Implementation of Modular Phase-Shifted Full-Bridge Converter

• Main Authors: XIE, ZONG-XIAN, 謝宗憲
• Other Authors: LIN, BOR-REN
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/wueqpz

碩士 === 國立雲林科技大學 === 電機工程系 === 106 === A modular phase-shifted pulse-width modulation (PWM) full-bridge converter with magnetic-coupling current-balancing (MCCB) cell for high input voltage and high output current applications is presented in this thesis. In high input voltage applications, the primary side of the proposed converter consists of three full-bridge circuits connected in series, and utilizes three split capacitors to limit the voltage stress on each modular at one third of input voltage. The input voltage auto-balance ability is achieved by introducing two flying capacitors. Additionally, in order to ensure each module can share load, the MCCB cells are used to make both the input-current sharing (ICS) and the output-current sharing (OCS) among constituent modules auto-balance. The methods of voltage and current balance are simple, reliable and easy expansion. Moreover, they also save redundant components and complex control circuits compared to conventional converters. For the purpose of low output voltage and high output current applications, the secondary side of the propose converter is composed of three current doubler rectifiers connected in parallel. Due to the diode currents and the output inductors currents are half of output load in each module, it can reduce conduction loss and increase the efficiency. Hence it can suppress the current rating of the transformer secondary winding. Finally, the operation principle and design consideration of the proposed converter are discussed in detail. The proposed converter is verified via simulation and experiments. Experiments with a prototype under 750~800 V input and 24V/60A output are provided to verify the theory analysis.