Computer aided design and complex power control effectiveness of large scale photovoltaic system integrated into a grid

This paper presents a modular photovoltaic power system designed for large-scale power plants integrated into the grid medium voltage. The Maximum Power Point Tracker (MPPT) box using the constant voltage algorithm is embedded in the inverter control system. To avoid the utilization of a DC-DC boost converter, the use of modules´ strings with high level of voltage (around 1000 V) has been applied for efficient power transfer in accordance with the inverter phase to phase output voltage (400 V) in the case of 500 kWp photovoltaic system. Furthermore, the DC-link voltage is maintained at a constant value using a Matlab script. A photovoltaic power plant of 20 MWp has been designed, and simulations made by using Simpower System Tool box of Matlab/Simulink. The system shows control ability and an accurate response in terms of maximum power point, unitary power factor and complex power exchanged.