Sliding Mode Controller for Buck-Boost dc-dc Converter in PV Grid-Connected System

This paper presents new alternatives of design and control for three-phase grid connected photovoltaic systems GCPS. In this work, the photovoltaic generation source PVG is connected to the main electric grid via two power electronics stages. The first stage consists on a buck-boost dc-dc converter that insures impedance adaptation between the PVG and the grid. This converter is controlled by the sliding mode control SMC to track the dc reference voltage required by the main grid. The second stage is composed by a dc-bus and a three-phase voltage inverter used to interface the PVG with the grid utility. The inverter is controlled by the Direct Power Control DPC in order to inject the PV power into the main grid with a high quality power factor. The model of the GCPS has been implemented in the Matlab/Simulink software and simulation studies have been presented to demonstrate the effectiveness of the proposed study.