A single ground fault of the rotor windings in a synchronous condenser can cause serious damage if the fault is not eliminated in time. This paper proposes a new rotor ground-fault diagnosis method for synchronous condensers based on the amplitude of the 150 Hz component of the voltage across a grounding resistance (GR) placed in the neutral of an excitation transformer. It can be seen that the amplitude of the 150 Hz component of the voltage across the GR increases with a decrease of the ground-fault resistance (GFR). This method is an improvement of existing algorithms for rotor ground-fault detection that requires less analyzing and can achieve online detection of the severity of a rotor ground fault at any point of the excitation winding. In addition, the influence of different excitation voltages on the algorithm based on phase-angle is analyzed considering actual working characteristics. Moreover, a model is built in the MATLAB/Simulink platform using the real parameters of a TTS-300-2 synchronous condenser to verify the effectiveness of the proposed method. Finally, a dual diagnostic criterion is given according to the results of simulations. The research conclusions can have a great significance on the healthy running of synchronous condensers and they can help to drastically reduce both cost and repair time.

中文翻译：

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基于电压幅值和相角的同步电容器转子接地故障诊断方法

如果不及时排除故障，同步电容器中转子绕组的单个接地故障会造成严重损坏。本文提出了一种新的同步电容器转子接地故障诊断方法，该方法基于位于励磁变压器中性点的接地电阻 (GR) 两端电压的 150 Hz 分量的幅值。可以看出，GR 两端电压的 150 Hz 分量的幅度随着接地故障电阻 (GFR) 的减小而增加。该方法是对现有转子接地故障检测算法的改进，分析量少，可实现对励磁绕组任意点转子接地故障严重程度的在线检测。此外，结合实际工作特点，分析了不同励磁电压对基于相角算法的影响。此外，使用TTS-300-2同步电容器的真实参数在MATLAB/Simulink平台上建立模型以验证所提出方法的有效性。最后根据仿真结果给出了双重诊断标准。研究结论对同步凝汽器的健康运行具有重要意义，有助于大幅降低成本和维修时间。根据模拟结果给出了双重诊断标准。研究结论对同步凝汽器的健康运行具有重要意义，有助于大幅降低成本和维修时间。根据模拟结果给出了双重诊断标准。研究结论对同步凝汽器的健康运行具有重要意义，有助于大幅降低成本和维修时间。