Re:What Needs to Happen Before Electric Cars Take Over the W...
by pilom on Tuesday December 19, 2017 @04:15PM
(#15964349)
Wouldn't there be an additional stepping at the transformer for level 1 and 2 chargers to go from AC distribution grid at 480V AC to 110V/220V where the level 3 superchargers can plug directly into the 480V AC mains without a transformer?
Re:What Needs to Happen Before Electric Cars Take Over the W...
by schiffern on Tuesday December 19, 2017 @04:45PM
(#15964634)
Yes, that's a great point. https://forums.tesla.com/forum/forums/updated-how-it-works-s...
For anyone that's confused, it's because now we're really getting into the weeds of how the grid works. :) It's only fair to look back and compare from the same point in the grid, in order to be an apples to apples comparison. Really we should look at the whole electricity supply chain.
Level 1 & 2 charging: high voltage AC transmission line -> local substation converts to 480V AC -> distribution lines (poles or buried) -> pole-mounted or buried transformer converts to 110/220V AC -> household wiring -> cable -> onboard charger converts to 400V DC -> battery
Level 3 charging: high voltage AC transmission line -> on-site transformer converts to 480V AC -> offboard charger converts to 400V DC -> cable -> battery
> the charger delivers exactly what the car needs
You're both right. A Level 3 charger does deliver the right DC voltage the car needs, and it does so using power electronics that convert regular old grid AC into DC.
Level 1 & Level 2 charging: AC grid -> cable -> onboard charger converts to 400V DC -> battery
Level 3 charging: AC grid -> offboard charger converts to 400V DC -> cable -> battery
Same number of steps, same conversion efficiency. Tesla even goes a step further and uses the same hardware, building out the (low volume) Superchargers "simply" by ganging together a dozen (high volume) on-board charger modules and stacking them inside a weatherized outdoor cabinet. This commonality maximizes their economies of scale.