Tesla HGV completes a 500 mile drive fully laden

[Oldgreybeard]

Thanks for the info on immersion cooling for HV transformer stuff etc.
My surprise now is that those are stationary installations, and are using oil-based coolant.

This seems to be a water (glycol?) based coolant, and is in a flexible cable that humans will abuse. They must be very confident of the quality of the cables/insulators/seals?

I'm pretty sure Supercharger cables have been liquid cooled (using glycol) for many years now. Same is true for all the high current greater than around 100kW) rapid chargers around. Much of the noise from them when charging is the heat pump in the base that cools the cable (Superchargers have that cable cooling unit in the power cabinet, rather than the kiosk, I believe). Same goes for batteries. Tesla run glycol through thin, flat tubes wrapped around the cells, others use cooled plates with glycol running on one or both side of the cells, one new replacement Leaf pack immerses the cells in liquid coolant (to overcome the issue the Leaf has with battery cooling when rapid charging): https://evsenhanced.com/aftermarket-battery/

[dan_b]

Yes they have -which is one of the reasons why the V3 cable is so thin relative to a similarly powerful non-Tesla CCS2 set-up. But that's not been via immersion cooling - see the picture I posted before? So a completely different engineering challenge?

[Oldgreybeard]

Yes they have -which is one of the reasons why the V3 cable is so thin relative to a similarly powerful non-Tesla CCS2 set-up. But that's not been via immersion cooling - see the picture I posted before? So a completely different engineering challenge?

Not really much difference, just a question of where you choose to fit the insulation and how robust it needs to be. You can double insulate cables (as we do for all household cables) or you can have a single insulated cable plus an insulated cooling fluid pipe. Upping the insulation integrity of the conductors and doing away with the insulation around the coolant is just a slight engineering change, really.

Years ago I worked in a building where all the comms cables coming in were encased in pressurised pipes, not for cooling, but for a combination of security, tamper detection and shielding. No big deal, as long as the pipes maintained a steady pressure there was a fair degree of confidence that no one had tried tamper with the cables (wire taps etc), plus the additional screening meant that crosstalk was very low, again useful in terms of security.

For what it's worth, pure water is a lousy conductor of electricity (0.05 µS/cm), glycol is slightly worse as an insulator 0.3 µS/cm. Oils tend to be near perfect insulators, as do most plastics used in cable construction.