Since dc distribution minimizes the number of power conversion stages, it lowers the overall cost, power losses, and weight of a power system. Critical systems use IT grounding because it is tolerant to the first-fault. Hence, this is an attractive option for hybrid electric aircraft (HEA), which combines gas engines with electric motors driven by power electronic converters. This letter proposes an accurate implementation for the procedure of first-fault detection with IT grounding. The ac component injection along with the sliding discrete Fourier transform (SDFT) is used to estimate the fault impedance. The procedure is very accurate due to the heavy filtering of the implicit moving average filter. Further computation savings are obtained by using the double look-up tables, and the Goertzel algorithm for the SDFT. Results are validated by simulations and experiments.

中文翻译：

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基于滑动离散傅立叶变换的 IT 接地直流配电首次故障检测

由于直流配电最大限度地减少了电源转换级的数量，因此降低了电源系统的总成本、功率损耗和重量。关键系统使用 IT 接地，因为它可以容忍第一个故障。因此，对于混合动力电动飞机 (HEA) 来说，这是一个有吸引力的选择，它将燃气发动机与由电力电子转换器驱动的电动机相结合。这封信建议准确实施 IT 接地的首次故障检测程序。交流分量注入与滑动离散傅立叶变换 (SDFT) 一起用于估计故障阻抗。由于隐式移动平均滤波器的重滤波，该过程非常准确。通过使用双重查找表和 SDFT 的 Goertzel 算法，可以进一步节省计算量。