Comparison of acoustic and electrical pulses produced by partial discharges in transformer oil

摘要

The detection of partial discharges in insulating systems is usually accomplished by the utilization of either electrical or acoustical monitoring techniques. Electrical techniques (RIV Apparent Charge, etc.) detect high frequency perturbations in the exciting power supply caused by partial discharges (PD's) in the insulation. Acoustic emission (AE) techniques on the hand monitor the mechanical stress waves which propagate in dielectric materials as a consequence of partial discharges. It can therefore be appreciated that the two approaches monitor different mechanisms caused by the same basic phenomena (PD's). It was therefore decided to compare the two signals in both the time and frequency domains.