基于广义形态滤波的电力系统采样信号处理

Processing of sampled power system data basedon generalized morphological filtering

数学形态学是以集合论和积分几何学为基础的一门对物体形态处理的学科,是一种非线性分析方法,在时域中对信号波形特征进行研究。针对电力系统采样信号,提出一种采用不同采样频率的广义形态滤波方法。该方法滤除白噪声和脉冲噪声时采用较高频率;滤除直流偏移时采用低频率。结构元素选取为与水平方向夹角为零度的直线型结构元素。由于滤除直流偏移时采用较低的采样频率,因此,结构元素较短、运算量较小、耗时少。仿真实验表明,该方法能有效地滤除白噪声、脉冲噪声和直流偏移量,信噪比显著增大,均方误差较小。

MM（Mathematical Morphology） is a subject concerning with the shape of an object based on set theory and integral geometry,which is a nonlinear approach,studying the waveform characteristics of signals in the complete time domain. A generalized morphological filtering method using different sampling frequencies is proposed for sampled power system signal. The higher frequency is used to filter white noise and impulse noise,while the lower frequency to filter the DC offset. The horizontal linear structure element is selected. The use of low frequency for DC offset filtering shortens structure element and reduces calculation time. Simulations show that it filters white noise,impulse noise and DC offset effectively with the SNR（Signal-to-Noise-Ratio） increased and the MSE（Mean Square Error） decreased.