| 引用本文: | 李振兴,王玲,黄悦华,孟晓星,李振华.大串补线路电流差动保护拒动因素及改进保护方法[J].电力自动化设备,2018,(1): |
| LI Zhenxing,WANG Ling,HUANG Yuehua,MENG Xiaoxing,LI Zhenhua.Analysis of current differential protection maloperation in power transmission line with high series compensation and corresponding improved protection method[J].Electric Power Automation Equipment,2018,(1): |
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| 摘要: |
| 大串联补偿设备在超高压输电系统中得到越来越广泛的应用，伴随着复杂多系统的互联，含大串联补偿设备的线路(简称串补线路)在特定运行方式下出现线路背侧系统阻抗较小，可能导致线路内部故障时系统电流反向，此时串补线路电流差动保护可能会因灵敏度不足而拒动。基于此，详细分析了串补线路电流反向的原因及其对差动保护的影响。重点对不同串补度、系统功角差和过渡电阻等影响因素下的差动保护的动作特性进行研究。进一步地，为解决差动保护拒动问题，提出一种基于串补线路两侧电流幅相综合制动的电流差动保护改进判据，该判据能够有效解决串补线路内部故障时灵敏度降低的问题。仿真结果显示，相比传统差动保护，改进方案能够明显提高保护灵敏度。 |
| 关键词: 串补设备 超高压输电线路 电流反向 电流差动保护 灵敏度分析 |
| DOI：10.16081/j.issn.1006-6047.2018.01.030 |
| 分类号:TM773 |
| 基金项目:国家自然科学基金资助项目(51477090)；强电磁工程与新技术国家重点实验室(华中科技大学)开放基金资助项目(2016KF003) |
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| Analysis of current differential protection maloperation in power transmission line with high series compensation and corresponding improved protection method |
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LI Zhenxing1, WANG Ling1, HUANG Yuehua1, MENG Xiaoxing2, LI Zhenhua2
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1.College of Electrical Engineering and New Energy, China Three Gorges University, Yichang 443002, China;2.Hubei Provincial Collaborative Innovation Center for New Energy Microgrid, China Three Gorges University, Yichang 443002, China
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| Abstract: |
| High series capacitor compensation device is more and more widely applied in EHV power transmission system. With the complex interconnection of multiple power systems, the system impedance in the back of transmission line with high series compensation maybe smaller in a certain operating mode, thus the fault current may reverse during the internal line fault, due to which, the current differential protection in transmission line with high series compensation may be rejected because of the lack of sensitivity. On this basis, the reasons of current reversion in power transmission line with high series compensation and its effect on differential protection are analyzed. The operation characteristics of differential protection under the multiple factors such as different series compensation degree, power angle difference and transition resistance are emphatically studied. Furthermore, the improved criteria based on the current amplitudes and phases at both sides of power transmission line with high series compensation are proposed to avoid the maloperation of current differential protection, which effectively improve the low protection sensitivity during the internal fault of transmission line with high series compensation. The simulative results show that the improvement scheme can obviously increase the protection sensitivity. |
| Key words: series compensation equipment EHV power transmission line reverse current current differential protection sensitivity analysis |
