Affiliation of Author(s):自动化学院
Journal:IEEE TRANSACTIONS ON POWER ELECTRONICS
Key Words:DC-DC converter LLC converter two transformer wide voltage range
Abstract:This paper proposes a novel modified LLC converter with two split resonant branches for wide input-range applications. It can operate in low-gain (LG) mode or medium-gain (MG) mode. The voltage gain of MG mode is 1.5 times that of LG mode, while they have same range of voltage gain M-tank_range, i.e., the ratio of maximum voltage gain to minimum one. Therefore, the input voltage can be regulated in a wide range by operating the converter in different modes. To achieve the transition between modes, the required Mtank range of the proposed converter is as low as 1.5, resulting in lower magnetizing current and higher efficiency within the entire operation range. Smooth transition can be achieved by adjusting the duty cycles of switches gradually. The proposed LLC converter with primary dual-bridge is analyzed in detail as an example. To verify the theoretical analysis and performance of proposed solution, a 1-kW 400-V output prototype with input voltage ranging from 80 to 200 V is built, tested, and compared with two existing full-bridge LLC converters. Analysis and experimental results indicate that smaller volume of transformers, reduced rectifying diodes, and higher overall efficiency are achieved with the proposed converter.
ISSN No.:0885-8993
Translation or Not:no
Date of Publication:2018-09-01
Co-author:Sun, Wenjin,Fred Wu,dingjie
Correspondence Author:xy,Fred Wu