Design of 100 kW Grid-Tie Photovoltaic System: A Simulation Study

This paper presents how a 100 kW grid tied photovoltaic system components are designed and simulated in the MATLAB/Simulink simulation program together with the controller of the system. Photovoltaic systems based on electricity generation from solar energy are one of the most important sources of renewable energy in terms of advantages such as sustainability, reliability, nature friendly and endless energy source. Grid-connected photovoltaic systems generally consist of PV panels, DC-DC converter, voltage source inverter (DC-AC converter), protection devices, monitoring system and harmonic filter. The photovoltaic power system is designed in two stages, DC part and AC part. The DC-DC converter is designed to adjust the photovoltaic array output voltage level to a certain voltage level between the photovoltaic array and the inverter. The three phase voltage source pulse width modulation (PWM) inverter is used to convert the output current of the photovoltaic array to the sinusoidal waveform synchronized to the grid. Due to the ease of design, the L filter has been designed and the required inductor value is calculated. Then, for control of the entire system, maximum power point tracking control on the DC side and control of the transmitted power to the grid on the AC side has been provided. The system is simulated and the simulation results show the validity of the MPPT algorithm in variable weather conditions. The efficiency of the overall system is found to be around 89%. It also is seen that the THD values of the inverter output current and voltage are below the %3 values specified in the IEEE standards and are synchronized with the grid voltage.