Author Topic: Microformer HV Distribution System  (Read 1958 times)

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OperaHouse

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Microformer HV Distribution System
« on: January 19, 2017, 09:26:51 AM »
I wish I had a remote hydro generator. I would love to implement a system like this. Came across
this a while ago and have waited for long distance transmission discussion. Just putting it out
there now before before I loose the info.

This is a great way to send power over long distances cheaply with high voltage.  A microwave oven
transformer is modified by removing the magnetic shunt pieces and adding a few extra turns of wire. 
That extra wire could be eliminated if your line voltage is lower. At these high voltages and low
current you could probably get away with using only one wire and appropriate insulators. The return
path could be through the earth. This high voltage is not for the squeamish. Check it out.

www.microformer.org/make-your-microformer/

Bruce S

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Re: Microformer HV Distribution System
« Reply #1 on: January 19, 2017, 01:57:42 PM »
That is one of the best write-ups for microwave xformer rebuilds I've seen.
I'm still reading the side bar stuff.

Bruce S
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SparWeb

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Re: Microformer HV Distribution System
« Reply #2 on: January 20, 2017, 12:52:04 PM »
Very interesting.
Poking around the website...  can you find any results?
Measurements of line voltage drop, power factor, etc.?
No one believes the theory except the one who developed it.  Everyone believes the experiment except the one who ran it.

System spec: 135w BP multicrystalline panels, regulated by Xantrex C40, DIY 8ft diameter wind turbine, regulated by Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024

Warpspeed

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Re: Microformer HV Distribution System
« Reply #3 on: January 20, 2017, 01:44:42 PM »
There is one point often overlooked when selecting transformers for high voltage transmission.
Common mains frequency transformers have voltages rated for 50Hz or 60Hz operation.

If your hydo or wind turbine creates a much higher frequency the transformer voltages can be increased accordingly.
For instance, a transformer winding rated for 220v 60Hz would be quite happy to run at 660v and 180Hz or any other multiple.
The flux density in the core will be the same and the transformer will be perfectly happy.
You do need to give some consideration to the insulation rating, but for any sane voltage increase, in practice it will work fine.

One other thing, by increasing both the voltage and the frequency (in proportion), the original current rating stays the same.  So it  also increases the power rating by the same multiple.

Submerging a transformer in oil is an excellent way to keep moisture out of it, and perfect for very harsh outdoor applications. Paint cans usually have very poor plating and are thin. Sand blasting by the wind will quickly remove the plating, then it will rust through very quickly. 

The paint can itself is fine, but it really needs an outer coating of something pretty tough like mastic tape for long term protection.



OperaHouse

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Re: Microformer HV Distribution System
« Reply #4 on: January 20, 2017, 03:02:00 PM »
I've had the handle bungs fall off from paint cans from the latex paint inside.  Keep this can inside.  Need to check out Tractor Supply for suitable transmission line insulators for electric fences.

joestue

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Re: Microformer HV Distribution System
« Reply #5 on: January 20, 2017, 03:28:29 PM »
insulators? we don't need no stinking ceramic insulators..

 a soda bottle on the end of a stick. screw the lid to something and thread the bottle on.

some bailing wire can hold the wire to the bottle.

OperaHouse

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Re: Microformer HV Distribution System
« Reply #6 on: January 20, 2017, 04:16:37 PM »
Interesting fact.  The first high voltage transmission line was in Telluride, CO.  Mine interests had the money.  They needed to run equipment near the mine and hauling fuel up was as bad as hauling unprocessed ore down.  They went high voltage to save wire costs.  The wires lit up at night because the diameter was so small.  And if it didn't work they could always turn it into a ski lift.
« Last Edit: January 20, 2017, 04:36:57 PM by OperaHouse »

joestue

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Re: Microformer HV Distribution System
« Reply #7 on: January 20, 2017, 04:55:10 PM »
corona losses?

