Abstrakt

PWM Switched Double Stage Buck Boost Converter with LC Filter for LED Lighting Applications

Akhiljith P.J, Leena Thomas, Ninu Joy

An integrated double buck–boost(IDBB) converter is proposed as a high-power-factor offline power supply for power-LED lamps. The IDBB converter features just one controlled switch and two inductors and is able to supply a solid-state lamp from the mains, providing high power factor and good efficiency. The IDBB converter is analyzed, and a design methodology is proposed. It is demonstrated that, with a careful design of the converter, the filter capacitances can be made small enough so that film capacitors may be used. In this way, the converter mean time between failures can be made as high as that of the solid-state lamp. PWM switching is used for controlling the switching pulses. Feedback circuit is provided with PI controller for accurate result. The converter is simulated using MATLAB 2010 and waveforms are analysed. Simulation results demonstrate that the output voltage of the desired converter can be stably maintained at 200 V and power factor can be improved upto 0.90.