Is anyone using a PMG

[assiduous1]

Hello all,

Is anyone using one of George's Permant Magnet Generators?  I like the fact that there 120V/220V with a clean sine wave.  Was told that the speed of the engine needed to be kept constant, ie needs a good governor.   I have been unable to locate anyone else selling a similar 120/220V PMG unit.   Has anyone seen anything similar?  PMG are supposed to start a little bigger induction motor than a typical generator head. 

Ken

[Doug]

Trouble with a PMG is you have no control over the field.
You can't raise or lower the voltage or compensate for power factor.

I can't say I know anyone who has one, so that's only the opinion of a man who worked in a winding shop.

If the best way to build a syncronous Generator was with permanent magnet fields don't you think everyone would build them?

There is also the long term possible problem of armature reaction slowly weakening the fields untill your generator output drops to useless levels.

It is a novel but unproven generator and the idea that a PMG can start a heavier induction motor load than than identical size conventional syncronous machine is not based on any proof nor is there any technical reason I can think of to back that up .

Doug

[oliver90owner]

Probably better suited to DC operation, but there are small wind turbines which produce 'wild' AC.  They are usually grid connected through an inverter/converterr of some description.

Regards, RAB

[Tom]

I wonder if using an AVR/transformer with a PMG would resolve the voltage issues with out eating up most of the efficiency gained by using a PMG in the first place.

[mobile_bob]

first of all we all assume the pmg's to be built to the same basic engineering standards of a conventional alternator,, and
this is the flaw in the analysis.

a conventional alternator can be built with little regard to self regulation, because we can use regulators/harmonic windings etc to correct
the voltage and improve the regulation.

you don't have the luxury of a regulator for a pmg, so you have to build to a higher standard and certainly design for much higher self regulation

this is not an easy task, and certainly not cheap!
this is why you don't see many folks offering them, most folks are resellers of others products
leaving utterpower to reach down deep in their pocket to fund the development of a tightly specified self regulated alterntor.

alternator design is something i have devoted many years studying, and all the engineering text have computations for "self regulation"
and means of getting a high level of self regulation.

the goal of a high level of self regulation is an altenator that can go from no load to full rated load with a very low level of voltage drop
a successful design in my opinion would be from approx 127vac (to maybe 130 and i would be ok with that) to a low of 110vac at full rated load
(and i would be ok with a low of maybe 108vac at full load.)

from what i have seen utterpower has accomplished that goal, and good on them. Actually from what i have seen if the pm gen is run within its
rated capacity it will stay within the 110-127 volt range from no load to full load,,, maybe even better on the new ones. iirc the pm will stay above the 108
vac at a 40% overload!

bob g

[SteveU.]

High strength rare earth PMs have been sucsessfully used by Robert Bosch/Germany and Delco Remy(Delphi)/USA in automotive starter motors for over 15 years now. You are probably driving around with one now. You didn't have a choice: it came "free" with the vehicle. Does require very good/tight manufacturing/engineering capabilities. Oddly, the best(my opinion) automotive electrical supplier Nippon Denso/Japan has so far stayed with Iron, Steel and Copper in this application.

You can easily Internet search and find three different Chinese companies  manufacturing and marketing complete PGM 1500/1800RPM AC generators. China has sucsessful Space/Nuclear/combat Jet and Marine programs. They have the manufacturing/engineering capabilities if applied.

If you decide to take the plunge into PGMs(the future-definately) out of Iron and Copper(the proven present) I'd highly recommend it's much safer to be backstopped by an available supplier/dealer.

Me, I'm still fence sitting on this.     Brushless, sealed, higher efficiency, less heating . . . .versus copper . .a rewind shop in nearly every city. . .

All my own opinions,
SteveU. 

[Doug]

I'm sceptical.

The best PM DC motors on the market suffer from poles demagnitizing overtime when subjected to DC drives or high inrush starting currents and I don't see any reason to believe the Chinese have cracked this problem.

As for the voltage regulation no PM generator will ever match a conventional Syncronous Alternator with a proper AVR.
There is no such thing as self regualtion on a machine with no field control.
Thats like calling brick on your accelerator cruise control.
127 to 108 volts NL to FL is outside the 10% limit that most electrical equipment is designed to run at and is nothing to boast about.

Show me some proof from an objective source and I will eat crow.

[rbodell]

I'm sceptical.

The best PM DC motors on the market suffer from poles demagnitizing overtime when subjected to DC drives or high inrush starting currents and I don't see any reason to believe the Chinese have cracked this problem.

As for the voltage regulation no PM generator will ever match a conventional Syncronous Alternator with a proper AVR.
There is no such thing as self regualtion on a machine with no field control.
Thats like calling brick on your accelerator cruise control.
127 to 108 volts NL to FL is outside the 10% limit that most electrical equipment is designed to run at and is nothing to boast about.

Show me some proof from an objective source and I will eat crow.

