Advances in Measuring Partial Discharge in Insulating Liquids

The IEC 61294 Technical Report, published in 1993, describes a simple test procedure to measure the PD Inception Voltage (PDIV) in insulating liquids and doesn't cover any other items related to the PD patterns and their evolution at higher voltages. This simplified approach should be considered superseded when taking into account the several studies published in the last decades concerning the PD detection in different dielectric liquids using PD patterns and Ultra Wide Band measuring systems with the aim to find a correlation between PD phenomena, breakdown event and liquid characteristics. The use of these advanced PD patterns and Ultra Wide Band detectors may also contribute to discriminate PD in insulating liquids and PD in regular voids in oil-paper insulations.