Crosslinked polyethylene (XLPE) insulation is widely used in power cables because of its excellent properties. Due to the remoteness of end users, the energy is generally transported over long distances. These cables cross various areas being sometimes exposed to different environmental stresses that affect their performance and increase their degradation. While most published literatures are limited to laboratory scales, this article uniquely deals with a multiscale analysis of a 30 months naturally weathered XLPE samples in two harsh environments. The first site is a marine environment with high humidity level, sea salt content in the air, seasonal variation of temperature, and concomitant radiation doses. The second one is a desert environment characterized by extremely high temperatures, which reached 50 °C during summer, coupled with thermal cycling and large solar radiation doses with UV rays of high energy wavelengths. Modifications in the XLPE insulation characteristics due to weathering were studied using different experimental techniques. The testing matrices included dielectric and mechanical characterization, scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and differential scanning calorimetry (DSC) measurements on fresh and weathered XLPE insulation samples. It is found that the degradation rate was faster in the arid desert climate compared with the coastal one. Furthermore, correlation mechanisms between the obtained results are discussed in order to better understand the weathering degradations.

中文翻译：

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两种极端环境下自然风化高压 XLPE 电缆绝缘的多尺度分析


交联聚乙烯（XLPE）绝缘因其优异的性能而广泛应用于电力电缆中。由于最终用户地处偏远，能源通常需要长距离输送。这些电缆跨越不同的区域，有时会暴露在不同的环境压力下，从而影响其性能并加剧其退化。虽然大多数已发表的文献仅限于实验室规模，但本文独特地讨论了在两种恶劣环境下 30 个月自然风化的 XLPE 样品的多尺度分析。第一个地点是海洋环境，湿度高、空气中海盐含量高、温度季节性变化以及伴随的辐射剂量。第二个是沙漠环境，其特点是极高的气温，夏季可达50°C，加上热循环和高能量波长紫外线的大量太阳辐射剂量。使用不同的实验技术研究了由于风化而导致的 XLPE 绝缘特性的变化。测试矩阵包括对新鲜和风化的 XLPE 绝缘样品进行介电和机械表征、扫描电子显微镜 (SEM)、衰减全反射傅里叶变换红外 (ATR-FTIR) 光谱以及差示扫描量热法 (DSC) 测量。研究发现，与沿海气候相比，干旱沙漠气候下的降解速度更快。此外，讨论了所获得的结果之间的相关机制，以便更好地理解风化退化。