Comparison of SOGI-FLL with SOGI-PLL for Single-Phase Grid-Connected Inverters

Abstract

Phase locked loop (PLL) is a feedback system that has a vital role in the grid-connected inverter systems. The primary function of PLL is to obtain various grid information, such as magnitude, frequency, and phase. That used as the basis for the synchronization process. The primary purpose of this paper is to model and compare the performance SOGI-FLL (Second Order Generalized Integrator-Frequency Locked Loop) With SOGI-PLL, which is a relatively standard PLL. Besides that, this paper also aims to investigate the effect of FLL feedback gain on synchronization performance. Based on the simulation results, the performance of SOGI-FLL in its steady state is superior to that of SOGI-PLL especially for the condition of a single phase power systems that change in frequency.