PV integrated grid synchronization technique using modified SOGI-FLL and zero-crossing detector

The operation of a grid-connected photovoltaic (PV) system with improvement in power quality depends mostly on the estimation of synchronizing signals. A hybrid algorithm for the estimation of the synchronizing unit templates has been proposed in this paper. Modified second-order generalized integrator (MSOGI) has been combined with the frequency locked loop (FLL) and the traditional zero-crossing detector (ZCD) to extract the synchronizing signal. The synchronizing signal produced from the proposed technique has almost zero total harmonic distortion. Work on the proposed MSOGI-FLL-ZCD has been verified through simulation and experimental studies conducted under different grid voltage problems such as phase shift, frequency change, harmonic, DC-offset and noise. In addition, the proposed algorithm has been successfully applied to the three-phase grid-connected solar PV system for improving power quality.

Automated summary

This paper proposes a hybrid algorithm for estimating synchronizing unit templates in grid-connected photovoltaic systems to improve power quality. The technique successfully minimizes total harmonic distortion in the synchronizing signal and has been verified through simulation and experimental studies. It has been applied to three-phase grid-connected solar PV systems for enhancing power quality.