作者：庞春梅1, 任颖2, 白艳兵1
作者单位：1. 山西省冶金设计院, 山西 太原 030001;
2. 国网晋中供电公司, 山西 晋中 030600
关键词：局部均值分解;分段三次Hermite插值;过包络;欠包络;暂态电能质量扰动检测
摘要：
为克服将已有局部均值分解（local mean decomposition，LMD）方法用于暂态电能质量扰动信号检测时存在的不足，提出一种基于分段三次Hermite插值（piecewise cubic Hermite interpolation，PCHI）的LMD暂态电能质量扰动检测方法。首先，利用PCHI方法获取信号的局部均值函数和包络估计函数；然后，按照LMD方法的原步骤计算信号的乘积函数（product function，PF）；最后，由PF分量的调幅函数求得信号的瞬时幅值，并采用Hilbert变换处理PF分量得到信号的瞬时频率。该方法能够准确定位扰动时刻，并且克服基于三次样条插值的LMD方法存在的过包络和欠包络问题，仿真信号分析结果验证该方法的有效性。
A method of transient power quality disturbance detection based on PCHI-LMD
PANG Chunmei1, REN Ying2, BAI Yanbing1
1. Shanxi Province Metallurgical Design Institute, Taiyuan 030001, China;
2. State Grid Jinzhong Power Supply Company, Jinzhong 030600, China
Abstract: In order to overcome the shortcomings of the existing local mean decomposition(LMD) method for transient power quality disturbance signal detection, a transient power quality disturbance detection method combined piecewise cubic Hermite interpolation(PCHI) with LMD is proposed. Firstly, the local mean function and the envelope estimation function of the signal are obtained by PCHI method. Then, the product function(PF) of the signal are calculated according to the original steps of the LMD method. Finally, the instantaneous amplitude of the signal is obtained based on the amplitude modulation function of the PF component, and its instantaneous frequency is worked out via Hilbert transform of the extracted PF component. The suggested method can precisely locate the disturbance moment and overcome the over-envelope and under-envelope problems of LMD method based on cubic spline interpolation. The simulation signal analysis results certify the availability of the proposed method.
Keywords: local mean decomposition;piecewise cubic Hermite interpolation;over-envelope;under-envelope;transient power quality disturbance detection
2017, 43(11): 112-116 收稿日期: 2017-05-23;收到修改稿日期: 2017-07-19
基金项目:
作者简介: 庞春梅(1965-),女,山西太原市人,高级工程师,研究方向为热能动力。
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