An Interleaved Flyback-Typed LED Driver with Energy Recovery of Leakage Inductance

• Main Authors: Pei-Shuo Su, 蘇培碩
• Other Authors: Hung-Liang Cheng
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/uae7q6

碩士 === 義守大學 === 電機工程學系 === 105 === This thesis proposes an interleaved flyback-typed LED driver with energy recovery of leakage inductance. The proposed circuit was composed of two flyback converters with two power MOSFETs as the active switches. Without adding any components to the converters, the current can flow through the active switch’s body diode, leading to zero-voltage switching-on (ZVS), and hence improving the overall efficiency. By add bypass diodes to divert the energy of the leakage inductance to flow to the output capacitor, the voltage spike across the active switches can be effectively reduced. Owing to the characteristic of interleaved operation, the output voltage ripple can be lower than traditional flyback converters. In this paper, detailed analyses on circuit operation are conducted and component parameters are designed. Finally, a 200-W prototype circuits are built to drive high-brightness LEDs for verifying the feasibility of the proposed circuit. The experimental results show that both active switches can achieve ZVS operation. Besides, the spike voltage of the active switches is effectively reduced. The overall efficiency is 95.1% at rated power operation.