| Summary: | 博士 === 國立臺灣大學 === 電機工程學研究所 === 93 === The major purposes of this dissertation are to perform circuit design, dynamic modeling, control and multi-module operation analysis for DC-DC converters. This dissertation presents a novel single stage push-pull boost converter with a improved integrated magnetics and ripple-free input current. First, most of the reported single-stage power factor corrected (PFC) rectifiers cascade a boost-type converter with DC-DC converter. It is found that the push-pull converter with the duty cycles greater than 50% can simplify the front of boost-type converter to a novel single stage converter. Secondly, coupled inductor techniques provide a method to reduce the converter size and weight, and achieve low ripple current. All the magnetic components including input filter inductor and step-down transformer are integrated into a single EI core. The proposed integrated magnetics structure has a simple core structure, a small leakage inductance and low core losses. The prototype is built to demonstrate the theoretical prediction.
Finally, the design and implementation of a multi-module parallel push-pull converter system is presented. In parallel operations, a master-slave current control technique is proposed to compensate the mismatch in current control characteristics of each parallel converter. The small-signal equivalent circuit and transfer function model of the multi-module converter system are found. Then the model reductions are performed using the concept of dominant energy mode. Based on the reduced converter model, a PI controller is quantitatively designed according to the prescribed regulating specifications. A three-module control scheme is proposed. The performance of the converter and the effectiveness of the proposed controller are demonstrated by some simulation and experimental results.
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