Fast E.V. Charging.

Well - if you charge with 3 phase, there is no need to even give it a neutral for load carrying, the 3ph. load is then obliged to be in balance.

Also, unless there is a lot more standardisation of motor voltages, battery chemistry and cell-stack build up,  for now at least the vehicle itself has to have the charger on board configured to be specific to it's batteries, so there is little point in having too much extra electronics on the forecourt, apart from some interlocking so contacts are dead and to tell the vehicle not to be too greedy if local supply capacity is limited. This is after all already how the domestic charge points work, for exactly the same reasons.

The only problem is that somewhere between 60A phase and 100A plus, the whole plug/socket and flexible cable thing  starts to get very tricky very quickly. In showland we'd stay at 230/400 and switch to running singles at that sort of power level,until we needed another genet, but that is not really a quick and safe approach for a lorry to be hooked up and un-hooked rapidly by unskilled persons, hence the experiments with 1000v DC.


3 phase also rectifies nicely (on a 6 diode bridge the un-smoothed DC has a 4.5% ripple factor ) so mains frequency smoothing before an SMPS  can be quite light.




edit PS - a link to some blurb about those high voltage silicon carbide transistors
https://www.wolfspeed.com/downloads/dl/file/id/860/product/0/simplifying_power_conversion_with_medium_voltage_sic_mosfets.pdf  

scary current density mind you in the new ones

For comparison, now more or less run of the mill these days 1700V 72A
https://www.wolfspeed.com/power/products/sic-mosfets/c2m0045170p

Well - if you charge with 3 phase, there is no need to even give it a neutral for load carrying, the 3ph. load is then obliged to be in balance.

Also, unless there is a lot more standardisation of motor voltages, battery chemistry and cell-stack build up,  for now at least the vehicle itself has to have the charger on board configured to be specific to it's batteries, so there is little point in having too much extra electronics on the forecourt, apart from some interlocking so contacts are dead and to tell the vehicle not to be too greedy if local supply capacity is limited. This is after all already how the domestic charge points work, for exactly the same reasons.

The only problem is that somewhere between 60A phase and 100A plus, the whole plug/socket and flexible cable thing  starts to get very tricky very quickly. In showland we'd stay at 230/400 and switch to running singles at that sort of power level,until we needed another genet, but that is not really a quick and safe approach for a lorry to be hooked up and un-hooked rapidly by unskilled persons, hence the experiments with 1000v DC.


3 phase also rectifies nicely (on a 6 diode bridge the un-smoothed DC has a 4.5% ripple factor ) so mains frequency smoothing before an SMPS  can be quite light.




edit PS - a link to some blurb about those high voltage silicon carbide transistors
https://www.wolfspeed.com/downloads/dl/file/id/860/product/0/simplifying_power_conversion_with_medium_voltage_sic_mosfets.pdf  

scary current density mind you in the new ones

For comparison, now more or less run of the mill these days 1700V 72A
https://www.wolfspeed.com/power/products/sic-mosfets/c2m0045170p