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Google Offers a Million Bucks For a Better Inverter
An anonymous reader writes: With the Little Box Challenge, Google (and IEEE, and a few other sponsors like Cree and Rohm) is offering a $1 million prize to the team which can "design and build a kW-scale power inverter with the highest power density (at least 50 Watts per cubic inch)." Going from cooler-sized to tablet sized, they say, would make a whole lot of things better, and the prize is reserved for the best performing entrant. "Our testing philosophy is to not look inside the box. You provide us with a box that has 5 wires coming out of it: two DC inputs, two AC outputs and grounding connection and we only monitor what goes into and comes out of those wires, along with the temperature of the outside of your box, over the course of 100 hours of testing. The inverter will be operating in an islanded more—that is, not tied or synced to an external grid. The loads will be dynamically changing throughout the course of the testing, similar to what you may expect to see in a residential setting." The application must be filled out in English, but any serious applicants can sign up "regardless of approach suggested or team background." Registration runs through September.
I just use a good old 74LS06, doesn't need a kilowatt.
An awesome way to smuggle a wifi sniffer - or something naughtier - into the googleplex!
Word is, there was no spec for lifecycle so the devices met the contract as stated, and the government couldn't return the devices.
So I'd recommend to Google: At some point, look in the box.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
Must be able to handle up to 2 kVA loads
Must achieve a power density of equal to or greater than 50 W/in3
Must be able to handle loads with power factors from 0.7–1, leading and lagging in an islanded mode
Must be in a rectangular metal enclosure of no more than 40 in3
Will be taking in 450 V DC power in series with a 10 resistor
Must output 240 V, 60 Hz AC single phase power
Must have a total harmonic distortion + noise on both voltage and current of 5%
Must have an input ripple current of 20%
Must have an input ripple voltage of 3%
Must have a DC-AC efficiency of greater than 95%
Must maintain a temperature of no more than 60C during operation everywhere on the outside of the device that can be touched.
Must conform to Electromagnetic Compliance standards as set out in FCC Part 15 B
Can not use any external source of cooling (e.g. water) other than air
Does not require galvanic isolation
If you're running devices that need a kW you're already at a reasonable size for your device, and you can build a lot of cheap, larger inverters for what it would cost to build this small one.
You could also probably build the powered devices to run off 12V for less than what this inverter would cost.
Is what is keeping AC power from the hinterlands this is intended to serve really the size of the inverter, or is it more likely the cost?
Everything that can be invented has been invented!
I have a great inverter design I just need to add 5% of harmonic distortion and noise on both voltage and current.
what is the state of the art w.r.t. the 12VDC->110VAC/60Hz 1kW inverters?
An inverter converts DC power to AC power. The most obvious use is for solar power. For rooftop solar arrays, you want efficiency, but you don't care much about density. In many cases, you have a small inverter under each panel, and size isn't an issue. But if you could get a few percent more AC out for a given DC in, that would matter.
On the other hand, if you want a solar-powered Chromebook, the inverter could be a deal-breaker on the weight. I'm guessing it's applications like that that have inspired this challenge. They want a Chromebook that you leave out in the sun to recharge. Or something similar.
Or maybe they have some other crazy idea I haven't thought of yet.
Why on earth would they call for 240V 60Hz? (almost) Nobody uses that. It's either 110V 60Hz (North America and colonies) or 240V 50Hz (UK, Europe and similar). And inverting to single phase is a lot harder than to 3-phase (and a lot less efficient).
If you can pull this off, I'd guess it would be worth a lot more than $1M.
The US does run 220(ish)V 60Hz for heavy loads. Really big appliances and light industrial.
planning to move as much as possible to 12V, so as to do away with converting up, then down again.
Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.
In the USA/Canada typical residential setups use two conductors at 120V to ground, but the conductors are out-of-phase so there is 240V between them.
There really isn't any such thing as 110V or 230V in the USA/Canada, both of which you'll sometimes see referenced. 208V does exist, it's the difference between two legs of a 3-phase setup where each leg is at 120V to ground.
because you are a selfless person and to make the world a better place?
Exactly. Only an idiot would give away such a thing for only $1 million. Sounds like it would be something that could be patented and the technology licensed for quite a lot of money.
It's "Islanded-mode", not "islanded-more".
Except it requires more wires. 220/240V split phase requires 3 wires.
3-phase generally requires 4.
