A wavelet method for power system frequency and harmonic estimation

This paper proposes a new method for estimating frequency and harmonic parameters in power system. The method is based on recursive wavelet transform and uses the wavelet transform coefficients of voltage and current signals. The complex magnitudes contain the phasor information of interest needed to estimate the frequency and selective harmonic components. This approach is capable of accurately estimating the frequency and selective harmonic parameter utilizing one cycle of an input signal. It features fast response and achieves high accuracy over a wide range of frequency variation. Effects of the sampling frequency and data window size on the algorithm performance are investigated. The two parameters can be selected to meet desirable applications requirements, such as fast response, high accuracy and low computational burden. Simulation results demonstrate that the proposed method achieves good performance.