A high voltage-gain LLC micro-converter with high efficiency in wide input range for PV applications

Author

Han-Dong Gui ; Zhiliang Zhang ; Xiao-Fei He ; Yan-Fei Liu

Author_Institution

Jiangsu Key Lab. of New Energy Generation & Power Conversion, Nanjing Univ. of Aeronaut. andAstronautics, Nanjing, China

fYear

2014

fDate

16-20 March 2014

Firstpage

637

Lastpage

642

Abstract

This paper proposes a novel high voltage-gain LLC micro-converter for PV applications. The converter has simple structure and minimum components with low cost. It can realize high voltage gain based on the voltage doubler rectifier with the optimal turns ratio. The main power switches can achieve ZVS and the output diodes can realize ZCS in wide input and load range. By utilizing the voltage doubler in the secondary side, the voltage stress over the output diodes can be reduced by half compared to the conventional center-tapped full-wave rectifier. A 24-48 V input, 380 V output and 200W prototype was built to verify the benefits of the proposed converter. The achieved efficiency of the converter peaks at 96.6% and the CEC weighted efficiency reaches 95.4%.

Keywords

photovoltaic power systems; zero current switching; zero voltage switching; CEC weighted efficiency; PV applications; ZCS; ZVS; high voltage-gain LLC microconverter; power switches; voltage doubler rectifier; voltage stress; Inductance; Magnetic resonance; Rectifiers; Stress; Switching frequency; Zero current switching; Zero voltage switching;

fLanguage

English

Publisher

ieee

Conference_Titel

Applied Power Electronics Conference and Exposition (APEC), 2014 Twenty-Ninth Annual IEEE

Conference_Location

Fort Worth, TX

Type

conf

DOI

10.1109/APEC.2014.6803375

Filename

6803375