The potential of using eco-friendly thermoplastic polypropylene (PP)-based insulation for high voltage direct current (HVDC) cable has been widely investigated but much less work on the PP-based semiconducting screen (SC). Considering a long service life (>30 years) under high temperature and high electrical stress is required for typical HVDC cables, and investigations on the effect of antioxidant (AO) concentration and thermal oxidative stability, mechanical, and electrical properties of PP-based SCs have been conducted. It has been demonstrated that an appropriate combination and amounts of AOs are critical for achieving high thermal stability and maintaining the mechanical properties of SC after ageing in a harsh environment (150°C, with Cu, in air, 7 days). Although higher amounts of space charges have been observed in SC/PP/SC samples with higher AO concentrations, the impact on space charge behaviours is less after ageing, suggesting that ageing (or operating at high temperature) leads to microstructure evolution in SC and can potentially mitigate space accumulation in PP-based insulating materials.

中文翻译：

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加速热老化对高压直流电缆用聚丙烯半导体屏蔽性能的影响——抗氧化剂的影响

使用环保型热塑性聚丙烯 (PP) 绝缘材料用于高压直流 (HVDC) 电缆的潜力已得到广泛研究，但对基于 PP 的半导体屏蔽 (SC) 的研究却少之又少。考虑到典型高压直流电缆在高温和高电应力下需要较长的使用寿命（>30年），并研究了抗氧化剂（AO）浓度和热氧化稳定性、聚丙烯基SC的机械和电气性能的影响已进行。事实证明，适当的 AO 组合和用量对于实现 SC 的高热稳定性和在恶劣环境（150°C，含铜，空气中，7 天）老化后保持机械性能至关重要。尽管在 AO 浓度较高的 SC/PP/SC 样品中观察到较高量的空间电荷，但老化后对空间电荷行为的影响较小，这表明老化（或在高温下操作）会导致 SC 中的微观结构演化，并且可以可能减轻基于 PP 的绝缘材料的空间积累。