| 摘要: |
| 针对柔性直流输电线路故障定位过程中信号易受噪声干扰、耐过渡电阻能力差的问题，提出了采用小波变换(wavelet transform, WT)进行消噪处理、并结合变分模态分解(variational mode decomposition, VMD)的柔性直流输电线路故障定位方案。首先利用基于Logistic函数的循环位移小波阈值去噪对故障信号进行处理。然后采用雪消融优化器(snow ablation optimizer, SAO)结合VMD对信号进行有效分解。最后对分解后的高频分量进行S变换(S-transform, ST)，选取对应频率下的幅值曲线进行波头标定。此外，提出了一种不依赖波速的测距算法。在PSCAD/EMTDC平台中搭建双端柔性直流系统并进行仿真验证。结果表明，所提方案不仅对采样率要求低，且能耐受300Ω的过渡电阻和30dB的噪声，在不同故障距离下均能准确进行测距。 |
| 关键词: 柔性直流输电 小波去噪 雪消融优化器 变分模态分解 S变换 故障测距 |
| DOI：10.19783/j.cnki.pspc.240217 |
| 投稿时间：2024-02-27修订日期：2024-04-25 |
| 基金项目:国家自然科学基金项目资助(51767014，51867013)；中国铁路总公司科技研究开发计划项目资助(2017010-C) |
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| Fault location scheme for dual-terminal flexible DC transmission based on SAO-VMD-S |
| WANG Sihua1,2,WANG Lingbai1 |
| (1. College of Automation & Electrical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China; 2. Rail Transit
Electrical Automation Engineering Laboratory of Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China) |
| Abstract: |
| A flexible DC transmission line fault location scheme is proposed to address the problem of signal susceptibility to noise interference and poor transient resistance capability in the fault location process, in which wavelet transform (WT) for noise cancellation and variational mode decomposition (VMD) are used. First, the fault signal is denoised using a Logistic function-based cycling displacement wavelet threshold. Then a snow ablation optimizer (SAO) and VMD are used to effectively decompose the signal. Finally, S-transform (ST) is conducted on the decomposed high-frequency components, and the amplitude curves at the corresponding frequencies are selected for wavehead calibration. In addition, a distance measurement algorithm independent of wave speed is proposed. Simulation verification is performed by building a double-ended flexible DC system in the PSCAD/EMTDC platform. The results show that the proposed scheme not only requires low sampling rate but also has the ability to withstand 300 transient resistance and 30 dB noise, so it is able to accurately measure distances at different fault locations. |
| Key words: flexible DC transmission wavelet denoising snow melting optimizer variational mode decomposition S transformation fault distance measurement |
