A new perspective for the IEEE standard 1459-2000 via stationary wavelet transform in the presence of nonstationary power quality disturbance

Power components, power factors and pollution factor are defined according to the IEEE Std. 1459-2000 based on the FFT. However, the FFT in the presence of nonstationary power quality (PQ) disturbances results in inaccurate values due to its sensitivity to the spectral leakage problem. In this paper, a new perspective for the IEEE Std. 1459-2000 definitions is introduced using the stationary wavelet transform (SWT). As a time-frequency transform, SWT can provide variable frequency resolution while preserving time information with no spectral leakage as the FFT. Moreover, unlike other time-frequency transform such as discrete wavelet transform (DWT), SWT possess the time-invariance property that keeps the time and frequency characteristics throughout all the decomposition levels. Results of different case studies including stationary, nonstationary of synthetic and real PQ disturbances proves the effectiveness of applying the SWT over FFT or DWT.