几种短时电能质量扰动分类和检测的双小波分析法

DOUBLE WAVELETS MEASUREMENTS AND CLASSIFICATION OF SHORT DURATION POWER QUALITY DISTURBANCES

提出了短时电能质量扰动分类和检测的双小波分析法。利用双小波 (db1和db2 4 )各自的优点 ,把电能质量 5种扰动 (电压凹陷、电压凸起、电压间断、暂态脉冲和暂态振荡 )有效地从含有噪声的采样信号中鉴别出来 ,并能实现扰动的各项指标测定。该方法弥补了以往小波检测方法中 ,当噪声污染严重或扰动发生、终止在工频相角为 0或π附近时 ,可能检测不到或误判断的不足。仿真计算结果表明 ,该方法对扰动的分类简单、有效 ,对扰动各项指标测定尤其是电压凹陷、凸起和间断的时刻及幅度的确定 。

This paper presents a double wavelet analysis method to detect and classify the short duration variations of power quality. By using the advantages of the double wavelets (db1 and db24), the method can identify the disturbance (including the voltage sag, voltage swell, voltage interruption, transient disturbance and transient oscillation) and detect indexes of all these power quality. It can also find out the voltage sag, voltage swell and voltage interruption when noise is serious or the phase angle of voltage is nearly zero or π, while these phenomena cannot be identified by traditional wavelet analysis. The simulation results demonstrate that the method is novel, efficient, and very accurate for detecting all indexes of power quality, especially for the determination of occurring-time and level of voltage sag, voltage swell and voltage interruption.