Incorporating positive temperature coefficient (PTC) ceramic particles into polymers provides a prospective alternative solution for suppressing severe electric field distortions caused by negative temperature coefficient (NTC) of electrical resistivity within polymer insulation in high voltage direct current cable. The effect of the Curie temperature of PTC particles on the inhibition of the NTC effect of cross-linked polyethylene (XLPE) is investigated in this study. Positive temperature coefficient particles with varied Curie temperatures are surface-modified and melt blending with XLPE. The modified particles are dispersed on averagely in the matrix. The electrical resistivity, space charge behaviour, and direct current (DC) electrical breakdown strength of the samples are investigated at different temperatures, exploring the effect of the Curie temperature of PTC particles on suppressing the NTC effect of XLPE. It is demonstrated that the reduction in Curie temperature can further suppress the NTC effect of XLPE, enhance the DC strength at elevated temperatures, and inhibit the internal space charge accumulation. The reduction in the Curie temperatures means that the initiation of the PTC effect advances, exhibiting a higher potential barrier and inhibiting the NTC effect more effectively. This work may give a reference for improving the temperature stability of DC properties for XLPE cable insulation.

中文翻译：

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不同居里温度正温度系数颗粒增强绝缘交联聚乙烯复合材料的电阻率-温度特性

将正温度系数 (PTC) 陶瓷颗粒掺入聚合物中，为抑制高压直流电缆中聚合物绝缘内电阻率的负温度系数 (NTC) 引起的严重电场畸变提供了一种有前途的替代解决方案。本研究研究了 PTC 颗粒的居里温度对抑制交联聚乙烯 (XLPE) 的 NTC 效应的影响。具有不同居里温度的正温度系数颗粒经过表面改性并与 XLPE 熔融共混。改性颗粒平均分散在基质中。研究了样品在不同温度下的电阻率、空间电荷行为和直流 (DC) 电击穿强度，探索PTC颗粒的居里温度对抑制XLPE的NTC效应的影响。结果表明，居里温度的降低可以进一步抑制XLPE的NTC效应，提高高温下的直流强度，抑制内部空间电荷的积累。居里温度的降低意味着PTC效应的引发提前，表现出更高的势垒，更有效地抑制NTC效应。该工作可为提高交联聚乙烯电缆绝缘直流特性的温度稳定性提供参考。并抑制内部空间电荷的积累。居里温度的降低意味着PTC效应的引发提前，表现出更高的势垒，更有效地抑制NTC效应。该工作可为提高交联聚乙烯电缆绝缘直流特性的温度稳定性提供参考。并抑制内部空间电荷的积累。居里温度的降低意味着PTC效应的引发提前，表现出更高的势垒，更有效地抑制NTC效应。该工作可为提高交联聚乙烯电缆绝缘直流特性的温度稳定性提供参考。