Dependence of UHF Partial Discharge Detection and Source Positioning in Power Transformers on Different Input Pulse Frequency Ranges

Abstract Transformer insulation is gradually weakened by partial discharges (PDs), which might eventually result in complete transformer failure if left unchecked. Different types of sources can produce PD signals, which can be detected throughout a wide frequency range. Preventive maintenance of power transformers depends on the characteristics of received ultra-high frequency (UHF) PD signals at sensors and the positioning of their source. This study compares and analyses the effects of different input pulse frequency ranges (IPFRs), the transformer tank, the active components of the transformer, dispositions of UHF sensors relative to PD source, the total efficiency of the used antenna and superimposed reflected waves on received signals’ waveforms, times of arrivals (TOAs) and magnitudes of their first peaks (FPs), time differences of appearances and magnitude ratios between the extreme amplitudes and FPs in their first wave packets, as well as variations in their amplitude spectra.