HHT在铁磁谐振过电压辨识中应用

Application of HHT to ferroresonance over-voltage recognition

铁磁谐振过电压在中性点接地的中高压电网中是常见的故障之一,通常情况下其幅值是正常运行时电压的数倍,为此提出了一种基于希尔伯特-黄变换(HHT)的快速定量辨识铁磁谐振过电压的新方法,运用HHT中的经验模态分解及相关系数法实现主模态分量的有效提取,并对该主模态分量进行Hilbert变换,计算其相对应瞬时幅值、瞬时频率,从而实现对铁磁谐振过电压类型、幅值、诱发时刻的准确定量分析。讨论了HHT在线辨识铁磁谐振过电压的应用,并运用该方法对3种不同类型的铁磁谐振过电压仿真信号及一组实测信号进行了定量分析。研究结果表明该方法能快速有效、准确地定位各种类型铁磁谐振过电压。

FOV（Ferroresonance Over Voltage） is a common fault in neutral network and its magnitude is times of normal voltage. A method based on HHT（Hilbert-Huang Transform） is introduced for quick and quantitative FOV recognition. The EMD（Empirical Model Decomposition） and correlation coefficient method are used to extract the key model function, the corresponding instantaneous amplitude and frequency of which are calculated using Hilbert Transform. The type, magnitude and induction time of FOV are thus quantitatively analyzed. Its online application is discussed and carried out for three types of simulative FOV signals and a set of measured signals. Results show that, this method canquickly, correctly and quantitatively recognize different types of FOV.