| 引用本文: | 李 洁,李亚飞,钱科军,等.基于线路多点电压信息的直流配电系统故障测距及保护方法[J].电力系统保护与控制,2025,53(11):147-157.[点击复制] |
| LI Jie,LI Yafei,QIAN Kejun,et al.Fault location and protection method for DC distribution networks based on multi-point voltage measurements[J].Power System Protection and Control,2025,53(11):147-157[点击复制] |
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| 摘要: |
| 直流暂态故障信号不存在基频分量，再加上线路参数存在明显的依频特性，基于R-L型或Π型线路模型的故障测距方法难以实现准确的直流配电线路故障测距。利用线路两端以及线路上另外两个测量点的电压信号，根据电压在线路非故障部分沿线均匀分布的特点，提出了用于直流配电系统的故障精确测距方法，并设计了测距式后备保护方案。所提方法采用最小二乘法求解超定方程组，提高故障测距精确度和可靠性。利用PSCAD/EMTDC中线路的相域依频模型搭建三端直流配电仿真系统，验证了所提故障测距方法在不同故障位置、过渡电阻、噪声环境和电压信号位置下的有效性和鲁棒性。 |
| 关键词: 直流配电系统 依频特性 故障测距 最小二乘法 后备保护 |
| DOI：10.19783/j.cnki.pspc.246176 |
| 投稿时间：2024-08-20修订日期：2024-10-24 |
| 基金项目:国家电网有限公司科技项目资助(SGJSSZ00KJJS 2312002) |
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| Fault location and protection method for DC distribution networks based on multi-point voltage measurements |
| LI Jie1,LI Yafei1,QIAN Kejun1,XU Xu1,YU Xiuyong2,ZHANG Xinsong2 |
| (1. Suzhou Power Supply Branch, State Grid Jiangsu Electric Power Co., Ltd., Suzhou 215000, China;
2. School of Electrical Engineering and Automation, Nantong University, Nantong 226019, China) |
| Abstract: |
| Since DC transient fault signals lack a fundamental frequency component and line parameters exhibit significant frequency-dependent characteristics, the R-L or Π type line-model based methods struggle to achieve accurate fault location in DC distribution lines. Leveraging the characteristic that voltage is evenly distributed along the healthy line, this paper proposes an accurate fault location method for DC distribution systems by utilizing voltage signals from both ends of the line and two additional measurement points along the line. A distance backup protection scheme based on this fault location method is also designed. The proposed approach applies a least squares algorithm to solve an overdetermined system of equations, thus enhancing the accuracy and reliability of fault location. A three-terminal DC distribution simulation model is built in PSCAD/EMTDC using a frequency-dependent phase-domain line model, and the effectiveness and robustness of the proposed fault location method are verified under different fault positions, fault resistances, noise environments, and positions of the voltage signal. |
| Key words: DC distribution systems frequency-dependent characteristics fault location least squares method backup protection |
