Projeto e análise de desempenho de um conversor ressonante LLC para aplicação em estações de carregamento de veículos elétricos

Abstract

This study analyses the performance of the LLC Series Resonant Converter for application in the isolation stage of power electronics converters used in electric vehicle battery charging stations. The analyses include two different operating modes: unity gain at resonant frequency and gain variation with frequency modulation. For the background, various aspects relating to high-power electric vehicle charging stations were discussed, including problems encountered in vehicle electrification and an extensive literature review on the subject. Theoretical and computational analyses, as well as experimental results obtained through the implementation of a prototype built in the laboratory on a reduced scale are presented. In order to achieve high levels of efficiency operating at high switching frequencies (above 100kHz), wide bandgap semiconductors were used, specifically silicon carbide. The results achieved efficiency above 97% for the experimental converter, and efficiency above 98% for the computer-simulated converter, at nominal power, validating the converter's application both as an isolating resonant converter and as an isolating converter responsible for output voltage variation.