基于双小波变换的抗干扰电压暂降检测方法研究

Study of Voltage Sag Detection Method Based on Double Wavelet with Anti-Interference Feature

针对目前电压暂降检测时存在的由于噪声和谐波等干扰导致的分析精度差、实时性不高等问题，提出一种基于双小波变换的电压暂降检测方法。该方法首先采用db20小波对信号进行多尺度分解，提取含暂降信息的基波信号。然后采用db10小波对基波信号进行单尺度分解，检测高频分量的模极大值对电压暂降实现定位，从而降低了噪声和谐波等干扰信号的影响，提高了小波分析的检测性能。

In view of the poor analytical accuracy and weak real-time performance caused by signal noise and harmonic wave exist in the voltage sag detection, a comprehensive voltage sag detection method is proposed to weaken the impact of the interference signals by the double wavelet analysis. This method decomposes the signal at multi-scale with db20 wavelet to catch the fundamental wave, and then decomposes the fundamental wave at single-scale with db10 wavelet to detect the modulus maximum of high-frequency components. The proposed method can suppress the interference signal and improve the performance of voltage sag detection by wavelet analysis.