Design, analysis and implemention of an interleaved pfc boost DC-DC converter for an LCD TV power supply

Nowadays, because of the increasing use of semiconductors and power electronics devices, current harmonics effects on the electrical systems have become intolerable. Therefore, it has become essential to reduce these harmonic currents, which affect the energy system quality negatively. This also affects the shape of current to achieve a good power factor. According to the EU standard for harmonic reduction IEC 61000-3-2, an active power factor control stage should be utilized if the power consumed by an LCD-TV is above 75 W. The largest power consuming sub-system of an LCD TV is the backlight driving circuit. Plasma technology was the first historical solution; however, Cold Cathode Fluorescents Lamps (CCFL) with LCD panels previously used for note books rapidly took the leadership. These florescent lamps came into use with only medium sized screen TVs, but they are now used in every size. The LED backlight solution for LCD TVs is started to become a very popular way to allow small depth design with slim cabinets, particularly with Edge LED solutions. This thesis studies the design stages of this technology in accordance with the slim converter board.The focus of this thesis is the design and implementation of such a high performance switched?mode power supply. The work involves the design and implementation of an interleaved power Factor correction (PFC) for high performance and small size, the controller design and implementation of flyback DC/DC converter. With Frequency Clamped Critical Conduction Mode (FCCrM) PFC, the overall system efficiency is increased since the active power consumption is decreased.The design procedure, including the design of the circuit components and the control loop, is implemented and the results are verified by a 150W prototype converter. The interleaved dual Boundary Conduction Mode (BCM) PFC controller operates two parallel-connected boost power converters 180 degree out of phase, extending the maximum practical power level of this control technique from 200-300W up to 800W. The converter designed in this work can be applied to CCFL or LED backlight LCD TV application since converter circuit driving the backlight unit is placed on a different board. Flexibility and adaptation for different backlight inverter units are satisfied by this application.