Partial Discharge Analyzer (PDA) is used to determine if there is or what is the level of partial discharge activities in the insulation of a power transformer. It could also be used for other electrical equipment like generators and motors to determine if there are partial discharges in its insulation. Some PDA can also determine or pin-point the location of partial discharges inside the transformer. Partial discharges in the insulation, if left untreated, causes further damage in the insulation, which could lead to catastrophic damage of the power transformer. Transformer damage is very costly.
Partial Discharge Analyzer (PDA) can be ultrasonic (sound) or UHF (electromagnetic) based.
PDA is, thus, helpful in monitoring the health of the transformer. However, there is some doubt on the necessity of using an online PDA for the power transformer. Online Partial Discharge Analyzer (PDA) monitors the transformer continuously, in real time, to immediately determine the presence of partial discharge.
Online PDA is helpful but it seemed to be unnecessary because any immediate presence of partial discharges inside the transformer can already be detected by an online Dissolve Gas Analyzer (DGA), which has, actually, many uses aside from detecting partial discharges. DGA can detect partial discharges if there is presence of Acetylene and Hydrogen gases in the transformer oil. It can also detect overheating of oil, hotspot, and degradation of insulating paper.
If the presence of Acetylene and Hydrogen gases was determined using online DGA, that would only be the proper time to test the transformer if there is indeed a presence of partial discharges using Partial Discharge Analyser but not necessarily online, portable DGA would suffice.
Partial Discharge Analyzer, thus, doest have to be online. Just a portable one is enough to serve as a back-up for the Dissolve Gas Analyzer. This would put savings for your transformer operations and maintenance expenses.