And unless you really need 3-phase, split phase is easier to deal with - with 3-phase you need to monitor all three phases to ensure they are working (failure of one phase is a common failure mode that requires immediate shutdown of the other two phases lest any dangerous currents develop).
Though, one thing I don't get about this challenge - they're using they want 2kVA output, but then demanding 50W/in^3 with a max size of 40in^3, meaning you have to provide 2000W.
And 2000W can mean providing way more than 2000VA. (The reason we use VA for inverters instead of watts is VA captures virtual power. 2000VA requires just as much power handling components (transformers, transistors, etc) as supplying 2000W at a 1.0PF (i.e., all resistive). Even if you have a really bad power factor and your real power draw is only 1000W - the hardware has to be able to instanteously supply the current and voltage for 2000W at periods in the cycle. The virtual power is virtual, because it's "given back" during another part of the cycle, but that means all the equipment has to handle it.
A lot of electric companies will have a power factor surcharge because of it - if your power factor can't be corrected to within limits, they charge more because they have to install bigger equipment.
The only real saving grace is that the input voltage is 450VDC, so you're really just doing a buck converter.
Stupid objection the first: "This is worth a lot more than a million dollars."
Response:
Stupid objection the second: (something stupid about 12 volts)
Response:
I know that slashdotters don't RTFA, but seriously, all of you jaw-jacking about 12 volts or about how a million is chump change are a bunch of Useless McToolbags. STFU already.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
240V would be used for kitchen stove/range, clothes drier, electrical heat (air and water). Some commercial cappucino machines use 240V.
A home shop could very well use 240V for a welder and any number of power tools...lathe, jointer, planer, tablesaw, mortiser, wide belt sander, dust collector, shaper, etc.
Only an idiot would comment without reading the article.
Then again, I didn't actually read the article either. I read the comment slightly above yours that showed that the submissions are not given to Google; the inventor retains the IP rights. But it sure makes it easy to troll!
If that is the case, stay as far as you can away from Google (and Apple, Samsung and Microsoft).
Whoah, google spent $7,300,000,000 on data centers last year and doesn't even know what voltage they run on? Time to sell my stock!
Google built its business by developing its own infrastructure, starting with custom servers in pizza boxes and lego. What crazy company runs out and develops its own filesystem for its own internal use? Google did.
3 Phase doesn't require the return neutral, unless your load is very unbalanced. So they both require 3 wires to transmit.
And yes, it does appear to be a simple buck converter. Though you could probably use a Z-Source inverter too.
Apparently on RTF, it says that the inventor retains IP rights.
IN that case.. never mind. :)
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
My "inverter" contains a plutonium RTG.
The base price for an off-the-shelf 2000 Watt Complete Grid-Tied DIY AC Solar Kit is $4600.
The kit includes eight 8 x 8 x 5 inch Enphase inverters weighing 6 lbs each. Retailing for about $150 each. All offers for Enphase M215 Micro-Inverter
It would seem that inverters loose some "energy" in the conversion process
What do you mean by energy that isn't tight. I've heard you Republicans use that term, but I've never met any of your kind that can explain what you mean.
I have a truly marvelous design for a kilowatt-scale power inverter which unfortunately this comment box is too narrow to contain...
CLI paste? paste.pr0.tips!
Can I use kittens in my design?
Thank-you for pointing out my spelling mistake.
Give a hand, not a hand-out.
The 240V 60Hz is so that it can handle both North American and UK voltage levels. If you look at the technical specifications document, you'll see that there are 2 different grounding configurations that the contestants may specify. In both configurations the inverter output is fed into an isolation transformer. One specification has the input of the isolation transformer center tapped and grounded which makes the AC outputs from the inverter swing +/- 120V from ground like you would expect in the USA. The other configuration doesn't have a center tapped transformer, but one leg of the input is grounded making one of the AC outputs swing +/- 240 V in referenced to ground and the other output is tied to ground. I suspect the 60Hz specification is due to the way transformers work. A transformer designed to operate at 50Hz using minimal materials will operate fine at 60Hz. However a transformer designed to operate at 60Hz using minimal materials will saturate magnetically at 50Hz causing it to overheat and eventually fail.