Bruce S

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Re: Microformer HV Distribution System
« Reply #8 on: January 20, 2017, 05:37:47 PM »
in the posting , they did say to paint the outside of the cans, and on a 72 inch smart-panel , you can see that can was in fact painted with what looked like the old fish-oil primer stuff.

My interests lay in the xformer itself. I have a few from the big GE badboys . I'd be interested in seeing the bi-directional usage.
Being that I currently urban bound, anything approaching a life sized VAWT will catch the city's eye (again) last time was given a warning.
I'd almost pay to see how well one of these would marry up to one of Ed Lenz's VAWTs.
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Ungrounded Lightning Rod

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Re: Microformer HV Distribution System
« Reply #9 on: January 21, 2017, 10:00:52 AM »
One other thing, by increasing both the voltage and the frequency (in proportion), the original current rating stays the same.  So it  also increases the power rating by the same multiple.

Another way to spin that is that a transformer with a higher frequency needs less core and winding  material for a given power capacity.

That's why much military equipment - especially in aircraft - ran at 400 Hz rather than 60.  (Called 'em "cycles (per second)" back then.)  Since the transformer iron core is most of the weight you could make the core lighter by a factor of 6 2/3, while the proportionally higher voltage per turn let you do the same for the windings, which were most of the REST of the weight.  If you're rectifying the output down to DC the higher frequency also scales down the filter capacitors (the bulk of that section) by the same factor, as well.

Seymour Cray used this same hack in his FIRST mainframe (the Control Data 1604) to substantially reduce the size and weight of the power distribution.  Each door-full of logic cards and 6-bit slice of core RAM had four little transformer-based three-phase powered dual-voltage output DC supplies, about the size of a brick, one in each corner of the door/rack.  There was a big motor-generator in the next room to do frequency and voltage conversion.  Result:  power handling was a very small amount of weight and size (both for the supplies and the wiring) in the mainframe's cabinet.

Thermal protection was cute, too.  He mounted one of the Honeywell home-style furnace thermostats - the round ones with the mercury capsule switch - in the top exhaust plenum of the machine, set the cycling-heater-resistor to zero ohms, and put it in series with the (normally-closed) "stop" button of the motor-generator's "contactor" relay.  That was a 24v low current control circuit, just what the thermostat was designed to switch.  If the exhaust temperature exceeds the 'stat's setpoint it stops "calling for heat", which turns off the motor-generator and thus the power to the computer - until it's manually restarted after the issue is resolved.  The mercury capsule switch in the thermostat means no "dirty contact" issues, too.

Using a furnace thermostat gave him easy-to-read fine control of the setpoint, an accurate monitor thermometer at the same location, and it was very cheap and reliable.

Ungrounded Lightning Rod

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Re: Microformer HV Distribution System
« Reply #10 on: January 21, 2017, 10:45:23 AM »
If your hydo or wind turbine creates a much higher frequency the transformer voltages can be increased accordingly.

One other thing, by increasing both the voltage and the frequency (in proportion), the original current rating stays the same.  So it  also increases the power rating by the same multiple.

This is also why you don't have to worry about saturating a transformer's core when you run it WAY below its rated fequency driven by a permanent-magnet-field and/or iron-core alternator.  The magnetization of the alternator is limited by the permanent magnets and/or the saturation of its own core.  The magnetization of the transformer's core is a very good model of the magnetization of the rotating machine driving it.  Slow the alternator down and the voltage drops in proportion.  If you're not saturating the transformer running the alternator unloaded at one speed, you won't saturate it at any lower speed, either.

It's very close to "if you don't saturate it at one speed you won't saturate it at ANY speed".  But you need a (very small) overdesign current margin on the transformer side to be sure of handling frequencies higher than nameplate.  This is because the winding resistance produces an inefficiency in the "clone the magnetization from the alternator's core to the transformer's" effect that is higher at lower frequencies.  It's not a lot (until you're almost stopped).  But if you're right at the edge of saturating the transformer at one frequency you might just manage it at a somewhat higher frequency.