Benchmarking of Grid Fault Modes in Single-Phase Grid-Connected Photovoltaic Systems

Pushed by the booming installations of single-phase photovoltaic (PV) systems, the grid demands regarding the integration of PV systems are expected to be modified. Hence, the future PV systems should become more active with functionalities of low-voltage ride through and grid support capability. The control methods, together with grid synchronization techniques, are responsible for the generation of appropriate reference signals in order to handle ride-through grid faults. Thus, it is necessary to evaluate the behaviors of grid synchronization methods and control possibilities in single-phase systems under grid faults. The intent of this paper is to present a benchmarking of grid fault modes that might come in future single-phase PV systems. In order to map future challenges, the relevant synchronization and control strategies are discussed. Some faulty modes are studied experimentally and provided at the end of this paper. It is concluded that there are extensive control possibilities in single-phase PV systems under grid faults. The second-order-general-integral-based phase-locked-loop technique might be the most promising candidate for future single-phase PV systems because of its fast adaptive-filtering characteristics and it is able to fulfill future standards.