电能质量扰动信号是一种典型的非平稳信号,采用二次型时频分布能够获得其时间频率联合特性。提出一种基于重排二次型时频分布的电能质量检测新方法,首先采用瞬时无功功率理论和广义形态滤波器将电能质量信号的基波成分和扰动成分分离,再利用重排二次型时频分布对扰动分量进行分析,从而获得时频聚集型更好的扰动分量的时频联合分布,直观地表达出扰动信号的时频特性。仿真算例验证了此方法对各种常见电能质量扰动和交叉电能质量扰动的检测和特征提取是有效的。
Bilinear time - frequency analysis is a useful character description to study non, static signal such as power quality disturbance. A new method based on rearranged bilinear time - frequency distribution is introduced for power quality disturbance detection. Firstly, the fundamental component and the disturbance are separated using instantaneous reactive power theory and generalized morphological filter, and then the disturbance is analyzed with rearranged bilinear time - frequency distribution, accordingly for better time - frequency concentration. Simulation results of common power quality disturbances and crossed power quality disturbances have proven the effectiveness of the proposed method.