Comparison Among Single-phase PLLs Based on SOGI

Single-phase phase-locked loop PLLs based on SOGI-QSGs present the most common alternative to the conventional QSG-PLLs and that is on account of their simplicity and efficiency in the extraction of the grid information (phase-angle, voltage amplitude, and frequency) which essential in the control of the power converters connected to the utility grid. In this paper, detail analysis among a set of QSG-PLLs based on SOGI (SOGI-PLL, MSOGI-PLL, MFFSOGI-PLL, SSOGI-PLL, SOGI-PLL-WPF) is presented. The robustness and the performance of the compared PLLs are evaluated using the experimental results under phase-jump, frequency variation, voltage sag, the existence of dc offset, and distorted voltage.