基于DSP的电压闪变检测法

本文提出了一种在DSP上实现的基于同步检波原理和小波多分辨率分析的电压闪变计算法.对原信号实施一层小波多分辨率分解,采用过零点法分段确定其逼近分量的同步信号和解调信号.为获取原信号的包络线,把解调信号分解到逼近分量的截止频率低于2倍电网频率为止,然后仅用最后的逼近分量进行小波重构.为使电压闪变检测装置能够连续不断地处理被检测信号,选取了合适的采样率和批处理时间间隔.同时通过数据延伸来解决小波分析中存在的边缘效应.实验结果表明:检测装置运行可靠,计算精度达到2%.

Approach of Voltage nicker detection realized on DSP

An approach of voltage flicker detection based on synchronous wave detection and multi-resolution analysis realized on DSP is proposed in this paper.After the original signal is decomposed using one level multi-resolution analysis,synchronization signal and demodulation signal of the approximation component are obtained by means of searching zero-crossing.To extract envelope of the original signal,the demodulation signal is decomposed to the level where the up limit frequency of the approximation component is less than double frequency of power network,and only the approximation component is employed in the process of reconstructing.In order to deal with detected signal continuously by the device,appropriate sampling frequency and interval of batch process are selected.Meantime,the boundary effects of wavelet transform is solved by extending data.The experiment results indicate that the device runs reliably and the accuracy of measurement is up to 2%.