Power Quality Improvement of a Single Stage Grid-Tied Photovoltaic System based on Resonant Control Scheme

This work deals with the design and implementation of a resonant current controller dedicated to single stage grid-tied photovoltaic (PV) power systems. It includes a maximum power point tracking (MPPT) controller to ensure optimal power extraction, along with a proportional-integral (PI) regulator to generate the grid reference current. In addition, a proportional-resonant (PR) control is employed to provide an infinite gain at the fundamental frequency, resulting in zero steady-state error. Analysis of the resonant controller is carried out and validated through simulations on Matlab/Simulink platform. The synchronization with grid is performed by a phase-locked loop (PLL), providing accurate detection of the grid voltage phase angle for effective power injection. An LCL filter is also inserted between the inverter and the grid. Simulation results confirm the effectiveness of the proposed control scheme.