The start up I work for practically has this product to a T. The only design spec's we don't match are the 40 in^3 (we are slightly larger, but smaller than a briefcase) and the output voltage (we do 480V 3-phase rather than 240 single). Otherwise (power density, harmonics, ability to handle loads, etc.) we've got covered. This isn't a ploy, but if anyone is interested in what we do (10 person team, solar inverter manufacturer in silicon valley) check out www.HiQSolar.com
As an actual product available right now, there's this 250 watt inverter. from Enphase, intended to work with one solar panel. That's 54 cubic inches, or 12W/cubic inch. Google wants 50W/cubic inch, so Google is asking for 4x the power density. This one happens to be configured for 48VDC input, but that's not hard to change. It exceeds the efficiency limit set by Google.
Enphase sells those little inverters for a one-inverter-per-solar-panel system, where power is combined on the AC side. The inverter, at 171 mm x 173 mm x 30 mm, is a lot smaller than the panel it sits behind. Making it smaller won't have any effect on system size.
One big difference: Enphase offers a 25 year warranty on that unit. Google only wants to run for 100 hours. They'll probably get something that will pass their tests but wouldn't last a year in a real solar installation.
Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.
3 phase makes electric motors more efficient, and that's it. Technically, you could have as many phases as you could imagine having... each making the motor a tad more efficient. But they are not "smoother" and don't improve transmission.
'Phase' is often considered by some to be some magic property of electricity that somehow makes it better... it's not at all. It's a purely mechanical feature that's revolves around generators and motors. 2 phase means there are 2 electro magnets on the motor. 1 to the north, 1 to the south. When the North magnet is near and electro magnet that magnet goes to +120v and by contrast the south is at -120v. When you have 3 phase it increases efficiency by having an extra electro magnet. So now north is at +120v, but there are now 2 electro magnets to the south that are both 1/3rd of the way from that south pole and therefor at -60v each... It's a purely mechanical distinction and has no affect on anything other than the mechanical operation of motors.
Oh yea, and you can get 3 phase in the US. I got it, and most welding/milling shops have it as well.
3 phase requires the return by code. Technically however, you are correct. That's just for safety and I often question if it makes any sense myself.
220v is mostly in single or duplex residential settings. Otherwise, it's often 208v (convieniantly available by connecting to two phases of 3 phase power).
Yeah, but if you add all three phases at any point in time, you get 1, which means constant torque. Isn't that the case?
I know nothing about electricity
So you figured you'd post your suggestion on /. instead of attempting even the most cursory self-directed research. Gotcha. Laziness for the win.
Is it just that we're so used to designing electronics etc. to use AC, or are there other benefits?
Its easier to transmit long distances, at high voltages.
Its trivial to step up and down to different voltage levels via transformers. The equivalent in DC is not simple.
Mechanical AC generators are simpler and cheaper to build and maintain. And nearly all electicity is generated from mechanical sources (turbines).
Hydro and tidal are water driven turbines. Coal, wood, biomass (methane), natural gas, nuclear, even geothermal electricity are all "steam driving turbine" eleciticity generators, wind is an air driven turbine.
That leaves solar, which IS DC. Worldwide, like 0.2% of electricy is from solar.
Batteries too, are DC, but are charged nearly exclusively from AC sources.
then why not put effort into designing AC sources of electricity?
I guess so. I mean, only 99.8% of electricity comes from AC sources. Just imagine what they could do if they put some effort into designing some AC sources, right? :p
Actually, we generate 3 phase just like everyone else. We just don't run all three to each house. Industrial and commercial users do commonly get 3 phase.
Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.
3 phase makes electric motors more efficient, and that's it. Technically, you could have as many phases as you could imagine having... each making the motor a tad more efficient. But they are not "smoother" and don't improve transmission.
3-Phase AC produces a smoother (considerably less ripple) DC current pattern when rectified than single or split-phase AC.
The people who should have already figured this out are the people sponsoring the event. Seriously, what backyard engineer is going to have the resources to design and prototype this thing? A million bucks would be a drop in the pan for the present commercial manufacturers, little incentive to reinvent their products. I see this going nowhere.
Couldn't find the answer on the site. May be blind.
Thanks. I've learned something, and yes, this was much easier than Googling. Now I just have to Google to find out if you're blowing smoke up my kilt or not.
But, seriously....thanks!
Give a hand, not a hand-out.
Though, one thing I don't get about this challenge - they're using they want 2kVA output, but then demanding 50W/in^3 with a max size of 40in^3, meaning you have to provide 2000W.
