Robust Optimal Current Control of a Single-Phase Grid-Connected PV Inverter Using LMI

The utilization of a linear matrix inequality-based optimization approach is prevalent in the field of control owing to its systematic design and robustness capabilities. This paper introduces a robust optimal current control strategy for a single-phase grid-connected photovoltaic inverter, taking into account the inherent uncertainty of the system. The primary goal of this controller is to effectively regulate the level of electric current being transferred from the DC source, derived from the photovoltaic system to the AC grid. This is accomplished by ensuring a swift and efficient response to sudden changes or fluctuations in the current flow. The proposed control strategy is a robust control approach that utilizes state feedback control augmented with integral action. This integration component effectively eliminates any steady-state error, while ensuring system stability. The efficacy of the control method is verified through a simulation study conducted using PSIM and MATLAB.