摘要详情

ID / 提交时间

11 / 2023-09-07 14:40:25

标题

An Optimized Light-Load Efficiency Scheme for LLC Converters Based on Variable Ratio Transformer

关键字

voltage regulator module (VRM), LLC resonant converter, Circuit reconfiguration, light-load efficiency promotion.

主题及专题

2.Power electronic technology and application > (1)、Power converter topologies and design

状态

终稿

作者

Tianqi Lv / School of Electrical Engineering； Southwest Jiaotong University

Xinghong He / Southwest Jiaotong University

Yundong Gu / Southwest Jiaotong University

Ruikun Mai / Southwest Jiaotong University

wei zhang / Ltd.；State Grid Smart Grid Research Institute Co.

Leyu Shen / Ltd.；State Grid Smart Grid Research Institute Co.

Yang Chen / Southwest Jiaotong University

摘要

The utilization of a two-stage voltage regulator module (VRM) structure is becoming increasingly popular in server applications. To ensure high efficiency during the CPU sleep-mode, the LLC converter is the most popular choice for the first stage due to its efficient output. This paper proposes a transformer structure with a variable primary side winding, which can dynamically adjust the primary side ratio based on the load condition. Under light load conditions, the Large Turn Ratio mode is utilized to decrease the maximum magnetic flux in the magnetic core, thus reducing core losses and achieving higher efficiency. Simultaneously, for heavy load conditions, the mode with a reduced primary side turn ratio is employed to ensure optimal system efficiency. An efficient 48-12/9.6/5.3 V LLC DCX has been designed with a peak efficiency of up to 93.5%. Experiments conducted on VRMs show remarkable enhancements in light-load efficiency due to these modifications.