A Digital Controlled High-power Bi-directional DC-DC Conversion System with Active Current Sharing

• Main Authors: Yi-Hsien Chiang, 江翊先
• Other Authors: Huang-Jen Chiu
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/s55n62

碩士 === 國立臺灣科技大學 === 電子工程系 === 106 === The aim of this thesis is to study and implement an isolated digital-controlled high-power bi-directional DC-DC conversion system, including hardware implementation, firmware design, circuit protection design and digital controller parameter design. The system is connected between DC micro-grid and Li-ion battery, and composed of several isolated bi-directional converter modules connecting in parallel. Hardware wise, the converter modules consist of isolated three-phase series resonant converters and interleaved buck/boost converter, due to specific control strategies, the output ripple can be significantly reduced. The CREE® SiC half-bridge module are introduced as power switches, which can significantly increase the efficiency and decrease the difficulty of system modularization. Firmware wise, TI® TMS320F28035 digital signal processor is introduced as a digital controller. Control Area Network (CAN) is introduced to implement an active output current -sharing technique. Parameter design wise, frequency-response analysis of the power converter, Z-transform and prewarping technique are studied. From the simulation and the experiment result, an 20 kW DC-DC conversion system with two modules are implemented, connected between Grid side 750 V and Battery side 400 V. When the load comes to 20 kW, the efficiency of the system can reach 95%, and the output current are balanced.