The nonlinear operation of metal oxide varistor (MOV)-protected series compensator in transmission lines introduces complications into fault detection approaches. The accuracy of a conventional fault detection schemes is adversely affected by continuous change of the system impedance and load current at the point of a series compensation unit. Thus, this study suggests a method for detecting the faulted phase in MOV-protected series-compensated transmission lines. Primarily, the fault feature is identified using the covariance coefficients of the current samples during the fault period and the current samples during the pre-fault period. Furthermore, a convenience fault detection index is established by applying the cumulative sum technique. Extensive validation through different fault circumstances is accomplished, including different fault positions, resistances, and inception times. The experimental results show that the proposed method performs well with high resistance or impedance faults, faults in noisy conditions, and close-in and far-end faults. The proposed method is simple and efficient for faulty phase detection in MOV-protected series-compensated transmission lines.

中文翻译：

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金属氧化物压敏保护串联补偿器的输电线路故障相识别

金属氧化物变阻器（MOV）保护的串联补偿器在传输线中的非线性运行将复杂性引入了故障检测方法。常规故障检测方案的准确性在串联补偿单元的点受到系统阻抗和负载电流的连续变化的不利影响。因此，这项研究提出了一种检测MOV保护的串联补偿传输线中故障相的方法。首先，使用故障期间的当前样本和故障前的当前样本的协方差系数来识别故障特征。此外，通过应用累积和技术来建立便利性故障检测指标。通过不同的故障情况进行了广泛的验证，包括不同的故障位置，电阻和起始时间。实验结果表明，该方法在高阻或高阻抗故障，嘈杂条件下的故障以及近端和远端故障中表现良好。该方法对于MOV保护的串联补偿传输线中的故障相位检测是简单有效的。