The application of complex wavelet transform in voltage fluctuations detection

It is difficult to obtain voltage fluctuation signal for determining flicker by orthogonal wavelets transform (OWT). In this paper, the compactly supported dyadic orthogonal linear phase complex wavelet is constructed using the compactly supported dyadic orthogonal real-valued wavelet in terms of lifting scheme. A pair of quadrature components with the same amplitude and the same frequency can be used to realize the demodulation of voltage fluctuation signal in this method. Simulation results show the method proposed can get better results than OWT without synchronous sample for power grid frequency, has the characteristic of shift-invariant. Result of voltage fluctuation detection is independent of initial time recording signal.