What type of multi-level input filter is used in The 3-Phase 30 kW Vienna PFC rectifier?

[JonasConstant]

Hello all,

I have been checking this 30 kW Vienna PFC rectifier reference design and didn't understand why all of these filters are used for this kind of application, I mean half of the board is inductors and capacitors for the filters.

Can someone explain what type of filters are used in this reference design? and why are used in this application in particular? Will any 30kW type of application require such filtering? and what is the process of designing similar filters?

Thank you,