Capacitor matched size

Hi !

I have found a large 3000W transformer (primary 220V secondary 13kV)
but I have a problem with finding matched value of tank capacitor.
Every design program needs to input secondary voltage and current to
count the size of capacitor. The transformer is not current limited and
I have to use a resitive ballast. My problem is that I can't get 3000W
from my power line. I can take only about 2200W so the transformer is
not working
with full power. I dont know if I schould use 230mA-3000W,13kV or
169mA-2200W,13kV to count the value of the capacitor?

Thanks for all answers

Kamil Kompa