen the alternators terminals yet so unsure if there are more reconnection oportunities, the
plate says 230/400 volt, and the diagram shows 12 wires, though on most set if this was the case you would have more voltage options on the plate.

Any help would be much appreciated

Thank you kindly, john