That would mean that in case you lose normal AC then you cannot extend your flaps ?
Correct. DC systems are not powerful enough to drive TE Flaps. I can confirm from my airplane wiring schematics that Xfr Bus 2 supplies AC power to the TE flap alternate drive motor.
Note that 28V DC Bus 1 is required for _controlling_ the supply of Xfr Bus 2 AC power to the TE flap drive motor and for powering the hydraulic bypass valve. However, if you lose AC Xfr Bus
1, you should still get DC Bus 1 power for flap control if the Bus Transfer Switch is in AUTO.