Space charge accumulation is the main factor in accelerating the degradation of polymeric insulation in high-voltage direct current (HVDC) cables. It is essential for the development of HVDC cables to suppress the space charge in the insulating layer. In this paper, an approach is presented to decrease carrier injection from the inner semiconductive layer to the insulating layer, using a magnetic semiconductive compound. The semiconductive shielding compound was prepared by adding strontium ferrite to a carbon black/ethylene-vinyl acetate/low-density polyethylene (LDPE) matrix. The addition of strontium ferrite led to an increase in the residual magnetic induction of the semiconductor shielding layer. Unmagnetized and magnetized semiconductive compounds were used as electrodes to test the injection of carriers into the LDPE insulation layer. When SrFe12O19 had been added, the charge injected into the LDPE by the magnetized semiconductive layer was less than with an unmagnetized semiconductive layer. When the content of SrFe12O19 was 5 wt. %, 10 wt. %, 30 wt. %, and 50 wt. % in the semiconductive compound, the charge in the LDPE was reduced by 4.2%, 8.1%, 12.5%, and 27.1%, respectively.

中文翻译：

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磁性复合电极对低密度聚乙烯空间电荷注入和积累的影响

空间电荷积累是加速高压直流 (HVDC) 电缆中聚合物绝缘降解的主要因素。抑制绝缘层中的空间电荷对于高压直流电缆的发展至关重要。在本文中，提出了一种使用磁性半导体化合物减少从内部半导体层到绝缘层的载流子注入的方法。通过将锶铁氧体添加到炭黑/乙烯-醋酸乙烯酯/低密度聚乙烯 (LDPE) 基质中来制备半导体屏蔽化合物。锶铁氧体的添加导致半导体屏蔽层的剩磁感应增加。未磁化和磁化的半导体化合物用作电极来测试载流子注入 LDPE 绝缘层。添加 SrFe12O19 后，磁化半导体层注入 LDPE 的电荷少于未磁化半导体层的电荷。当 SrFe12O19 的含量为 5 wt. ％，10 重量。％，30 重量。％，和 50 重量。在半导体化合物中，LDPE 中的电荷分别减少了 4.2%、8.1%、12.5% 和 27.1%。