Summary: | 碩士 === 國立東華大學 === 電機工程學系 === 97 === For satisfying the power factor requirement of Energy Star for solid state lighting and the harmonic regulation of IEC 1000-3-2 Class C, LED driver has to provide the power factor correction function (PFC). The objective of this thesis is to design the drive circuit with high PF for the small capacity LED lighting. The research contains the following topics: (1) In addition to introduce the theoretical base of the LED and its driving characteristic, this research also explores various PFC circuit topologies and control methods. (2) For the low voltage applications, this research indicates the difficult points and proposes a solution based on the boost topology. A feedforwrd control is presented to shape the input current to increase the input PF as well as reduce the LED ripple current. (3) For the high input voltage application, this research presents various single-stage single-switch (S4) PFC topologies including the isolated and non-isolated types to reduce the circuit volume and cost. (4) This research presents the detail design of the Boost-Buck S4 PFC LED driver. Including the quantitative design procedure, circuit modeling and controller design. The effectiveness of the proposed methods is confirmed with some simulation and experiment results.
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