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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 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 paper covers both the testing and modeling of PD phenomena in high-voltage power modules. A high dV/dt PD testing platform is proposed, which involves a Super-High-Frequency (SHF, >3GHz) down-mixing PD detection receiver and a high-voltage scalable square wave generator. The proposed method captures SHF PD signatures and determines PDIV for packaging insulation. Using this platform, this paper 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 paper further provides a model using space charge accumulation to explain the PD difference under DC and PWM waveforms. Both simulation and sample testing results are included in this paper to support this hypothesis. With this new model, the paper includes an updated insulation design procedure for high-voltage power modules. 

In the power electronics equipment, passive EMI filters occupy up to 30% of system's volume and weight. In order to reduce the size of passive EMI filter in the power electronics system, active EMI filters (AEF) is introduced. With the AEF approaches, the size of the passive component within the EMI filter can be reduced by more than 50%. The higher attenuation achieved by AEFs, the more size reduction can be obtained through AEFs methodology. However, the performance of AEF with feedback control is limited to around 24 dB attenuation in the reported work. New methodology needs to be found to push forward the performance. In this study, a novel digital active EMI filter (DAEF) with the resonant controller, which provides ultra high-gain at frequencies of interest, is demonstrated for DM noise attenuation. The experimental test results show that the proposed EMI filter has 45 dB more attenuation at 150 kHz than the conventional passive EMI filter, which is also the highest attenuation reported in the AEF literature.