电老化聚乙烯强场电导的研究

A Study on the High Field Conduction of LDPE After Being Aged by Electrical Stress

运用电声脉冲法测量了不同直流电场下聚乙烯试样中空间电荷分布，研究了不同温度及不同电老化阶段的纯聚乙烯和含有电压稳定剂的聚乙烯薄膜试样的强场电导特性，并运用空间电荷限制电流理论计算了材料中陷阱的能级分布形式．结果表明电压稳定剂能有效地减少老化过程中深陷阱的产生，从而延长了聚乙烯的绝缘寿命，从一个侧面验证了聚合物电老化陷阱理论的合理性．

The space charge distributions of low-density polyethylene under different dc electrical stresses are measured with the pulsed electro-acoustic (PEA) method. The high field conduction of low-density polyethylene thin films (with and without the voltage stabilizer) after being aged at different times are measured and the energy level distributions of traps in the samples are calculated by the space-charge-limited-current (SCLC) theory. In addition, the high field conduction of polyethylene at different temperatures is measured. It is shown by test results that the voltage stabilizer can effectively reduce the producing of deep traps in the samples during the electrical aging process. Therefore adding the stabilizer will reduce the energy of hot electrons caused by recombination or trapping of charge carriers and lengthen the lifetime of the samples.