Harmonic Analysis of Power Quality Monitoring Device Based on IEC61850

Based on IEC61850, a framework of power quality monitoring device is constructed in this paper. In the meantime, an improved algorithm is proposed based on fast Fourier transform and wavelet transform for the harmonics analysis in the power quality monitoring device. In the improved algorithm, fast Fourier transform algorithm is used for steady harmonic to make the real-time analysis, and wavelet transform is used to identify transient harmonic. The simulations with ATP and MATLAB reveal that wavelet transform has double resolutions in both time & frequency domains, which can effectively avoid the drawback caused by a single FFT algorithm. The results obtained show that the improved algorithm has perfect practicability and flexibility, especially under the condition of singularities and perturbations.