基于LabVIEW的电压暂降检测与分析软件设计

为了对电压暂降问题进行监测和分析,采用USB2831数据采集卡和Lab VIEW虚拟仪器开发平台设计了一套电压暂降检测与分析软件。USB2831数据采集卡用于获取电压电流信号,在Lab VIEW环境下用短时傅里叶变换作为时频信号的检测和分析工具,生成基波幅值曲线和最大频谱幅值曲线,以确定电压暂降深度、暂降的起止时刻以及各次谐波分量的幅值。将其检测结果与有效值算法的检测结果对比可知,短时傅里叶变换算法检测电压暂降的精度高,扰动定位能力强。所设计软件具有界面友好、扩展性强、使用方便等优点。

Design of a LabVIEW-based Voltage Sag Detection and Analysis Software

This paper gives the design of a voltage sag detection and analysis software based on USB2831 data acquisition card and the LabVIEW virtual instrument development platform. Voltage and current signals are obtained by USB2831 data acquisition card, and short time Fourier transform (STFT) is applied to detect and analyze time-domain signals in LabVIEW environment. The curve of fundamental frequency amplitudes and the curve of maximum spectral amplitudes are generated to determine the depth of voltage sag, the starting and ending time of voltage sag and the amplitudes of each harmonic component. In comparison with the results of RMS algorithm, the STFT algorithm proves to have higher accuracy and stronger disturbance positioning capacity in voltage sag detection, and the software designed also has advantages of user-friendly interface, strong expansibility and ease of use.