A simulation study on tracking and restructuring AC signals based on enhanced SOGI-PLL

Abstract

This paper presents an enhanced phase-locked loop (PLL) based on the second-order generalized integrator (SOGI) for tracking and restructuring alternating current (AC) signals with unknown amplitude, DC offsets, frequency, phase angle and phase sequence. According to the second-order generalized integrator configured as a quadrature signal generator (SOGI-QSG), amplitudes, DC offsets and the phase error are deduced. The phase error is used to estimate the frequency and phase by the PI regulator and integrator. The phase sequence is determined by the sign function. The proposed algorithm for tracking and reconstruction of single-phase and three-phase AC signals are both proposed. Compared to the existing dual second-order generalized integrator phase-locked loop (DSOGI-PLL), the effectiveness of the proposed algorithm has been validated through simulations.