High-efficiency converter based on wide bandgap electronic devices for solar photovoltaic energy applications

The implementation of solar photovoltaic energy is in full growth due to the need to combat global warming through the use of renewable energy. For these reasons, it is important to develop high-efficiency converters. In the past years wide bandgap devices made of SiC and GaN semiconductors have been introduced into the market. This thesis studies the benefits and feasibility of wide bandgap devices for solar photovoltaic converters particularly, the DC/AC converter. The project includes the study of the state of the art in topologies for solar photovoltaic installations and power converters for solar photovoltaic systems, and a comparison between conventional and WBG devices. The work also includes the simulation of a conventional and a WBG DC/AC converter in order to compare both technologies, as well as the modification of an existing DC/AC converter equipped with Si devices for SiC devices. Laboratory experimental testing was performed to study efficiency, total harmonic distortion and switching frequency for each converter. The results show that WBG devices, especially, the SiC cascode JFETs, increase the solar PV DC/AC converter efficiency in comparison with silicon devices. It has been proved that SiC devices enable the converters to operate at higher frequencies, and this allows a reduction in the size of the reactive components and increases the power density of the converters. The total harmonic distortion produced by the converter based on SiC is minimized at the nominal switching frequency and rated power. As a conclusion of the project, SiC devices have been verified as a suitable alternative for solar photovoltaic converter applications.