Moreover, it is worthy to note that most existing PD detection
methods have been applied only within laboratory-based
experimental settings [20]. Autonomous PD pattern recognition,
having the potential to displace and support expert-based
PD diagnostics through automatic diagnostics, is key to future
development of on-line PD distributed monitoring [14], [13].
Consequently, in this section we review the current on-line PD
monitoring techniques of power system components in order
to understand recent developments and trends. [23] provides
general comparison about on-line and off-line PD monitoring,
the summary of this analysis can be seen in Figure 1.