论文部分内容阅读
为深入研究不同脉冲频率下机械应力对高温硫化硅橡胶中电树枝生长特性的影响，该文对硅橡胶中电树枝的生长情况进行观测，分析电树枝生长对脉冲频率的依赖关系及不同拉伸形变和压缩形变对电树枝生长特性的影响规律和影响机理。结果表明：拉伸形变的增大提高了电树枝的起始概率，促进了电树枝的生长，扩大了累积损伤破坏面积，加速了电树枝对绝缘材料的破坏；压缩形变的增大降低了电树枝的起始概率，延缓了电树枝的生长，减小了累积损伤破坏面积，抑制了电树枝对绝缘材料的破坏；不同机械应力下脉冲频率的增大都提高了电树枝的起始概率，加速了电树枝的生长。研究同时发现，电场强度较低时，加压后电树枝不会立即引发，电树枝的起始可以分为明显的三个阶段；电场强度较高时，加压后迅速出现单树枝通道。该文建立了机械应力与电树枝老化之间的关系，为电缆附件应力控制分析提供了参考依据。“,”To investigate the effects of mechanical stress on treeing growth characteristics in HTV silicone rubber under different pulse frequencies, electrical tree growth process was observed. The dependence of electrical tree characteristics on pulse frequency was analyzed. Moreover, the electrical tree propagation characteristics and mechanism were researched under different tensile strain and compressive strain. The results indicate that the tree initiation probability becomes higher with accelerating the propagation of the electrical tree when the tensile strain is increased. Furthermore, the accumulated damage of the treeing area is also enlarged as the tensile strain increasing, which aggravates the destruction for the insulation materials. However, when the compressive strain is increased, the tree initiation probability becomes lower with retarding the propagation of the electrical tree. The accumulated damage of the treeing area is also reduced as the compressive strain increasing, indicating the destruction for the insulation materials is restrained. The tree initiation probability is improved and the propagation of electrical tree is accelerated as pulse frequencies increasing regardless of the mechanical stress. When the sample is stressed under lower electric field, the tree channels are not instantly initiated and the tree initiation process can be distinctly divided into three stages; while the single tree channel is immediately generated after the higher electric field is applied on the samples. In the paper, the relationship between the electrical tree and mechanical stress is established, which provides a reference for the stress control analysis of the cable accessories.