Discontinuous conduction mode controlled boosting power-factor-correction (PFC) converters suffer from high differential-mode electromagnetic interference (EMI) and require a large input filter due to high inductor current ripples at a single switching frequency. To remedy the shortcomings, a downward spread-spectrum frequency modulation (SSFM) is proposed in this letter. The SSFM can be used by boosting PFC converters for reduced EMI and improved efficiency. On top of the frequency modulation, a novel adaptive three-level current (ATC) scheme is devised with three-level boost PFC using multilevel capability to obtain further reductions of peak current and EMI amplitude. Analyses and experiments validate that the proposed SSFM and ATC scheme can bring improvements of EMI and efficiency at the cost of increased output-voltage ripple.

中文翻译：

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具有自适应三电平电流方案的扩频调频以改善三电平升压 DCM PFC 的 EMI 和效率

非连续导通模式控制的升压功率因数校正 (PFC) 转换器受到高差模电磁干扰 (EMI) 的影响，并且由于单个开关频率下的电感器电流纹波高，因此需要大输入滤波器。为了弥补这些缺点，在这封信中提出了向下扩频频率调制 (SSFM)。SSFM 可用于升压 PFC 转换器，以降低 EMI 并提高效率。在频率调制的基础上，设计了一种新颖的自适应三电平电流 (ATC) 方案，采用三电平升压 PFC，使用多电平能力进一步降低峰值电流和 EMI 幅度。分析和实验证实，所提出的 SSFM 和 ATC 方案可以以增加输出电压纹波为代价带来 EMI 和效率的改善。