A Multifunctional Single-Phase Grid-Integrated Residential Solar PV Systems Based on LQR Control

This paper presents a multifunctional single-stage residential photovoltaic power supply based on a linear quadratic regulator (LQR). The system makes use of a single-phase power converter connected to the grid through an LCL filter. A robust LQR with added integral action (LQRI) controller is designed to incorporate added functions such as a power line conditioner, an active power regulator, and a voltage stabilizer. The perturb-and-observe algorithm is used to generate the reference signal for the fluctuating dc bus voltage as well as to extract the maximum power from the solar panels. Full modeling of the converter in the D-Q reference frame is presented. An LQRI is designed to achieve the optimal multifunctionality operation of the residential power supply. Simulation and experimental results confirm the expected performance of the proposed controller for insolation and load variations.