Experience with Resonant Grounding in a Large 34.5-kY System

Since early 1946, when grounding of the 34.5-kV system of the Wisconsin Michigan Power Company was established through installation of a Peterson coil, very complete records have been maintained with regard to all ground faults on the system. The results of an analysis of these records, covering 19 years of operation with resonant grounding, are contained in the paper. Resonant neutral grounding was selected because it promised the elimination of many voltage dips which, otherwise, would be the causes of interruptions in the manufacturing processes of many paper mills in the area of the utility company since paper mill drives are extremely sensitive to speed variations brought about by sudden voltage dips. Experiences with this kind of system grounding have been most satisfactory.