内部缺陷对高压直流电缆电场分布影响的有限元分析

高压直流电缆实际运行过程中可能会有缺陷出现，使得电缆内部电场分布发生畸变，加速绝缘材料的老化。运用有限元分析的方法，对直流电缆电场分布进行了二维和三维建模和仿真分析，研究了不同电缆绝缘层温差、缺陷位置及尺寸情况下电缆中单个球形缺陷对周围绝缘材料的影响，得到了较为通用的直流电缆缺陷对电场畸变的计算公式。研究发现三维仿真更加适合对缺陷进行研究，稳态下缺陷对电场的加强决定于材料的电导率，且缺陷对绝缘材料的影响是局部的.

Analysis on Influence of Internal Defect on Electric Field Distortion of HVDC Cable with Finite Element Method

Defects may probably appear during the lifetime of HVDC cable, and possibly distort the electric field distribution of HVDC cable and further accelerates insulation degradation.Two-dimension and three-dimension finite element analysis (FEA) are applied to study the influence of single spherical defect on the surrounding dielectric under differernt conditions including different temperature difference level across insulation, different defect location and size. A general equation for describing field distortion by spherical defect in HVDC cable is given in the paper, and it is concluded that three-dimension analysis is advantageous in researching the defect distortion, electric conductivity is the key factor in determining the electric field enhancement by defect and the influence of defect on surrounding insulation material is limited in a small region.