电力电子中周期共模EMI分析与抑制：预测同步信号数字有源EMI滤波器研究

This paper investigates mitigation techniques for periodic common-mode (CM) electromagnetic interference (EMI) using predictive synchronized signal (PS2) digital active EMI filter (DAEF) in power electronics. The conducted CM EMI model of a SiC-based buck DC-DC converter is first developed and quantified by considering the circuit topologies, high-frequency parasitic parameters, and switching waveforms. Second, the spectrum and the spectral envelope of the CM noise of the converter are derived through theoretical analysis. Third, a method for determining high-frequency parasitic parameters in the CM EMI model based on time-domain measurement waveforms is presented. Next, based on the CM EMI models, the CM noise before and after the addition of the PS2 DAEF was accurately predicted. Then, the predictive synchronized signals can be determined. The overall experimental setups with the PS2 DAEF are elaborated upon. Applying the PS2, the PS2 DAEF can suppress CM EMI without a CM sensing circuit. The measurement results finally confirm the effectiveness of the PS2 DAEF.