低压电缆绝缘老化对材料力学性能作用

The Effect of Insulation Aging on Material Mechanical Properties of Low-voltage Cables

在变电站领域中,为更好地研究低压电缆聚氯乙烯绝缘老化对其材料力学性能的影响程度,文章在加速老化处理低压电缆样本的基础上,对聚氯乙烯绝缘老化特征、力学性能特征进行全面分析。分别制备4组低压电缆样本,其中,不对A组样本进行老化处理,将其设置为对照组,在剩下的3组样本上,分别进行加速老化试验。当加速老化试验结束后,分别运用扫描电子显微镜、红外光谱仪、卤素水分仪、力学拉伸仪,全面测试聚氯乙烯微观形貌和聚氯乙烯化学结构、聚氯乙烯含水量、聚氯乙烯绝缘力学性能参数。测试结果表明,经过加速老化后的3组样本,同时出现电力学老化现象、电化学老化现象,造成聚氯乙烯表现出越来越低的绝缘力学性能。随着老化时间不断延长,样本弹性模量下降速率呈现出先降低后上升的变化趋势,所以,在样本不同老化阶段中,电力学、电化学特点直接影响聚氯乙烯绝缘力学性能的变化趋势。

In the field of substations,in order to better study the impact of PVC insulation aging on the mechanical properties of low-voltage cables,this article comprehensively analyzes the aging characteristics and mechanical properties of PVC insulation based on accelerated aging treatment of low-voltage cable samples.Prepare 4 sets of low-voltage cable samples separately,with Group A samples not subjected to aging treatment and set as the control group.Perform accelerated aging tests on the remaining 3 sets of samples.After the accelerated aging test is completed,scanning electron microscopy,infrared spectroscopy,halogen moisture analyzer,and mechanical tensile tester are used to comprehensively test the microstructure,chemical structure,moisture content,and mechanical properties of polyvinyl chloride insulation.The test results showed that after accelerated aging,the three groups of samples exhibited both electrical aging and electrochemical aging,resulting in lower insulation mechanical properties of polyvinyl chloride.As the aging time continues to extend,the rate of decrease in the elastic modulus of the sample shows a trend of first decreasing and then increasing.Therefore,in different aging stages of the sample,the electrical and electrochemical characteristics directly affect the trend of changes in the mechanical properties of PVC insulation.