聚丙烯高压直流电缆绝缘研究进展与展望

Research Progress and Perspective of Polypropylene-based Insulation for HVDC Cables

聚丙烯(Polypropylene,PP)绝缘材料具有绝缘性能优良、无需交联、可熔融再利用等优点,是环保型高压直流电缆绝缘的重要发展方向。聚丙烯基绝缘材料存在电气和力学性能难以协同调控的矛盾,是国产高压直流电缆聚丙烯绝缘所面临的主要瓶颈问题。为此从聚丙烯绝缘聚集态结构角度出发,介绍了聚丙烯绝缘聚集态结构及其表征方法,综述了共混与共聚、成核剂添加、结晶温度控制三种调控手段在调控聚丙烯聚集态结构及宏观性能方面的研究进展,论述了不同调控方法对高压直流电缆聚丙烯绝缘电气与力学性能的作用机理。分析表明,β成核剂可抑制聚丙烯绝缘中空间电荷的注入与积聚,提高击穿场强,同时显著提升其抗冲击性能;适当的结晶温度可提升聚丙烯结晶度,控制球晶尺寸,协同提升绝缘电气与力学性能。最后从高压直流电缆的实际运行工况出发,分析并展望了聚丙烯绝缘材料的应用前景与发展方向。

Polypropylene(PP)insulation material has the advantages of excellent insulation performance,no cross-linking and melting reuse,which is an important development direction of environment-friendly HVDC cable insulation.The contradiction between electrical and mechanical properties of polypropylene based insulation materials is difficult to coordinate control,which is the main bottleneck of domestic high voltage DC cable polypropylene insulation.From the aggregate structure of polypropylene insulation,the aggregate structure of polypropylene insulation and its characterization methods are introduced,with a brief summary of the research progress of blending and copolymerization,nucleating agent addition and crystallization temperature control in regulating the aggregate structure and macro properties of polypropylene,and the influence of different control methods on the electrical and mechanical properties of polypropylene insulation for HVDC cables are discussed.The results show thatβnucleating agent can inhibit the injection and accumulation of space charge in polypropylene insulation,improve the breakdown field strength,and significantly improve its impact resistance.Appropriate crystallization temperature can improve the crystallinity of polypropylene,control the spherulite size,and improve the electrical and mechanical properties of insulation.Finally,based on the actual operation condition of HVDC cable,the improvement method and application prospect of aggregate state control of polypropylene insulation material are analyzed and prospected.