To suppress the conducted electromagnetic interference (EMI) of power supplies, the passive EMI filter (PEF) composed of inductors and capacitors is usually adopted. However, the large volume of PEF limits the further improvement of power density. This study presents an active EMI filter (AEF) based on predictive pulsed compensation (PPC) to suppress the common mode (CM) noise of boost converters. The proposed AEF is easy to implement and low cost. Its core circuit contains an online adjustable voltage source, a half-bridge driver, and a pair of Y-capacitors. The circuit generates a rectangular pulse with adjustable amplitude to cancel CM noises. Besides, this research contributes by identifying and resolving the challenges that hinder the application of PPC-based AEF to boost converters, including the amplitude, time delay, and edge slope of the pulse. The position order of AEF and PEF is also discussed. A prototype with 48 V input and 100 kHz switching frequency is tested experimentally to verify the proposed AEF. Experimental results show that the proposed AEF achieves a 21 dB reduction in CM noise at 200 kHz and consumes only 45 mW of power. Furthermore, the proposed AEF achieves a 47% reduction in volume compared with the conventional PEF.

中文翻译：

---

使用预测脉冲补偿来抑制升压转换器共模噪声的有源 EMI 滤波器


为了抑制电源的传导电磁干扰（EMI），通常采用由电感和电容组成的无源EMI滤波器（PEF）。然而，PEF体积较大限制了功率密度的进一步提高。本研究提出了一种基于预测脉冲补偿 (PPC) 的有源 EMI 滤波器 (AEF)，用于抑制升压转换器的共模 (CM) 噪声。所提出的 AEF 易于实施且成本低。其核心电路包含一个在线可调电压源、一个半桥驱动器和一对Y电容器。该电路生成幅度可调的矩形脉冲以消除 CM 噪声。此外，这项研究还有助于识别和解决阻碍基于 PPC 的 AEF 应用于升压转换器的挑战，包括脉冲的幅度、时间延迟和边沿斜率。还讨论了 AEF 和 PEF 的位置顺序。对具有 48 V 输入和 100 kHz 开关频率的原型进行了实验测试，以验证所提出的 AEF。实验结果表明，所提出的 AEF 在 200 kHz 下实现了 21 dB 的 CM 噪声降低，并且仅消耗 45 mW 的功率。此外，与传统的 PEF 相比，所提出的 AEF 体积减少了 47%。