Abstract
An acoustic emission method (AE) is widespread and often applied for
partial discharge (PD) diagnostics, mainly due to its ease of application
as well as noninvasiveness and relatively high sensitivity. This paper
presents comparative analysis of AE signals measurement results archived
under laboratory conditions as well as on-site actual AE signals generated
by inside PDs in electrical power transformer during its normal service.
Three different PD model sources are applied for laboratory research:
point to point, multipoint to plate and surface type. A typical measuring
set up commonly used for on-site transformer PD diagnostics is provided
for the laboratory tasks: piezoelectric joint transducer, preamplifier,
amplifier and measuring PC interface. During the on-site research there
are three measuring tracks applied simultaneously. Time domain,
time-frequency domain and statistical tools are used for registered AE
signals analysis. A number of descriptors are proposed as a result of the
analysis. In the paper, at- tempt of AE signals descriptors, archived
under laboratory condition application possibilities for on-site PD
diagnostics of power transformers during normal service is made.
Go to article