Impact Factor:3.367
DOI number:10.1109/ACCESS.2019.2913153
Journal:IEEE Access
Key Words:Bidirectional power flow; DCX; fixed voltage gain; LLC converter; optimal duty cycle tracking
Abstract:The LLC resonant converter can be used as a dc-dc transformer (DCX) to provide isolation and fixed voltage transfer ratio. For applications requiring bidirectional power transmission, this paper proposes a PWM modulation and control strategy to achieve naturally bidirectional power flow for LLC-DCX, even in the case when the resonant parameters vary. Without the loss of generality, the proposed modulation can achieve ZVS of one side switches and ZCS of other side switches. Meanwhile, the additional benefits are that the PWM logic exchanging of the primary full bridge and the secondary full bridge is avoided and the auxiliary SR circuit is not needed. This simplifies the control and makes the converter to achieve naturally bidirectional power flow. Meanwhile, according to the analysis, it can also provide a fixed voltage conversion ratio independent of switching frequency if properly designed. Furthermore, to accurately locate the zero-crossing instant of the current when resonant parameters vary, the optimal duty cycle tracking based on the perturbation and observation method (P&O) is adopted. The characteristics and design considerations of the proposed modulation and control are also presented in detail in this paper. Finally, the experimental results are given to verify the effectiveness and advantages of the proposed solution.
Co-author:Yang, Jian, Jiang, Taowen, Su, Mei, Sun, Yao, Wang, Hui, Zheng, Minghui
First Author:Xu, Jingtao
Indexed by:Journal paper
Correspondence Author:Xu, Guo
Document Code:18648550
Discipline:Engineering
First-Level Discipline:Electrical Engineering
Document Type:J
Volume:7
Page Number:54693-54704
ISSN No.:2169-3536
Translation or Not:no
Included Journals:EI、SCI
Links to published journals:http://libdb.csu.edu.cn/rwt/EI/https/P75YPLUFN3UXT5UFMW3GT5UHP3VXZ5DBM7TT6Z5QNF/search/doc/detailed.url?SEARCHID=5549527a7d5d4ae483fecc7d7f765655&DOCINDEX=1&database=16826499&pageType=quickSearch&sear