Intelligent Fuzzy PI Control of a Quasi-Resonant Flyback Converter

• Main Authors: Ming-Zhi Lu, 盧明志
• Other Authors: 李祖添
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/3u4c4a

碩士 === 國立臺北科技大學 === 電機工程系研究所 === 99 === In this thesis, we use the quasi-resonant (QR) flyback converter to greatly reduce the switching losses by turning on switch at the zero voltage point generated by the resonance between the magnetizing inductance and parasitic capacitance of the switch. Two major types of control in the power converter are voltage mode control (VMC) and current mode control (CMC). Both of these methods must be derived a small signal model through the control theory to design the location of pole and zero of compensator to improved the performance of the closed-loop system. However, the process of the design is very complicated. Therefore, we propose a PI-type fuzzy logic controller for QR flyabck converter. Its major advantage is that expert knowledge can be incorporate into the fuzzy controller using simple linguistic rule to achieve the control objective without involving the power converter’s mathematical model. This makes it well suited in resolving the time-varying nonlinear nature of DC-DC power converter. In addition, we use a fuzzy controller to obtain a large range of load changes and fast dynamic response. To illustrate the effectiveness and applicability of the proposed method, simulation results are provided.