退役110kV XLPE电缆绝缘材料聚集态结构分析

Analysis on Aggregation Structure of Retired 110 kV XLPE Cables Insulation

通过对不同运行年限退役的110 k V XLPE电缆绝缘切片试样进行击穿和力学性能实验,结果显示运行10年以上的退役电缆绝缘试样的击穿强度和断裂伸长率与新电缆相比没有明显变化。为寻找更能表征老化状态的参数,尝试通过傅里叶红外光谱测试、凝胶含量测试、差示扫描量热法、动态热机械分析评价绝缘状态。结果表明:羰基指数、交联度、结晶度、动态力学损耗等参数能从聚集态结构方面很好地表征绝缘老化状态,且具有较好的一致性。

The breakdown strength and mechanical properties of retired XLPE insulation serving for differ- ent years were studied, and the results showed that the cables operated for more than 10 years had no obvious difference on the breakdown strength and elongation at break from new cable. In order to search parameters which can characterize the ageing state more effectively, Fourier infrared spectrum, gel content test, differential scanning calorimetry, and dynamic mechanical analysis were used to evaluate the insula- tion state. The results indicate that the carbonyl index, degree of crosslinking, degree of crystallinity, and dynamic mechanical loss can characterize the ageing state of XLPE insulation from aggregation structure, and these parameters have good consisitency.