| 引用本文: | 王艳婷,樊顺跃,刘 乐,等.基于频域能量比值的柔性直流输电线路单端量高可靠性保护方案[J].电力系统保护与控制,2025,53(20):1-10. |
| WANG Yanting,FAN Shunyue,LIU Le,et al.High-reliability non-unit protection for flexible DC transmission lines based on frequency-domain energy ratio[J].Power System Protection and Control,2025,53(20):1-10 |
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| 摘要: |
| 针对柔性直流输电线路频域量保护缺乏有效整定依据以及雷击干扰易导致保护误动的问题，提出了一种基于频域能量比值的单端量高可靠性保护方案。首先，分析柔直输电系统在线路区内接地故障、区外接地故障、线路雷击干扰以及雷击故障4种典型情况下的线模电压反行波频域表达式，揭示其频域分布特性。在此基础上，引入能量算子对电压反行波幅频曲线进行加权处理，以增强高频部分的差异性，并利用不同频段能量积聚量比值构建区内外故障识别判据。同时，结合雷击干扰在低频段能量分布的显著特征，提出一种高效的雷击干扰识别方法，最终形成完整的单端量线路保护方案。该保护方案具有明确的理论整定依据。大量的仿真验证表明，所提保护能够快速、可靠地识别线路故障，同时准确区分雷击干扰，具有较高的耐过渡电阻能力和抗干扰能力。 |
| 关键词: 柔性直流输电系统 直流线路保护 频域保护 能量积聚量 雷击干扰识别 |
| DOI：10.19783/j.cnki.pspc.241714 |
| 分类号: |
| 基金项目:国家自然科学基金项目资助(52407142)；中国博士后科学基金项目资助(2021M690126)；陕西省科技厅项目资助(2024JC-YBMS-285) |
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| High-reliability non-unit protection for flexible DC transmission lines based on frequency-domain energy ratio |
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WANG Yanting1, FAN Shunyue1, LIU Le2, 3, KANG Xiaoning2, 3, SHI Zhaoyuan1, CHEN Xuming2, 3
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1. School of Electrical Engineering, Xi’an University of Technology, Xi’an 710054, China; 2. School of Electrical Engineering,
Xi’an Jiaotong University, Xi’an 710049, China; 3. Key Laboratory of Smart Grid in Shaanxi Province, Xi’an 710049, China
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| Abstract: |
| To address the lack of effective setting criteria for frequency-domain protection of flexible DC transmission lines and to mitigate the protection maloperation issue due to lightning interference, this paper proposes a high-reliability non-unit protection based on frequency-domain energy ratio. First, this paper analyzes the frequency-domain expressions of line-mode voltage traveling waves under four typical conditions in flexible DC transmission systems: internal ground faults, external ground faults, line lightning interference, and lightning faults, revealing their frequency-domain distribution characteristics. Based on this, an energy operator is introduced to weight the voltage backward traveling wave amplitude-frequency curve, enhancing the discrimination of high-frequency components. Then, the energy accumulation ratio across different frequency bands is used to establish a criterion for identifying internal and external faults. Additionally, considering the significant differences in energy distribution in the low-frequency range due to lightning interference, an efficient method for lightning interference identification is proposed. Finally, a complete non-unit protection criterion for DC transmission lines is developed, supported by clear theoretical setting principles. Extensive simulation results validate that the proposed protection can quickly and reliably identify line faults while accurately detecting lightning interference, exhibiting strong tolerance to transition resistance and excellent anti-interference capability. |
| Key words: flexible DC transmission system DC line protection frequency-domain protection energy accumulation lightning interference identification |
