Acoustical method for partial discharge detection in high power capacitors

One of the most important aspects to be verified in the field is the presence of Partial Discharges (PD) inside the capacitors. A Partial Discharge activity in capacitors generates the emission of current pulses, which can be detected by electrical sensors or circuits, and acoustical waves, which can be detected by an acoustic sensor placed on the external surface of the capacitors. Electrical PD measurements, while possible in well controlled laboratory conditions, can not be practical on site. The main task of this paper is to verify the efficiency of the alternative acoustical measurements, which may be more easily applied in the field