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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.
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?
what is the state of the art w.r.t. the 12VDC->110VAC/60Hz 1kW inverters?
An awesome way to smuggle a wifi sniffer - or something naughtier - into the googleplex!
...more like an awesome way for Google to grab a profitable patent in exchange for the prize money.
Seriously - if you can pop those kind of specifications, you can make a hell of a lot more than a million bucks from the patent alone.
Quo usque tandem abutere, Nimbus, patientia nostra?
The US does run 220(ish)V 60Hz for heavy loads. Really big appliances and light industrial.
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.
A chromebook would run off of DC power, so the inclusion of an inverter would be a waste of technology. Why take the DC from solar cells and invert it to line-voltage AC just to rectify it again to the 12Volts and lower that a chromebook would use?
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.
Except they are not claiming any of the IP, just a 100 hr license to use it for the test. Also, why they claim they will not open the box up.
Your ad here. Ask me how!
If you've got a patent for it, you just let everyone use it for 15 years then sue them all for billions in damages.
Isn't that how patents work?
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.
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
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.
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.
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.
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.
Which gives a power density of 0.78 watts per cubic inch. The Google challenge calls for a minimum power density of 50 watts per cubic inch.
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
Quebec is a ridiculous backwater corrupt banana republic with a monstrous, bloated bureaucracy that not even Google can deal with.
Mostly random stuff.
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.
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.
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.
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?
I looked at http://www.amsc.com/pdf/PM3000...
The spec sheet claims "power density of up to 130 W/in. (7.9 W/cm)"
But I also see:
Dimensions 38.2in*19.8in*18.7in = 14100 in^3
AC Power 690V * 750A = 520000 VA
Density: 37 VA/in^3 (also an upper bound on W/in^3)
What is the justification for the 130 W/in^3 claim?