电缆中聚乙烯界面微观结构对击穿强度的影响

本文选用特殊添加剂对电力电缆中半导电层以化学改性，为减薄电缆绝缘厚度，提高交联聚乙烯电缆的击穿强度，提供了有效途径。从理论上定性解释了聚乙烯的击穿强度与界面片晶取向角的关系。由微观结构分析结果表明，改性半导电层经热压后，会改变聚乙烯界面结晶取向，改善半导电层中碳粒凝聚状态。最后，由电缆模型试片的击穿强度结果予以证实：改性半导电层比普通半导电层，可使聚乙烯的１％威布尔击穿强度提高８９％。平均击穿强度提高４０％。本文结果对提高交联聚乙烯电缆质量是有意义的。

Influence of interfacial Microstructure of Polyethylene on Breakdown Strength in Power Cable

The special additives were used to modify semiconducting layer chemically so as to reduce the thickness of insulation and to increase the breakdown strength Eb of PE in XLPE cable, provied an effective way. In this paper, the relationship between the crystal orientation angle of PE interface and the Eb is explained theoretically.The results of microstructure analysis pointed out the modify semiconducting layer was able to change the crystal orientation of PE interface during thermally procesaing and size agglomeration of carbon particle in semiconducting layer was reduced by TEM observation.The results of model cable specimens proved that additives AB2 possessed the best modifying effect and it can enhance E1(1% Weibull distribution) of PE by 89% and power frequency Eb by 40%.The conclusion in this paper significant for enhancing quality of XLPE cables.