Pure sinusoidal input voltage based bridgeless PFC converter using TMS320F2812 digital signal processor

摘要

This paper presents a new method to eliminate the harmonics contents of the input current. In conventional Power Factor Converters the input voltage is assumed to be a sinusoidal wave and the converter switching is controlled such that the input current is aligned with the input voltage. Since the input voltage is not always a sinusoidal wave and may include different harmonics the input current aligned with the input voltage will also include the same harmonics of the input voltage. For the purpose of eliminating the current harmonics caused by the input voltage harmonics a sinusoidal wave is generated considering the zero crosses of the input voltage and this wave is taken as the reference to obtain an input current of minimum Total Harmonic Distortion (THD) value. The zero crossing point of the ac input voltage is detected using the digital controller that is implemented with TI DSP of TMS320F2812. The bridgeless converter topology is selected for this investigation to improve efficiency, and the average-current control strategy is adopted to control input line current waveform as well as output DC voltage. The simulations were performed in MATLAB/Simulink program. The simulation results are verified by the results obtained from the experiments.