In the EV EHV Charger: Level 1&2 diagram it highlights isolation between the AC system and the DC battery pack.
Is this isolation provided by the power transformer really nessisary? And if so, why? What benefit does the transformer provide?
The diagram specifies a 400+ V battery pack. Is the transformer something other than a 1:1 ratio?
If the battery pack had a maximum voltage of less than 100 V would the transformer still be nessisary?