基于改进VMD算法的直流微网纹波检测方法  

Ripple detection method of DC micro-grid based on improved VMD algorithm

作　　者：杜旭东 罗德荣[1] 吴婷 李明[2] Du Xudong;Luo Derong;Wu Ting;Li Ming(School of Electrical and Information Engineering,Hunan University,Changsha 410006,China;Zhejiang Research Institute of Metrology,Hangzhou 310000,China)

机构地区：[1]湖南大学电气与信息工程学院,长沙410006 [2]浙江省计量科学研究院,杭州310000

出　　处：《电测与仪表》2023年第10期36-42,共7页Electrical Measurement & Instrumentation

基　　金：国家重点研发计划资助项目(2018YFF0212903)。

摘　　要：凭借线路成本低、效益高等优势,直流微网成为未来新的配用电趋势,但其多源多变换的特点易导致系统中存在多种形式的纹波发生源。纹波的大量存在不仅直接影响直流微网电能质量,且不便于准确计费,能否准确检测纹波对于直流微网的可靠供电有着重要意义。文中提出了一种基于改进变分模态分解算法(Modified VMD,MVMD)的纹波检测方法,可用于稳态纹波与暂态纹波的准确检测。在MVMD方法中,基于频谱特征相关度的方法确定最佳分解尺度,通过VMD算法将直流检测信号分解为一系列的本征模态分量(IMF),进行希尔伯特变换(HT),可获得纹波分量的一系列参数,以及暂态纹波信号起止时间,采用MVMD方法与经验模态分解(EMD)算法进行对比,实验证明所提出方法相比EMD算法具有较高的检测精度以及噪音鲁棒性,适用于直流微网的纹波监测。With the advantages of low line cost and high efficiency,DC micro-grid has become the novel trend of power distribution in the future,but its multi-source and multi-transform easily lead to the existence of multiple forms of ripple generation sources in the system.The existence of a large number of ripples not only directly affects the power quality of DC micro-grid,but also is not convenient for accurate billing,so the accurate detection of ripples is important for the reliable power supply of DC micro-grid.In this paper,a ripple detection method based on modified variational modal decomposition(MVMD)is proposed,which can be used to accurately detect steady-state ripple and transient ripple.In the MVMD method,the best decomposition scale is determined based on the spectral feature correlation,and the VMD algorithm decomposes the DC detection signal into a series of intrinsic modal components(IMF),Hilbert transform(HT)is applied to obtain a series of parameters of the ripple components and the starting-ending time of the transient ripple signal.The MVMD method is compared with the empirical modal decomposition(EMD)algorithm,and it is proved that the proposed method has higher detection accuracy and noise robustness than the EMD algorithm,and is suitable for the monitoring of DC micro-grid ripple.

关 键 词：变分模态分解 纹波检测 希尔伯特变换 频谱特征相关度 

分 类 号：TM72[电气工程—电力系统及自动化]