Comparison of RC Detector and HFCT for PD measurement in liquid insulation

Partial Discharge (PD) measurement is a very effective method in monitoring and diagnosing the condition of insulation of a high voltage equipment. There are many methods in measuring PD in liquid insulation, two of them are by making use of PD Detector and High Frequency Current Transformer (HFCT). In this paper the system scheme and the technique of measuring PD using the two method will be presented. The case that become the focus of the research is PD activity of mineral oil under lightning impulse stress. The waveform of lightning impulse voltage is set according to the IEC standard. The results from both PD measuring method on samples receiving different impulse ageing will be compared.