Exactly my point. Does a VFD care if the utility power coming in is DC?
Indeed. We have made VFI systems that use a common DC input bus.
But I think kyou miss or misunderstood my point. It isn't being proven as you suggest. It already has been.
How is it done today when a PV array is charging a battery bank?
And a charge controller.
Here's the first link I found. No doubt there are others.
http://www.solarjourneyusa.com/learn-buy-equipment.php#drawarray
Correct, which is why it will be done last.
It's exactly why it might not.
As for the receptacles I could guess anything, but chances are the end product will do its task with little if any compromise.
Nail on head. End product. It would need
all existing units to be ripped out and replaced with something much larger, more complex, and
much more expensive.
I don't know how much you've played around with DC on any significant scale. I've designed and installed systems up to 40,000Adc. Others up to a few thousand volts. Some water cooled, some force air cooled, some air natural. They were all specialist applications that really needed DC. I can promise you that DC is an entirely different beast. And I intentionally used that word.
A little salutary tale.
We did a converter for the VSOE, the Orient Express. It was a resurrection of that one made famous by Agatha Christie in "Murder on the Orient Express".As I said, A luxury train that crossed several European countries. The input had to cope with all the frequencies and voltages on the line between countries. Including 3000Vdc.
It was tested in the railway lab in Vitry on the outskirts of Paris. At 3000Vdc, a fault was simulated. At the time, we couldn't get 3000Vdc rated semiconductor fuses so we put three 3kV AC fuses in series.
Big mistake. They didn't clear the fault and ended up as a molten mass in the bottom of the enclosure.
As I said, DC is an entirely different beast and demands a different level of respect.
Nope, a single 4 watt unit will do.
Really?? For a gas compressor rated at 6,600kW? About 9,000hp.
A real world example of an opti coupler (U1) at work, typical for most computer/cell phone chargers as seen here:
http://powersupply33.com/wp-content/uploads/2011/07/60-Watt-Laptop-battery-charger.jpg
But my cell phone, monitor, laptop, printer, camera charger, Kindle, DVD player, Blackberry, and various battery operated power tools need different voltages. So you would still need different voltage converters for each.
And possibly less for DC to DC conversion. Getting more efficiency out of a kHZ transformer is nothing.
And possibly not.
Everything. Generation to utilization. HVDC projects are popping up and expanding all over the world with consumer electronics/appliances nearly all having inverters built into them.
I don't think my laptop has a built in inverter. Nor my printer, cell phone........etc.
With respect, I don't think you do.