Improved power conditioning system for grid integration of photovoltaic solar energy conversion systems

The increasing utilization of photovoltaic (PV) solar systems in distributed (or dispersed) generation systems imposes new requirements for the operation and management of the distribution grid, especially when high penetration levels are achieved. Under this scenario, the power electronics technology plays a vital role in managing an effective grid integration of the PV system, since it is subject to requirements related not only to the intermittent source itself but also to its effects on the grid operation. This paper proposes an improved structure of power conditioning system (PCS) for the grid integration of PV solar systems. The topology employed consists of a three-level cascaded Z-source inverter and allows the flexible, efficient and reliable generation of high quality electric power from the PV array. A full detailed model is described and its control scheme is designed. Validation of models and control schemes is carried out through digital simulations using the MATLAB/Simulink environment.