Study and Implementation of an Isolated High-power Bi-directional DC-DC System with Current Sharing Control

• Main Authors: Chih-Wei Chu, 朱致緯
• Other Authors: Jing-Yuan Lin
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/e2yf77

碩士 === 國立臺灣科技大學 === 電子工程系 === 106 === In this thesis, an isolated high-power bi-directional DC-DC system with current sharing control is studied and implemented. The system is composed of two the same isolated high-power bi-directional DC-DC converter. The converter consist of two stages of bi-directional DC-DC converter. The stage attached to the battery-side is an interleaved buck/boost converter, and the stage of the grid-side is a three-phase series resonant converter. The battery-side stage consists of two buck/boost converters with interleaved control, so the load current not only can be shared to reduce the stress of the switch circuit but also decrease the output current ripple. The grid-side stage mainly consists of three half-bridge legs and six switches. There are three isolated transformers and three resonant tanks, the control signal for each leg has a phase-shift of 120° with each other. This converter stage is operated as a series resonant converter. The three isolated transformers are Y-connected on both the primary and secondary sides. Compared with traditional single-phase full-bridge converter, the three phase Y-Y control converter can share the output power with three transformers, so that the size of each transformer are decreased, and the cost can be reduced.