【摘要】 电压闪变是影响电能质量的一个重要因素,针对闪变水平的计算问题,将希尔伯特-黄变换(HHT)应用于电压波动信号的时变分析中。首先,对提取的电压包络信号进行了HHT变换,从而获得了波动电压的时变参数;然后,将瞬时幅值按照"频率—电压波动"曲线进行加权,得到了瞬时闪变视感度;最后,通过统计计算,得出了短时闪变严重度。对新算法进行了仿真,以含有10 Hz与20Hz闪变成分的电压信号为例,每0.01 s可输出一个闪变值,实例的统计结果与理论结果误差仅为3.863%,符合IEC的要求。研究结果表明,该算法与IEC法、FFT法相比,具有多分辨率的特点,可用于获取电压幅值、频率的瞬时信息,提供更及时有效的瞬时闪变值;另外该算法还能够适用于非平稳信号的闪变测量。更多还原

【Abstract】 Voltage flicker is one of the most important factors of electric power quality.Aiming to calculate flicker level,the application of Hilbert-Huang transform(HHT)to voltage fluctuation testing was investigated.HHT was applied to voltage envelope to get time-varying information.Then instantaneous flicker sensation was derived from product of instantaneous voltage amplitude and its weighting coefficient in corresponding frequency.The short-time flicker severity was obtained after statistical analysis.A simulation was made to analyze voltage signal with 10 Hz and 20 Hz.100 flicker outputs can be obtained per second.After statistical analysis,the error between experimental result and theoretical result is only 3.863%,which can meet the requirement of IEC.The result indicates that,compared with other approaches such as method based on IEC and FFT,HHT is more capable in processing non-stationary signal,and can provide quick and effective results while presenting real-time information of voltage and frequency.更多还原