Fast and accurate monitoring of the phase

amplitude

and frequency of the grid voltage is essential for single-phase grid-connected converters. The presence of DC offset in the grid voltage is detrimental to not only grid synchronization but also the closed-loop stability of the grid-connected converters. In this paper

a new synchronization method to mitigate the effect of DC offset is presented using arbitrarily delayed signal cancelation (ADSC) in a second-order generalized integrator (SOGI) phase-locked loop (PLL). A frequency-fixed SOGI-based PLL (FFSOGI-PLL) is adopted to ensure better stability and to reduce the complexity compared with other SOGI-based PLLs. A small-signal model of the proposed PLL is derived for the systematic design of proportional-integral (PI) controller gains. The effects of frequency variation and ADSC on the proposed PLL are considered

and correction methods are adopted to accurately estimate grid information. The simulation results are presented

along with comparisons to other single-phase PLLs in terms of settling time

peak frequency

and phase error to validate the proposed PLL. The dynamic performance of the proposed PLL is also experimentally validated. Overall

the proposed PLL has the fastest transient response and better dynamic performance than the other PLLs for almost all performance indices

offering an improved solution for precise grid synchronization in single-phase applications.