I kind of have my doubts that they would demagnatize all that fast or that much. You would probably have to have some pretty sensative equipment to see it over a couple of years.   I have a military surplus 1/3 HP 192 RPM PMDC motor I have had hooked up to numerous drives and used as a DC generator. Mostly it runs about 20 to 25 amps but I have had it up to 35 amps and hot enough to burn the paint off of it a couple of times but it hasn't lost anything you could notice without test equipment over the last 15 years. Being military surplus it is probably better quality than most, but then magnets are magnets are magnets and these have been mistreated at best.

[mobile_bob]

10% regulation is optimum from a design view or goal, but sadly hardly ever the reality even on the grid!

most electronics today can do just fine with a very broad input voltage far outside what a pm alternator can deliver.
switching power supplies can intake from around 90-240 vac and go on just like there is no tomorrow. things like puters use em
as do tv's, stereos dvd players, etc.

even alot of todays smart appliances use motors that are variable input types, with inverter drives and all that.

when i mentioned 108-127 i used that as an example of what i would find quite acceptable for a pm alternator.

i can check easy enough to determine actual numbers and they are likely better than what i would find acceptable.

the plus side of not having to have an avr, no brushes, higher build quality, no rectifier, and higher efficiency far outweigh some swing in voltage
in my opinion, and with a bit of crafty control (external multitap autotransformer) and, a bit of extra control one could get the voltage
within very tight tolerances pretty easy.  the added switching could be useful in dual purpose anyway.

i know the pm alternators are not for everyone, but they certainly have their place especially with high fuel costs, their lack of needing
maintenance (brushes and sliprings) and quality make them very attractive to anyone wanting a unit that will do the job.

might not make sense for a guy that just wants a backup genset, that only runs a few hours a year, but
even that sort of application probably could benefit from not having sliprings corrode from months of non use.

i have no doubt at all i could take one of those pm heads and obtain regulation within 5% with no problem at all within the operating range
i would have it running at.

just think about it
if the head is rated at 3 kwatt, and will deliver it at 115vac, and at 2kwatt the voltage climbs to 120vac, and at 1kwatt it comes in at 125vac
that is more than good enough for anyone with any appliance on the market. if one wants to run at under 1 kwatt he is wasting his time anyway
there are more efficient means of produceing low levels of power to start with.

not having harmonic windings, and having skewed stators, all aid in a clean sinewave.

AVR's are a necessary evil for less than perfectly designed or implimented installations.

bob g

[SteveU.]

assiduous1 I think you now have the answeres to your questions.
Nobody has claimed using one of these promoted units because one or more of the following reasons:
1) They are still in Alpha/Beta developement--and NOT Available.
2) They have failed Beta testing--and NOT Available.
3) Their distribution is being tightly controled; therefore--NOT Available for just anybody to use.

So either noboby is knowingly using them or are under restictions to talk about it.

Untill they are available to be put in a varity of service condition by a varity of operators all of our talking about it is really Sterling/swashplate/unobtianium/100 mile carburator usless jabber.

Mobile Bob you've seen and touched these units. I've seen your work. You are contactable. I trust you.
I have an immediate need for a 3kw sized AC unit to be able to proceed with some light stainless steel welding.
Get me one of these PMG units and I will use it. And I won't need any handholding. Just a unit with a Requirements/Characteristics sheet.

Best reguards
SteveU.

[Doug]

assiduous1 
 
Ken I have been around a long time.
I know my trade I AM a winder and electrician and I challange any other know it alls to produce tickets.
Buyer beware you are dealing with Utterpower and you will be happy with your purchase or get no technicl suport if you complane.

Bob, time to be honest you defend George too often to be unbiased and too strongly to be ignored.
Do you have a financial interest in the company?

 
 

[mobile_bob]

for the record

1. i know George, and find him to be an honorable guy in every way.

2. i have no financial interest in utterpower at all

3. i have bought a few products from utterpower

4. i have bought many products from powersolutions (suffice it to say enough to satisfy the needs of at least a dozen DIY'ers)

5. i have no financial interest in powersolutions

6. i know the owner of powersolutions and also find him to be an honorable guy in every way.

now having said that.

both of these men are much like me they are older and sometimes grumpy when pushed hard.
both of these men are humans and like me (and everyone else they have feelings too)
both of these men work hard to develop and provide products such as engine's, generators and other related parts.

neither of these guys are making a lot of money providing these products, and quite frankly if i were them i wouldn't do it!

i also know of nobody that has bought anything from either of these men that when faced with a problem did not receive help to resolve
the issues, unless
the buyer gets stupid and comes here bitching and complaining before they have given the supplier a chance to rectify the problem.

my point basically comes down to this

there is a demand for these products, and there are those that come and go that provide these products. some have stood the test of time
some flake out on and off again, some flash in the pan and are gone.

George seems to be sticking in there as does the owner of powersolutions, week after week, month after month, year after year.

balance this against the average diy'er doesn't have the experience, tooling, money or time to produce some of these parts.

so yes i come to the defense of these two guys, without them there would be a lot of folks wanting and not able to find the stuff they need
to build a genset.

another thing to consider is the investment these two men have in providing these products, it costs alot of money to produce and stock dozens of each size
of serpentine pulley's, warehouse them, package/handle and mail them, and all the while having their money tied up waiting for a buyer for the products that may never
materialize.

