Overvoltages Caused by DSG Operation: Synchronous and Induction Generators

This paper demonstrates that abnormally high and possibly damaging overvoltages can occur on isolated feeders connected to a Distribution System Generator (DSG). The mechanisms for producing the overvoltages are based on ferroresonance phenomena and are not extremely sensitive to types of generators, types or connections of transformers, location of capacitors or other equipment parameters. The overvoltage depends on the establishment of a harmonic resonant circuit utilizing transformer saturation characteristics, the existence of power factor correcting capacitors on the feeder and a tion.source of energy sufficient to maintain transformer saturation