硅橡胶中空间电荷的形成机理

文中采用电声脉冲法，在不同的直流电场作用下，测量了硅橡胶中空间电荷的分布，并分析了其与加压时间的关系。同时测量了短路电极时空间电荷分布的变化，讨论了电极短路试样中残留电荷的分布及其影响。研究发现，在场强相对较低(5kV／mm)与较高(60kV／mm，70kV／mm)时，电极附近介质中的电荷分布均为异极性电荷，但其形成机理完全不同；而在中场强(10kV／mm，30kV／mm)下可出现同极性电荷。文章还讨论了Al和Cu电极在不同电场强度下的电子或空穴注入现象以及其在空间电荷形成中的作用。

FORMATION MECHANISM OF SPACE CHARGE IN SILICONE RUBBER

The space charge distributions in silicone rubber under different DC stress and its change after short circuit are measured using Pulsed Electro-acoustic (PEA) method. The experiment results reveal that the charge distributions near electrodes are hetero-charge under low (5kV/mm) and high electrical field (60kV/mm, 70kV/mm), but their formation mechanism is different. And the homo-charge will appear under middle electrical field (10kV/mm, 30kV/mm). Al and Cu electrodes can eject electrons and holes according to their polarity, respectively. The change of space charge with time under different voltage and the remnant charge distributions in sample after short circuit are analyzed. The space charge formation mechanism is also discussed.