Emerging applications of compact high-voltage SiC modules pose strong challenges in the module package insulation design. Such SiC module insulations are subjected to both high-voltage dc and pulsewidth modulation (PWM) excitations between different terminals during different switching intervals. High dV/dt strongly interferes with partial discharge (PD) testing as it is hard to distinguish PD pulses and PWM excitation-induced interferences. This article covers both the testing and modeling of PD phenomena in the high-voltage power modules. A high dV/dt PD testing platform is proposed, which involves a super-high-frequency (SHF) (SHF >3 GHz) down-mixing PD detection receiver and a high-voltage scalable square wave generator. The proposed method captures SHF PD signatures and determines PD inception voltage (PDIV) for packaging insulation. Using this platform, this article provides a group of PDIV comparisons of packaging insulation under dc and PWM waveforms and discloses discrepancies in these PDIV results with respect to their excitations. Based on these PD testing results, the article further provides a model using the space-charge accumulation to explain the PD difference under dc and PWM waveforms. Both simulation and sample testing results are included in this article to support this hypothesis. With this new model, the article includes an updated insulation design procedure for the high-voltage power modules.

中文翻译：

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空间电荷积累及其对直流和 PWM 波下高压功率模块局部放电的影响：测试和建模

紧凑型高压 SiC 模块的新兴应用对模块封装绝缘设计提出了严峻挑战。在不同的开关间隔期间，这种 SiC 模块绝缘材料会受到不同端子之间的高压直流和脉宽调制 (PWM) 激励。高的dV/dt强烈干扰局部放电 (PD) 测试，因为难以区分 PD 脉冲和 PWM 激励引起的干扰。本文涵盖了高压电源模块中 PD 现象的测试和建模。高dV/dt提出了PD测试平台，包括超高频（SHF）（SHF>3GHz）下混PD检测接收器和高压可扩展方波发生器。所提出的方法捕​​获 SHF PD 特征并确定用于封装绝缘的 PD 起始电压 (PDIV)。使用该平台，本文提供了一组直流和 PWM 波形下封装绝缘的 PDIV 比较，并揭示了这些 PDIV 结果在激励方面的差异。基于这些PD测试结果，文章进一步提供了一个使用空间电荷累积的模型来解释dc和PWM波形下的PD差异。仿真和样本测试结果都包含在本文中以支持这一假设。有了这个新模型，