State-of-the-Art Review on Topology and Deductive Methods of LLC Resonant Converter

The LLC resonant converter has many advantages, such as low operating loss, wide output range, small size, and simple structure. It is widely used in the fields of automobile charging, special power supply, and new energy power generation. Topology is a very important part of the LLC resonant converter. However, at present, the overview of LLC resonant converter topology only briefly summarizes some traditional topologies, which cannot cover the emerging new topologies. In this paper, the topology and deductive methods of LLC resonant converter, which concerns the literatures in the past five years, are reviewed. At the same time, for the integrity of this article, the modulation strategy of the LLC converter is introduced briefly. This paper firstly introduces the basic working principle and characteristics of the LLC resonant converter, and then discusses the basic topology and modulation strategy of the LLC resonant converter. Classification and deductive methods of related topologies are summarized in detail, and the related results help engineers analyze, select, and design LLC resonant converters. Finally, the future development trend of LLC resonant converter is predicted and discussed according to the status of industrial applications.