A simple Discrete Fourier Transform-based synchronization method for power quality measurement

A simple method for real-time synchronization of power quality measurements in low-voltage supply systems is presented. Proper synchronization between the data acquisition window and the power system frequency is necessary to accurately measure the harmonic distortion. The proposed method is based on the use of the standard Discrete Fourier Transform method using a 10-cycle width rectangular window and a fixed sampling frequency. The algorithm iteratively adjusts the sampling window width in order to reduce the synchronization error due to the spectral leakage produced by the truncation of the signal in the time-domain. Simulated results demonstrate the good performance of the method proposed.