| 引用本文: | 刘晓军,孙林远,杨冬锋,等.适用于分布式电源谐波注入的灵活接地系统高阻故障选线方法[J].电力系统保护与控制,2026,54(04):38-49.[点击复制] |
| LIU Xiaojun,SUN Linyuan,YANG Dongfeng,et al.High-impedance fault line selection method for flexible grounding systems considering harmonic injection from distributed generators[J].Power System Protection and Control,2026,54(04):38-49[点击复制] |
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| 摘要: |
| 针对灵活接地系统高阻接地故障场景下，分布式电源(distributed generator, DG)谐波注入导致故障特征失真的问题，提出一种计及DG谐波注入的灵活接地系统高阻故障选线方法。首先，建立灵活接地模型，分析中性点小电阻退出运行的暂态调控过程对系统参数的影响。然后，基于小电阻退出后的系统参数分布特性，提取馈线群间的主谐振分量，并量化故障馈线与非故障馈线主谐振分量的相位差异特征。最后，采用交叉小波变换提取线路间的高相关时域特征，并利用平稳性检验消除DG注入谐波对高相关时域的干扰，构建相位差异系数故障选线判据，实现谐波-暂态双因素耦合场景下的高阻故障选线。Simulink仿真结果表明，所提方法适用于过渡电阻不超过4000 的接地故障，在弧光接地、强噪声干扰等极端工况下仍具有较高的可靠性。 |
| 关键词: 灵活接地系统 高阻接地故障 小电阻退出 分布式电源 故障选线 |
| DOI：10.19783/j.cnki.pspc.250725 |
| 投稿时间：2025-07-03修订日期：2025-12-07 |
| 基金项目:国家自然科学基金项目资助(52377170) |
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| High-impedance fault line selection method for flexible grounding systems considering harmonic injection from distributed generators |
| LIU Xiaojun,SUN Linyuan,YANG Dongfeng,QU Yuehan |
| (Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology,
Ministry of Education (Northeast Electric Power University), Jilin 132012, China) |
| Abstract: |
| In flexible grounding system under high-impedance grounding faults, harmonic injection from distributed generators (DG) can distort fault features, making accurate fault identification difficult. To address this issue, a high- impedance fault line selection method for flexible grounding systems that accounts for DG harmonic injection is proposed. First, a flexible grounding system model is established, and the impact of the transient control process caused by the withdrawal of the neutral-point small resistor on system parameters is analyzed. Then, based on the system parameter distribution characteristics after the small resistance is withdrawn, the dominant resonant components among feeder groups are extracted, and the phase difference characteristics between the dominant resonant components of faulty and healthy feeders are quantified. Finally, the cross-wavelet transform is applied to extract highly correlated time-domain features between lines, and stationarity tests are applied to eliminate the interference of DG-injected harmonics on the highly correlated time-domain signals. A phase difference coefficient fault selection criterion is constructed, enabling high-impedance fault line selection under coupled harmonic-transient scenarios. Simulink simulation results show that the proposed method is applicable to grounding faults with a transition resistance of up to 4000 Ω and maintains high reliability under extreme conditions such as arcing grounding and strong noise interference. |
| Key words: flexible grounding system high-impedance grounding fault small resistance removal distributed generator fault line selection |
