Paralleling with Utility - Voltage rise with load


Thread Starter


I am troubleshooting a high voltage warning condition on a 2 MW unit paralleled with utility. Gen output is 480 VAC and, via transformer, stepped up to 12,470.

Voltage regulator is set for power factor regulation of 0.95. Unit is set for 1.6 MW baseload but sees an increase in voltage from 480 to 506 at set baseload. Decrease load to 1 MW and voltage drops to 499.

The local utility says there is no noticeable increase in voltage at the plant. Transformer impedance? I understand that voltage drop occurs across a loaded transformer, but if that loaded transformer is connected to utility does that "drop" in the secondary side actually equate to a rise in the primary side?