Phase resolved analysis of PD measurements for typical discharge models of oil-immersed insulation

The reliability and lifetime of equipment and components as applied for high voltage power transmission and distribution system are always effectively influenced by the behavior of its insulation system. And the Partial Discharge (PD) measurement is a sensitive method to assess the quality and condition of the oil-immersed insulation system, such as the oil-insulation transformer. In other words, the insulation condition of an oil-immersed transformer is related to its discharge characteristic. According to the actual PD types existed in an oil-immersed transformer, several typical discharge models are designed in this paper. The PD characteristics of these models are measured both in air and transformer oil, and the related phase-resolved distributions are obtained simultaneously. These works will be helpful to the pattern recognition of the PD in a power transformer.