基于AVMD与改进能量算子的非稳态谐波分析  

Power system harmonic analysis under non-stationary situations based on AVMD and improved energy operator

作　　者：计志勇 唐求[1] 李雅鑫 滕召胜[1] 邱伟[1] Ji Zhiyong;Tang Qiu;Li Yaxin;Teng Zhaosheng;Qiu Wei(Cllge of Electrical and Information Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学电气与信息工程学院,长沙410082

出　　处：《仪器仪表学报》2022年第7期209-217,共9页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(52077067);湖南省自然科学基金(2021JJ30124)项目资助。

摘　　要：针对非稳态谐波分析中时频参数检测精度较低的问题,提出一种基于自适应变分模态分解(AVMD)与改进能量算子的非稳态电力谐波分析方法。首先,采用AVMD对非稳态谐波信号进行分解,其中采用波形特征匹配法对非稳态谐波信号进行延拓以减轻边界效应影响,并提出能量差和相关系数作为AVMD中模态分解个数的判据;结合模态分量,提出改进间隔采样能量算子快速提取谐波的瞬时幅值和频率,根据差分和信号完成其起止时刻的定位,实现非稳态谐波时频参数的快速准确测量。仿真与实测结果表明,本文方法能够在电网工频波动、间谐波以及噪声干扰等情况下有效完成非稳态谐波的准确检测,实现暂态谐波的精确定位,且对非稳态谐波频率、幅值的最大检测误差分别为0.094 9%和0.931 4%。The detection accuracy of time-frequency parameters in non-stationary harmonic analysis is low. To address this issue, a new method based on the adaptive variational mode decomposition(AVMD) and the improved energy operator is proposed. Firstly, AVMD is used to decompose the unsteady harmonic signal, in which the waveform feature matching method is used to extend the unsteady harmonic signal to reduce the influence of boundary effects. The energy difference and correlation coefficient are utilized as the modal decomposition factors in AVMD. Combined with the modal components, an improved sampling energy operator is proposed to quickly extract the instantaneous amplitude and frequency of harmonics, and complete the positioning of its start and end times according to the difference sum signal. In this way, the detection of time-frequency parameters of unsteady harmonics is realized. The simulation and actual measurement results show that the method can effectively complete the accurate detection of non-steady harmonics under the condition of power frequency fluctuation, inter-harmonic and noise interference, and realize the accurate positioning of transient harmonics. The maximum detection errors of non-steady harmonic frequency and amplitude are 0.094 9% and 0.931 4%.

关 键 词：谐波分析 波形特征匹配 自适应变分模态分解 改进能量算子 非稳态信号 

分 类 号：TM935[电气工程—电力电子与电力传动] TH89[机械工程—仪器科学与技术]