Hilbert变换求取电压闪变有关参数

随着电力系统中大容量冲击负荷的不断增加，配电网中的电压闪变也愈发严重，因此需要对其进行检测和分析，进而提出具体的治理方案。基于统计评价的指标只能定量地给出闪变的强弱或严重程度，而无法说明闪变的具体参数特征。文中提出基于Hilbert变换的电压闪变参数化快速计算方法，能够计算出闪变调制的频率和幅值，以及电压闪变的近似均方根幅值和基波频率。针对含有高次谐波的闪变信号，提出应用小波去噪方法将高次谐波作为噪声滤去的实用预处理方法。去噪后的信号再进行具体参数的计算。仿真以及现场采集的闪变信号的实例验证了此方法的可行性和准确性。

PARAMETER ESTIMATION OF VOLTAGE FLICKER THROUGH HILBERT TRANSFORM

With the rapid increase of portion of large capacity arc furnace load in power systems, voltage flicker has become a more serious problem. In order to develop solutions to the problem, detained analysis and accurate measurement of voltage flicker is needed. Only quantified seriousness can be retrieved from the flicker's statistical assessing indices. Difficulties are how explain the features of the flicker. A fast method of flicker envelope detection based on Hilbert transform is proposed in this paper. The frequency and magnitude of the flicker can be obtained after envelope detection. Approximate RMS magnitude and fundamental frequency are calculated as well. It is helpful to find the origins of the flicker, hence providing solutions to the problem. With regard to flicker comprising of high order harmonics, wavelet de-noising approach is represented in the paper to remove noises and high order harmonics. Feasibility and correctness of the method are evaluated by the illustration of two simulation examples and one field collected flicker signal.