| 引用本文: | 刘 健,丁俊鹏,杨东明,等.小电流接地配电网单相接地过渡电阻估计[J].电力系统保护与控制,2025,53(12):24-32.[点击复制] |
| LIU Jian,DING Junpeng,YANG Dongming,et al.Estimation of transition resistance for single-phase grounding faults in small current grounded distribution networks[J].Power System Protection and Control,2025,53(12):24-32[点击复制] |
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| 小电流接地配电网单相接地过渡电阻估计 |
| 刘健1,2,丁俊鹏2,杨东明2,王毅钊1,2,常小强1,张志华1,张小庆1 |
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| (1.国网陕西省电力有限公司电力科学研究院，陕西 西安 710100;2.西安理工大学电气工程学院，陕西 西安 710048) |
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| 摘要: |
| 为了通过单相接地故障时过渡电阻的差异来判断故障是发生在电缆段还是架空段，研究了小电流接地配电网中过渡电阻的估计方法。首先，论述了4种修正方法的基本原理，包括全近似估计法，即直接采用观测到的零序电压、零序电流和正常时的相电压来估计过渡电阻，以及接地电流幅值修正法、接地电流全相量修正法和接地电流全相量+等效零序电压源幅值修正法。其次，对上述方法进行了定量误差分析，并探讨了典型馈线负荷分布的影响。研究表明全近似估计法的误差较大，但各种修正措施都有助于提高过渡电阻的估计精度。然后，采取接地电流全相量 + 等效零序电压源幅值修正法后，在典型馈线负荷分布情况下，虽然在低阻接地情况下，相对误差较大，但其绝对误差并不大，能够满足应用需求。最后，仿真和实验验证结果表明所提方法的可行性和有效性。 |
| 关键词: 配电网 消弧线圈接地系统 单相接地故障 过渡电阻估计 误差分析 |
| DOI：10.19783/j.cnki.pspc.240728 |
| 投稿时间：2024-06-12修订日期：2024-09-08 |
| 基金项目:国家电网有限公司总部科技项目资助(5226SX22001C) |
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| Estimation of transition resistance for single-phase grounding faults in small current grounded distribution networks |
| LIU Jian1,2,DING Junpeng2,YANG Dongming2,WANG Yizhao1,2,CHANG Xiaoqiang1,ZHANG Zhihua1,ZHANG Xiaoqing1 |
| (1. State Grid Shaanxi Electric Power Research Institute, Xi’an 710100, China; 2. School of Electrical Engineering,
Xi’an University of Technology, Xi’an 710048, China) |
| Abstract: |
| To identify whether a single-phase grounding fault occurs in a cable section or an overhead line section based on differences in transition resistance, this paper investigates estimation methods for transition resistance in small-current grounded distribution networks. The fundamental principles of four correction methods are discussed, including total approximation (TA) based on the detected zero-sequence voltage, zero-sequence current, and phase voltage; grounding current amplitude correction (GCAC); grounding current vector correction (GCVC); and GCVC plus equivalent zero voltage source correction (GCVC + EZVC). Next, a quantitative error analysis of these methods is conducted, along with a discussion of the impact of typical load distribution. The study shows that while TA has relatively large errors, all the correction methods significantly improve the estimation accuracy of the transition resistance. With GCVC+EZVC, in the case of typical feeder load distribution, although the relative errors are large during low-resistance grounding, the absolute error remains small enough to meet practical requirements. Finally, simulation and experimental results verify the feasibility and effectiveness of the proposed method. |
| Key words: distribution networks arc suppression coil grounding system single-phase grounding faults transition resistance estimation error analysis |
