A series of poly(ethylene terephthalate) (PET) films with different additives were subjected to identical electrical stresses to investigate their partial discharge (PD) degradation behaviour. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to study the surface chemistry changes of the degraded samples. The filled samples showed markedly better PD resistance and lifetime compared to the unfilled PET. A filler ‘pile-up’ effect has been directly observed for the filled samples and is proposed as the mechanism underlying the enhanced stability. PD-induced breakdown results also revealed that TiO₂ filled PET has a superior PD lifetime to BaSO₄ filled PET, which could be attributed to both the higher permittivity of the TiO₂ fillers and the voids that are created around the BaSO₄ particles during the film orientation process. Further improvements to PD resistance and PD lifetime, through the reduction of surface oxidation, are observed for a BaSO₄-filled sample additionally containing the UV stabilizer Tinuvin 1577.

一系列具有不同添加剂的聚对苯二甲酸乙二醇酯（PET）薄膜受到相同的电应力，以研究其局部放电（PD）降解行为。傅里叶变换红外光谱（FTIR），扫描电子显微镜（SEM）和X射线光电子能谱（XPS）用于研究降解样品的表面化学变化。与未填充的PET相比，填充的样品显示出显着更好的PD耐受性和使用寿命。对于填充的样品，已经直接观察到了填料的“堆积”效应，并被认为是增强稳定性的基础。PD引起的击穿结果还表明，填充TiO _2的PET具有比BaSO ₄更长的PD寿命填充的PET，这既可以归因于TiO ₂填充剂的较高介电常数，也可以归因于薄膜取向过程中在BaSO ₄颗粒周围形成的空隙。通过减少表面氧化可以进一步观察到PD耐受性和PD寿命的改善，这是通过填充BaSO _4的样品额外包含UV稳定剂Tinuvin 1577引起的。