Robust H∞ DC link control design for high-power density converters with high-order filter in PV systems

This paper proposes a DC link controller based on H
_∞
method for robust and reliable operation of a single-phase grid-connected inverter with an LCL-filter in photovoltaic (PV) applications. The H
_∞
DC link controller minimizes the bus voltage fluctuations caused by the power variations of PV system. Also, the controller ensures system robustness against such power variations, which conventional controllers fail to guarantee. Furthermore, the controller improves the quality of the injected current into the grid as the reference of output current is generated by the proposed DC bus voltage controller. Simulation results and experimental results prove the superior performance and robustness of the proposed controller.