What limits rate of SuperCharging?

[Cottonwood]

I seriously doubt there are 3 "sub-chargers" in each module. It's likely just 2 additional diodes in the front end (3 phase full wave bridge) before PFC.

The THD limits on the current waveforms and the very high power factor for the AC->DC conversion imply a design that is much more sophisticated than a diode bridge on the input. The Current THD and power factor limits that Europe imposes require very close to a resistive load or its simulation. To meet those requirements, my guess is that there are three sub modules as FlasherZ suggests, and that each submodule has a sophisticated voltage/current converter that simulates the draw of a resistive load.

 

[Ingineer]

Okay, it's not as simple as just 2 diodes, but you don't have to build 3 separate submodules. A Vienna-Topolgy front end will suffice.

View attachment 84612

 

[mgboyes]

The THD limits on the current waveforms and the very high power factor for the AC->DC conversion imply a design that is much more sophisticated than a diode bridge on the input. The Current THD and power factor limits that Europe imposes require very close to a resistive load or its simulation. To meet those requirements, my guess is that there are three sub modules as FlasherZ suggests, and that each submodule has a sophisticated voltage/current converter that simulates the draw of a resistive load.

Interesting chat.

I'd always assumed (based on the behaviour of the car) that there are 3 sub-chargers, and have had this confirmed in conversation with TM staff, but of course they may not be privy to the technical details.

What is certain is that
* no part of the charging relies on there being a 120 degree phase relationship between L1/2/3 - if you put single phase power down multiple phases the car happily charges from it
* there is a hard 16A limit on the current that can be fed into each phase (originally 32A single phase charging on cars with only one charger was implemented by the EU UMC being hotwired to route single phase power down all 3 of the phase pins, and these days the relay module that sits between the Type 2 socket and the chargers has been updated so it can do this phase-bridging internally when needed)
* failures where one of the three phases stops working seem to be relatively commonplace.

I guess there are various implementations that would lead to the behaviours described above. Not my area of expertise!