Research On Grid Connected PV Inverter With Repetitive Current Control Technique

Currently, due to the global energy crises, most of the countries in the world begin to take the researches on the renewable energy resources seriously. Among all these renewable energy resources, Photovoltaic (PV) generation is regarded as having the most delighted foreground. But there are some differences obviously between the PV generation system and the traditional electricity generation system. First of all, the photovoltaic cells to form a significant non-linear characteristics of electricity, in order to ensure the highest efficiency of photovoltaic power generation, the need for timely discharge of its battery to track the maximum power point (MPPT). Second, the PV power generation system is a typical distributed generation, the majority of its energy needs to be transmitted through the power grid, so the need to increase research into the corresponding photovoltaic power generation technology.In the photovoltaic grid-connected inverter control, simply rely on the traditional PI control and can not play a very good effect, this paper based on the needs of the study proposed a new control scheme, PI control and repeat control combination, And further proposed the use of TMS320LF2407 chip to ensure that the system in the grid current and grid voltage synchronization control, to ensure its reliability. The simulation results show that, under the control mode proposed in this paper, the grid-connected current can realize the tracking with the given current to a great extent. The current waveform is well controlled and Harmonic distortion rate greatly reduced, less than 5%, in line with the provisions of the state for the inverter and the grid. Finally, experiments were carried out on a 10KW PV grid-connected inverter platform. The experimental results show that the proposed scheme significantly reduces the total harmonic distortion (THD).