A three-phase three-level NPC inverter based grid-connected photovoltaic system with active power filtering

This paper presents a three-phase three-level neutral point clamped (NPC) inverter based single-stage grid-connected photovoltaic (PV) system with shunt active power filter (APF) functionality. The proposed system can perform both the maximum real power injection with the perturb and observe (P&O) maximum power point tracking (MPPT) algorithm from the PV panels into the grid and active power filtering to compensate the load current harmonics. Thus, the PV system operates more efficiently compared to the conventional PV systems and can be useful for power system applications. Control of the proposed system is based on synchronous reference frame control algorithm and hysteresis band current control technique. The effectiveness of the proposed system is demonstrated with Matlab/Simulink simulations and validated through dSPACE DS1103 real-time control platform based laboratory experimental results.