Harmonic Problems in Plant

Harmonic filters are commonly used...

http://ewh.ieee.org/conf/tdc/Eliminating_harmonic_problems_APQ_T_D.pdf

We can assume your power supply to the VFDs is directly from the generators(?). The harmonic content will most likely cause extra heating in the iron laminations of your equipment, it should appear in your generator, or in any step-down transformers between the generators and the VFDs. The filters will fix the problem, however I would select them from the VFD supplier recommendations, who have first hand knowledge of the characteristic of the equipment. Your kindly generator supplier could have recommended 1900kW filters to protect their generators, if they weren't looking out for your best interests.

If you have transformers, and if your transformers are generously sized, they may be able to deliver the required power without damage and without a filter.

I have first hand knowledge of the destruction of a 2000kVA load center transformer, in the late 1990s, where the load was almost 100% (PWM) inverter, and even though just above half load, the windings were cooked to failure.