The electronic current transformer (ECT) acquisition card is widely used in smart grids with many advantages. However, with the continuous improvement of the power grid and localized intelligent electronic devices, the electromagnetic environment under the operating conditions of gas insulated switchgear (GIS) substations is becoming more complicated. The reliability and safety of the ECT acquisition card will be endangered due to the complicated electromagnetic environment. In order to solve these problems, this paper investigates the electromagnetic disturbed mechanism of the ECT acquisition card. The effects of different grounding methods on the electromagnetic interference of the ECT acquisition card were studied. A platform based on IEC 61000-4-4 was built, and the electromagnetic interference (EMI) of the ECT acquisition card with different grounding methods was measured. The results show that the lower grounding impedance of the ECT acquisition system increased the internal EMI. Further, the high frequency electrical fast transient/burst coupling mechanism was analyzed. The parasitic parameters of the acquisition card were extracted based on the critical circuit by using the finite element method. Then, the high-frequency EMI coupling model of the ECT acquisition card was established.

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电子电流互感器采集卡在高频电磁干扰下的电磁干扰机理

电子电流互感器（ECT）采集卡被广泛应用于智能电网，具有许多优势。然而，随着电网和局部智能电子设备的不断改进，气绝缘开关设备（GIS）变电站在运行条件下的电磁环境变得越来越复杂。由于复杂的电磁环境，ECT采集卡的可靠性和安全性将受到威胁。为了解决这些问题，本文研究了ECT采集卡的电磁干扰机理。研究了不同接地方式对ECT采集卡电磁干扰的影响。建立了基于IEC 61000-4-4的平台，并测量了不同接地方式的ECT采集卡的电磁干扰（EMI）。结果表明，ECT采集系统的较低接地阻抗会增加内部EMI。此外，分析了高频电快速瞬变/突发耦合机制。利用有限元方法，基于临界电路提取了采集卡的寄生参数。然后，建立了ECT采集卡的高频EMI耦合模型。利用有限元方法，基于临界电路提取了采集卡的寄生参数。然后，建立了ECT采集卡的高频EMI耦合模型。利用有限元方法，基于临界电路提取了采集卡的寄生参数。然后，建立了ECT采集卡的高频EMI耦合模型。