Fault location algorithms for transmission lines use the parameters of the transmission line to locate faults after the faults have occurred along the line. Although these parameters can be estimated by the phasor measurement units (PMUs) at the terminal(s) of the transmission line continuously, the uncertainty in the measurements will give rise to stochastic errors in the measured values. Thus, the uncertainty in measurements definitely influences the estimations of the parameters of the transmission line, which, in turn, influences the results of fault location algorithms. Inaccurate results of fault location algorithms may lead to costly maintenance fees and prolonged outage time. Therefore, in this article, we estimate the parameters of the transmission line considering the uncertainty in the measurements so that a more accurate fault location can be derived. The uncertainty in the measurements will be modeled as a stochastic distribution, and the maximum likelihood estimation (MLE) method will be adopted to reduce the uncertainty in the measurements. In addition, as an illustration, the telegrapher's equations will be used to calculate the parameters of the transmission line, and the two-terminal positive sequence network fault location algorithm will be used to locate the fault. In a simulation, a case study of a real-life transmission line the influence of the uncertainty in the measurements on the transmission line parameter estimations and the effectiveness of the MLE method for estimations are simulated and analyzed. The results show that the influence of the uncertainty in the measurements on the positive sequence network fault location algorithm should not be neglected and that the proposed method is very effective in significantly reducing the influence of the uncertainty in the measurements.

中文翻译：

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测量不确定度对输电线路参数估计和故障定位的影响


输电线路故障定位算法在线路发生故障后，利用输电线路的参数进行故障定位。虽然这些参数可以通过传输线终端的相量测量单元（PMU）连续估计，但测量的不确定性将导致测量值的随机误差。因此，测量的不确定性肯定会影响输电线路参数的估计，进而影响故障定位算法的结果。故障定位算法的不准确结果可能会导致昂贵的维护费用和延长停电时间。因此，在本文中，我们考虑测量的不确定性来估计输电线路的参数，以便得出更准确的故障定位。测量中的不确定性将被建模为随机分布，并采用最大似然估计（MLE）方法来减少测量中的不确定性。另外，作为说明，将使用电报员方程计算输电线路的参数，并使用两端正序网络故障定位算法来定位故障。在仿真中，以实际传输线为例，对测量不确定性对传输线参数估计的影响以及 MLE 估计方法的有效性进行了仿真和分析。 结果表明，测量不确定度对正序网络故障定位算法的影响不容忽视，并且该方法能够有效地显着降低测量不确定度的影响。