As for the pm alternators, yes they have been in development for a number of years and at a huge investment in research and development before the first
were shipped for testing.

i know of no one else that has bellied up to the bar and put their money where their mouth is! no one!

what i have seen are comments frpm others that are skeptical having never seen one,  having never seen an advertisement for one, pricing for one, or a spec
sheet on one! and...

i have not seen anyone that has one post anywhere that they are dissatistified with one of them!

as for the assertion that the pm magnets will lose their effectiveness over time, i offer high power stepper motors used in industrial machines,,they seem to just keep on
going and going?

i haven't seen a single report of failing magnets on any motor that uses them?

all that aside

i stand by my previous post, i see no reason that there would be any problem using one, however i do see several advantages to using one.

as for myself i am working on a product for the offgrid market, but quite frankly having witnessed how some folks respond to products,  i have to tell you
the DIY market likely would not be my target demographic, at least i don't think so at this point. ( at the very least i would be incredibly selective who i would
sell to)

some of you guys think George is tuff to deal with, in my opinion he has incredible patience
far more than i would have!

and lastly i while i am just as critical of claims made by suppliers, i am critical on the forum when they are here to defend themselves and their products
if however they are not present to defend either, i think we should give them the benefit of the doubt?

bob g

[Doug]

One more dance before the last polka Bob....

"i also know of nobody that has bought anything from either of these men that when faced with a problem did not receive help to resolve
the issues, unless
the buyer gets stupid and comes here bitching and complaining before they have given the supplier a chance to rectify the problem"

How about Sid and Mkdutchman I supose they are Stupid idiots then right?
Or does that just aply to Petteroids....
Oh wait... what about the Listerods I spent years indexing and tracking.

You can fool some of the people some of the time but I have the names and serial numbers.

Good bye, so long, fair well......

Dough!

[mobile_bob]

Doug:

i fail to see your point!

1. is it that you don't like George?  (which that is fine you can like or dislike who you choose, as can George or anyone else)

2. or is it you don't like the pm heads? (which this is the subject matter of the OP)

i won't argue #1, but
i damn sure will argue #2!

so far you have presented no evidence refuting the pm heads effectiveness or longevity!
i clearly presented a few of the benefits of the pm heads, do you have issue with any of those?
if so which ones?

as for your spending years compiling complaints from buyers vs suppliers, quite frankly i could give a shit
if you want to spend your time developing a list, by all means knock yourself out. however i would assert if you compile long
enough you will find every supplier will have a dud that will get sold to a dissatisfied customer.
and you should also factor in the fact that you have only a very narrow sampling of the numbers of units sold and an equally narrow
sampling of buyers as well.
also it is a well accepted fact that 1 satisfied customer might tell 7 folks about his experience, while a dissatisfied customer will tell
everyone he knows, everyone that will listen, forever.
that will skew your list results as well.

i guess what i am saying is, maybe, if you are going to go to the trouble to develop a list you might be well served to learn how to
read the results of your data and factor the results appropriately.

if you have been in business as long as i have, you would come to know that sometimes things happen
that are beyond the control of either yourself or your buyer, sometimes you can't make everyone happy.
actually you will never make everyone happy all the time.

anyway, getting back to the OP

specifically what do you have against the pm alternator?
(pardon me if i don't just take your assertion on faith, based on your years of experience)

it is one thing to say something is bad, poor or a bad idea, but quite another to support your assertion
that is where the rubber meets the road buddy!

don't get me wrong Doug, i am sure there have been times that i taken a position that is against the claims of some supplier
or a particular product, but
i am fairly certain that i support my issue with the claim with some reasoned logic.

thats all i am asking from you,
you don't like them, tell me specifically why you don't like em!
or rather tell me what you don't like about them, and then tell me why or specifically what is wrong
and be prepared to support your assertion.

seems fair to me? how bout you?

i fully realize that the sword cuts both ways,, so if i ever make an assertion and base it on
"hey i have been a certified master diesel mechanic for 34 years, and that is why it is no good"
i don't expect you to take that as an answer either!
i expect you to hold my feet to the fire as well and call me out on it!
make me support my assertions!

now is that fair enough?

bob g

[mobile_bob]

Doug:

"There is no such thing as self regualtion on a machine with no field control. "

there most certainly is! just as there is for transfomers

it is the ability of an alternator to hold its voltage within design limits over a range of loads
as i am sure you are well aware.

a hundred years ago, the self regulation of an alternator was a well known factor in determining the
quality of a design,, and the higher the self regulation the more expensive the alternator

with the advent of voltage regulators (originally all mechanical) determining self regulation was left as an excersize
for the engineering dept and no one else gave it much thought.

now a hundred years later and with the advent of neo magnets engineers that haven't been faced with being concerned
with self regulation and the factors that improve it have had to go back and relearn some of those old lessons that folks like
tesla/westinghouse/edison laid out.

basically a cheap low iron, short on copper alternator will have extremely low self regulation, as opposed to
a heavy iron lots of copper alternator which will have significantly better self regulation.

the neo pm heads must be built to very tight tolerances, fine laminations, lots of copper etc to get as high of self regulation as they can get
them in order to be successful. And that makes em more expensive.

bob g