Comparative analysis about dynamic performances of grid synchronization schemes

For a grid-connected Voltage-Source Converter (VSC), dynamics of the grid synchronization plays an important role in affecting the converter performances and stability. Due to its significance, this paper gives a comparative analysis about some basic grid synchronization schemes, through viewpoint of dynamic performances, which appeared as the impacts of voltage perturbation on the estimated angle error (δθ). The analyzed synchronization schemes cover Synchronous-Reference-Frame Phase-Locked Loop (SRF-PLL), Second-Order Generalized Integrator Frequency-Locked Loop (SOGI-FLL)-based scheme, and Decoupled Double SRF-PLL (DDSRF-PLL), in which their small-signal models, regarding the voltage perturbation, are derived in the stationary-reference frame and compared with the frequency responses diagrams. Based on the analysis, their common features and differences are summarized and finally validated through experimental tests.