不同频带下电压故障行波极性的一致性分析

输电线路故障后产生的电压故障行波是一个宽频带信号。由于电容式电压互感器不能有效传变宽频带电压行波信号,给行波保护投入电力系统实际应用带来困难。文中应用数学分析工具——小波变换,以及小波变换的多分辨率分析特性,将电压故障行波分解成多个频带信号,并研究了各个频带下电压故障行波初始极性之间的关系。研究结果表明：电压故障行波各...

Polarity Consistency Analysis of Voltage Transient Traveling-wave in Different Frequency Band

Voltage fault traveling-wave after transmission line faults is a wide frequency band signal.It brings about difficulties for traveling-wave based protection to be applied into power systems because capacitor voltage transformer cannot transmit wide frequency band voltage traveling-wave effectively.The mathematic tool—wavelet transform is utilized,and its multi-resolution signal decomposition characteristic is used to decompose the voltage fault traveling-wave into different frequency band signals.Besides,the polarity relationships among the initial voltage fault traveling-wave in different frequency bands are studied.The studied results show that the initial polarities of voltage fault traveling-wave in different frequency band signals are consistent,and the initial polarities of power frequency components in voltage fault traveling-wave are consistent with the wave front polarity of the initial voltage fault traveling-wave.This conclusion provides theoretic basis for new traveling-wave based directional comparative protection principle.