基于改进ELMD和sinc插值校正的电压闪变参数检测

新能源发电并网及大量非线性、冲击性负荷的应用造成的电压波动与闪变已成为不可忽视的电能质量问题。为实现非稳态电压闪变参数的准确提取，提出一种基于改进集合局部均值分解(ensemble local mean decomposition, ELMD)和sinc插值校正的闪变参数分析方法，通过sinc插值法替代局部均值分解法中移动平均插值，并利用噪声的统计特性构建改进集合局部均值分解方法，基于改进ELMD将非稳态电压闪变信号分解成一系列的本征模函数(intrinsic mode function, IMF)分量，然后对各分量进行Hilbert变换获得非稳态电压闪变包络信号的瞬时幅值和瞬时频率，最后针对局部均值分解(local mean decomposition, LMD)测量大于12 Hz闪变分量幅值误差较大的局限性，构建基于sinc插值的幅值误差校正模型，据此实现非稳态电压闪变参数的完整检测与分析。通过仿真和实验证明所提出的改进ELMD和sinc插值校正闪变检测相比传统基于LMD的闪变检测方法具有更高的准确度，受电网基波频率波动的影响很小，抗干扰性强，能有效实现非稳态电压闪变包络参数准确检...

Voltage flicker parameter detection based on improved ELMD and sinc interpolation correction

The voltage fluctuation and flicker caused by the grid connection of new energy generation and the application of a large number of nonlinear and impulsive loads have become a power quality problem that can not be ignored in the current new power system. In order to extract the unsteady voltage flicker parameters, a flicker parameter analysis method based on improved ensemble local mean decomposition (ELMD) and sinc interpolation correction is proposed in this paper. The sinc interpolation method replaces the moving average interpolation in the local mean decomposition method, and an improved ensemble local mean decomposition method is constructed by using the statistical characteristics of noise. The unsteady voltage flicker signal is decomposed into a series of intrinsic mode function (IMF) components, and then the instantaneous amplitude and frequency are obtained by Hilbert transform. Aiming at the limitation of large amplitude error of flicker component greater than 12Hz measured by local mean decomposition (LMD), an amplitude error correction model based on sinc interpolation is constructed to realize the complete detection and analysis of voltage flicker parameters. Simulation and experiments show that the improved ELMD and sinc interpolation correction flicker detection proposed in this paper have higher accuracy than the traditional LMD-based flicker detection method, which is less affected by the frequency fluctuation of the power grid fundamental and has strong anti-interference, and can effectively realize the accurate detection of non-steady-state voltage flicker envelope parameters.