| 引用本文: | 楼倩凌,范春菊,王笑然.同塔不换位线路的不对称度对差动保护的影响分析[J].电力系统保护与控制,2026,54(09):1-13. |
| LOU Qianling,FAN Chunju,WANG Xiaoran.Impact of asymmetry in non-transposed same-tower transmission lines on differential protection[J].Power System Protection and Control,2026,54(09):1-13 |
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| 摘要: |
| 针对同塔不换位线路参数不对称引起零序不平衡电流进而严重影响零序差动保护动作可靠性的问题，提出一种量化分析不对称度对差动保护影响及评估保护适应性的方法。首先，利用改进六序分量法构建阻抗解耦模型。然后，引入不对称度计算零序纵差动电流与零序横差动电流，理论分析不对称度对保护性能的影响规律。最后，PSCAD/EMTDC 仿真结果表明，不对称度增大会提高零序纵差动电流，迫使保护提高整定值以避免区外误动，从而降低其抗过渡电阻的能力。零序横差动电流不仅随不对称度增大而增大，且易受故障位置影响，在不换位线路中适应性较差。研究成果可为不换位线路中差动保护的整定与改进提供参考依据。 |
| 关键词: 同塔不换位线路 不对称度 零序纵差动保护 零序横差动保护 高阻接地短路 |
| DOI：10.19783/j.cnki.pspc.251202 |
| 分类号: |
| 基金项目:国家自然科学基金项目资助(52337006)；中国电力科学研究院科技项目资助(JBB51202401892) |
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| Impact of asymmetry in non-transposed same-tower transmission lines on differential protection |
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LOU Qianling, FAN Chunju, WANG Xiaoran
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School of Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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| Abstract: |
| To address the issue that zero-sequence unbalanced currents caused by parameter asymmetry in non-transposition same-tower transmission lines seriously affect the reliability of zero-sequence differential protection, this paper proposes a method to quantitatively analyze the impact of asymmetry on differential protection and to evaluate protection adaptability. First, an impedance decoupling model is constructed using an improved six-sequence component method. Subsequently, the degree of asymmetry is introduced to calculate both zero-sequence longitudinal differential current and zero-sequence transverse differential current, and the influence mechanism of asymmetry on protection performance is theoretically analyzed. Finally, simulation results using PSCAD/EMTDC demonstrate that increased asymmetry leads to a rise in zero-sequence longitudinal differential current, forcing higher protection settings to prevent maloperation during external faults, thereby reducing the ability to withstand transient resistance. Furthermore, the zero-sequence transverse differential current not only increases with asymmetry but is also affected by fault location, resulting in poor adaptability in non-transposed lines. The research findings provide a reference and basis for the setting and improvement of differential protection in non-transposed transmission lines. |
| Key words: non-transposed same-tower transmission line asymmetry zero-sequence longitudinal differential protection zero-sequence transverse differential protection high-resistance ground fault |
