Performance and mitigation strategy of distributed AC-stacked PV inverter architecture under grid background harmonics

Grid-tied Photovoltaic (PV) inverters are required to have harmonics mitigation control to reduce harmonics distortion on the output current caused by the impact of grid background harmonics. In this paper, a decentralized control strategy for reduction of the impact of distorted grid voltage on the AC-stacked PV inverter architecture is proposed. Two control schemes with the selective harmonics mitigation strategy and without any handshaking among the inverters are proposed for this architecture and analyzed to present the improvement of the power quality as well as the operating margin of the architecture. The proposed methods are analyzed by impedance analysis and verified their feasibility and performance through a controller hardware-in-the-loop test.