基于递归复小波变换的电压暂降检测虚拟仪器的设计

分析了检测电压暂降的现有算法,通过分析比较,最终选择了基于递归的复小波作为电压暂降的检测算法,由于复小波分析结果中既包含幅值信息,又包含相位信息,所以无论电压暂降信号是否具有电压幅值跳变,都能成功检测到故障发生或结束时刻。同时,利用信息熵寻找最优的小波尺度,使检测结果更加准确。利用虚拟仪器开发软件LabVIEW建立了电压暂降检测系统,利用复小波变换算法,判断电压暂降发生的起始与终止时间,最终实现了电压暂降故障的实时检测、故障报告的自动生成以及故障报文查询等功能。最后,通过模拟故障实验,验证了电压暂降检测算法的有效性。

Virtual voltage sag tester based on recursive complex wavelet

The existing voltage sag detection algorithms are discussed and the one based on recursive complex wavelet is selected,which includes both amplitude information and phase information.It can effectively detect the start time and end time of voltage sag no matter there is voltage amplitude jump or not.The entropy is used to search the optimal wavelet scale,which makes the detection more precise.The voltage sag detection system is developed with LabVIEW,which uses complex wavelet to realize the real-time voltage sag detection,fault report generation and fault information query.The experiments of simulative voltage sags verify its effectiveness.