Talk-Polywell.org

MSimon wrote:The supply needs to be able to go from 5KV to 100KV. That is the regulation problem I'm talking about.

I guess you didn't read the part where I mentioned using saturatable reactors in the primarys of the transformer ?


That easily solves the 5kv to 100 kv problem for coarse voltage regulation.

I'll enhance my schematic tomorrow.


David

ravingdave wrote:

MSimon wrote:The supply needs to be able to go from 5KV to 100KV. That is the regulation problem I'm talking about.

I guess you didn't read the part where I mentioned using saturatable reactors in the primarys of the transformer ?


That easily solves the 5kv to 100 kv problem for coarse voltage regulation.

I'll enhance my schematic tomorrow.


David

We don't like Mag Amps in the power industry because they generate a lot of harmonics. And reducing line harmonics is a big deal these days. For a 100 KW power supply I'd just eat the extra costs (from the power Co). At 5 MW the harmonics are a little harder to eliminate.

I really like the Digitec stuff because it is a standard buck converter - thus low losses. And if you need more power you just add another phase (or ten) to the power supply. At $.25 a watt the cost is not too bad for all the wonderful goodness you get. And the best thing about it for now? COTS!

But hey - a 40 MW DC supply for $50K or even $100K It could be well worth it. BTW are you sure it is 40MW and not 40KW? The Cu in the transformer alone has to be worth more than the shipping.

Jeeze - mag amps. I haven't had serious contact with them since my Navy days. Talk about solid state. They were a fad for a while in switching regulator circles. Think MagAmps at 100 KHz. You don't see that sort of thing advertised much in the power magazines these days. Every one wants to go solid state. IGBT is where the big power action is these days. I saw one rated at 6,500 volts and 600 AMPs. Now of course you have to derate them for actual use - 4,000 volts and 400 Amps is about right. About 30 of those and you are up to being able to control about 4 MW. Of course keeping the semiconductors cool is a trick. Twenty five of them fed DC and you have 100,000 volts at 400 Amps at your disposal. There is your 40 MW.

MSimon wrote: We don't like Mag Amps in the power industry because they generate a lot of harmonics. And reducing line harmonics is a big deal these days. For a 100 KW power supply I'd just eat the extra costs (from the power Co). At 5 MW the harmonics are a little harder to eliminate.

I really like the Digitec stuff because it is a standard buck converter - thus low losses. And if you need more power you just add another phase (or ten) to the power supply. At $.25 a watt the cost is not too bad for all the wonderful goodness you get. And the best thing about it for now? COTS!

But hey - a 40 MW DC supply for $50K or even $100K It could be well worth it. BTW are you sure it is 40MW and not 40KW? The Cu in the transformer alone has to be worth more than the shipping.
.

Well the specs say this...

Manufacturer: Westinghouse
Serial Number = RBR64991
Manufacturing date: 1965
Voltage: 67 / 12.47 kV
MVA Rating: 30 / 40 MVA
Impedance: 6%
Phases = 3
Core and Coil = 68,880 lbs
Case = 34,000 lbs
Oil Gallons = 3780
Oil Weight = 28350 lbs
PCB Report = 16 ppm

I think a smaller transformer could be found eventually.

MSimon wrote: Jeeze - mag amps. I haven't had serious contact with them since my Navy days. Talk about solid state. They were a fad for a while in switching regulator circles. Think MagAmps at 100 KHz. You don't see that sort of thing advertised much in the power magazines these days. Every one wants to go solid state. IGBT is where the big power action is these days. I saw one rated at 6,500 volts and 600 AMPs. Now of course you have to derate them for actual use - 4,000 volts and 400 Amps is about right. About 30 of those and you are up to being able to control about 4 MW. Of course keeping the semiconductors cool is a trick. Twenty five of them fed DC and you have 100,000 volts at 400 Amps at your disposal. There is your 40 MW.

I think the real deal is going to work out like you say. I'm just postulating a poor boy Mad Scientist version of a Test reactor that can prove the concept works or doesn't.


In any case, this is sorta what I was talking about.




The Load carrying tube will probably have to be made, and may have to be a bank of several tubes, and even then might have to be shunted with a very large resistor. The whole thing requires a MicroController with AD and DA conversion etc. If the thing turns out to be non linear ( a very likely prospect ) it's easier to just write code to deal with it than it is to work out the headaches in hardware.



There are several design issues with this approach, but I believe they can be resolved with enough number crunching.


David

How would we do it today? Forget the MagAmps. Just switch the 120KV DC at 5 KHz in a buck converter. At 4 KV per that is 30 power modules in series. If you could build the modules for $10,000 each that is $300,000 to control 20 to 40 MW.

MSimon wrote:
And reducing line harmonics is a big deal these days.

20 yrs ago in the Golf Course bizz, our electric motors for pumping water for the sprinklers started getting high tech, everyone one was stressing the need for clean filtered power for the new equipment.

Roger wrote:

MSimon wrote:
And reducing line harmonics is a big deal these days.

20 yrs ago in the Golf Course bizz, our electric motors for pumping water for the sprinklers started getting high tech, everyone one was stressing the need for clean filtered power for the new equipment.

Eventually we will get good enough with motor control (even in the small sizes) that adding a motor to the line will reduce harmonics.

MSimon wrote:How would we do it today? Forget the MagAmps. Just switch the 120KV DC at 5 KHz in a buck converter. At 4 KV per that is 30 power modules in series. If you could build the modules for $10,000 each that is $300,000 to control 20 to 40 MW.

