Polypropylene (PP)/elastomer blend is a promising candidate for high voltage direct current (HVDC) cable insulation. Space charge accumulation in HVDC cable is an important factor for safe and stable operation of HVDC transmission system. In this paper, propylene based elastomer (PBE) and ethylene-octene copolymer elastomer (EOC) were added into PP to prepare the blend sample. Space charge accumulation behavior was estimated by the pulsed electro-acoustic (PEA) method, and the influence of compatibility between the PP and the elastomer on the charge accumulation behavior was investigated. Polarized optical microscope (POM), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and dynamic mechanical analysis (DMA) measurements were performed to assist the understanding of the compatibility dependent space charge accumulation behavior. The obtained results showed that the amount of space charge in the PP/PBE blend was lower than that in the PP/EOC blend. As compared with the PP/EOC blend, higher crystallinity with integrated crystal morphology and β-crystal form were observed in the PP/PBE blend for better compatibility between PP and PBE. It is suggested that deeper trap centers are formed in the PP/PBE blend than in the PP/EOC blend due to the compatibility, by which the charge injection is restricted.

中文翻译：

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HVDC 电缆绝缘聚丙烯/弹性体共混物的兼容性相关空间电荷累积行为


聚丙烯 (PP)/弹性体混合物是高压直流 (HVDC) 电缆绝缘材料的有前途的候选材料。高压直流电缆中的空间电荷积累是高压直流输电系统安全稳定运行的重要因素。本文将丙烯基弹性体(PBE)和乙烯-辛烯共聚物弹性体(EOC)添加到PP中制备共混样品。采用脉冲电声（PEA）方法评估了空间电荷积累行为，并研究了PP与弹性体之间的相容性对电荷积累行为的影响。进行偏光显微镜 (POM)、差示扫描量热法 (DSC)、X 射线衍射 (XRD) 和动态机械分析 (DMA) 测量，以帮助了解兼容性相关的空间电荷积累行为。结果表明，PP/PBE 共混物中的空间电荷量低于 PP/EOC 共混物中的空间电荷量。与 PP/EOC 共混物相比，PP/PBE 共混物具有更高的结晶度，具有完整的晶体形态和 β 晶型，从而使 PP 和 PBE 之间具有更好的相容性。研究表明，由于相容性，PP/PBE 共混物中比 PP/EOC 共混物中形成了更深的陷阱中心，从而限制了电荷注入。