Investigation of Three-Phase Grid-Connected Inverter for Photovoltaic Application

This paper describes the investigation of the grid-connected three-phase inverter for photovoltaic (PV) application. The inverter control system modeling is carried out in MATLAB/SIMULINK environment. With the aids of the proportional-integral controllers, sinusoidal pulse-width modulation (SPWM) control technique and Park transformation, the inverter control system managed to convert PV power to ac power, stabilize the output voltage and current, and feeds the excess power to the utility grid. The control system generates the PWM signals for power devices, the insulated gate bipolar transistors in order to regulate the output voltage and current. In addition, the system is simulated with the PV simulator in order to facilitate the real PV power that to be fed to the input of the inverter. The control system produced 2.48% and 4.64% of output voltage and current total harmonic distortion, respectively. The simulation results such as the ac output voltages and currents, inverter system power flow, and grid disturbances detection signals, proved the effectiveness of the developed control algorithm. For the validation, this model is to be linked to the inverter prototype by utilizing the dSPACE controller. Streszczenie. W artykule badano trójfazowy przekształtnik w zastosowaniu do urządzeń fotowoltaicznych podłączonych do sieci. Układ składa się ze sterownik PI, układu modulacji SPWM i transformacji Parka i umożliwia konwersję napięcia z systemu fotowoltaicznego do sieci ac, stabilizację napięcia i prądu. (Badania nad trójfazowym przekształtnikiem podłączonym do sieci w zastosowaniu do urządzeń fotowoltaicznych)