On-line partial discharge detection on transformers

Different diagnostic techniques are currently available for on-line insulation condition assessment of power transformers. Amongst these techniques a relatively new technique for detecting partial discharges (PD) in the Ultra High Frequency range of the spectrum is also introduced. The UHF technique has been recently presented in the field of transformer diagnostics, and although it is under development it shows great potential for on-line detection, recognition and location of PD activity. Comparison of the available techniques showed that Dissolved Gas Analysis and Partial Discharge measurements are complementary. Based on this, a suggestion will be made for a condition assessment program combining the available diagnostics with PD measurements.