General > General Technical Chat
EV-based road transportation is not viable
TimFox:
Again in the US, the Federal Government as part of its infrastructure program will require rationalization of payments at charging stations, specifically to accept normal credit/debit cards and not require a mobile-phone app.
(From same newspaper article about negotiations with Tesla about opening their charging stations to other makes of EV.)
Marco:
European market is big enough not to have to worry about that.
TimFox:
--- Quote from: Marco on February 16, 2023, 11:20:42 pm ---
--- Quote from: tggzzz on February 16, 2023, 09:54:46 pm ---A charger must have the ability to read a payment device
--- End quote ---
At the point you're filling the entire country with chargers, it's far cheaper to just give people without a mobile phone one with a free sim, which can only be used to access a payment portal.
Regardless of any other aspect of the design, it will massively simplify the charger.
--- Quote ---Numbers please, e.g. voltages, currents, components, x/y/z dimensions.
--- End quote ---
Papers for existing prototype systems you can look up yourself.
Lets say a 4 plate system with plates 10x10cm. Then with 2 mm of 100x relative permittivity insulator the series capacitance would be around 2 nF. At 100 kHz that's an impedance of 5k. Lets assume simple impedance matched resistive load to get some ballpark figure, 1800V RMS required for 3 kW. Ballpark doable with a high permittivity insulator, without it not so much.
--- End quote ---
1800 V rms across 2 mm of air is about (1250 V peak)/mm, which is OK for dry air (3 kV/mm).
However, if you have 2 mm of high-k ceramic and a thin air gap, the E field in the air gap is multiplied by the dielectric constant of the ceramic (maybe 10?).
This a usual problem in high-voltage engineering--avoiding air gaps and bubbles with dielectric insulators.
tom66:
Problem is converting AC electricity to 100kHz then transmitting it across a gap then rectifying it back into DC to charge the battery will add losses. Presumably you could modulate the generating side to track the battery voltage, but if not, include a DC-DC converter in that with further losses. Also you will need bidirectional comms.
So the convenience your solution offers needs to be >> than a simple type2 cable, for which the connector and cable hardware costs under 100 euros in bulk.
Marco:
It's not for convenience, it's to be able to put the charging connector on the curb and take up no room.
I'm not saying it's _the_ solution, I'm just saying in high density older European towns every solution to curb side charging has a ton of problems. The simple solution of just putting a charging pole every 6 meters will not work, not because of material cost but simply because it will make the street completely unusable. Every not simple solution is pretty far out there.
PS. all the pop up charger test runs don't seem to have UI either, so presumably all app based. But even popup chargers will take up a ton of extra space on the curb, unless there's so many of them they can pop up in between cars.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version