Power supplies for partial discharge testing of power capacitors

Power capacitors are important components in modern power systems. Power supplies that permit the detection of partial discharges in this equipment class as a diagnostic test are investigated. Tunable air-cored coils for achieving resonant conditions at power frequency are considered, but rejected in this research program because of size and cost. Very low frequency testing has been investigated by previous researchers, primarily for machine testing, is seen as a viable alternative, subject to the demonstration of suitable equipment, both to generate suitable V.L.F. voltages and to facilitate partial discharge measurement. An approach is presented relying upon an originally developed charge transfer procedure, that satisfies both requirements concurrently.