| 引用本文: | 池梓斌,夏成军,杨明嘉.基于参数优化VMD和TET的柔直线路单端故障测距方法[J].电力系统保护与控制,2024,52(4):1-11. |
| CHI Zibin,XIA Chengjun,YANG Mingjia.Single-end fault location method for MMC-HVDC transmission lines based on parameter-optimized VMD and TET[J].Power System Protection and Control,2024,52(4):1-11 |
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| 摘要: |
| 单端行波故障测距方法在考虑频变波速影响时需要提取故障行波时频域特征，但现有方法存在时频分辨率较低、波头识别困难和波速计算不准确的问题。为此，提出一种基于参数优化变分模态分解(variational mode decomposition, VMD)和瞬态提取变换(transient extraction transform, TET)的单端故障定位方法。首先，利用麻雀搜索算法(sparrow search algorithm, SSA)优化VMD参数，提取含有故障特征的高频模态分量。然后，对该模态分量进行瞬态提取变换，通过去除短时傅里叶变换中模糊的时频能量，保留与信号瞬态特征密切相关的时频信息，得到故障行波时频域全波形。最后，在故障行波全波形中提取主频分量并标定初始波头与第二反射波头，通过计算主频分量下的波速度，结合行波定位方法实现单端故障测距。在PSCAD/EMTDC中搭建四端柔性直流电网的仿真结果表明，所提算法对过渡电阻和噪声具有较强的耐受性，即使在较低采样率下也能实现准确的故障定位。 |
| 关键词: 柔性直流输电 单端故障测距 频变波速 变分模态分解 时频分析 |
| DOI：10.19783/j.cnki.pspc.230911 |
| 分类号: |
| 基金项目:国家重点研发计划项目资助(2022YFB2403500) |
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| Single-end fault location method for MMC-HVDC transmission lines based on parameter-optimized VMD and TET |
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CHI Zibin1, 2, XIA Chengjun1, 2, YANG Mingjia1, 2
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1. School of Electric Power, South China University of Technology, Guangzhou 510640, China; 2. Guangdong Province
New Energy Power System Intelligent Operation and Control Enterprise Key Laboratory, Guangzhou 510663, China
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| Abstract: |
| The single-ended traveling wave fault location method needs to extract the time-frequency domain characteristics of the fault traveling wave when considering the influence of frequency-dependent wave velocity. However, existing methods have low time-frequency resolution, difficulty in identifying the wave head, and inaccurate calculation of wave speed. Therefore, a single-ended fault location method based on parameter-optimized variational mode decomposition (VMD) and transient extraction transform (TET) is proposed. First, the VMD parameters are optimized using the sparrow search algorithm (SSA) to extract the high-frequency modal components containing fault features. Then, a time-frequency analysis method based on transient extraction transform is proposed. This removes the ambiguous time-frequency energy in the short-time Fourier transform and only retains the time-frequency information closely related to the transient characteristics of the signal, accurately extracting the time-frequency characteristics of the fault traveling wave. Finally, this paper extracts the main frequency component of the fault traveling wave full waveform and calibrates the initial wavehead and the second reflected wavehead, and calculates the wave velocity under the main frequency component, so as to realize the single-ended fault location. The simulation results of a four-terminal flexible DC grid built in PSCAD/EMTDC show that the proposed algorithm has strong tolerance to transition resistance and noise, and can achieve accurate fault location even at low sampling rates. |
| Key words: MMC-HVDC single-ended fault location frequency-variable wave speed variational mode decomposition time-frequency analysis |
