基于形态小波的畸变信号电能计量

Distortion signal energy metering based on morphological wavelet

数学形态学是一种非线性的信号处理方法,在处理信号时能够使信号幅值不发生偏移、相位信息也不衰减,因此在电力系统中得到了广泛的应用,如暂态信号谐波分析、奇异点检测与消噪、电能质量检测、故障诊断、继电保护与故障测距等,但尚未应用于对非线性信号的电能计量中。结合小波变换的多分辨率分析特性,用形态小波计算非线性负荷存在下的电能。形态小波具有运算速度快、边缘信息准确检测等优点,信号分析性能优于传统的小波变换。通过仿真分析表明该方法能够准确的检测非线性信号,提取基波电能,提高计量的准确性。

Mathematical morphology is a nonlinear signal processing method,which can lead to a satisfied result without shifting the signal amplitude and decaying the phase information. Hence,it has been widely used in the power system such as transient signal harmonic analysis,singular point detection and de-noising,power quality detection,fault diagnosis,relay protection and fault location,et al.. However,it hasn't been used in nonlinear signal energy measurement until now. In this paper,combing with the multi-resolution analysis feature of the wavelet transform,the morphological wavelet is used to calculate the power with the presence of non-linear load power. The morphological wavelet has the advantages of high computing speed and accurate edge information detection,etc. Its signal analysis performance is better than traditional wavelet transform. The simulation results show that the method can accurately detect various nonlinear signals,and extract the fundamental energy,which improves the measurement accuracy.