Super Charging Etiquette

[STS-134]

Up to 7 cabinets (28 stalls) can draw from a common DC bus that they all share. Except for the mega-sites that have 56 stalls (ever wonder why it's 56 rather than 64?), that pretty much covers the entire V3 site.

I'm a bit curious as to how they all draw from the same DC bus. Each vehicle will have a slightly different voltage depending on the battery SoC and the voltage you need to apply at any given time depends on the desired current and the battery voltage.

 

[Rocky_H]

I'm a bit curious as to how they all draw from the same DC bus. Each vehicle will have a slightly different voltage depending on the battery SoC and the voltage you need to apply at any given time depends on the desired current and the battery voltage.

It's not a straight line of wire pass-through all the way to the car. Four stalls are controlled and run by a charger cabinet. That sets the levels going to each of those four cars. This DC bus thing is saying that each of those cabinets can also draw in extra power from that bus, but then it will still manage it to send what is appropriate to each of its four stalls.

 

[RTPEV]

I'm a bit curious as to how they all draw from the same DC bus. Each vehicle will have a slightly different voltage depending on the battery SoC and the voltage you need to apply at any given time depends on the desired current and the battery voltage.

I think @Rocky_H's response probably said enough, but just to add a bit, each cabinet has an AC/DC converter to pull in grid power onto the common DC bus, and multiple DC/DC converters to take power off that common DC bus and output it to each pedestal. I can't recall the V3 architecture off the top of my head, but in V2 Superchargers there were 12 DC/DC converters--each one capable of supplying 12kW--in each cabinet that could be separately allocated to each of the two stalls. Which is why your power level was typically a multiple of 12kW. And, these, at least originally, were the same DC/DC converters on board the Model S, so Tesla was able to gain some manufacturing efficiency and reliability.

But back to V3, here are the internals of the V3 cabinet:

I suspect the 5 boxes on top are the AC/DC converters, and the 8 on the bottom are the DC/DC converters, each capable of 125kW, but unlike the V2 Superchargers, there would be no need for them to be separately allocable to each pedestal, so I suspect two are dedicated to each stall.

Here is a nice reference for Superchargers (and the source of the above photo): Supercharger SuperGuide – TeslaTap