A Practical Approach for the Calibration of Partial Discharges Measurements at Field

Partial discharges (PD) measurements at field are a useful tool for predictive maintenance of high voltage equipment for preventing in service failures. This paper shows a practical procedure for the calibration of partial discharges measurements at field, when high frequency current transformers (HFCT) installed in equipments' grounding conductors were used for the PD detection. The calibration procedure can help estimating magnitude and potential risk of PD activity present in the equipment, and also, can turn measurements made in different equipments comparable between each other, or measurements performed in the same equipment in different time frames comparable between each other, even if performed with diverse measuring HFCT.