CONVERTIDOR DC-DC DE POTENCIA PARCIAL PARA SISTEMAS FOTOVOLTAICOS EN CONFIGURACIÓN STRING

Abstract

Solar photovoltaic energy has experienced an accelerated growth rate in thelast few years. This growth has enabled the development of power electronicssystems to enhance the cost savings and eficiency of this type of systems.This work proposes the design of a DC-DC converter for its application in photovoltaicsystems in string configuration. The proposed converter is based ina principle called partial power, in which the semiconductors of the converterhandle only a portion of the total power delivered by the photovoltaic system,which translates in a greater eficiency of the converter. This principle is studiedand a topology based on the Full-bridge converter is proposed.The system is controlled by two PI loops in cascade, one to control the currentand the other to control the voltage of the photovoltaic string. To set the voltagereference a MPPT algorithm is used to obtain the maximum power extractionfrom the system in diverse operating conditions.The converter is put to the test in diverse operating points, calculating theeficiency in each case. Simulations were made in Plecs software and a prototypeconverter and system is built in the laboratory, obtaining experimental resultsthat validate the design of the converter.