Abstract-Power quality and voltage control are among the most important aspects of the grid-connected power converter operation under faults. Non-sinusoidal current may be injected during unbalanced voltage sag and active or/and reactive power may include double frequency content. This paper introduces a novel control strategy to mitigate the double grid frequency oscillations in the active power and dc-link voltage of the two-stage three-phase grid-connected Photovoltaic (PV) inverters during unbalanced faults. With the proposed control method, PV inverter injects sinusoidal currents under unbalanced grid faults. In addition, an efficient and easy-to-implement current limitation method is introduced, which can effectively limit the injected currents to the rated value during faults. In this case, the fault-ride-through operation is ensured and it will not trigger the overcurrent protection. A Non-MPPT operation mode is proposed for the dc-dc converter. The mode is enabled under severe faults, when the converter cannot handle the maximum PV power. Finally experimental validation is provided by implementing method in an experimental setup including a 2kW PV inverter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.