中压电力电缆用半导电屏蔽料电阻率温度系数研究

Study on Resistivity Temperature Coefficient of Semi-Conductive Shielding Material for Medium Voltage Power Cables

中压电力电缆半导电屏蔽层的附加损耗与体积电阻率相关。电缆工作温度上升,半导电屏蔽层电阻增大,则电缆tgδ变大,半导电界面热效应变坏,影响电缆使用寿命,因此半导电屏蔽层电阻率的温度特性应平稳。相应的,半导电屏蔽层所用半导电屏蔽料的电阻率温度特性也应平稳。通过研究半导电屏蔽料的电阻率温度特性,认为通过考核电阻率的温度系数来评估半导电屏蔽材料的电气性能稳定性是一种可行且操作简便的试验方法,并给出了电气热稳定性较好屏蔽料的电阻率温度系数α范围。

The additional loss of semi.conductive shielding layer of medium voltage power cable is related to volume resistivity. When the working temperature of the cable rises and the resistance of the semi.conductive shield increa. ses, the TG delta of the cable becomes larger and the thermal effect of the semi.conductive interface is deteriorated, which is unfavorable to the service life of the cable, so the temperature characteristic of the resistivity of the semi.con. ductive shielding layer should be stable. Correspondingly, the resistivity and temperature characteristics of the semi. conductive shielding material used in the semi.conductive shielding layer should also be stable. By studying the resis. tivity temperature characteristics of the semi.conductive shielding material, it is considered that it is a feasible and easy to operate test method to evaluate the electrical performance stability of the semi.conductive shielding material by examining the temperature coefficient of the resistivity, and gives the range of the resistivity temperature coefficient of the electrical thermal stability of the shielding material.