Simulation of photovoltaic grid-connected generation system with maximum power point tracking and voltage control strategy

The fluctuating of the reactive load could largely affect the terminal voltage in distribution systems. By controlling the AC voltage of grid-connected bus in photovoltaic generation system, it could improve the voltage level of distribution systems. Based on the structure of the photovoltaic grid-connected system, it established the dual-loop feedback control strategy. The voltage loop was considered as the external loop, and the grid-connected current loop as the internal loop. The grid-connected current was decoupled into active current and reactive current via the abc/dqo coordinates transformation. The DC voltage reference from the maximum power point tracking (MPPT) used to adjust the active current, and the AC voltage reference from the system voltage used to dominate the reactive current. In this way, it achieved the MPPT and voltage control technology of the three phase photovoltaic grid-connected generation. The simulation results show that the MPPT and voltage control strategy can not only implement the maximum power point tracking but also control the AC voltage of grid-connected bus. It can further upgrade the application future of photovoltaic grid-connected generation system.