PLL and Current Mode Control Design Methodologies Applied to Improve the Performance of a Grid-Tie Photovoltaic System

Currently, several forms of electric generation have been investigated, one of the most promising being the photovoltaic system. These systems produce electricity in DC format and the electrical networks in AC format, being necessary to use DC-AC converters to make the connection between the photovoltaic source and the conventional grid. For this work, it is proposed to use the current mode control and the Phase-Lock-Loop (PLL) to ensure the synchronization of the connection of the photovoltaic panels in the network. In both controllers, PI control structures are used. In the PLL the gains are obtained by the Roots Locus method and CHR method and the Current Mode Control the gains were obtained by the poles and zeros cancellation method. Finally, simulations were performed for panel irradiance variation, and also for temperature variation. For voltage sag in the PLL controller and reference change for the operation of the Current Mode control.