How to determine the input and output of the dc-dc converter connected to the battery in EV?

Hello firendsI want to simulate an EV in which it battery is connected to the dc-link through a dc dc converter. I want to know that how can I determine the nominal input and output power of the converter. My battery has 500 volts and my electric motor in the vehicle is 60 kw and 400 volts AC.

Do I need to design power converter element by element according to mathemathical equations, for example, a boost converter.could your please guide me?