What is it you don't get?
Requirements are >=50W/in^3 and <= 40in^3.
I would expect some of the entrants will exceed those requirements - doing more W/in^3 and/or less space.
Heh, once, in a pinch, I have made due with a "special" extension cord - with two 3 prong 110 heads spliced onto a 220 socket... All I had to do was find two outlets on different phases and I was in business ;-)
Don't worry, I cut it up when I was done.
This issue is a bit more complicated than you think.
is your name Galois?
If someone makes a battery with associated inverter that does 2kVA for 100 hours per the spec, then it still exceeds the inverter spec they wanted (since you'd need that to get the power output from the battery anyways, that's kinda the point of this challenge), and you also have a battery that holds 200-300 times the energy of the latest battery (assuming you draw no input). Google would be happy to pay you $1mil for that thing, hell you could probably get $100mil for that.
They picked a power density that is very high, and the challenge is targeted at solar for the home, there isn't really anyway you can cheat without first solving the problem.
It was posted to the google blog by Eric Raymond. The one from "Cathedral versus the Bazaar" fame? I think so... cool!
Its easier to transmit long distances, at high voltages.
For long distances, DC is easier to transmit because it only has to be designed for the RMS voltage instead of the peak voltage. This is especially important for underground cables, where you would also have to worry about much higher capacitance too. But even for above ground cables, very high voltage lines are limited by corona discharge, and DC will gain you an extra sqrt(2) roughly. AC isn't about transmission easy, it is all about transformers and mechanical systems.
since when is the UK at 60Hz? also a transformer may run hotter at 60Hz and even if it runs OK other components may not
That was a dickhead intro but very good on the rest. Quite a few of us probably learned something.
A few friends who are electrical engineering majors certainly might achieve this. After all, it was a small group of college kids who created Google, Microsoft, and Facebook. On the other hand, 10 Google employees sitting in meetings to discuss the requirements document costs over $2,000 / hour once you factor in taxes and such. A million dollars is enough to motivate some ramen-eating college kids, and small enough that it's not much more than the cost of paperwork and approvals for many projects at large companies.
They exclude people in various places from entering. https://www.littleboxchallenge... I can see why Cuba, Iran, N Korea, Syria & Sudan are listed. But why on Earth are Brazil, Italy & Quebec on the list?
3 phase requires the return by code. Technically however, you are correct. That's just for safety and I often question if it makes any sense myself.
In an industrial settings I deal with a lot of loads that are three phase L1, L2, L3 + safety ground only (shield on cable, chassis on machine). No Neutral. Even 4160V loads. Unbalanced loads are brought back through L1, L2, L3.
Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.
3 phase makes electric motors more efficient, and that's it. Technically, you could have as many phases as you could imagine having... each making the motor a tad more efficient. But they are not "smoother" and don't improve transmission.
3-Phase AC produces a smoother (considerably less ripple) DC current pattern when rectified than single or split-phase AC.
I've seen 3 phase 700V+ DC drives at over 1000kW that are very harmonic rich. Over 100% THD. Not smooth AT ALL.
AC isn't about transmission easy, it is all about transformers and mechanical systems.
I guess it would be more correct to say that AC is easier to transmit *because* of the relative simplicity of transformers at the end points.
Actually, 240V 60 Hz, is what North America uses on their transmission lines to connect businesses/homes. For most homes, they will have 240V and 200 A being brought in. But, it will then be split into 240 and 120 V. And yes, north America uses 1150-120V, not 110.
And that is why this is a CONTEST. It IS difficult. BUT, if done right, it will mean that one company will have millions of $ in sales.
They're fairly clear that they want the ability to provide both 2kVA and 2kW. Presumably that implies you only have to be able to deliver 2kW into a resistive load, and that if they present a load with power factor 0.7, you need to be able to provide it with 1400W and 2kVA.
Not enough cube. You want 9 million nanoscale exercycles powered by the souls of the damned. I dare you to open the box.
The number of conductors needed for three phase depend on if you are delta or wye connected...
In that sense, it depends on the situation then. Long distance transmission lines use HVDC because the conversion cost is fixed by the gains for using DC instead of AC scales with distance. The conversion costs continue to come down, so the systems that use this will become more and more common.
Exactly. I live in rural farm country, and I work on irrigation so everyday I drive by a hundred or more 3 phase motors used to pump water. A couple times a week I'm installing 3-phase motors and control panels. There is three phase equipment all over this country.
