In this paper, charge distributions in three-layered epoxy resin and epoxy resin impregnated paper samples under AC and AC-DC superimposed electric fields are measured by the improved high-speed pulsed electro-acoustic system. To exclude the interferences caused by the discontinuity of relative permittivity, a method to distinguish between net dipolar charges and free charges is proposed. Through analysis, the influences of frequency, AC component and DC component on the charge transport and trapping characteristics in multi-layered epoxy composites are obtained, which could provide important reference to the structural design and optimization of converter transformer bushings.

中文翻译：

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交流和交直流叠加电场下环氧树脂浸渍纸的空间电荷特性


本文利用改进的高速脉冲电声系统测量了三层环氧树脂和环氧树脂浸渍纸样品在交流和交直流叠加电场下的电荷分布。为了排除相对介电常数不连续性造成的干扰，提出了一种区分净偶极电荷和自由电荷的方法。通过分析，得出频率、交流分量和直流分量对多层环氧复合材料电荷传输和俘获特性的影响，为换流变压器套管的结构设计和优化提供重要参考。