Conventional passive EMI filters are bulky and occupy up to 30% of converter volume and weight. Active EMI filters are a key technology that enables the volume reduction of passive components in the EMI filter. The effectiveness of traditional active EMI filter for volume reduction is limited by the additional overhead from the passive components for noise sensing and compensation to ensure stability. In this article, a novel active EMI filter is proposed and demonstrated for differential mode noise attenuation. The filter consists of a twin circuit made up of low voltage/current components that mimic the high-power passive filter components in the main circuit. Unlike the conventional active EMI filter, the proposed filter uses compensation networks which consists of low-voltage surface-mount components only. The modeling of the entire circuit is carried out, and verified with small-signal measurements. The filter is then tested in a converter and the experimental results are shown to be consistent with the model and the small-signal measurements.

中文翻译：

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具有模拟孪生电路的差模有源 EMI 滤波器的建模与分析

传统的无源 EMI 滤波器体积庞大，占据转换器体积和重量的 30%。有源 EMI 滤波器是使 EMI 滤波器中无源元件体积减小的关键技术。传统有源 EMI 滤波器减小体积的有效性受到用于噪声检测和补偿以确保稳定性的无源元件的额外开销的限制。在本文中，提出并演示了一种用于差模噪声衰减的新型有源 EMI 滤波器。该滤波器由一个双电路组成，该电路由模拟主电路中的高功率无源滤波器组件的低电压/电流组件组成。与传统的有源 EMI 滤波器不同，所提出的滤波器使用仅由低压表面贴装元件组成的补偿网络。对整个电路进行建模，并通过小信号测量进行验证。然后在转换器中测试滤波器，实验结果与模型和小信号测量结果一致。