基于改进S变换的电压暂降起止时刻检测  

Voltage Sag Starting-ending Moment Detection Based on Improved S-transform

作　　者：汪洋[1] 徐方维[1] 陈礼频[1] 肖先勇[1] 

机构地区：[1]四川大学电气信息学院,成都610065

出　　处：《电力系统及其自动化学报》2014年第7期28-33,共6页Proceedings of the CSU-EPSA

基　　金：四川省科技支撑计划资助项目(2010GZ0256)

摘　　要：电压暂降起止时刻是重要的暂降特征量,在分析改进S变换基础上提出一种改进S变换基频幅值向量和基频差分平方向量相结合的暂降检测方法。首先通过改进S变换基频幅值向量判断信号是否发生暂降,再利用改进S变换基频差分平方向量检测暂降信号起止时刻,最后依据基频幅值向量和暂降起止时刻的检测误差曲线来确定改进S变换高斯窗宽调节因子,达到更优时频分辨率。所提方法能更准确地检测发生在不同持续时间、不同波形点和不同幅值深度的暂降所对应的起止时刻。仿真和实测结果验证了方法的有效性。Voltage sag starting-ending moment is an important characteristic. On the basis of analyzing improved S transform, the fundamental frequency vector and its difference squared vector of improved S transform are constructed to detect voltage sag starting-ending moment. Initialy, the fundamental frequency vector is used to decide whether sag happens or not, then its difference squared vector is employed to detect the starting-ending moment of sag. According to fundamental frequency vector and sag starting-ending moment detection error curve the Gaussian window width of improved S transform can adaptively obtain better time-frequency resolution. The proposed method can detect sag starting-ending moment of different durations, waveform points and amplitudes with highee precision. Simulated and practical signals validate the effectiveness of the proposed method.

关 键 词：电压暂降 改进S变换 暂降起止时刻 基频差分平方向量 

分 类 号：TM712[电气工程—电力系统及自动化]