Maximum Power Point Tracking Method for Grid-Connected PV Systems Using Maximum Power Line

In order to maximize energy production from a photovoltaic (PV) system, maximum power point tracking (MPPT) methods should rapidly track the maximum power point (MPP). This paper proposes an efficient MPPT method for grid-connected PV systems that can rapidly track the MPP while avoiding the power oscillations around the MPP. To achieve these, the proposed method employs output power control instead of PV array voltage control used in the conventional MPPT methods. The reference for the output power of PV systems is set to the maximum power line, which is the locus of MPPs under various irradiances at a given temperature. The proposed MPPT method forces the operating point of a PV array to rapidly converge to the MPP without the power oscillations. The simulation results clearly demonstrate that the proposed method can achieve a higher tracking efficiency than the conventional methods. Therefore, the proposed method helps foster the penetration level of PV generation in a costeffective way.