Control Strategy of Grid-connected Photovoltaic Power Generation System

As energy crises and environmental issues worsen, photovoltaic (PV) power generation, as a clean and renewable energy source, has gained significant attention, particularly in grid-connected control technology. This paper focuses on a twostage PV grid-connected system and proposes an integrated control strategy. This strategy includes maximum power point tracking (MPPT), T-type three-level inverter modulation, and linear active disturbance rejection control (LADRC) for gridconnected applications.Firstly, the MPPT algorithm is enhanced by fuzzy sliding mode control to improve dynamic response and disturbance rejection. Secondly, the space vector pulse width modulation (SVPWM) algorithm for the T-type three-level inverter is simplified. A carrier-based modulation strategy is introduced, and zero-sequence component injection is used to address the neutral-point potential imbalance. Finally, an LCLtype filter is designed, and LADRC dual-loop control is applied to suppress resonance and enhance grid-connected current quality.Simulation results indicate that, compared to traditional PI control, the proposed strategy demonstrates significant advantages in harmonic suppression, dynamic response, and disturbance rejection, meeting national PV grid-connection standards.