I actually thought of something similar using big tubes. A set of several tubes working sequentially as a charge pump (thereby reducing the load duty cycle on each tube) at a high frequency. (aren't microprocessors wonderful! )

However it is to be done, the thesis of this thread is that it can be done more cheaply, and I think that we have established this, at least in the case of the power supply.

I have always thought that the real expense (for an amatuer) is finding or building a suitable vacum vessel and pumping apparatus. From my understanding, this thing requires a pretty hard vacuum, and from my reading of various threads, this is not easy to do cheap.

I understand that vacuum vessels have to be "outgassed" using large heaters all over the inside surface. (I wonder if the heaters would work just as well on the outside ? )

I also thought making feed throughs that could withstand the voltages, pressure differentials, and temperature differentials might be a little tough, but i've got some ideas on how to do it.


David

Just started looking around for info on Vacuum Chambers. Thought this was a pretty picture.




The company that produced this advertises they can make one 10' in diameter and 6'6" in length. Not big enough for a polywell, but interesting none the less.


David

Sounds like Aluminum is the way to go.

Why change my vacuum system to aluminum?
“ Use Aluminum!” when you are:



1) having trouble with long pump-downs,

2) experiencing to much H 2 , H 2 O contamination,

3) experiencing surface desorption of gases in a high energy photon environment,

4) experiencing a & b particle damage on your substrate,

5) in need of a light weight vacuum system,

6) having Fe, Cr, C, CO, CO 2 contamination in a plasma environment,

7) in need of a electrically isolating environment,

in need of a large process tool with a small foot print,

9) need a low magnetic environment,

10) experiencing synchrotron or process generated Bremsstrahlung radiation,

http://atlasuhv.com/reference_info/alum ... esFAQs.php



David

I am not saying you can build a working power plant for $ 1 million. I am saying you can build something that will ignite a fusion reaction sufficient to prove the concept.

Well, you might be able to build something like WB-7 and get measurable fusion from pulses, but of course we already have WB-7.

What needs to be proven is scaling, and I don't see any way to get 5T magnetic fields cheaply, even for a pulse.

TallDave wrote: What needs to be proven is scaling, and I don't see any way to get 5T magnetic fields cheaply, even for a pulse.

Use university slav... unh student... labor

TallDave wrote:

I am not saying you can build a working power plant for $ 1 million. I am saying you can build something that will ignite a fusion reaction sufficient to prove the concept.

Well, you might be able to build something like WB-7 and get measurable fusion from pulses, but of course we already have WB-7.

What needs to be proven is scaling, and I don't see any way to get 5T magnetic fields cheaply, even for a pulse.

A long time ago I posted an idea of using lead coated copper tubing wound into coils and cooled with liquid helium. (At the time I looked it up, you could get liquid helium for under $1/gallon.) Large quantities of liquid helium are available as they are used to cool the magnents in MRI machines, etc.

Lead becomes superconducting at +8K ( if I remeber correctly) and so with a large supply of liquid helium (Maybe $10,000-$20,000 worth) and a cryostat, it ought to be possible to charge up a superconducting coil to 5T. (If that's the required spec. )

Of course if you GET a >than breakeven Pulse, it would probably blow the supeconductor immediatly, and possibly fry the coils.

I guess blowing the coils is a possible indicator of success !

So if this idea won't work, tell me why.


David

ravingdave wrote:

TallDave wrote:

I am not saying you can build a working power plant for $ 1 million. I am saying you can build something that will ignite a fusion reaction sufficient to prove the concept.

Well, you might be able to build something like WB-7 and get measurable fusion from pulses, but of course we already have WB-7.

What needs to be proven is scaling, and I don't see any way to get 5T magnetic fields cheaply, even for a pulse.

A long time ago I posted an idea of using lead coated copper tubing wound into coils and cooled with liquid helium. (At the time I looked it up, you could get liquid helium for under $1/gallon.) Large quantities of liquid helium are available as they are used to cool the magnents in MRI machines, etc.

Lead becomes superconducting at +8K ( if I remeber correctly) and so with a large supply of liquid helium (Maybe $10,000-$20,000 worth) and a cryostat, it ought to be possible to charge up a superconducting coil to 5T. (If that's the required spec. )

Of course if you GET a >than breakeven Pulse, it would probably blow the supeconductor immediatly, and possibly fry the coils.

I guess blowing the coils is a possible indicator of success ! :)

So if this idea won't work, tell me why.


David

Got a chart of Jc vs Magnetic Field?

MSimon wrote:

ravingdave wrote:
A long time ago I posted an idea of using lead coated copper tubing wound into coils and cooled with liquid helium. (At the time I looked it up, you could get liquid helium for under $1/gallon.) Large quantities of liquid helium are available as they are used to cool the magnents in MRI machines, etc.

Lead becomes superconducting at +8K ( if I remeber correctly) and so with a large supply of liquid helium (Maybe $10,000-$20,000 worth) and a cryostat, it ought to be possible to charge up a superconducting coil to 5T. (If that's the required spec. )

Of course if you GET a >than breakeven Pulse, it would probably blow the supeconductor immediatly, and possibly fry the coils.

I guess blowing the coils is a possible indicator of success !

So if this idea won't work, tell me why.


David

Got a chart of Jc vs Magnetic Field?

Nope. Do you have one, or a link ?

David

Never mind. Lead won't work. It can't support a strong enough field. That means the coils would have to be made out of one of the designer superconductor materials with their associated higher costs.

That's still not a deal killer. Either MSimon or Tom Ligon posted some sources awhile back for relatively inexpensive superconducting wire that might do the job.


David