电力系统故障录波数据实用压缩方法

Practical data compression method for power system fault records

针对电力系统大量故障录波数据的传输问题,以故障录波数据在整体录波文件占据较小比例为依据,提出一种立足于录波数据整体的分通道分时段数据压缩新方案。对于周期信号的压缩,快速傅里叶变换(FFT)算法具有压缩比高的特点,因此先对分段数据进行FFT计算,若误差较大则改用小波变换压缩。在电力系统频率偏移额定值的情况下,采用加窗傅里叶变换校正算法,保证压缩率和压缩精度。仿真研究和实际录波文件的压缩应用表明,算法能获得较高的压缩性能和较小的误差,验证了该方案的可行性和有效性。

Because the fault records occupy only a small proportion of the whole record file,a channelspecific and segment-specific data compression method is proposed for the mass data transmission of power system fault records. Because the FFT（Fast Fourier Transform） algorithm has higher data compression ratio for periodic signals,the segment data are treated by FFT algorithm first. If the error is bigger,the wavelet transform is then applied. If the frequency offset of power system is greater than the rated value,the windowed Fourier transform algorithm with frequency calibration is applied to ensure the compression ratio and compression precision. Simulation and actual compression of record file show that the proposed algorithm has better compression performance and smaller error,verifying its feasibility and validity.