广义内插小波在电能质量扰动信号分析中应用

Application of generalized interpolating wavelet in power quality disturbance signal analysis

广义内插小波(GIW)具有对称性、紧支撑性、双正交性、内插性和高阶消失矩等优点,并消除了分解初始化时的Mallat误差。介绍了GIW的基本概念和分解、重构算法。将GIW应用于电能质量扰动信号的分析,对电压骤升、电压骤降、局部跌落、瞬时断电、频率漂移和局部振荡进行了仿真,并比较了GIW、Bior 3.7、Coif3、Db 4等4种小波在电压骤升、局部跌落、局部振荡时的信号定位性能,结果表明:虽然选取的GIW的滤波器长度要大于其他3种小波,但其对突变信号定位的幅值和偏移点数等参数仍优于其他三者;检测突变信号时,选用紧支撑对偶、具有高阶消失矩的小波可以更精确地检测突变点。分析可知,GIW具有很好的综合性能指标,可以有效地检测出各种微小扰动。

GIW （Generalized Interpolating Wavelet） has merits of symmetry ,compact support,dual orthogonality,interpolation,high-order vanishing moment,and so on. Furthermore,it eliminates the Mallat error during decomposition initialization. Its basic concepts and algorithms of decomposition and reconstruction are introduced. It is applied to power quality disturbance analysis and different cases are simulated ：voltage swell,voltage sag,voltage dip,momentary interruption,frequency drift and oscillatory transient. The signal locating performance is compared among GIW,Bior3.7,Coif3 and Db 4 wavelets for voltage swell,voltage dip and oscillatory transient. Results show that,although the filter of GIW is longer than other three,signal locating parameters are better,such as magnitude and deviation points. The wavelet with compact support and high-order vanishing moment is better for detecting sudden change point. GIW has excellent synthetic performance and can well detect various minor disturbances.