It's pretty pointless to hook a neutral up to a delta-wired motor, code or no :D
3-phase 4-wire feeds are used all the time for commercial power here in Canada. Either 208V or 600V depending on what is required. Single phases are circuited off for 208V/120V or 347V single-phase feeds, respectively. A neutral conductor is definitely required for this application, yes. 208V single-phase circuits don't use a neutral, since they use two of three phases as if they were single phase. Their "split neutral" would be ~60V with respect to ground.
Just about anything apartment-wise after the 80s uses split phase 240RMS/277 typical peak.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Just about any component after the transformer will work fine, frequency independent, minus things like oscillators, radio crystals, etc. resistors DGAF, caps DGAF as long as you match or are lower than its rated voltage, diodes are voltage drops and DGAF about frequency...
Do you even basic electronics?
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
But many components will be ok. It is why you can find foreign plug adapters with a built in transformer that will change the voltage but not do anything about frequency. In this case at least, a 60 Hz transformer is slightly smaller than a 50 Hz one (which is why airplanes will use 400 Hz).
Let's tether technological advancement purely to up front cost.
Are there no savings to be had from smaller inverters with higher power density? Do you have no imagination left? Too many years kowtowing to PHBs and budgets, I expect.
We're not talking about building a colony on Pluto. There are very real advantages to improving our energy infra.
The same old repetitive question:
Why?
The answer is simple...
Because we should keep trying.
A DC drive is generally variable voltage/current and switched through a scr. At full power, they would be smoother. At low power, the switching frequency will cause severe ripple. 3 phase is better for simple rectifiers and is indeed smoother.
I have determined that my sig is indeterminate.
Please Google, educate the people and use metric specifications in your projects and requirements
I was promised a flying car. Where is my flying car?
Do you even basic electronics?
Do you even basic english?
"Island Mode" for Generator Operation...
"Inland Moor" for burying your enemies...
"I Landed More" for increased Air Miles...
I assume they mean "must be able to handle input ripple current up to 20%" and "must be able to handle input ripple voltage up to 3%" because those are in the hands of the lab's 450V DC test supply powering the inverter.
In both configurations the inverter output is fed into an isolation transformer.
Which is going to be bigger and heavier than the inverter module. And have higher losses as well.
So what was the point of this contest?
Have gnu, will travel.
It seems contradictory that they're worried about power factor, and also want to force contestants to output nice clean sine waves. Best way to get a PF of 1.0 with cheap switching power supplies, is to send them a square wave... Sucks for induction motors, but works for most everything else, including motors with brushes.
And with a simple 450VDC input you could split it over multiple circuits in series, through requiring some legwork to boost it to the exact voltage, and even it out across circuits with different load-levels, but far less than running it all through a transformer.
Such a device could be extremely efficient. I wonder what their needs are, that such a device isn't sufficient.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
One million space bucks! We'll be able to pay off Pizza the Hut...
Oh wait..... It was regular bucks.... never mind then!
Thanks for the laugh dear AC
Do /you/ even basic English?
So what's the RMS Voltage of a (say) 1000 kV DC line? Are you sure you're not confusing DC with AC?
CLI paste? paste.pr0.tips!
dunno if this helps but if you can up the AC cycling frequency ...
the transformer can be smaller
plasma can rectify also.
that's all. good luck!
So what's the RMS Voltage
Well, he gets pretty amped up about Ubuntu...
If you were going to feed it into something that was just going to rectify it again and use DC, than a lot of the specs they give don't matter. However, just about anything electromechanical is potentially going to have problems. There are still lots of things around using motors, and depending on the load, running a 50 Hz motor on 60 Hz can significantly increase the current draw, and could cause problems with the start up circuit switching out too quickly.
"And unless you really need 3-phase, split phase is easier to deal with - with 3-phase you need to monitor all three phases to ensure they are working (failure of one phase is a common failure mode that requires immediate shutdown of the other two phases lest any dangerous currents develop)."
Losing a phase will not result in dangerous currents in the supply system. The most common three phase load is a motor. If you start a three phase motor and remove one of the phases the motor will continue to run on a single phase BUT it will try to draw more current to compensate for the loss of the phase. You now have overloaded windings and the motor will quickly burn itself out. You use phase protection relays on your motors to open the contactor when a phase loss is detected. So you only need to protect your motors.
