Optimized Synchronization Technique for Single Phase Grid-connected Converters

The performances of the synchronization unit have become a crucial issue in applications involving grid-connected power converters.In view of the topologies of modern power systems, control algorithm of Distributed Generation (DG) sources are required to respond effectively to grid faults in order to support and enhance the stability of the grid. Thus, improving the accuracy and the robustness of the synchronization method during normal or distorted conditions is important to fulfill these requirements. The objective of this paper is to improve the performances of a Phase-Locked Loop (PLL) through an optimized tuning of the PI controller. This synchronization technique is based on a second order generalized integrator and it is intended for single-phase Photovoltaic (PV) systems. Its performances are evaluated by simulating its behavior during grid faults. An experimental prototype is developed to validate the operation of the synchronization unit when connected to the single-phase grid.