Hello everyone,

I am designing a three-phase EMI filter on the AC side of a 25 kW FM3 three-phase inverter (CRD25DA12N-FMC).

I am using a proper EMI test setup with LISNs and have already implemented a first passive EMI filter. However, even with relatively large filter components, I am unable to meet the Class B conducted EMI limits.

The main issue appears to be very high common-mode noise. I've tried increasing the common-mode choke and Y-capacitance, but the improvement is still not sufficient.

Has anyone worked with this inverter before or successfully passed Class B limits with it? or any other EMC test ? I would appreciate any insights regarding effective filter topologies, grounding/shielding practices, or known common-mode noise challenges with this platform.

Thanks in advance!