Implementation of an Isolated Bi-directional DC-DC Converter with High Voltage Ratio using DSP

• Main Authors: Jian-Yang Li, 李健暘
• Other Authors: 黃明熙
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/ta7c67

碩士 === 國立臺北科技大學 === 電機工程系所 === 98 === In this thesis, an isolated bi-directional DC-DC converter with high voltage ratio transformer, which provides both 12V and 400V DC voltage as 12V battery back-up power module for automatic door application, is realized by digital power control. The low-voltage side and high-voltage side of the proposed converter are realized by push-pull and full-bridge circuit structure respectively. A phase-shift full-bridge circuit with zero-voltage switching is utilized in high-voltage side of transformer as a charging circuit. An LC filter is added between in the entry of battery to improve the battery charging quality. For discharging mode, the paralleled diodes of power switches in full-bridge are used as a rectifier to yield 400V DC voltage. In order to perform continuous current conduction of inductor and reduce the voltage ratio of transformer, a current-fed push-pull control is proposed in battery discharging mode. As to efficiency and reliability improvement, a resonant circuit constructed by a leakage inductance of the transformer, a external capacitor and a power switch is performed in high-voltage side of transformer to yield zero current switching in low-voltage side circuit under discharging mode. In order to verify the effectiveness of the proposed converter, a DSP-based digital power controller is established to provide 120W power with 12V and 400V DC voltage. All the control algorithms are implemented by assembly language to shorten the execution time. Finally, some experimental results are provided to show its successful operation.