Harmonic separation from grid voltage using ensemble empirical-mode decomposition and independent component analysis

Abstract

Summary Harmonics and subharmonics in power systems distort grid voltage, reduce the quality of power, and affect the security of the power grid. Rapid and accurate harmonic separation from grid voltage is the crucial technology to ensure that power systems operate safely and stably. The blind source separation method based on independent component analysis has been used to separate the components of grid voltage. As the grid voltage is acquired in only a single channel, harmonic separation from it is classed as a single-channel independent component analysis problem. Hence, this paper proposes a method for the harmonic separation of single-channel grid voltage that combines ensemble empirical-mode decomposition and FastICA. Compared with 2 traditional methods, the fast Fourier transform and the discrete wavelet transform, the proposed method is superior in that it does not require prior knowledge of the frequency of the original source, does not feature mode mixing, and is more robust against noise. Results obtained from both synthetic and real-life signals demonstrated the excellent performance of the proposed method.