I'm working with a system that has 3 2MVA transformers for which there is an existing estimate of the peak load and the power factor. The xfmrs appear to have a greater thermal capability than the rating (up to ~120% per xfrmr), and we're adding a shunt cap-bank ~1MVA to improve the voltage regulation.
I'm trying to nail down what the MVA rating of the cap bank is going to be and whether to increase or lower the rating to decrease the load to the thermal capability of the xfmrs. However, I don't know how to estimate the quantity of voltage regulation given the thermal capability. I'm assuming this is due to I^2 R losses in the transformers.
Much appreciated.
Best Answer
Turns out I was making this too difficult. ~120% thermal capability of the transformers means they can each have 120% of their KVA rating.
Hence the bank will need about 647 KVAR of additional caps.