A DC power supply that runs on three phase won't be affected much but the bridge rectifier can be overloaded and output ripple will increase. It will also attempt to pull more current through the remaining phase and blow a fuse or breaker. So again, its only dangerous to the load. If a 3 phase heater loses a phase, then guess what? You get less heat. That's it. Resistive heater loads can tolerate a phase loss with zero electrical problems. Your process will be affected but thats about it.
A three phase alternator does not care what the load balance on any of its phases is as long as they aren't overloaded. Same goes for a transformer. Many homes are ran off of a three phase 120/208 Y (sometimes spelled wye). Homes still get single phase 120/208 but are connected to the supply (phases A, B, C and Neutral) as follows:
A-N-B
B-N-C
C-N-A
The split is repeated for homes and they balance out the grid nicely. Splitting each of the three high voltage legs from a feeder into a neighborhood and stepping it down using center tapped 120/240 transformers makes balancing a problem. You can't interconnect any of the three separate 120/240 lines as the neutral or center taps must be grounded. Now you have 3 sets of 3 wires to deal with and you have to ensure you even distribute loads across three separate 120/240 supplies. Are you going to run 7-9 wires down a block to balance out that mess? No, of course not. So now you have individual blocks of 120/240 which may be unevenly loaded. Three phase is much easier as three houses in a row can easily balance out a 3 phase feeder. Both systems are used in residential neighborhoods (and at random might I add) but anything new is always three phase fed.
My home in Queens NY is serviced by a 120/240 center tapped 100kVA transformer that feeds only our street from corner to corner. The neutral connects to the other poles but everyone else in the surrounding area is on three phase. The poles do have 2400/4160 three phase feeders on top so getting three phase is not an issue. How we became a 120/240 island is beyond me but it might have been a leftover from old practices, never upgraded or left alone for a specific reason. Out on long island the neighborhood I lived in for a short while has 120/240 and only a single high voltage leg running along the pole. So they have to balance out the load on the feeder side.
Isn't that the main feed on virtually all residential structures in the US? Yes the outlets put out 110/120 (I've measured my house at 125) but that is only because the main feed is split off into 110/120s except for a few high draw circuits (Electric Dryer, AC). I would assume that the intent here is to allow for better solar/wind integration into homes. Current inverters are quite large, I've seen some setups that take up more space than an entire water system (softener, heater & pressure tank). Shrink all that down to something that can fit on the side of your house like a telco box and it would probably make integration far cheaper.
The RMS voltage of a 1000 kV DC line is 1000 kV...
If you tried to transmit the same power using AC, you would need ~1400 kV peak which will need more insulation distance and cause a crap ton of more corona discharge in overhead lines.
Actually where I live it's 250V split to 125V sides.
What if a team creates the solution and presents it to Google successfully, but the US federal government confiscates the device and takes the patents for itself as an item of national security importance? (This means the inventor is not even entitled to compensation!)
I am asking about this scenary, because such high power-density electric inverters already exist and they are being used in the latest generation of fighter jets (e.g. America's F-22 Raptor or Europe's Gripen NG and Eurofighter Captor). They are used in the power supply chain of onboard radars with active electronic beam-steering (AESA) antennas.
Such super-density inverters are extremely expensive, totally secret and currently require non-aquatic liquid cooling, using the plane's jet fuel as a heat transfer medium or even phase-change ammonia. (For example the Gripen NG received two new ungainly air-intake scoops to fit the extra cooling's bulky radiators.)
If a "basement-dwelling" team of geniuses invented a simple ram-air cooled equivalent, with same or better inverter performance, the "Skunk Works" guys from the "military-industrial complex" would be all over that in no time.
It seems contradictory that they're worried about power factor, and also want to force contestants to output nice clean sine waves. Best way to get a PF of 1.0 with cheap switching power supplies, is to send them a square wave...
The challenge is a challenge. The goal is clearly to produce usable power, not to need more filtering. While the requirements for this contest don't require grid-tie, that's something that can be implemented later.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
if you design it for the contest, it becomes google's property. If I designed one, patented it, and licensed it I could earn more that $1M easily.
Why ??? do you have any idea of how much heat 50W per cubic inch produces ? Tablet size is not possible with today's technology.
