瞬态过电压波形的滤波、重建与拟合

在测量电力系统瞬态过电压时,分压器的响应特性、测量和采样中产生的误差及各种背景噪声的干扰,很容易导致实际测量得到的波形产生畸变,从而影响对波形的观察与分析。为此,提出了一套解决上述问题的方案:先通过对实际测得的波形进行离散Gabor滤波,去除采样误差与背景噪声引入的畸变;再经过Wiener反卷积,消除分压器响应特性引入的畸变,从而较好地还原原波形;最后通过该方案中的波形拟合功能,更直观地得到各种参数,从而更便于分析。对IEC1083-2TDG(Test Data Generator)所产生的波形进行的测试结果证实,该方案具有上述功能,并具有相当的准确性与稳定性。

Filtering, Rebuilding and Curve Fitting of Overvoltage Transient Signals

Because of the characteristics of the voltage divider,the error of measurement and sampling,and the noise of background,the transient overvoltage signals captured from the grid would be distorted.According to the characteristics of the factors which cause the distortion,this paper provides a new plan to solve these problems mentioned above:at first,the distorted wave passes the discrete Gabor filter,and the distortion caused by measurement,sampling and noise of background would be eliminated;then the wave passes the Wiener deconvolution system,and the distortion caused by the characteristics of the voltage divider would be dispelled;when all factors caused the distortion have cleared up,the rebuilt wave would be similar with the origin one in a perfect way;at last,the curve fitting part calculates the parameters of the rebuilt wave,and figures a curve out with these parameters,so observation and analyses would become more convenient and visual.Calculation results from the IEC1083-2 TDG(Testing Data Generator)show that this plan is suitable for transient overvoltage signal measurement:it can clear up the distortion caused by the characteristics of the voltage divider and every kinds of background noise,the rebuilt signal is identical with the origin wave just the amplitude is zoomed down with the proportion of the voltage divider;the curve fitting part calculates the parameters precisely,and provides a curve which fits well.Moreover,the plan is compatible and stable.