Optimal Trajectory Control of LLC Resonant Converters for Soft Start-Up

Author

Weiyi Feng ; Lee, Fred C.

Author_Institution

Center for Power Electron. Syst., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA

Volume

29

Issue

3

fYear

2014

fDate

Mar-14

Firstpage

1461

Lastpage

1468

Abstract

In this paper, the soft start-up process for the LLC resonant converter is investigated and optimized based on a graphical state-trajectory analysis. By setting a current limitation band, several optimal switching patterns are proposed to settle the initial condition. After that, by sensing the output voltage, the optimal switching frequency is determined within the current limiting band. This virtually guarantees that there will be no current and voltage stress in the resonant tank during the soft start-up process. Meanwhile, the output voltage is built up quickly and smoothly.

Keywords

optimal control; resonant power convertors; switching convertors; trajectory control; zero current switching; zero voltage switching; LLC resonant converter; current limitation band; graphical state-trajectory analysis; optimal switching frequency; optimal switching pattern; optimal trajectory control; resonant tank; soft start-up process; voltage stress; Capacitors; Limiting; Steady-state; Stress; Switches; Time-domain analysis; Trajectory; LLC resonant converter; optimal trajectory control; soft start-up;

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/TPEL.2013.2261094

Filename

6512043