Heh, once, in a pinch, I have made due with a "special" extension cord - with two 3 prong 110 heads spliced onto a 220 socket... All I had to do was find two outlets on different phases and I was in business ;-)
Don't worry, I cut it up when I was done.
Ridgid and other brands sell cords that split 220 into 110. They are made to be used with their generators and work like a charm. No need to cut them up after you are done. :-)
If you could get a mechanical inverter to work for a max of 100 hrs using new electrode technologies... you should be able to make it small enough.I'm talking spin switched.
In short, My question is, electrodes are getting extremely good maximizing conduction and minimizing wear, but are they good enough to make mechanical switching a possibility?
Say funnel a MAX of say 20 amps @ 12vDC to a spin a high efficiency brushless DC motor nice and fast. The DC motor would be attached to a plate that would have a Rotating I (maybe an X?) of High tech carbon nanotube ended graphene electrodes spining in a circle. Spinning at the right frequency, it should convert the DC to square AC. Round it out, and then a computerized Vmeter + tied back to an ESC could regulate the motor's speed keeping the phase locked good n tight, minimizing fluctuations.
I'm not an EE though, I feel like there's something wrong w/ this, that the loss might be too high, or maybe that kind of electrode technology isn't there yet?
Just curious..
How much is your data worth? Back it up now.
You don't need to do more filtering. Most devices will run BETTER on square wave output than on sine wave output.
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True enough, but if I'm reading correct, OP was talking about the exact opposite - combining a pair of 110 feeds to get 220. For "normal" US household service, incoming is 220V, and any 110V circuit simply uses just one of the two legs, so you'll typically have roughly half of your outlets using each leg.
Check your house's breaker box. Most likely you DO have 240V/60Hz coming in. And with any digital inverter worth it's salt, 50Hz is just a matter of a jumper or switch.
Custom electronics and digital signage for your business: www.evcircuits.com
I think their use of the term islanded may refer to more than just the technical specifications. I bet Google wants this tech for off-shore floating data centers.
In general, this appears to mean that Google has an application that has access to a lot of DC power, and they need AC. Solar Panels, producing DC, and they need to power existing AC appliances in the house? "Island mode"? I'm curious to know what is producing so much DC power. If it's close to whatever needs the power, it never needs to be converted to AC. AC won out over DC in the early days of electricity because of DC's limited range of transmission. If the distance goes away, direct DC can come back. Appliances can switch over.
It doesn't make sense that it has anything to do with cars, because people tend not to use AC appliances in the car. I've always wanted a direct DC power supply to go from car power to directly powering a computer.
Maybe I'll start rewiring my house to also include some DC outlets. Seems like Google is up to something, here.
(As I post this, the "prove you're human" word is "ground". Interesting.)
Those are distribution lines. And only the drop to the customer carries 240V. That's converted down from about 2-4KV at the pole transformer off the distribution line.
Transmission lines are what connect distribution areas to generating plants and carry tens of thousands of volts.
Haven't these guys ever been to Harbor Freight?
It's not AC vs DC. Somewhere along the way, your input voltage won't match your output voltage, and conversion is needed. That voltage conversion is where the expensive equipment and losses come in. Adding a DC to AC step in there, adds very nominal losses to above voltage conversion step.
Since the world standardized on AC power over a century ago, it's as good of an output option as any other.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
"...and the prize is reserved for the best performing entrant."
I think the hard part in this case will be the physical design and construction to stay within the thermal constraints. Brick style power converters have power densities and efficiencies in this range but are designed to be attached to a metal surface for heat dissipation and Google's requirements do not allow for that.
Active forced air cooling would help a lot but also make long term reliability poor.
These different patterns all exist for motors. 3-phase simplifies the design and deployment of induction motors used in industry. That is all. There's not a substantial difference between the efficiency or simplicity of various AC output formats. The various phases exist for historical reasons.
Hardware is much more difficult (and requires deep experience) than software because it involves cold, hard physics. So script kiddies like Zuckerberg need not apply.
Based on your commend, I suspect someone wired out your building in 230V 3 phase, since it's "close enough" to get away with in place of 120V/240V split phase; and, lets them put in more efficient 3 phase pumps and air conditioning systems. Some residential buildings and residential neighborhoods are wired out in 3 phase but the private residences only uses 2 of the 3 phases, except for the A/C system. Usually that's done in 208V 3 phase; but, it's conceivable someone could have put in 230V transformers.