In medium voltage direct current (MVDC) systems, charge carriers gradually inject into the bulk of a dielectric, leading to space charge accumulation. As more charge carriers inject and accumulate, the effective thickness of a dielectric decreases, reducing the breakdown voltage. This phenomenon intensifies at high temperatures. Our previous research has demonstrated the effectiveness of electrets in mitigating space charge accumulation and space-charge-induced breakdown in dielectric materials via electric field neutralization. However, the impacts of high temperatures have yet to be investigated. This study employs the electret-based electric field neutralization approach to prevent space-charge-induced breakdown at higher temperatures. We peformed numerical analysis using bipolar charge transport models at various temperatures to estimate the effects of using electrets. Then we performed experiments, including instantaneous and delayed breakdown measurements at three different temperatures: 25°C, 50°C, and 75°C. The results of this study demonstrate that electrets effectively prevent charge carrier injection and space-charge-induced breakdown at elevated temperatures.

中文翻译：

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在不同温度下使用驻极体防止空间电荷引起的击穿


在中压直流 (MVDC) 系统中，电荷载流子逐渐注入电介质主体，导致空间电荷积累。随着更多的电荷载流子注入和积累，电介质的有效厚度减小，从而降低击穿电压。这种现象在高温下会加剧。我们之前的研究证明了驻极体通过电场中和来减轻介电材料中的空间电荷积累和空间电荷引起的击穿的有效性。然而，高温的影响还有待研究。这项研究采用基于驻极体的电场中和方法来防止较高温度下空间电荷引起的击穿。我们使用双极电荷传输模型在不同温度下进行数值分析，以估计使用驻极体的效果。然后我们进行了实验，包括在 25°C、50°C 和 75°C 三种不同温度下的瞬时和延迟击穿测量。这项研究的结果表明，驻极体可有效防止高温下载流子注入和空间电荷引起的击穿。