挤塑高压直流电缆绝缘中空间电荷问题研究进展

Research Progress in Space Charge Problems in Extruded HVDC Cable Insulations

挤塑高压直流电缆是柔性直流输电的核心装备和构建直流电网的物理基础。绝缘材料中的空间电荷问题是制约挤塑高压直流电缆发展的关键技术难题,也是电气绝缘领域研究的热点。电热耦合场下电导率、电场、空间电荷的时空演化及关联影响机理的研究是解决空间电荷问题的理论基础。重点从空间电荷形成与空间电荷抑制两个方面探讨和分析了高压直流电缆绝缘中空间电荷的形成过程、空间电荷与电热耦合场的关联关系、绝缘及屏蔽料改性方法和原理、空间电荷抑制机理。最后,展望了高压直流电缆绝缘中空间电荷问题的未来研究方向,并指出电热耦合场作用下空间电荷长期时空演化过程对直流电缆绝缘老化的影响评估及老化机理研究、绝缘材料特性参数匹配调控对高压直流电缆的发展和长期可靠运行具有重要意义。

Extruded high voltage direct current (HVDC) cable is the core equipment for a flexible HVDC transmission and a physical basis for the construction of direct current (DC) power grids. The space charge problem in insulating material is a key technical problem that restricts the development of extruded HVDC cable, and it is also a hot research point in the field of electrical insulation. The study of the temporal and spatial evolution and the related mechanism of electric conductivity, electric field and space charge under the electro-thermal coupling field is the theoretical basis for solving the space charge problem. Consequently, from two aspects of space charge formation and space charge suppression, we discuss and analyze the space charge formation process, the relation between the space charge and the electro-thermal coupling field, the method and principle of the insulation and shielding material modification and space charge suppression mechanism in the HVDC cable insulation. Finally, we make a prospect to the future research tends of space charge in HVDC cable insulation, and point out that impact assessment and aging mechanism research of the long-term space-time evolution of space charge under electro-thermal coupling field on insulation aging of DC cable and matching control of insulating material characteristic parameters are of great significance to the development and long-term reliable operation of HVDC cables.