Recently published papers have proved the effectiveness of electromagnetic time reversal (EMTR) in locating the position of faults such as phase-to-ground shunt connections in power grids. EMTR directly transposes the idea of focusing energy back to its source introduced in original time-reversal (TR) methods. The current interpretation of EMTR, based on metrics measuring energy or peak-amplitude of focusing, is shown to suffer from ambiguities that increase the risk of inaccurate fault location. After pointing out under what conditions TR focusing occurs, an original frequency-domain reformulation of EMTR is introduced, showing that EMTR should more accurately be interpreted as a correlation estimator. New metrics based on this observation are introduced, taking into account the inhomogeneous transmission of electrical energy throughout complex networks, enabling a direct quantitative evaluation of the likelihood of locating a fault. Extensive numerical simulations confirm that the proposed formulation systematically improves the reliability of EMTR location estimates when faults occur in power grids of realistic complexity, highlighting the accrued risk that comes with the use of metrics that measure the scale of TR focusing rather than its quality.

中文翻译：

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作为相关估计器的电磁时间反转：电网故障定位的改进度量和设计标准

最近发表的论文证明了电磁时间反转 (EMTR) 在定位故障位置（例如电网中的相对地并联连接）方面的有效性。EMTR 直接将在原始时间反转 (TR) 方法中引入的将能量聚焦回其源的想法进行了转换。目前对 EMTR 的解释，基于测量能量或聚焦峰值幅度的度量，被证明存在歧义，增加了不准确故障定位的风险。在指出在什么条件下发生 TR 聚焦后，引入了 EMTR 的原始频域重构，表明 EMTR 应该更准确地解释为相关估计量。引入了基于此观察的新指标，考虑到电能在整个复杂网络中的不均匀传输，能够对定位故障的可能性进行直接定量评估。广泛的数值模拟证实，当现实复杂的电网中发生故障时，所提出的公式系统地提高了 EMTR 位置估计的可靠性，突出了使用衡量 TR 聚焦规模而不是其质量的指标所带来的累积风险。