LM -
Give us some context. I don't expect to help, VSD system design is not even close to any of my areas of expertise. I'm hoping to learn something.
I am associated with active front end, 8000hp drives. There is testing ongoing that has installed temporary, small, series line reactors, and has changed the front-end capacitance. The drives had to be retuned for the change in front-end reactances. Other than that the drives seemed to run fine.
So, I'm thinking you may have an area of study or references that will be of interest. I'm interested in having a better understanding of the design/physics issues.
ice