Symmetrical components based technique for power quality event detection and classification

This paper presents a new approach for the detection of the power quality events using symmetrical components in time domain. Power quality (PQ) events like sag, swell, interruption, harmonic, flicker, transients, notches, and spike can be easily detected and classified with this method. As this method is free from the computational burden like in wavelets, S-transform and Hubert transform, so it can be easily used for the on-line applications. Single phase PQ event signal is taken along with the two other phases generated 120° and 240° difference using phase locked loop (PLL) so as to calculate the symmetrical components in the time domain. Triggering points for PQ events can be detected easily from the negative symmetric component of PQ event signal and the events can be easily classified from the signatures of the waveforms using the summation of the positive and negative sequence components. Simulated and real time results are presented for a number of power quality events to show the effectiveness of this method for the PQ event detection and classification.