| 引用本文: | 张 帆,王晓卫,王新茜,等.基于幅值比与相位差的灵活接地系统单相高阻故障检测方法[J].电力系统保护与控制,2025,53(11):41-50.[点击复制] |
| ZHANG Fan,WANG Xiaowei,WANG Xinqian,et al.Single-phase high-impedance fault detection method for flexible grounding system based on amplitude ratio and phase difference[J].Power System Protection and Control,2025,53(11):41-50[点击复制] |
|
| 摘要: |
| 灵活接地系统的保护主要采用小电阻接地系统的定时限零序过电流保护，适应过渡电阻能力较低，导致现有方法难以有效检测出故障馈线。针对这一问题，提出了一种基于零序电流幅值比与相位差的检测方法。首先，通过时域方程分析小电阻投入后各馈线与中性点的零序电流。其次，结合配网固有参数，得出小电阻投入后各馈线幅值比与相位差的具体差异。最后，通过比较故障馈线与中性点零序电流的幅值比，发现其明显大于健全馈线，由此构造判据1。通过分析故障馈线与中性点零序电流的相位差，发现其与健全馈线相差90°，由此构造判据2。仿真与实测结果表明，该方法能够准确实现灵活接地系统的单相高阻接地故障检测，且不受电流互感器反接、数据缺失、间歇性电弧以及强噪声的影响。 |
| 关键词: 灵活接地系统 单相高阻故障 幅值比 相位差 |
| DOI：10.19783/j.cnki.pspc.241015 |
| 投稿时间：2024-07-31修订日期：2024-12-16 |
| 基金项目:国家自然科学基金项目资助(52177114，61403127)；国网陕西省电力有限公司科技项目资助(5226KY23001U) |
|
| Single-phase high-impedance fault detection method for flexible grounding system based on amplitude ratio and phase difference |
| ZHANG Fan1,WANG Xiaowei1,WANG Xinqian1,FAN Linhui1,WANG Yizhao2,BAI Hao3 |
| (1. School of Electrical Engineering, Xi’an University of Technology, Xi’an 710054, China;
2. Power Research Institute of State Grid Shaanxi Electric Power Co., Ltd., Xi’an 710100, China;
3. Southern Power Grid Research Institute Co., Ltd., Guangzhou 510663, China) |
| Abstract: |
| Protection in flexible grounding systems mainly relies on time-limited zero-sequence overcurrent protection methods used in low-resistance grounding systems, which have limited capability to tolerate transition resistance. As a result, existing methods struggle to effectively detect faulty feeders. Aiming at this problem, a detection method based on the amplitude ratio and phase difference of zero-sequence currents is proposed. First, time-domain equations are used to analyze the zero-sequence currents between each feeder and the neutral point after low-resistance grounding. Then, by incorporating the inherent parameters of the distribution network, the specific differences between the amplitude ratio and phase difference of each feeder after adding the small resistors are obtained. Finally, by comparing the amplitude ratio of the zero-sequence current between the faulty feeder and the neutral point, it is found to be significantly higher than that of healthy feeders, thus forming Criterion 1. Additionally, by analyzing the phase difference of the zero-sequence current between the faulty feeder and the neutral point, it is found to differ by 90° from healthy feeders, thus forming Criterion 2. Simulation and field test results indicate that the proposed method can accurately detect single-phase high-impedance ground faults in flexible grounding systems, and is robust against current transformer polarity reversal, data loss, intermittent arcs, and strong noise. |
| Key words: flexible grounding systems single-phase high-impedance fault amplitude ratio phase difference |
