加速老化下油纸绝缘气隙缺陷模型放电的特征演化与参量表征研究

Cavity induced discharge has been acknowledged one of the most common form of partial discharge(PD)in transformers. Figuring out the PD evolutional behavior of oil-paper insulation cavity defect under various aging conditions would contribute to the quantitative evaluation of risk in transformers. To investigate the developing characteristics of the cavity induced discharge and offer the parameters charactering aging degree and discharge risk of the insulation,four oil-paper insulation samples with different aging degrees were prepared by accelerating thermally aging procedures, and a PD detection platform of oil-paper insulation was established to obtain the PRPD pattern. Conclusions can be drawn that: PD inception voltage and breakdown voltage show a decreasing trend with aging condition; the Weibull scale parameter α and average discharge power P change remarkably; and the time interval(Δt) between two consecutive discharges shows a tight correlation with the discharging stage and aging condition of the insulation, indicating that it is applicable to quantitative risk assessment of the insulation in the presence of PD.