In this paper, space charge behavior over a large range of electric field and temperature, of two kinds of epoxy resins are investigated using an improved pulsed electro-acoustic method. Significant influence of high electric field and high temperature on the space charge accumulation in epoxy are found. Hetero charge accumulation starts to build up at 80 °C under 120 kV/mm for amine-type hardener cured epoxy (EP-AM), while at 140 °C under 60 kV/mm for anhydride-type hardener cured epoxy (EP-AH). The accumulated charge increases with the increasing of electric field and temperature. The maximum enhancement of local electric field of is 135 and 123 % at 140 °C for EP-AM and EP-AH, respectively. Quantum chemical calculation is performed to clarify the mechanism of space charge characteristics in the two types of epoxy. It is indicated that ionization of remnant unreacted hardener and electrode injection may be the main sources of space charge. The interaction between molecular chains of EP-AH is stronger than that of EP-AM, which makes it have better space charge characteristics even under high temperature.

中文翻译：

---

高温高电场对功率模块用环氧树脂空间电荷行为的影响

在本文中，使用改进的脉冲电声方法研究了两种环氧树脂在大范围电场和温度下的空间电荷行为。发现高电场和高温对环氧树脂中的空间电荷积累有显着影响。对于胺型固化剂固化环氧树脂 (EP-AM)，在 80 °C 下，在 120 kV/mm 下，杂电荷开始累积，而在 140 °C 下，酸酐型固化剂固化环氧树脂 (EP-AH) 在 60 kV/mm 下开始累积）。累积电荷随着电场和温度的增加而增加。EP-AM 和 EP-AH 在 140°C 下的局部电场的最大增强分别为 135% 和 123%。进行量子化学计算以阐明两种环氧树脂中空间电荷特性的机制。表明残余未反应硬化剂的电离和电极注入可能是空间电荷的主要来源。EP-AH分子链间的相互作用强于EP-AM，使其即使在高温下也具有更好的空间电荷特性。