| Photovoltaic (PV) power generation as renewable and clean energy has been developing rapidly. With the decrease of PV power generation cost, increase of efficiency and the support of government policies, large and medium-sized PV grid-connected power station will become one of the main directions.Grid-connected PV power generation is a complex and real-time controlling system which combines some key technologies including grid connection, maximum power point tracking (MPPT) and island detection. Firstly, the characteristics of solar battery are analyzed and the mathematical model is established, then the principle of MPPT including two algorithms (Perturb & Observe and Incremental Conductance method) for solar battery is illustrated. The core of the circuit is grid-connected inverter which has a lot of topologies in the application of PV power generation. The mathematical model, principle, controlling methods and parameters design of the PWM rectifier are analyzed in detail. Island effection is the special phenomenon in distributed power generation system. This paper introduces the conception of island, detecting standard as well as active and passive island detection methods. Based on the theory foundation above, a 100KW PV power generation system with the controller of TMS320LF2407 adopting synchronous PI current control technology is designed. Finally, simulation research on this system is carried out and experiment is finished.Simulations and experiments mainly include a power rating of the grid, MPPT and detection island. The experimental results verify the circuit configuration of the system, the device parameters as well as the controllor are correct and reliable; verify that grid-connected inverter with synchronous PI current controlling technology can realize four-quadrant operation; verify that active power interference and reactive power compensation in the island detection are reliability and accuracy.
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