基于HHT的电能质量检测新方法

提出了用HHT方法对电能质量扰动信号（电压凹陷、电压凸起、电压间断、暂态震荡、暂态脉冲等）和谐波（整数次谐波和间谐波）进行检测及时频分析的新方法.该方法由经验模态分解法（EMD）和Hilbert变换（HT）两部分组成.通过EMD得到固有模态函数（IMF）后,再进行HT,可以定量、准确地刻画相应时刻的瞬时频率和幅值.通过该方法可以确定非平稳的电能质量扰动信号的时间、频率和幅值信息;同样也可以精确的检测出谐波的幅值和频率.仿真结果表明,该法不但适用于非平稳信号的处理,而且对平稳信号的分析、处理也有很好的效果.

A NEW METHOD FOR POWER QUALITY DETECTION BASED ON HHT

Hilbert-Huang Transform is introduced for detection and analysis of power quality disturbances (voltage sag and swell, voltage interruption, transient interruption and oscillation etc.) and harmonics (integer and non-integer harmonics). The method is composed of Empirical Mode Decomposition (EMD) and Hilbert Transform. The signal is decomposed into Intrinsic Mode Function (IMF) by the EMD method. Then amplitude and frequency of corresponding time can be detected accurately and quantitatively. It can detect time, amplitude and frequency of the power quality disturbances and also detect amplitude and frequency of harmonics by this method. Simulation results show that this method has good performance to analyze non-stationary and stationary signals.