基于多级EEMD和WVD分布的谐波/间谐波检测方法

Method to detect harmonics and inter-harmonics based on multiple-level EEMD and Wigner-Ville distribution

为了有效抑制多种噪声和准确检测谐波/间谐波频率,提出了基于多级集合经验模态分解(EEMD)和Wigner-Ville分布(WVD)的谐波/间谐波检测方法。利用白噪声的幅值可调性,对含有噪声的检测信号进行多级EEMD分解,平滑脉冲干扰和削弱白噪声的同时,得到了一组固有模态函数(IMF)分量,对每个IMF进行WVD计算,可准确检测出谐波/间谐波频率,有效抑制了交叉项和噪声干扰。采用最小二乘算法估计各频率分量的幅值,实现了噪声背景下的谐波和间谐波检测。仿真结果验证了该方法的可行性与有效性。

In order to effectively suppress noise and detect the parameters of harmonics and inter-harmonics,a multiple-level ensemble empirical mode decomposition（ EEMD） and Wigner-Ville distribution（ WVD） based method to detect harmonics and inter-harmonics is proposed. Using adjustable white noise amplitude,the intrinsic mode function（ IMF） is gained by multiple-level EEMD. It can effectively suppress pulse interference and white noise and accurately detect the harmonics and inter-harmonics signals frequency by WVD of each IMF,and then the least square method is applied to estimate the amplitude of signals,thus the detection of harmonics and inter-harmonics under noises background is implemented. Simulation results show the feasibility and effectiveness of the method.