电压极性和加压时间对XLPE电力电缆等温松弛电流的影响

Effect of Voltage Polarity and Time Duration on Isothermal Relaxation Currents of XLPE Power Cables

针对电力电缆老化状态评估中较有效的等温松弛电流法,研究了振动噪声对等温松弛电流的影响,等温松弛电流的可重复性,电压极性和加压时间对等温松弛电流的影响。试验结果表明,等温松弛电流的可重复性较好,改变电压极性不一定改变松弛电流的极性,即存在反常放电电流现象,极化时间30 min交联聚乙烯极化已达到稳定状态。

Isothermal relaxation current method is an effective way to evaluate the aging state of crosslinked polyethylene insulated power cables.In this paper,the effect of vibration noise on isothermal relaxation current is firstly investigated,and the repeatability of isothermal relaxation current is studied,finally the effects of voltage polarity and time duration on isothermal relaxation current are considered.It is shown that the repeatability of isothermal relaxation current is good,and the relaxation current polarity is not necessarily altered when the voltage polarity is changed.The polarization of crosslinked polyethylene achieves a stable state if the polarization time is 30 min.